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Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Sources and contamination assessment of heavy metals in the green land soils in Tongzhou District, Beijing
SUN Jingyu, SUN Xiangyang, LI Suyan, WANG Chenchen, YUE Zongwei
doi: 10.11833/j.issn.2095-0756.20230435
[Abstract](2) [HTML](0) [PDF](1)
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  Objective  The types of land use in Tongzhou District of Beijing have changed greatly. Heavy metals in the soil of green land were investigated, source analysis and risk assessment were carried out to understand whether the current use of green land meets the requirements of cleanliness and safety, and suggestions on risk prevention and control of heavy metals were given.   Method  The pH values and total amounts of heavy metals including Cd, Cr, Pb, Hg, As, Cu, and Zn in 60 surface soil samples from the study area were determined. Source apportionment was carried out using Principal Component Analysis and the Absolute Principal Component Scores-Multiple Linear Regression (APCS-MLR) receptor model. The assessment of heavy metal element pollution was conducted using the Geo-accumulation Index method and the Potential Ecological Risk Assessment method.   Result  The average contents of 7 heavy metals Cd, Cr, Pb, Hg, As, Cu and Zn in the soil were 0.53, 47.87, 11.95, 0.25, 6.71, 4.64 and 51.21 mg·kg−1, while the average content of the remaining elements were below the background. All of the samples’ heavy metal concentrations were less than the screening values for Soil Pollution Risk Control Standards for Agricultural Land (GB 15618−2018). Principal component analysis demonstrated that Cd, Pb, Hg and As were influenced by human sources, including coal combustion, traffic pollution, industrial and agricultural activities pollution; Zn originated from natural sources and was related to the soil parent material; Cu and Cr were mixed sources reaulted by soil parent materials and agricultural pollution. The contribution rates of sources calculated by APCS-MLR were as follows, a certain amount of Cd accumulated on the surface came mostly from human sources (92%); Hg was from source 3 (29%), source 1 (17%), source 4 (13%), and there were also 35% unknown sources, which were suggested as mixed sources. Moreover, sources 1, 3, and 4 were all anthropogenic sources, while source 2 was a natural source. Environmental quality evaluation of green soil was investigated through the ground accumulation index, which illustrated that Cd and Hg performed a higher ecological risk response. Most of the comprehensive potential risk values in the study area were slight and medium potential ecological risks, only few points were belonged to severe ecological risks.   Conclusion  The study shows that the overall risk level of green land soil in Tongzhou District is in the middle and low risk. The main elements causing the risk are Cd and Hg, which are the priority control elements of ecological risk, and can be controlled from the control of coal burning, traffic and industrial emissions. [Ch, 5 fig. 4 tab. 32 ref.]
Impact of site factors on forest regeneration in Mount Tianmu mixed coniferous and broad-leaved forests
YE Zilin, DOU Xiaowen, TANG Mengping
doi: 10.11833/j.issn.2095-0756.20230446
[Abstract](11) [HTML](2) [PDF](3)
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  Objective  The objective is to study the impact of site factors on forest regeneration in the mixed coniferous and broad-leaved forests in Mount Tianmu, and provide a theoretical basis for the management of subtropical mixed coniferous and broad-leaved forests.   Method  A mixed coniferous and broad-leaved forest in Mount Tianmu was taken as the research object. Spearman’s correlation analysis was conducted between forest regeneration factors, soil factors and terrain factors. One-way ANOVA was used to analyze the differences in forest regeneration among different soil and terrain factors. A linear regression model was constructed to quantitatively describe the relationship between forest regeneration and terrain and soil factors.   Result  (1) There were 79 species of mixed coniferous and broad-leaved forests in Mount Tianmu, among which the dominant species were Camellia fraterna, Cyclobalanopsis glauca, Lithocarpus brevicaudatus, Cyclobalanopsis myrsinifolia, Machilus pingii, Rhododendron ovatum, Torreya grandis, Lindera glauca, Eurya japonica, and Litsea coreana. (2) There was a highly significant negative correlation between available potassium and the total number of updated tree species (P<0.01), a highly significant positive correlation between altitude and the total number of updated tree species (P<0.01), a significant negative correlation between organic matter and the number of updated tree species (P<0.05), and a highly significant positive correlation between available potassium and the total number of updated tree species (P<0.01). (3) There was a significant difference in the total number of updated tree species with different slope orientations and available potassium levels (P<0.05). There were significant differences in the number of updated tree species with different grades of slope and soil organic matter (P<0.05). (4) In the linear regression model with the total number of upgraded tree species as the dependent variable, the regression coefficients of available potassium and altitude were significant (P<0.05).   Conclusion  In the mixed coniferous and broad-leaved forests in Mount Tianmu, altitude, slope, aspect, soil organic matter and available potassium have significant effects on forest regeneration. [Ch, 3 fig. 5 tab. 49 ref.]
Molecular regulatory mechanisms of cambium activity in woody plants
YE Qingqing, ZHOU Mingbing
doi: 10.11833/j.issn.2095-0756.20230473
[Abstract](20) [HTML](2) [PDF](2)
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The vascular cambium is located between the xylem and phloem, which is responsible for many growth and development processes, and also plays an important role in wood production. In simulating cambium growth and potential molecular processes, deep imaging combined with gene expression analysis is a cutting-edge research direction, and mathematical modeling and simulation combined with real-time imaging have important application prospects. Based on this technique, some representative achievements at the molecular level of cambium activity are summarized, and the future research prospects are proposed. At present, molecular studies on cambium activity in plants mainly focus on: (1) cambium activity is regulated by plant hormone signaling; (2) cambium activity is regulated by transcription factors and peptide receptor signaling; (3) cambium activity is regulated by receptor kinase signals peptide receptor signaling. The main conclusions are that WOX4, WOX14, HB4, HB7, HB8 and ANT positively regulate the activities of tree cambium and can be used as the first choice for transgenic wood roughening breeding. In the future, the analysis of cell-to-cell communication connections in the cambium through computer models can better analyze the molecular mechanism of vascular cambium development in woody plants. [Ch. 3 tab. 68 ref.]
Simulation of micro-droplet injection process and key parameters based on 3DP equipment of wood-plastic composites
LIU Zixin, WANG Qi, YAN Chenglin, WANG Xinxu, LI Xiaoxu
doi: 10.11833/j.issn.2095-0756.20230511
[Abstract](19) [HTML](6) [PDF](5)
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  Objective  Based on the self-developed wood-plastic composite material 3DP equipment micro-droplet injection system, research on the process of UV adhesive micro-droplet injection is aimed to optimize the processing parameters and the structural parameters of the micro-droplet injection system, and provide data support for the study of droplet spreading and infiltration in the 3DP process of wood plastic composite materials.  Method  The displacement characteristics of the needle-type jet valve and the rheological properties of the UV adhesive were analyzed to determine the injection parameters affecting the micro-droplet injection process of the wood plastic composite 3DP processing. The finite element method was used to simulate the micro-droplet injection process to analyze the influence of injection parameters and obtain the variation characteristics of droplet velocity, pressure and mass flow rate at the nozzle during the micro-droplet injection process. The needle velocity, nozzle diameter and UV adhesive supply pressure as evaluation factors, and the mass of the droplet and the main droplet velocity as indicators, simulation experiments were conducted to optimize parameter combination.   Result  The results of the single factor experiment indicated that needle speed 0.3−0.9 m·s−1, nozzle diameter 0.10−0.20 mm, UV adhesive supply pressure 0.1−0.3 MPa were reasonable printing parameters. The results of the orthogonal experiment indicated that nozzle diameter is a significant factor of droplet mass, and the UV adhesive supply pressure is a significant factor of the droplet velocity. The droplet mass and droplet velocity are good when the nozzle diameter is 0.10 mm, the needle speed is 0.9 m·s−1, the UV adhesive supply pressure is 0.1 MPa, and the valve seat cone angle is 130°.   Conclusion  The VOF finite element model of 3DP micro-droplet injection process of wood-plastic composite was established on the basis of pre-experiment and theoretical analysis. The study on the influence of injection parameters on micro-droplet injection has been completed, and the optimal combination of injection parameters has been obtained. [Ch, 8 fig. 4 tab. 17 ref.]
Research progress of phloem unloading in horticultural plants
LIU Jie, HUANG Ziyang, KANG Jie, CUI Qi, REN Ziming, MA Si, LOU Jianhua, XIA Yiping, WU Yun
doi: 10.11833/j.issn.2095-0756.20230427
[Abstract](25) [HTML](4) [PDF](5)
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Phloem unloading contains a series of complex processes. Phloem unloading plays an important role in the transportation and distribution of assimilates in horticultural plants(fruit trees, vegetables, ornamental plants). This study summarizes the main ways of phloem unloading, and focuses on the main research results of phloem unloading in the growth and development of horticultural plants, including: (1) the main sugar substances transported by phloem; (2) phloem unloading mode; (3) research approaches for phloem unloading; (4) research on phloem unloading in horticultural plants. The key enzymes and sucrose transporters involved in phloem unloading process need further clarification with in-depth research combining the emergence of new technologies, which will help to further elucidate the underlying molecular regulation mechanism of phloem unloading during the key economic and (or) ornamental traits formation in horticultural plants, as well as to provide new ideas for detail research on phloem unloading in other plants. [Ch, 1 fig. 1 tab. 75 ref.]
Analysis on chloroplast genome of Wikstroemia indica
WU Minhua, YE Xiaoxia, TAN Jingyi, LIANG Qiuting, WU Zijian, HUANG Qionglin
doi: 10.11833/j.issn.2095-0756.20230412
[Abstract](18) [HTML](5) [PDF](5)
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  Objective  This study is aimed to clarify the structure traits of chloroplast genome and phylogenetic status of medicinal plant Wikstroemia indica, providing a scientific basis for the resource protection and sustainable utilization of W. indica.   Method  An Illumina high-throughput sequencing platform was employed to acquire the chloroplast genome sequence which was then assembled, annotated, compared and analyzed using bioinformatics technologies and software.   Result  The chloroplast genome of W. indica was an annular quadripartite molecule with a length of 149 864 bp and composed of a large single copy (LSC, 86 347 bp), a small single copy (SSC, 10 601 bp) and a couple of inverted repeat (IR, 26 458 bp) and 124 genes were annotated in the chloroplast genome. In the chloroplast genome there were a total of 24 180 codon, which were divided into 64 types of which 30 types of codon were used frequently and 29 of them ended with A/T. Altogether 93 chloroplast simple sequence repeat (SSR) were identified from the chloroplast genome with Mononucleotide being the predominate type taking up a number of 72 and the motifs formed by A/T contributing the most and obvious variations were observed in IR boundary between W. indica and closely related plants whereas sequence alignment and phylogenetic tree revealed that W. indica shared high sequence identity with W. nutans.   Conclusion  The chloroplast genome of W. indica exhibited typical structure of plant chloroplast genome, and possessed codon preference and several SSRs with rich polymorphism. Additionally, the chloroplast genome of W. indica showed the closest similarity to W. nutans. [Ch, 5 fig. 2 tab. 24 ref.]
Regeneration system and genetic transformation of Populus yunnanensis
ZHANG Xiaolin, ZONG Dan, LI Jiaqi, YANG Ling, YU Jinde, HE Chengzhong
doi: 10.11833/j.issn.2095-0756.20230304
[Abstract](18) [HTML](8) [PDF](7)
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  Objective  This study is aimed to establish a highly efficient system for regeneration and genetic transformation of in vitro leaves of Populus yunnanensis so as to help genetic engineering breeding research in P. yunnanensis.   Method  First, with P. yunnanensis leaves as explants, an investigation was conducted of the effects of different combinations of exogenous hormone concentrations on the induction of callus, adventitious bud differentiation and rooting so as to obtain regenerated seedlings of P. yunnanensis. Then, Agrobacterium tumefaciens mediated method was used to explore the effects of bacterial concentration, infection time and co-culture time on the genetic transformation efficiency of P. yunnanensis.   Result  The optimal medium for callus induction was 1/2 MS + 0.005 mg·L−1 thidiazuron (TDZ) + 0.010 mg·L−1 1-naphthylacetic acid (NAA), with an induction rate of 91.7%. The optimal medium for the induction of adventitious bud was 1/2 MS + 0.002 mg·L−1 TDZ + 0.010 mg·L−1 NAA, with an induction rate of 75.0% whereas the optimal medium for rooting was 1/2 MS + 0.010 mg·L−1 NAA + 0.100 mg·L−1 3-indolebutyric acid (IBA), and the rooting rate was as high as 96.7%, with an average number of 2.57 roots. The optimal concentration of transforming bacterium D(600) was 0.2, the infection time was 5 min, and the co-cultivation time was 2 days. During differentiation, the optimal concentration of cefotaxime to inhibit the growth of A. tumefaciens was 200 mg·L−1, and the optimal concentration of kanamycin in the screening medium for resistant buds was 20 mg·L−1. The regenerated plants were identified by β-glucuronidase (GUS) staining and PCR, identified 20 positive plants, with a positive transformation rate of 45.45%.   Conclusion  The leaf regeneration system and genetic transformation system of P. yunnanensis were successfully established. [Ch, 5 fig. 5 tab. 27 ref.]
Effect of N and Si addition on phytolith-occluded organic carbon in Phyllostachys edulis
YANG Jie
doi: 10.11833/j.issn.2095-0756.20230460
[Abstract](41) [HTML](13) [PDF](8)
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  Objective  This study aims to investigate the response of phytolith and phytolith-occluded organic carbon (PhytOC) formation to exogenous nitrogen (N) and silicon (Si), and study the effect of exogenous N and Si addition on PhytOC sequestration capacity of Ph. edulis.   Method  N-Si two factor three level orthogonal cultivation experiment was designed [CO(NH2)2: 0(N0), 250(N1), 500(N2) mg·kg−1, Na2SiO3: 0(Si0), 75(Si1), 150(Si2) mg·kg−1], and samples of leaves, branches, culm, culm stump and litter were collected to analyze PhytOC content in different organs under different treatments.  Result  With the increase of Si addition, PhytOC content of different organs and litter showed an upward trend. PhytOC contents in different treatments of leaves, branches, culm, culm stump, and litter were 3.15−4.68, 2.10−3.47, 0.30−1.18, 1.09−2.15 and 3.21−4.63 g·kg−1, respectively, and all showed the highest content of PhytOC in N2Si2 treatment [CO(NH2)2: 500 mg·kg−1, Na2SiO3: 150 mg·kg−1], while the lowest content of PhytOC in N0Si0 treatment [CO(NH2)2: 0 mg·kg−1, Na2SiO3: 0 mg·kg−1]. The results of the difference significance analysis showed that PhytOC content showed significant differences (P<0.05) between N0Si1, N0Si0 and N2Si2 treatments in culms. The correlation analysis results showed that there was a highly significant positive correlation between PhytOC and Si (R2=0.481 8, P<0.01), as well as between PhytOC and phytolith (R2=0.463 2, P<0.01). There was a highly significant negative correlation between PhytOC and C (R2=0.318 3, P<0.01).   Conclusion  Exogenous N addition contributes to the absorption of Si and the accumulation of organic matter in Ph. edulis, while Si addition helps to increase the content of phytolith and PhytOC, as well as the proportion of PhytOC to C. [Ch, 1 fig. 9 tab. 36 ref.]
Identification and expression analysis of bZIP gene family under ABA treatment in Phoebe bournei
YANG Yong, ZHANG Junhong, HAN Xiao, ZHANG Yuting, YANG Qi, TONG Zaikang
doi: 10.11833/j.issn.2095-0756.20230342
[Abstract](58) [HTML](14) [PDF](11)
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  Objective  This study is aimed to identify the bZIP transcription factor family members from Phoebe bournei and investigate the response levels of its members to abscisic acid (ABA) treatment.   Method  A bioinformatic method was employed to identify the PbbZIPs family throughout the whole genome and to analyze its physicochemical properties, gene structure, evolutionary relationships, cis-acting elements in promoter, and the expression patterns under ABA treatment by RT-qPCR.   Result  A total of 63 PbbZIP genes were identified from 12 chromosomes in P. bournei, divided into 12 subfamilies with significantly different in gene structure and motifs, but highly conserved in the same subfamily. Most of the PbbZIPs were localized in the nucleus, and their encoded protein were 110−835 amino acid in length, −1.19~−0.19 in hydrophobicity, and 4.48−11.95 in isoelectric point. The 27 pairs of PbbZIPs distributed on 12 chromosomes were featured with collinearity existence, which was the main pattern of PbbZIPs family expansion. A variety of abiotic stress-related action elements were found in the upstream promoter region of PbbZIPs, among which ABA, salicylic acid and methyl jasmonate were more abundant response elements and the genes expression of RT-qPCR revealed that 17 PbbZIPs were induced differentially by ABA signals and generally up-regulated in leaves and roots when P. bournei was treated with 2 mmol L−1ABA for 1−72 h, with the relative expression of PbbZIPs in roots being generally lower than that in leaves.   Conclusion  The 63 PbbZIPs identified from the P. bournei genome were unevenly distributed across the 12 chromosomes and highly similar in gene sequences, whereas the chromosomal localization genetic structure and conserved motifs were evolutionarily diverse and different between subgroups. The PbbZIPs in leaves and roots responded differently to ABA treatment and got involved in the regulation of other abiotic processes. [Ch, 9 fig. 35 ref.]
Effects of ethylene and 1-MCP treatment on puffiness and albedo cell wall metabolism of post-harvest Citrus reticulata ‘Ponkan’ fruit
WANG Xinsheng, ZHANG Shuning, KE Fuzhi, ZHENG Shuqi, GONG Jinli, SUN Xuepeng, ZHANG Lanlan
doi: 10.11833/j.issn.2095-0756.20230422
[Abstract](41) [HTML](14) [PDF](5)
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  Objective  For the purpose of developing storage and fresh-keep technology, this study is aimed to evaluate different post-harvest methods that target at the prevention of puffiness, a common physiological disorder that occurs in mature or post-harvest storage stages of citrus fruits (Citrus reticulata) which seriously affects its marketability.   Method  Ethylene and 1-methylcyclopropene (1-MCP) were used to treat the postharvest ‘Ponkan’ fruit, and the main quality indexes and puffing index, as well as the characteristics of albedo cell morphological and physiological changes were studied after treatment.   Result  (1) Ethylene treatment brought about an increase of soluble solid content during fruit storage, accelerated the decline of cell density, cellulose content, and pectin content of the albedo, while promoting an increase in lignin content and the activity of cell wall-degrading enzymes (cellulases, pectin esterases, and polygalacturonases). (2) 1-MCP treatment slowed down the decrease of albedo cell density and cellulose content, delaying the increase of lignin content and the activity of cell wall degrading enzymes (cellulase, pectin esterase and polygalacturonase), and therefore slowing down the rise of puffiness index.   Conclusion  Ethylene treatment accelerated the physiological and metabolic level of ‘Ponkan’ fruit during storage and aggravated the occurrence of puffiness whereas 1-MCP treatment inhibited the peel physiological and metabolic level during storage and alleviated the occurrence of puffiness. As a result, the peeling difficulty of the fruit can be controlled by ethylene or 1-MCP treatment during production. [Ch, 7 fig. 31 ref.]
Production and adsorption properties of activated charcoal fromBambusa sinospinosa
TIAN Huayu, LIU Huan, WANG Guorui, HAO Haiyan, WANG Tianci, ZHANG Wenbiao
doi: 10.11833/j.issn.2095-0756.20230307
[Abstract](22) [HTML](4) [PDF](6)
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  Objective  This study, with an investigation of the production process and application fields of activated charcoal of Bambusa sinospinosa, is aimed to make full use of B. sinospinosa, improve its utilization rate, and improve its added value.   Method  First, with B. sinospinosa charcoal used as the raw material, steam activation method as well as single factor experiment were employed to explore the effect of temperature, time, steam vapour amount on the yield of B. sinospinosa activated charcoal and its adsorption performance. Then, Fourier infrared absorption spectrometer (FTIR), X-ray diffractometer (XRD), specific surface area and porosity analyzer (BET), scanning electron microscope (SEM) and other testing instruments were utilized to test and characterize the prepared activated charcoal of B. sinospinosa.   Result  (1) The activation process of the B. sinospinosa activated charcoal was optimal when activation temperature was 875 ℃, activation time was 2.0 h while steam vapour amount was 0.50 L·h−1 under which the yield of activated carbon was 29.07%, the strength was 97.68%, the adsorption value of iodine was 1 235.03 mg·g−1, and the methylene blue adsorption value was 276 mg·g−1, making a favorable adsorption performance. (2) The infrared absorption spectra showed that the absorption peaks started to weaken at 3 130, 3 010 and 1 670 cm−1 until they disappeared at 876, 809 and 747 cm−1 but the main peaks persisted; XRD analysis showed that the activated carbon contained graphite α-axis structure and as shown by surface area test and electron microscope observation, the pore volume and pore size of activated carbon activated by the optimal process were developed, with the total pore volume, the micropore volume, the average pore size and the BET specific surface area being 0.489 cm3·g−1, 0.388 cm3·g−1, 23.378 nm, and 837.005 m2·g−1 respectively.   Conclusion  The B. sinospinosa activated charcoal prepared by the optimal activation process had good performance and could be used on various occasions such as adsorption and decontamination. [Ch, 5 fig. 1 tab. 27 ref.]
Niche distribution of Monochamus saltuarius and Arhopalus rusticus on host Pinus koraiensis
DONG Yifan, YU Haiying, WANG Jiao, FAN Jianting
doi: 10.11833/j.issn.2095-0756.20230167
[Abstract](24) [HTML](5) [PDF](8)
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  Objective   This study aims to clarify the spatial distribution of Monochamus saltuarius and Arhopalus rusticus on Pinus koraiensis from the perspective of vertical space, and explore the interspecific relationship between these two species, so as to provide theoretical basis for their control measures.   Method  Adults of M. saltuarius and A. rusticus were simultaneously detected in P. koraiensis forest in Fushun, Liaoning Province, and both species of beetle larvae were found on the same P. koraiensis tree. Taking P. koraiensis as the habitat resource of longhorn beetle larvae and the vertical height of P. koraiensis as the resource sequence, P. koraiensis affected by longhorn beetles was selected using 40 cm as a unit to study the morphological characteristics, distribution location, niche width and niche overlap of M. saltuarius and A. rusticus larvae.   Result  The distribution of M. saltuarius larvae on P. koraiensis was (87.20±8.45) heads per plant, and that of A. rusticus larvae was (24.40±2.37) heads per plant. The distribution of M. saltuarius larvae was positively skewed on P. koraiensis, with the largest distribution of (16.40±2.38) heads per plant at 80−120 cm above ground, significantly higher than the number below 80 cm and above 120 cm (P<0.05). A. rusticus larvae were evenly distributed in the aboveground parts of the affected trees, with the most abundant at a height of 200−280 cm, accounting for 33.63% of the total number of larvae, significantly higher than the number below 120 cm, 160−200 cm and above 320 cm (P<0.05). No larvae of these two pests were found in the underground parts of damaged P. koraiensis. There was a certain difference in niche width between M. saltuarius and A. rusticus larvae, with values of 0.694 4 and 0.757 6, respectively, and a niche overlap value of 0.804 6.   Conclusion   M. saltuarius larvae are mainly distributed in the middle and lower parts of the trunk of P. koraiensis, while A. rusticus larvae are evenly distributed at various heights of the trunk. The ecological niche overlap between the two is relatively high on P. koraiensis, and the degree of similarity in ecological characteristics is relatively high, indicating a high competitive relationship between the two in P. koraiensis forest to a certain extent. [Ch, 2 fig. 25 ref.]
Analysis of root morphological characteristics of Pinus yunnanensis seedlings at different stump-ages
CHENG Sili, WANG Dan, HE Bin, HU Zhaoliu, CHEN Lin, TANG Junrong, CHEN Shi, XU Yulan, CAI Nianhui
doi: 10.11833/j.issn.2095-0756.20230466
[Abstract](47) [HTML](12) [PDF](9)
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  Objective  This study aims to analyze root morphological characteristics of Pinus yunnanensis seedlings after stumping at different ages, and to provide evidence for selecting suitable stump-age.   method  ​ Taking P. yunnanensis seedlings aged 6, 10, 14, 18 and 30 months as materials, all seedlings were pruned to a uniform height of 5 cm. The root morphology and biomass were measured at 60, 120, 180, 240, 300, 360, 420, and 480 d after stumping, and the root structure of different seedling ages of P. yunnanensis after stumping was analyzed.   Result  ​ Stumping at different seedling ages significantly affected the root morphological characteristics of P. yunnanensis seedlings (P<0.05). At 480 days after stumping, the seedlings stumped at 6 months had smaller average root diameter (0.825 mm) and root volume (4.435 cm3) compared with those stumped at 30 months, which had an average root diameter of 1.302 mm and root volume of 16.282 cm3, but the total root length was larger. The specific root length for 6 to 30-month-old stumped seedlings showed a decreasing tendency, and the root specific surface area, root tissue density, and root fineness of the seedlings stumped at 6 months were significantly greater than those of the seedlings stumped at other ages (P<0.05), showing a decreasing trend with increasing seedling age. There was no significant difference in the growth rate of average root diameter, root volume, and root biomass, while total root length, root surface area, and root biomass showed a trend of decreasing growth rate with increasing seedling age.   Conclusion  ​Younger seedlings build finer and denser root systems, which is conducive to the absorption and utilization of water and nutrients. The seedlings aged 6 months showed the best effect of stumping. [Ch, 2 fig. 5 tab. 40 ref.]
Effect of UV-B radiation on mass fraction of phenolic substances, antioxidant capacity and genes expression in Tetrastigma hemsleyanum
XIA Jingqing, LIU Hairong, GU Yiwen, WANG Ziyue, XING Qiaoyue, ZHANG Yuxiang, LI Shan, BAI Yan
doi: 10.11833/j.issn.2095-0756.20230385
[Abstract](52) [HTML](10) [PDF](8)
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  Objective  This study aims to investigate the effects of UV-B radiation on phenolic components, antioxidant capacity and relation genes expression in Tetrastigma hemsleyanum.   Method  Three-year-old T. hemsleyanum seedlings were subjected to continuous UV-B radiation for 12.0 h and their phenotypes were observed at 0, 0.5, 1.0, 3.0, 6.0, and 12.0 h. With those untreated as control (ck), some other T. hemsleyanum were irradiated for 1.0 and 3.0 h (T1 and T3), and supplemented with dark treatment for 24.0 h (T1+23 and T3+21). Mass fractions of phenolic substances (total phenols and total flavonoids), antioxidant capacity, anti-stress enzyme activity, malondialdehyde (MDA) mass molar concentration in leaves were determined and transcriptome analysis was made.   Result  Continuous UV-B radiation had an effect on the phenotype of T. hemsleyanum. The leaves of 3-h group were partially yellowed, while the leaves of 6-h and 12-h groups were significantly yellowed and slightly curled. The mass fractions of total phenols (2.65 and 2.63 mg·g−1) and total flavonoids (7.16 and 7.30 mg·g−1) in leaves and root tubers, as well as the antioxidant capacity (86.56%) in root tubers reached the maximum in T1+23 group. Meanwhile, dark treatment after UV-B radiation promoted a significant increase in activities of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD), which reached the maximum in T1+23 group. The MDA mass molar concentration was the highest in T3+21 group (7.21 mmol·g−1). UV-B radiation and dark treatment down-regulated the expression of flavonoid synthesis pathway genes (ThF3H, ThANS, ThCHS, ThANR, etc.) and up-regulated the expression of oxidation-related regulators (CAT and SOD).   Conclusion  Darkness treatment after UV-B radiation increases the mass fraction of phenolic substances, antioxidant capacity and anti-stress enzymes activity of T. hemsleyanum, reaching the maximum in T1+23 group. The expression of flavonoid synthase genes is down-regulated and the expression of oxidative stress-related genes is up-regulated. [Ch, 7 fig. 2 tab. 52 ref.]
Identification and bioinformatics analysis of R2R3-MYB subfamily in cucumber
GUO Yuting, DU Changxia
doi: 10.11833/j.issn.2095-0756.20230278
[Abstract](102) [HTML](15) [PDF](13)
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  Objective  This study is aimed to conduct an in-depth study of the functions associated with members of the R2R3-MYB subfamily in cucumber (Cucumis sativus).   Method  First, an analysis was conducted of the whole cucumber genome so as to identify R2R3-MYB subfamily members. Then, bioinformatics was employed to analyze their phylogenetic relationships, physicochemical properties of proteins, chromosomal localization, gene structure, conserved motifs, and cis-acting elements, as well as the protein interactions.   Result  The whole cucumber genome contained 99 R2R3-MYB transcription factors with typical structural domains, and the protein sequences contained amino acids ranging from 195 to 552, with conserved motifs and amino acid sites. They were unevenly distributed on chromosomes. They were unstable proteins with the instability index of most subfamily members being greater than 40. As was shown by the analysis of cis-acting regulatory elements, most of the elements contained in the promoter regions of genes were closely related to hormone regulation, MYB binding sites, and stress.   Conclusion  The R2R3-MYB family members were obtained through whole cucumber genome identification, which were divided into 30 subgroups and mapped on 7 chromosomes and the upstream promoter region of this family members contained stress-related action elements. [Ch, 7 fig. 1 tab. 36 ref.]
Height-diameter model of Pinus massoniana and Schima superba mixed forest in central Guizhou
RAN Jiaxuan, QI Yujiao
doi: 10.11833/j.issn.2095-0756.20230363
[Abstract](60) [HTML](14) [PDF](20)
Abstract:
  Objective  To establish a tree height-diameter model for mixed forests of Pinus massoniana and Schima superba, introduce tree species as dummy variables into the model, and consider the spatial autocorrelation and heterogeneity of residuals of the model, in order to provide theoretical basis for the construction of the tree height-diameter model of mixed forests and the scientific management of mixed forests.  Method  Based on the survey data of 727 groups of tree height-diameter in mixed forests of P. massoniana and S. superba in Kaiyang County, Guizhou Province, we constructed ordinary least squares (OLS), generalized additive model (GAM), linear mixed model (LMM), geographically weighted regression model (GWR), and geographically weighted regression kriging (GWRK) models for tree height-diameter-whole-forest model, on the basis of which tree species was introduced as a dummy variable, and five model residuals spatial autocorrelation and spatial heterogeneity were selected for global Moran’I, local Moran’I, and intra-block variance analyses with the coefficients of determination (R2), mean squared error (MSE), and the Akaike information criterion (AIC) to evaluate the models.   Result  (1) The fitting accuracies of the whole-forest base models of P. massoniana-S. superba mixed forest were OLS<GAM<LMM<GWR<GWRK in descending order. (2) The fitting accuracies of the models were higher than those of the whole-forest base models after introducing tree species as a dummy variable into the models. (3) The global Moran’ I of the residuals of the OLS and GAM models was significant at the α=0.05 level (Z>1.96), and there were more hot spots in the local Moran’I distribution maps, which showed strong spatial autocorrelation. In contrast, the global Moran’I of the residuals of the LMM, GWR and GWRK models is insignificant at the α=0.05 level (−1.96≤Z≤1.96) and there are more cold spots in the local Moran’I distribution plot, indicating that spatial autocorrelation of the model residuals has been eliminated. (4) The intra-block variance of the residuals of the five models show a tendency to increase with the lag distance, but the GWR and GWRK models have smaller intra-block variance, which can better reduce the heterogeneity of the model residual space.   Conclusion  The OLS and GAM models do not have high fitting accuracy and cannot eliminate spatial autocorrelation and heterogeneity of model residuals, so they are not the best choices for modeling tree height-diameter. The LMM, GWR, and GWRK models perform well in improving the model fitting accuracy and decreasing the spatial autocorrelation, but the GWR and GWRK models are more significant in decreasing the spatial heterogeneity, and they are the most appropriate of the tree height-breast diameter models. [Ch, 2 fig. 3 tab. 38 ref.]
Population structure and dynamics of wild Acanthopanax senticosus in different regions of Northeast China
WEI Hongling, XIE Shengnan, TIAN Xuchen, TANG Zhonghua, LIU Ying, LI Dewen
doi: 10.11833/j.issn.2095-0756.20230377
[Abstract](112) [HTML](26) [PDF](22)
Abstract:
  Objective  This study aims to analyze the structural characteristics of wild Acanthopanax senticosus population in Northeast China, clarify its survival status and predict the future succession trend, so as to provide scientific basis for conservation, utilization and sustainable development of A. senticosus population in Northeast China.  Method  Survey sample plots were set up in representative habitats in Xiaoxinganling, Zhangguangcailing and Changbai Mountain and the plants in the sample plots were surveyed. Based on sample survey and data statistics, the age structure of wild A. senticosus was mapped, its static life table was compiled, survival and mortality curves and survival function curves were fitted, and survival analysis and quantitative dynamic parameters were used to predict population development trend.  Result  (1) The age structure of wild A. senticosus population in the three regions was similar to a “pyramid” type, and the number of young and mature plants accounted for 68.58%~83.04% of the total number of the species and the age structure of the population was stable. (2) In the three regions, the dynamic indices of quantitative changes in the population structure (\begin{document}${V}_{{\rm{p}}n})$\end{document} and the population age structure index considering future external interference (\begin{document}${V'_{{\rm{p}}n}}$\end{document}) were greater than 0, and the survival curves tended to be Deevey-Ⅱ type, indicating a growth type with high sensitivity to external interference. (3) In the three regions, the number of plants at the 1st age level was significantly lower than that at the 2nd and 3rd age levels, indicating that the low rate of seed germination was currently a bottleneck for the population renewal and development. The population in all the three regions gradually decreased in the early stage and stabilized in the later stage, but the risk rate gradually increased, indicating a decline trend in the population in the later stage.   Conclusion  At present, the population structure of wild A. senticosus in the three regions is of a growth type, but the number of young plants is small and the development potential of the number of old individuals in the population is small. It is difficult to maintain an overall long-term stability of wild A. senticosus population. It is recommended to strengthen the precise nurturing and management of 1-year-old individuals, improve the seedling preservation rate through artificial measures, and promote the sustainable development of wild A. senticosus population. [Ch. 3 fig. 5 tab. 35 ref.]
Water pattern changes of Tongxiang City based on multi-source remote sensing data
XU Chenkai, WANG Ke, HUANG Lu
doi: 10.11833/j.issn.2095-0756.20230288
[Abstract](104) [HTML](27) [PDF](20)
Abstract:
  Objective  Tongxiang City of Zhejiang Province is a typical “canal town in south of the Yangtze”. Its water system has been greatly disturbed by human activities. Assessing the changes of the water system in Tongxiang is of vital importance to optimize the water pattern and enhance the sustainable development.   Method  Based on six multi-source remote sensing images and land use survey data from 1975, 1998, 2005, 2012, 2016 and 2019, the water system data were obtained by visual interpretation method. The quantitative changes in the number, structure, shape, function, and spatial distribution of rivers and ponds in Tongxiang since 1975, were studied using river network water system indicators, landscape pattern indices, and spatial overlay analysis.   Result  (1) The length and area of rivers in Tongxiang increased before 2005, declined sharply during the period of rapid urbanization, and recovered rapidly after 2016. The length and area of Class-I rivers increased in all phases, but the tributaries changed significantly. (2) The river network density, tributary development coefficient, and fractal dimension increased first, then declined, and finally increased rapidly throughout the process. The river water surface rate continued to grow but the growth rate stagnated significantly during the period of rapid urbanization. The ring degree of river network and the actual integration degree fluctuated continuously and reached its peak in 2016. (3) The variation of river network density in suburban and exurbs was much larger than that of urban areas. Before 2005, the changes of water surface rate were larger in urban area than that in exurbs and suburbs. But during the rapid urbanization period, the changes of water surface rate were larger in urban area than that of suburbs and exurbs. The changes of tributary development index was not significant in exurbs. (4) The areas of pond experienced the same process as that of the river. It first increased, then decreased and finally increased rapidly. And the structure of the pond was constantly changing. The proliferation of farming ponds was the main factor in the change of pond area. The shape of the pond became regular during the development, and its distribution gathered, then dispersed, and finally reconnected. Large-scale aggregation of the pond occurred in in the western of exurbs.   Conclusion  The changes in the water system of Tongxiang in different periods have been greatly influenced by urban development policies, mainly including urbanization development, agricultural structure adjustment, ecological governance, and restoration, and showed obvious periodicity. The characteristics of changes in plain water network cities of the same type are similar and different. [Ch, 3 fig. 8 tab. 36 ref.]
Variation and selection of half-sib families of Falcataria falcata during seedling stage
YAN Shu, WEI Ruping, WANG Runhui, HUANG Rong, ZHENG Huiquan
doi: 10.11833/j.issn.2095-0756.20230371
[Abstract](108) [HTML](18) [PDF](19)
Abstract:
  Objective  The study aims to explore the genetic variation in seedling growth and nitrogen fixation traits of Falcataria falcata and select fast growing families with strong nitrogen fixation ability.  Method  Seedlings of 1 to 6 months in 37 half-sib families from the 1st generation clonal seed orchard of F. falcata were used as materials. Indicators such as seedling height, ground diameter, relative chlorophyll content, biomass, and number of root nodules were investigated and measured. The methods of genetic variation analysis, correlation analysis and cluster analysis were used to compare growth and select seedlings.   Result   There was no significant difference in growth traits among 1−2 month seedlings in 37 half-sib families, but the height or ground diameter of 4-month seedlings in more than 16 families was significantly better than that of the mixed seeds of mother forests (ck) in Raoping County . The family heritability of seedling height and ground diameter was 0.89−0.90 and 0.84−0.86, respectively, and the genetic progression was 0.118 9−0.221 4 and 0.096 2−0.154 3, respectively, at a selection rate of 30%. There was a highly significant or significant positive correlation between different traits (P<0.01 or P<0.05). 13 families were selected, accounting for 34% of the population. Compared with the population mean, the realistic gains in seedling height and ground diameter were 27.99% and 12.73%, respectively, and the genetic gains were 24.91% and 10.69%, respectively. Compared with ck, the realistic gains were 62.47% and 41.65%, and the genetic gains were 55.59% and 34.98%, respectively.   Conclusion  The half-sib families of F. falcata have significant genetic variation in growth traits such as seedling height and ground diameter from 4 months of seedling age, and have a high level of family heritability and good selection potential. Based on the synergistic analysis of growth and nitrogen fixation traits, 13 excellent families with both seedling growth advantage and efficient nitrogen fixation capacity are selected. [Ch, 3 fig. 4 tab. 23 ref.]
Identification and analysis of floral scent compounds of Prunus mume cultivars
YANG Yu, WANG Yiguang, DONG Bin, XIAO Zheng, ZHAO Hongbo
doi: 10.11833/j.issn.2095-0756.20230279
[Abstract](223) [HTML](41) [PDF](26)
Abstract:
  Objective  This study, with a comparison of the different floral scent compounds of different cultivars of Prunus mume, is aimed to investigate the floral composition of P. mume so as to lay a foundation for mining the key enzyme genes in the pathway of floral aroma metabolism and molecular breeding in the future.   Method  With 20 cultivars of P. mume from different groups selected as experimental materials, headspace solid phase microextraction method and gas chromatography-mass spectrometry (HS-SPME-GC-MS) were employed to determine the floral components of 20 cultivars of P. mume and identify the characteristic aroma substances of P. mume before an analysis was conducted of the floral components and relative content differences of P. mume in different cultivars groups whereas a cluster analysis was conducted of the cultivars in accordance with the floral components.   Result  A total of 43 volatiles were identified from 20 cultivars of P. mume, among which benzene/phenylpropane compounds were the most diverse and had the highest content, and their relative content in all cultivars was higher than 85%. Among the volatiles, the benzyl acetate, benzyl alcohol, eugenol, methyl eugenol, benzaldehyde and cinnamyl alcohol were the main components of P. mume flower fragrance, the number of floral compounds in Cinnabar Purple and Pink Double group was the highest, followed by that in Versicolor and Green Calyx group, and the number of floral compounds in Alboplena and Pendulous Mei group was relatively smaller. Cluster analysis showed that 20 cultivars of P. mume could be divided into 5 categories according to the types and contents of flower aroma components.   Conclusion  The aroma components and relative contents of different cultivars of P. mume were different, so was the contribution of different floral components to the aroma of different cultivars of P. mume. [Ch, 1 fig. 11 tab. 28 ref.]
Vertical distribution of soil moisture in typical plantation in the loess region of western Shanxi Province
HUANG Jinghan, BI Huaxing, ZHAO Danyang, WANG Ning, LIU Zehui, ZHANG Rong
doi: 10.11833/j.issn.2095-0756.20230228
[Abstract](107) [HTML](39) [PDF](17)
Abstract:
  Objective  This study, with an investigation of the dynamic characteristics of 0 − 500 cm soil moisture in the restoration process of artificial forests in the loess region of western Shanxi Province, is aimed to provide theoretical basis for improving soil water environment of plantation and realizing forest water balance.   Method  First, with five typical plantations (Robinia pseudoacacia, Platycladus orientalis, Pinus tabuliformis, R. pseudoacacia-Platycladus orientalis, R. pseudoacacia-Pinus tabuliformis) selected as the research objects, oil drill drying method was employed to measure the soil moisture content of 0 − 500 cm before an anlysis was conducted of the vertical distribution and dynamic change characteristics of soil moisture in artificial forests.   Result  The average soil water content of plantations from large to small is Platycladus orientalisR. pseudoacacia-Platycladus orientalisPinus tabuliformisR. pseudoacacia-Pinus tabuliformisR. pseudoacacia, showing a significant difference in the soil content and that precipitation and soil texture were the main factors affecting soil water content in plantations (P<0.05). Vertically, the variation degree of soil water content was moderate, and the variation coefficient decreased with the increase of soil depth with the variation of soil water content of each plantation becoming steady at a depth of about 360 cm whereas the artificial vegetation mainly affected the soil water in the range of 0 − 360 cm with the water variation of R. pseudoacacia forest being the highest, and that of Platycladus orientalis forest being the most stable. The vertical layers of soil water in the plantation were divided into exchange layer, use layer, regulation layer and stability layer by using the ordered clustering method with some differences in the depth of the layers among different stands.   Conclusion  The artificial forest land can reduce soil moisture to some extent in the study area and the consumption of deep soil water increases with the occurrence of drought in R. pseudoacacia, Pinus tabuliformis, R. pseudoacacia-Pinus tabuliformis, especially R. pseudoacacia forest. Therefore, it is suggested that during the construction of forestry ecological engineering, efforts should be made to reduce the planting of R. pseudoacacia forest and increase the planting of Platycladus orientalis in an appropriate manner, as well as transform the existing R. pseudoacacia forest with poor soil water status into a mixed forest, so as to improve the soil water environment and achieve forest water balance. [Ch, 5 fig. 2 tab. 28 ref.]
Response of soil bacterial community to wetland degradation in the Napahai Plateau
ZHAO Dingrong, LU Mei, ZHAO Xuyan, SHAN Shengyang, SUN Guanfa, SUN Yujia, LIU Guoqing, GUO Chuniao, CHEN Zhiming
doi: 10.11833/j.issn.2095-0756.20230331
[Abstract](92) [HTML](53) [PDF](23)
Abstract:
  Objective  This study aims to explore the spatiotemporal dynamic characteristics of soil bacterial structure and diversity in plateau degraded wetlands, so as to provide key data support for understanding the response process and mechanism of soil microbial communities to plateau wetland degradation.   Method  Illumina high-throughput sequencing technology was used to detect the dry and wet seasonal changes of soil bacterial community composition and diversity during different wetland degradation stages (swamp wetlands, swamp meadows, and meadows) in the Napahai Plateau.   Result  (1)A total of 10 phyla and 21 genus of soil bacteria were detected, dominated by Proteobacteria and unclassified genera, with relative abundance of 35.92% and 20.64%, respectively. (2) Compared with native swamp wetlands, the relative abundance of Proteobacteria and Acidobacteria in swamp meadows increased by 14.06% and 47.72%, respectively, while that of Chloroflexi significantly decreased by 38.54% (P< 0.05). The relative abundance of Acidobacteria, Actinobacteria, Verrucomicrobia and Planctomycetes in meadows increased by 210.15%, 231.37%, 229.55% and 315.22%, respectively. The relative abundance of above phyla was greater in the dry season than in the wet season. The relative abundance of Firmicutes in swamp meadows significantly increased by 72.38% in the dry season and decreased by 73.17% in the wet season (P< 0.05). The relative abundance of Bacteroidetes in meadows significantly decreased by 55.43% in the dry season and increased by 223.59% in the wet season (P<0.05). (3) The Shannon index of swamp meadows and meadows significantly increased compared with native swamp wetlands (P<0.05). The Shannon indices in swamp wetlands and marsh meadows were higher in the wet season than in the dry season, while those in meadows showed an opposite pattern. (4) Mentel test indicated that the composition of bacterial community structure in the dry season was regulated by soil pH and the concentrations of nitrogen, phosphorus and potassium, while in wet season it was mainly regulated by soil water content, organic matter, nitrogen, phosphorus and pH. The Pearson correlation analysis showed that the controlling factors affecting bacterial diversity in the dry season were soil water content, organic matter, nitrogen and pH, while those in the wet season were soil phosphorus and potassium and carbon nitrogen ratio.  Conclusion  The degradation of plateau wetlands leads to a decrease in soil moisture and pH, which in turn affects the nutrient status of soil carbon, nitrogen, phosphorus, and potassium, ultimately regulating the dry and wet season changes in soil bacterial community composition and diversity. [Ch, 4 fig. 4 tab. 47 ref.]
Remote sensing monitoring of subtropical forest disturbance and restoration in Songyang County, Zhejiang Province
ZOU Weimin, DING Jun, HUANG Zihao, HUANG Lei, SONG Meixuan, LI Xuejian, DU Huaqiang
doi: 10.11833/j.issn.2095-0756.20230324
[Abstract](194) [HTML](46) [PDF](28)
Abstract:
  Objective  Songyang County in Zhejiang Province is rich in forest resources and has great potential for carbon sinks, and is a tertiary linkage area of Baishanzu National Park. This study aims to monitor forest disturbance and restoration in Songyang County, so as to provide an important reference for forest management in this region and ecological protection for Baishanzu National Park.   Method  Using the LandTrendr algorithm of the Google Earth Engine (GEE) cloud platform, as well as Landsat satellite remote sensing time series data from 1987 to 2020, the forest disturbance and restoration status in Songyang County, Zhejiang Province from 1987 to 2020 were detected, and the spatial and temporal characteristics of forest disturbance and restoration were analyzed.   Result  (1) The overall accuracy of the LandTrendr algorithm in detecting forest disturbance and restoration reached 82%, and the production accuracyand user accuracy of forest disturbance and restoration were both higher than 80%, indicating that the monitoring of forest disturbance and restoration in Songyang County was effective. (2) The total area of forest disturbance and restoration in Songyang County reached 148.14 and 236.86 km2, accounting for 12.74% and 20.37% of the forest land area, indicating a net increase in forest area in Songyang County from 1987 to 2020. (3) Forest changes in Dadongba Township, Banqiao She Township, Xinxing Township and Yuyan Township in Songyang County were relatively frequent, and the area of forest disturbance and restoration was higher than that in other townships. In particular, the forest area of Dadongba Township changed the most, with an increase of 20.04 km2.  Conclusion  The LandTrendr algorithm based on the GEE cloud platform has achieved precise monitoring of forest disturbance in this county. The overall forest area in Songyang County has shown an increasing trend in the past 30 years. [Ch. 3 fig. 3 tab. 46 ref.]
Effect of foliar fertilization on seed quality of Torreya grandis ‘Merrillii’ during seed filling period
HAO Qichun, XIE Jiquan, DAI Wensheng, LI Keyu, YU Chenliang, YU Weiwu
doi: 10.11833/j.issn.2095-0756.20230194
[Abstract](140) [HTML](50) [PDF](21)
Abstract:
  Objective  This study aims to explore aspects of Torreya grandis ‘Merrillii’ seeds, including appearance, nutritional quality, element content, flower bud differentiation, and expansion and fruit setting, so as to provide a theoretical basis for supplementing tree nutrition and improving seed quality.   Method  During the seed filling period of T. grandis ‘Merrillii’ from June to August, the seeds were treated with water as a control and sprayed with 7 commercial foliar fertilizers (amino acid water-soluble fertilizer, fulvic acid water-soluble fertilizer, active potassium water-soluble fertilizer, high-strength calcium water-soluble fertilizer, liquid boron water-soluble fertilizer, trace element water-soluble fertilizer, and macro-element water-soluble fertilizer). Physiological indicators of seeds in terms of seed morphology, oil content and fatty acid composition, crude protein content, starch content, soluble sugar content, and flowering intensity were measured and their effects on seed quality were analyzed.   Result  Spraying amino acid water-soluble fertilizer and macro-element water-soluble fertilizer significantly increased (P<0.05) the kernel shape index, single kernel mass, nucleation rate, kernel type index, and single kernel mass of seeds, as well as oil content, soluble sugar content, and flowering intensity, and significantly reduced starch content. Among them, the single kernel mass of seeds treated with amino acid water-soluble fertilizer increased by 9.8% compared with the control, while the starch content decreased by 1.9%. The single kernel mass, oil content, and soluble sugar content of seeds treated with macro-element water-soluble fertilizer increased by 9.5%, 11.9%, and 15.9%, respectively, compared with the control. At the same time, spraying amino acid water-soluble fertilizer significantly promoted (P<0.05) the content of taxoleic acid in seeds, which increased by 15.9% compared with the control, while spraying macro-element water-soluble fertilizer significantly (P<0.05) increased the content of unsaturated fatty acids in seeds by 4.2% compared with the control. In addition, high-strength calcium water-soluble fertilizer had a significant promoting effect (P<0.05) on the increase of kernel yield, flowering intensity, and fruit setting rate, which were 3.3%, 17.1%, and 10.9% higher than the control. The active potassium water-soluble fertilizer significantly increased the protein content of seeds by 13.6% compared with the control. Principal component analysis showed that the comprehensive quality score of seeds treated with amino acid water-soluble fertilizer was the highest.   Conclusion  The amino acid water-soluble fertilizer treatment has the best effect, followed by high-strength calcium water-soluble fertilizer and macro-element water-soluble fertilizer. [Ch. 3 fig. 5 tab. 29 ref.]
Cover
2024, 41(1).  
[Abstract](58) [PDF](30)
Abstract:
Contents
2024, 41(1): 1-2.  
[Abstract](46) [HTML](17) [PDF](17)
Abstract:
Effects of straw and its biochar application on soil ammonia-oxidizing microorganisms and N cycling related enzyme activities in a Phyllostachys edulis forest
PAN Lixia, JIANG Zhenhui, ZHANG Wenyi, ZHOU Jiashu, LIU Juan, CAI Yanjiang, LI Yongfu
2024, 41(1): 1-11.   doi: 10.11833/j.issn.2095-0756.20230388
[Abstract](306) [HTML](52) [PDF](60)
Abstract:
  Objective  The objective is to investigate the effects of different exogenous carbon application(Zea mays straw and its biochar) on soil ammonia-oxidizing microorganisms and N cycling related enzyme activities in a subtropical Phyllostachys edulis forest, so as to reveal the biological mechanism of soil nitrification.   Method  A 1-year field experiment was conducted in a typical subtropical Ph. edulis forest. Three treatments were set up: control (no application), straw (5 t·hm−2) and biochar (5 t·hm−2). Soil samples were collected at the 3rd and 12th month of the treatment. Quantitative PCR and high-throughput sequencing techniques were used to analyze the changes in soil ammonia-oxidizing microbial community structure characteristics, enzyme activities and gross nitrification rate under different treatments.   Result  Straw and its biochar treatment significantly changed the abundance and community structure of ammonia oxidizing bacteria (AOB) in soil (P<0.05), but had no significant effect on the abundance and community structure of ammonia oxidizing archaea (AOA). Compared with the control, straw treatment significantly increased the abundance of AOB and the relative abundance of Nitrosospira, the activities of soil protease and urease, and the gross nitrification rate of soil (P<0.05), while biochar treatment had the opposite effect. Correlation analysis showed that AOB abundance and the relative abundance of its dominant genus Nitrosospira, protease and urease activity were positively correlated with the content of NH4 +-N, NO3 -N and water-soluble organic nitrogen ( WSON ) , and the soil gross nitrification rate. Redundancy analysis revealed that the contents of NH4 +-N, NO3 -N, microbial biomass nitrogen (MBN) and WSON had a significant impact on the community structure of AOB (P<0.05).   Conclusion  The application of straw biochar reduces the contents of soil NH4 +-N, NO3 -N and WSON, as well as soil AOB abundance and relative abundance of dominant genera, weakens N cycling related enzyme activity, and inhibits soil nitrification. Compared with direct application of straw, straw biochar is beneficial for reducing soil N2O emission and soil nitrogen loss in a Ph. edulis forest. [Ch, 6 fig. 1 tab. 57 ref.]
Characteristics and influencing factors of soil carbon stocks in different vegetation restoration models in red soil erosion areas
LI Peng, LIU Xiaojun, LIU Yuanqiu, TAO Lingjian, FU Xiaobin, MAO Menglei, LI Wenqin, WANG Chen
2024, 41(1): 12-21.   doi: 10.11833/j.issn.2095-0756.20230408
[Abstract](131) [HTML](22) [PDF](29)
Abstract:
  Objective  This study is to explore the soil carbon stock characteristics of different vegetation restoration models in the process of vegetation restoration in red soil erosion areas of Jiangxi Province, so as to provide scientific support for revealing the impact mechanism of vegetation restoration on soil carbon sinks and ecological restoration and carbon pool management in red soil erosion areas of Jiangxi Province.  Method  The research objects included 6 types of forest stands after 27 years of vegetation restoration and reconstruction: Pinus massoniana pure forest (PM), P. elliottii pure forest (PE), Schima superba pure forest (SS), P. elliottii and S. superba mixed forest (MES), replanting S. superba with P. massoniana (RMS), and replanting S. superba with P. elliottii (RES). Natural restoration sites without artificial disturbance (ck) were used as controls to compare the changes in soil organic carbon (SOC) content and storage under different vegetation restoration models, and analyze their influencing factors.  Result  (1) Compared with ck, SOC mass fraction increased significantly (P<0.05) in the 0−20 cm soil layer in all 6 artificial vegetation restoration models. In the 20−30 cm soil layer, except for PM and PE, SOC mass fraction of the other 4 vegetation restoration models was significantly higher than that of ck (P<0.05). In the 30−40 cm soil layer, only SS and MES had significantly higher SOC mass fractions than ck (P<0.05). (2) SOC mass fractions of the 7 vegetation restoration models in the study area showed a strong surface aggregation effect, but the differences between soil layers of different vegetation restoration models were different, among which SS had the largest SOC mass fraction, with a difference of 33.26 g·kg−1 between 0−10 cm soil layer and 30−40 cm layer, and ck had the smallest difference, with only 4.90 g·kg−1. (3) The change rules of SOC density and SOC content were basically the same, both of which were the result of the joint action of vegetation factors and soil physicochemical properties. The correlation coefficient between litter nitrogen mass fraction (r=0.322, P<0.01) and SOC density was the largest among vegetation factors, and the correlation coefficient between SOC mass fractions (r=0.932, P<0.01) and SOC density was the largest among soil physicochemical traits. (4) From high to low, SOC storage increased by 50.12 Mg·hm−2 in SS, 42.73 Mg·hm−2 in MES, 38.20 Mg·hm−2 in RMS, 33.03 Mg·hm−2 in RES, 26.93 Mg·hm−2 in PE, and 20.85 Mg·hm−2 in PM, respectively, compared with ck, with a maximum enhancement of 2.46 times and a minimum enhancement of 1.02 times.  Conclusion  Artificial vegetation restoration and reconstruction have significant effects in red soil erosion areas and can be further promoted in future construction in the research area to promote plant community restoration and enhance and maintain the stability of soil carbon pool. [Ch, 4 fig. 2 tab. 40 ref.]
Effects of thinning on soil heterotrophic respiration of oak-pine mixed forests in Qinling Mountains
CAO Li, WANG Weifeng, MA Xuehong, WANG Xiangfu, LI Yu, LI Li, YU Shuiqiang
2024, 41(1): 22-29.   doi: 10.11833/j.issn.2095-0756.20230193
[Abstract](192) [HTML](29) [PDF](32)
Abstract:
  Objective  This study, with an investigation of the effects of thinning on soil heterotrophic respiration in oak-pine mixed forests in the Qinling Mountains, is aimed to better understand the carbon loss caused by forest soil heterotrophic respiration under thinning treatments, providing a scientific basis for forest management decisions in the study area.   Method  The static chamber-gas chromatography technique was employed to monitor the variations of soil heterotrophic respiration flux in the growing season for the unthinned plots (4 replicates, ck) and the thinning plots (4 replicates) 4 and 12 years ago (4 a and 12 a), respectively. The temperature sensitivities (Q10) of heterotrophic respiration were also calculated.   Result  (1) There was a remarkable decrease in the soil microbial biomass carbon content (P<0.05), but a significant increase in the the soil pH (P<0.05) in both 4 a and 12 a compared to ck, while the decrease in the soil organic carbon content of 4 a after thinning was significant (P<0.05). Generally, the soil physical and chemical index in 12 a were closer to that in the ck than the 4 a treatment. (2) The soil heterotrophic respiration during the growing season showed a “bimodal” pattern, and the peaks appeared in June and October, respectively. However the cumulative heterotrophic respiration increased after thinning but not significantly, with the order from large to small being 12 a>4 a>ck. (3) The soil temperature was significantly and exponentially correlated with the soil heterotrophic respiration (P<0.05). The temperature sensitivities Q10 decreased after thinning, with the order from large to small being ck>12 a>4 a.   Conclusion  The soil temperature is a key factor affecting soil heterotrophic respiration in oak-pine mixed forests and the thinning treatment do not promote soil heterotrophic respiration of the oak-pine mixed forests in the growing season at the Qinling Mountains. [Ch, 3 fig. 2 tab. 34 ref.]
Impact of subtropical forest landscape pattern on forest carbon density in Lishui City of Zhejiang Province
WANG Jianwu, JI Biyong, WANG Zhengyi, ZHU Chenghao
2024, 41(1): 30-40.   doi: 10.11833/j.issn.2095-0756.20230205
[Abstract](150) [HTML](42) [PDF](34)
Abstract:
  Objective  This study, with an quantitative analysis of the effects of forest landscape pattern on forest carbon density in Lishui City, Zhejiang Province, is aimed to provide theoretical basis for forest management, ecological protection and restoration so as to improve forest carbon sink function.   Method  First, the forest carbon density of the continuous forest inventory plots was measured by using the biomass model and carbon coefficient. Then, the distribution map of regional forest carbon density was formed by ordinary Kriging interpolation before an analysis was conducted of the spatial autocorrelation characteristics of forest carbon density. Lastly, five landscape pattern indicators and three natural factors were selected, and multiscale geographically weighted regression (MGWR) models were used to investigate the effects of forest landscape pattern on forest carbon density, while the spatial non-stationarity affecting the results was analyzed.   Result  From 2012 to 2019, the average forest carbon density in Lishui increased from 23.19 t·hm−2 to 31.96 t·hm−2, and the spatial distribution showed a significant positive spatial autocorrelation. Forest landscape pattern significantly affected forest carbon density, showing different scale effects, and the degree of impact was also different in space. Landscape pattern indexes contagion (CONTAG) and patch density (PD) had a greater driving force on forest carbon density, while largest path index (LPI) had a smaller one.   Conclusion  The effects of forest landscape pattern on forest carbon density showed obvious spatial heterogeneity and the results of this paper can provide reference for making differentiated forest management policies and implementing targeted ecosystem protection and restoration projects. [Ch, 3 fig. 4 tab. 42 ref.]
Undergrowth plant diversity in the northern part of secondary forest in Hanshan Mountain, Inner Mongolia
ZHAO Pengwu, GUAN Lijuan, ZHOU Mei, SHU Yang, WU Yiheng, CHEN Jiajia
2024, 41(1): 41-48.   doi: 10.11833/j.issn.2095-0756.20230204
[Abstract](139) [HTML](30) [PDF](26)
Abstract:
  Objective  Qingshan Reserve is a typical area in the northern section of the secondary forest in Hanshan, Inner Mongolia, in order to understand the characteristics of plant diversity under the forest death gradient in the northern section of the Hanshan secondary forest in Inner Mongolia, and to provide a basis for scientific protection and utilization of forest autogenous plant communities and explore plant communities more suitable for forest development.   Method  Taking the secondary forest of Populus davidiana in Qingshan Reserve as the research object, the plant composition of different dead gradients was investigated by sample survey method, and the differences in plant composition and diversity were analyzed by using biodiversity index and community similarity coefficient.  Result  There were 45 plant species in the northern section of Hanshan secondary forest area, Inner Mongolia, including 9 species of trees, 5 species of shrubs and 31 species of herbs, and the number of plant species in the sample plot was as follows: mild death plot>severe death plot>moderate death plot. The Simpson and Shannon-Wiener indices in the same field showed mildly dead stands>severely dead stands>moderately dead stands. Moderately dead plots had the highest richness and Pielou uniformity index. The greatest variation in communities within mildly fatal plots was found by PCoA analysis. The SI index was in the range of 55%−61%, there were 13 species in different death gradient forest stands, the difference between the relative coefficient of the tree layer and the shrub layer was not large, and the reduction benefit of herbaceous diversity was obvious, resulting in the difference of SI index of different death gradient forest stands became larger, and overall, with the increase of aspen mortality degree, the difference in vegetation composition also increased.  Conclusion  The mass forest mortality inhibits the development of herbaceous plant diversity, but promotes the renewal of trees and shrubs. The dominance of aspen in the study area declined, and whether the diversity of forest renewal could form mixed forests needed to be further studied. [Ch, 4 fig. 3 tab. 26 ref.]
Pinus yunnanensis volume estimation model based on UAV multispectral image
DENG Zaichun, ZHANG Chao, ZHU Xiali, FAN Jinming, QIAN Hui, LI Chengrong
2024, 41(1): 49-56.   doi: 10.11833/j.issn.2095-0756.20230263
[Abstract](187) [HTML](43) [PDF](24)
Abstract:
  Objective  Unmanned aerial vehicle (UAV) multispectral remote sensing images, with richer spectral information than visible light images, have great potential in forest volume estimation. Taking UAV-borne multispectral remote sensing images as the main data source, this study aims to explore the remote sensing estimation model of forest volume, so as to overcome the drawbacks of traditional ground survey, such as heavy workload, long time consumption and high cost.  Method  Taking the typical natural pure Pinus yunnanensis forest in Luomian Township, Fumin County, Kunming City as the research object, the single-band reflectance, vegetation index and texture feature were extracted according to the UAV multispectral image, and the standard ground mean of each characteristic variable was calculated. The characteristic variables significantly correlated with the forest volume were screened, and the forest volume estimation model was established using multiple linear regression, random forest and support vector machine. The model accuracy was evaluated by coefficient of determination (R2), root mean square error (ERMS), mean absolute error (EMA) and mean relative error (EMR).   Result  (1) Among the three models, the random forest had the highest accuracy (R2=0.89, EMA=4.69 m3·hm−2, ERMS=5.45 m3·hm−2, EMR=14.5%), followed by the support vector machine (R2=0.74, EMA=5.27 m3·hm−2, ERMS=8.31 m3·hm−2, EMR=13.1%). The multiple linear regression model had the minimum accuracy (R2=0.35, EMA=10.12 m3·hm−2, ERMS=12.85 m3·hm−2, EMR=28.1%). The estimation accuracy of the three models in the test set decreased. The random forest had the best performance, followed by the support vector machine, and the multivariate linearity was the worst. (2) The three models had certain underestimation and overestimation in the estimation of P. yunnanensis forest volume. (3) Texture feature was still an important factor that could not be ignored in estimating the forest volume of P. yunnanensis based on UAV multispectral images.   Conclusion  Based on the multi-spectral images of UAV, the single-band reflectance, vegetation index, and texture factor mean values of the standard ground were extracted without individual tree segmentation, and the variables suitable for volume estimation were screened to construct an estimation model. Through the precision evaluation of the three models, the random forest is the best model for estimating P. yunnanensis volume. [Ch, 2 fig. 5 tab. 27 ref.]
Meteorological drought characteristics of tea in Zhejiang based on relative humidity index
LU Xiang, HAN Furong, GAO Xinyu, SHU Sufang, LU Debiao, JIN Zhifeng
2024, 41(1): 57-66.   doi: 10.11833/j.issn.2095-0756.20220724
[Abstract](181) [HTML](54) [PDF](28)
Abstract:
  Objective  The objective is to study the evolution law of tea meteorological drought in Zhejiang, which is important for safe production of tea.   Method  Based on the daily data (temperature, precipitation and sunshine duration) of 68 meteorological observation stations in Zhejiang Province for 50 years (1971−2020), the spatial and temporal distribution characteristics of tea meteorological drought in Zhejiang were studied by relative humidity index, orthogonal empirical function (EOF), and wavelet analysis.   Result  The intensity and frequency of tea drought in summer were higher than those in autumn in Zhejiang, higher in the west and lower in the east. The drought intensity and frequency of drought were the strongest in the central and western parts of the province, especially in Jinqu Basin, followed by northern Zhejiang, and the least in coastal areas. The proportion of tea drought stations in summer decreased year by year, while in autumn it increased first and then decreased. After 2000, there was an increase in years of extreme large-scale tea drought in the summer and autumn seasons. The first modal of EOF of tea drought intensity in summer and autumn showed the consistency of changes in the whole province. In the second modal, local coastal areas and inland areas showed an inverse phase change. The main mode time series of drought intensity in summer and autumn had oscillation periods of 2−6, 2−4, and 6−10 years respectively.   Conclusion  The frequency of tea drought during summer and autumn in Zhejiang is decreasing, but the probability of extreme droughts has increased in recent years. Special attention should be paid to the improvement of drought monitoring and warning capability in the main tea producing regions. [Ch, 8 fig. 1 tab. 26 ref.]
Genetic diversity analysis and core collection of pinewood nematodiasis-resistant Pinus massoniana germplasm resources
DENG Lili, LIU Qinghua, ZHOU Zhichun, GAO Kai, LUO Dinghui
2024, 41(1): 67-78.   doi: 10.11833/j.issn.2095-0756.20230333
[Abstract](161) [HTML](20) [PDF](22)
Abstract:
  Objective  This study, with analyses conducted of the genetic diversity and population structure of 114 germplasm resources of pinewood nematodiasis-resistant Pinus massoniana from Anhui Academy of Forestry and Forestry Technology Extension and Farm tourism Service Center of Linhai in Zhejiang Province, and the construction of a core collection of the germplasm resources, is aimed to provide a theoretical basis for the scientific management and efficient utilization of germplasm resources of P. massoniana.   Method  First, a total of 114 resistant P. massoniana germplasms were detected before their principal co-ordinates analysis (PCoA), population structure and genetic diversity parameters were calculated by bioinformatics software. Then, the core collection was constructed by using M strategy and random sampling strategy so that a comparative analysis was conducted of the genetic diversity indicators of different core collection in order to determine the most suitable construction method.   Result  115 alleles were detected in 114 resistant P. massoniana germplasms, with an average effective allele number (Ne) of 5.54, an average Shannon’s diversity index (I) of 1.51, and an average PIC value of 0.90 for polymorphic information content, which had a high genetic diversity. The population structure analysis based on Structure software showed that the 114 resistant P. massoniana germplasm resources were divided into four subgroups, and the result of principal coordinate analysis was basically consistent with the above. Based on the genetic diversity parameters and the sampling quantity, the core collection constructed by the M strategy could retain the maximum genetic diversity of the original germplasm with the minimum sampling quantity, which was the optimal sampling strategy. 72 core collections were obtained using this strategy, which retained 100% alleles of the original germplasm, with the ration rates of Ne, I, expected heterozygosity (He), PIC being 95.67%, 94.96%, 98.12%, 100.00%. No significant difference in genetic diversity was shown between the constructed core germplasm and the original germplasm according to the PCoA and UPGMA cluster analysis.   Conclusion  The level of genetic diversity of 114 resistant P. massoniana germplasm was high. The 72 core germplasm of resistant P. massoniana were constructed to remove genetic redundancy, which is conducive to the effective conservation and scientific utilization of resistant P. massoniana germplasm resources, and lays the foundation for excellent gene discovery and new cultivar selection. [Ch, 7 fig. 8 tab. 37 ref.]
Functional analysis of ammonium nitrogen transporter gene JrAMT2 in Juglans regia
FAN Tingting, ZHANG Jiaqi, LIU Huijun, WANG Fengmin, MA Yuhang, WU Yuwei, HU Hengkang, HUANG Youjun, LI Yan, WANG Ketao, HUANG Jianqin, ZHANG Qixiang
2024, 41(1): 79-91.   doi: 10.11833/j.issn.2095-0756.20230296
[Abstract](148) [HTML](40) [PDF](30)
Abstract:
  Objective  The objective is to study the efficient utilization of nitrogen genes and the ammonium nitrogen transporter protein JrAMT2 gene, which is of great significance for variety improvement, rapid growth, and yield of Juglans regia.  Method  Using J. regia JrAMT2 overexpression (OE) seedlings as experimental materials, bioinformatics analysis was conducted on JrAMT2 gene. The growth and development, nitrogen absorption, chlorophyll content, and chlorophyll fluorescence of J. regia JrAMT2-OE plants were analyzed through gene expression level and phenotype determination.   Result  Fluorescence detection, polymerase chain reaction, and fluorescence quantitative PCR were performed on J. regia JrAMT2-OE plants to verify that the JrAMT2 gene is stably expressed in J. regia JrAMT2-OE plants. Compared with the wild type, the plant height, internode length, biomass and other growth parameters of JrAMT2-OE lines significantly increased, and the plant height and internode length of J. regia seedlings increased by 68.2% and 50.3%. The aboveground and underground biomass of JrAMT2-OE lines increased significantly, with a maximum increase of 56.26% (fresh weight) and 56.26% (dry weight) in the aboveground parts, and a maximum increase of 344.38% (fresh weight) and 354.33% (dry weight) in the underground parts. The uptake of ammonium nitrogen and nitrate nitrogen in the underground part of J. regia JrAMT2-OE significantly increased by 114.1% and 70.3% respectively. The JrAMT2 gene mediated the transport of ammonium nitrogen from the underground part to the aboveground part, and the content of ammonium nitrogen in the aboveground part increased significantly, up to 59.1%. The ratio of chloroplast surface area to monolayer cell surface area and chlorophyll content of JrAMT2-OE increased significantly, with the highest increase of 22.94% and 74.3%. The analysis of chlorophyll fluorescence parameters showed that the activity, quantum yield and electron transfer efficiency of the oxygen-reactive body in the leaves of J. regia JrAMT2-OE plants significantly improved.  Conclusion  The JrAMT2 gene of J. regia plays a significant role in the growth and development, nitrogen absorption and photosynthesis of J. regia seedlings. [Ch, 9 fig. 2 tab. 41 ref.]
Chloroplast genome characteristics and codon usage preference of Solanum tuberosum var. cormosus ‘Huaiyushan’
HONG Senrong, ZHANG Mutong, XU Zilin, ZHANG Qinrong, LUO Yuxin, TIAN Wenhui, WANG Xinyu
2024, 41(1): 92-103.   doi: 10.11833/j.issn.2095-0756.20230169
[Abstract](79) [HTML](26) [PDF](18)
Abstract:
  Objective  This study aims to analyze the chloroplast genome characteristics and codon usage preference of Solanum tuberosum var. cormosus ‘Huaiyushan’, so as to provide a reference and theoretical basis for future research on chloroplast genome codon optimization, chloroplast genome modification, exploration of species evolution, and increased expression of exogenous genes.   Method  The chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’ was sequenced by high-throughput sequencing technology. The structure, gene composition and codon preference of the assembled and annotated chloroplast genome were analyzed using bioinformatics analysis software.   Result  The chloroplast genome size of S. tuberosum var. cormosus ‘Huaiyushan’ was 155 296 bp, which was a classical 4-segment structure. The length of large single copy region (LSC), small single copy region (SSC) and inverted repeat region (IR) was 85 737, 18 373 and 25 593 bp respectively, and the proportion of total guanine and cytosine (GC ratio) was 37.88%. A total of 133 genes were released, including 87 CDS genes, 37 tRNA genes, 8 rRNA genes and 1 pseudogene. A total of 38 simple sequence repeat (SSR) loci (36 single base repeats and 2 double base repeats) and 32 long repeat sequences (16 forward repeats and 16 palindrome repeats) were detected in the chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’. The variation range of nucleotide diversity of chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’ was 0 − 0.139 27. The hypervariable regions were mainly distributed in LSC and SSC regions. LSC region had the highest mutation rates of trnL-UAA-trnF-GAA, cemA, rps12-exon1-clpP1 and clpP1 genes, while SSC region had the highest mutation rates of rpl32-trnL-UAG and ycf1 genes. The average effective number of codon (ENC) value of 87 CDS genes in the chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’ was 47.29, and there were 60 genes with ENC value larger than 45, indicating weak codon preference. The preference for codons ending with A and U in the chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’ was largely affected by natural selection, and less affected by mutation pressure. CGU, AAA, CUU, GUU, GGA, GUA, GGU, UCA, GCU, and CCU were the 10 best codons in the chloroplast genome of S. tuberosum var. cormosus ‘Huaiyushan’.   Conclusion  S. tuberosum var. cormosus ‘Huaiyushan’ has a close genetic relationship with S. tuberosum ‘Desiree’. [Ch, 5 fig. 3 tab. 41 ref.]
Generation and application of a fluorescent probe for phosphatidic acid in Arabidopsis thaliana
MA Shuyan, ZHENG Yueping, ZHENG Zhifu
2024, 41(1): 104-112.   doi: 10.11833/j.issn.2095-0756.20230355
[Abstract](195) [HTML](35) [PDF](12)
Abstract:
  Objective  Phosphatidic acid (PA) serves as an important signal molecule involved in the regulation of plant growth and development and different responses to various stresses as well as a general precursor for glycerolipid biosynthesis. However, little is known thus far about the dynamic changes of PA in plant cells. This study attempted to construct a fluorescent probe that can effectively monitor the changes of PA in plant cells and use it to measure the changes of intracellular PA under saline-alkaline stresses.   Method  The corresponding nucleotide sequence for PA-specific binding domain within the Spo20p protein was fused to the green fluorescent protein gene. Transgenic Arabidopsis thaliana lines bearing the fusion gene under the control of the constitutive promoter UBQ10 was then generated via genetic transformation. The resulting fusion protein constituted a fluorescent probe specifically binding to PA. Subsequently, this probe was employed to monitor the changes of cellular PA under saline-alkaline stresses.   Result  Seven transgenic A. thaliana lines homozygous for single insertion of the fusion gene was generated. Real time quantitative PCR (RT-qPCR) analysis showed that expression levels of the fusion gene varied among different lines. Experiments with various exogeneous PA concentrations revealed that as the expression level of the PA probe increased, it could effectively monitor the changes of cellular PA in the root tips treated with 2 μmol·L−1 exogenous PA for 10 min, whereas this was not the case when the expression level of the probe was low, indicating that the sensitivity of the probe for PA detection is, to a certain degree, associated with its expression level. Based on this fluorescent PA probe, PA accumulation at the plasma membrane or in the intracellular space was evident in the root tips under saline-alkaline stresses for 5 min, implying that PA may play important roles in early plant responses to saline-alkaline stresses.   Conclusion  A fluorescence probe for effective monitoring of cellular PA was developed in this study. This probe can monitor the alterations in cellular PA level during early plant responses to saline-alkaline stresses, thereby providing a new tool to study early responses to various stresses. [Ch, 7 fig. 1 tab. 36 ref.]
Analysis and evaluation of flower and fruit characteristics of different Prunus mume cultivars
WANG Shuang, DONG Bin, WANG Yiguang, ZHAO Hongbo
2024, 41(1): 113-123.   doi: 10.11833/j.issn.2095-0756.20230213
[Abstract](177) [HTML](73) [PDF](31)
Abstract:
  Objective  Prunus mume is an ornamental and fruit plant widely cultivated in China. The aim of this study is to select and evaluate P. mume cultivars with both flower and fruit functions, so as to provide basis for fruit processing and utilization.   Method  The 28 P. mume cultivars were selected as research object. Flower traits, fruiting capacity, fruit quality indexes were measured and evaluated by principal component analysis and cluster analysis.   Result  The flower diameter of 28 cultivars ranged from 19.14 to 31.38 mm, with 5−23 petals. White cultivars accounted for the largest proportion. There were significant differences in fruit setting among P. mume cultivars, with ‘Lijiang Zhaoshui’, ‘Yulong Hongfei’ and ‘Yulong Feixue’ being more prone to fruit setting. In addition, there were differences in fruit appearance and internal quality among different P. mume cultivars. Principal component analysis was conducted on 28 cultivars, and 16 indexes were simplified into 4 common factors, with a variance explanation percentage of 82.72%. The comprehensive scores showed that ‘Die Yuchong’, ‘Gu Lihong’, ‘Danfen Chuizhi’, ‘Hongyan Zhusha’, ‘ZAFU-CZ02’, ‘Jiangmei’ and ‘Lijiang Zhaoshui’ had higher scores. Cluster analysis showed that when the Euclidean distance was 24, P. mume cultivars could be divided into 6 groups. Based on the results of principal component and cluster analysis, 4 excellent varieties for both flower and fruit use were selected, including ‘Danfen Chuizhi’, ‘Lijiang Zhaoshui’, ‘Gu Lihong’, and ‘Hongyan Zhusha’.   Conclusion  There are differences in flower traits, fruit setting and fruit quality among different P. mume cultivars. According to the comprehensive characteristics of the flower, fruit yield, and fruit quality, it can be concluded that ‘Danfen Chuizhi’ and ‘Lijiang Zhaoshui’ are easy to bear fruit and have the best comprehensive fruit quality. They are excellent suitable for both flower and fruit. ‘Gu Lihong’ and ‘Hongyan Zhusha’ have bright flower color, with semi double petals and easy to bear fruit. They are suitable for flower and fruit production. [Ch, 6 fig. 6 tab. 30 ref.]
Flowering characteristics and breeding system of Aerides rosea
ZHENG Pengrui, DONG Chunyan, CHEN Zhiguang, XU Yan, GE Hong, YANG Shuhua, ZHAO Xin, KOU Yaping, ZHU Jinyu, JIA Ruidong, WU Ronghua
2024, 41(1): 124-131.   doi: 10.11833/j.issn.2095-0756.20230308
[Abstract](127) [HTML](28) [PDF](23)
Abstract:
  Objective  This study, with an investigation of the breeding system of the Aerides rosea, is aimed to provide theoretical basis for the protection of its germplasm resources.   Method  The floral characteristics and flowering process of A. rosea under greenhouse cultivation conditions were carefully observed and recorded before the breeding characteristics were studied through the detection of pollen viability and stigma acceptability, and the estimation of hybridization index (OCI) and test of artificially pollination.   Result  (1) A. rosea blossomed from May to July with fragrance and the florescence of a single plant lasted about 15 d and that of a single flower lasted about 10 d, with the bud stage being 1−5 d before flowering, the initial flowering stage of 1−4 d after flowering, the full flowering stage of 5−6 d after flowering, the final flowering stage of 7−8 d after flowering, and the fade stage of 9−10 d after flowering. (2) A. rosea belonged with raceme with each plant having 1−4 inflorescences which were featured as long and densely packed with dozens of flowers, with a consistent flowering period throughout the entire plant. (3) During the bud stage before flowering, the pollen already displayed viability and stigma pollinability which reached the highest at 5−6 d of flowering and the OCI of A. rosea was 4. (4) The fruit set rate was 0 without artificial pollination, while the fruit set rate for those with artificial self-pollination, artificial cross-pollination of the same plant and artificial cross-pollination of the different plants was 85.71%, 88.00% and 84.00% respectively, higher than the ones without artificial pollination.   Conclusion  The flowering of A. rosea started in early May and ended at the end of July with a relatively short flowering period of about 2 d and the breeding system was a mixed mating system of self-pollination and cross-pollination that required pollinators to mix. [Ch, 6 fig. 3 tab. 22 ref.]
Effects of PEG 6000 simulated drought stress on physiological and chlorophyll fluorescence characteristics of Dendrobium candidum seedlings
FENG Rui, ZHOU Qi, WU Lingshang, ZHU Yuqiu, GAO Yanhui
2024, 41(1): 132-144.   doi: 10.11833/j.issn.2095-0756.20230301
[Abstract](214) [HTML](57) [PDF](28)
Abstract:
  Objective  The objective is to study the effects of PEG 6000 simulated drought on physiological and chlorophyll fluorescence characteristics of Dendrobium candidum, so as to provide reference for variety selection, industrial cultivation, and near wild cultivation of D. candidum.   Method  The seedlings of D. candidum ‘Jingpin No. 1’ were used as experimental materials and treated with PEG 6000 at different concentrations to simulate drought stress. The stem segment and leaf cell structure of D. candidum seedlings were observed, and the dynamic changes of peroxidase (POD), catalase (CAT) activity, malondialdehyde (MDA), soluble sugar, soluble protein, chlorophyll content and chlorophyll fluorescence parameters in D. candidum leaves were detected.  Result  (1) The content of chlorophyll in the stem and leaf cells of D. candidum decreased after treatment with high concentration of PEG 6000 (20%−30%). (2) PEG 6000 simulated drought stress significantly affected the content of soluble sugar and protein, MDA, POD and CAT activity of D. candidum seedlings. The soluble sugar content increased with the increase of PEG 6000 concentration and the extension of treatment time, reaching its highest value on the 12th day, while the soluble protein showed a downward trend. MDA content, POD and CAT activity increased first and then decreased with the increase of PEG 6000 concentration, reaching the peak at a PEG 6000 concentration of 20%. (3) PEG 6000 simulated drought treatment of D. candidum seedlings significantly affected chlorophyll fluorescence parameters such as maximum photochemical efficiency (Fv/Fm), photosynthetic efficiency (α), electron transfer rate (ETR), photochemical quenching coefficient (qP) and non-chemical quenching coefficient (qNP). With the extension of PEG 6000 stress treatment time and the increase of PEG 6000 concentration, α, ETR, Fv/Fm and qP showed a significant downward trend, while qNP showed a trend of first increasing and then decreasing.  Conclusion  20% PEG 6000 treatment for 12 days can be used as a method for screening drought resistant varieties of D. candidum, which can resist and adapt to a certain degree of drought stress by increasing the content of soluble sugar, reducing the content of soluble protein and improving the activities of defense enzymes such as POD and CAT. The maximum light energy conversion efficiency of D. candidum seedlings decreases, and the photosystemⅡ (PSⅡ) is damaged by stress, which seriously affect the photosynthesis of D. candidum seedlings. At the same time, D. candidum seedlings consume the excess light energy absorbed by the PSⅡ reaction center by activating the qNP pathway to maintain normal photosynthesis. Therefore, soluble sugars and protein, POD and CAT, and chloroplast fluorescence parameters can all be used as indicators of drought resistance in D. candidum. [Ch, 6 fig. 44 ref.]
Toxic effects of the elution from the different feedstock biochars on seeds germination and seedling growth of radish
HU Xiaopiao, HAN Jialin, XIA Honglei, WANG Lei, FANG Chaochu, WANG Minyan, ZHANG Jin, SHAN Shengdao
2024, 41(1): 145-153.   doi: 10.11833/j.issn.2095-0756.20230227
[Abstract](148) [HTML](24) [PDF](30)
Abstract:
  Objective  This study, with an investigation of the toxic effects of biochar on seed germination and seedling growth, is aimed to provide a theoretical basis for the potential screening of typical organic waste carbonization in agriculture and the safe use of dosage, which is conducive to the safe application of biochar in agriculture.   Method  With kitchen waste biochar (KB), pig manure biogas digestion residues derived biochar (PB), and rice straw biochar (RB), chosen as the raw materials and the control group treated with deionized water, an assessment was conducted of the influence of biochar extracts with different solid-liquid ratios (1∶20, 1∶50, 1∶100, m/V) on seed germination and seedling growth of radish (Raphanus sativus).   Result  Compared with the control without biochar extracts, the biochar extracts with the solid-liquid ratio of 1∶100 have no significant effect on radish seed germination and seedling growth but those with the solid-liquid ratio of 1∶20 and 1∶50 inhibit the radish seed germination significantly (P<0.05). The seedling fresh weight, root length, and seedling length cultured by biochar extracts with a 1∶50 solid-liquid ratio were reduced by 29.55%−51.89%, 20.77%−76.04%, and 37.73%−56.01%, respectively, indicating a significant growth inhibition effect of biochar extracts (P<0.05). When cultured with 1∶20 biochar extract, the survival rate of radish seedlings was lower than 12%. The inhibitory effects of different kinds of biochar reduced in the following order: kitchen waste biochar>rice straw biochar>pig manure biogas digestion residues derived biochar. The pH, total concentration of inorganic salts, As, Na, and K concentration of the extract solution were negatively correlated with radish seed germination and seedling growth (P<0.05) and served as the main factors inhibiting radish growth. The root activity of radish seedlings cultured with the 1∶50 solid-to-liquid ratio decreased whereas the content of malondialdehyde (MDA) increased, indicating the destruction of seedling root cell membranes and the occurrence of resultant lipid peroxidation.   Conclusion  The biochar extracts with a high solid-liquid ratio (>1∶50, m/V) had toxic effects on radish seed germination and seedling growth. [Ch, 3 fig. 4 tab. 29 ref.]
Effects of metal ions on digestion and metabolism of Odontotermes formosanus
QI Mengwen, SHEN Yi, YANG Guiying, YU Ting, LI Wuhan, ZHOU Qihuan, XIE Xiaojun, ZHU Yaning, MO Jianchu
2024, 41(1): 154-160.   doi: 10.11833/j.issn.2095-0756.20230219
[Abstract](100) [HTML](26) [PDF](26)
Abstract:
  Objective  This study aims to explore the role of metal ions in influencing the digestive generation process of Odontotermes formosanus, which is beneficial to explore the potential value of resource treatment of agricultural and forestry waste and kitchen waste containing metal ions by O. formosanus.   Method  According to the concentration gradient method, the bait containing different mass fraction of Al3+, Ca2+, Fe3+ and Mg2+ was fed to O. formosanus to determine the maximum edible mass fraction of metal ions in bait for O. formosanus. ICP-OES was used to measure the corresponding metal elements in O. formosanus body and new-built fungus combs, and to obtain the effects of feeding baits containing Al3+, Ca2+, Fe3+ and Mg2+ on the corresponding metal elements mass fraction in O. formosanus body and new-built fungus combs. The activities of laccase and cellulase in O. formosanus body and new-built fungus combs were determined by kit method, and the effects of feeding baits containing Al3+, Ca2+, Fe3+ and Mg2+ on the activities of these enzymes were determined.   Result  The maximum edible mass fraction of Al3+, Ca2+ and Fe3+ in baits of O. formosanus was 1.00 g·kg−1, and Mg2+ in baits was 10.00 g·kg−1. Mg enrichment occurred both in O. formosanus body and new-built fungus combs after feeding baits containing 10.00 g·kg−1 Mg2+; Fe was only enriched in new-built fungus combs after feeding baits containing 1.00 g·kg−1 Fe3+. The laccase activity in O. formosanus body improved significantly after feeding baits containing 1.00 g·kg−1 Al3+. The laccase activity in O. formosanus body improved significantly, but the cellulase activity reduced significantly after feeding baits containing 1.00 g·kg−1 Ca2+. The laccase activity in O. formosanus body and cellulase activity in new-built fungus combs improved significantly, but the laccase activity in new-built fungus combs and cellulase activity in O. formosanus body reduced significantly after feeding baits containing 1.00 g·kg−1 Fe3+. The cellulase activity in O. formosanus body and the laccase activity in new-built fungus combs improved significantly, but the cellulase activity in new-built fungus combs reduced significantly after feeding foods containing 10.00 g·kg−1 Mg2+.   Conclusion  O. formosanus can feed on baits containing 1.00 g·kg−1 Al3+, Ca2+ or Fe3+ or 10.00 g·kg−1 Mg2+, and 1.00 g·kg−1 Al3+ can improve the combined degradation of lignin by O. formosanus and fungus-comb microbiome. O. formosanus have application potential for resource treatment of agricultural and forestry waste and kitchen waste. [Ch, 3 fig. 1 tab. 30 ref.]
Effect of tatD gene deletion of Listeria monocytogenes on virulence and gut microflora in mice
NIU Junhui, LI Qi, MAO Fuchao, QIAN Man, JIA Yanyan, DING Ke, ZHANG Chunjie, CHENG Xiangzhao, LIAO Chengshui
2024, 41(1): 161-168.   doi: 10.11833/j.issn.2095-0756.20220758
[Abstract](78) [HTML](32) [PDF](5)
Abstract:
  Objective  This study, with an investigation of the effects of tatD gene deletion in Listeria monocytogenes on virulence and gut microbiota in mice (Mus musculus), is aimed to provide reference for the role of tatD in the interaction between L. monocytogenes and the host, as well as for the study of attenuated vaccines.   Method  First, mice were orally infected with LM10403s, LM10403sΔtatD and LM10403sCΔtatD strains using the Bliss method to determine the strain’s median lethal dose (LD50) for mice before immunoprotective effect of LM10403sΔtatD was observed in mice immunized with 1.00×105 CFU orally. Then, forty 6-week-old female mice were randomly and equally divided into PBS (ck), LM10403s, LM10403sΔtatD, and LM10403sCΔtatD groups, with those in the ck group gavaged with 200 μL of sterile PBS and the ones in the experimental group gavaged with 200 μL of bacterial solution containing 1.00 × 106 CFU, respectively. Next, after 24 h of gavage, the mice in each group were dissected and killed, with intestinal contents collected before Illumina Hiseq sequencing technology was used to determine the sequences of the microbial 16S rRNA V3−V4 regions of the cecum samples from each group so that a comparative analysis was conducted of the structure of microbial communities, diversity, and signaling pathway enrichment.   Result  The LD50 of LM10403sΔtatD was 8.11×107 CFU, which was less virulent than that of the parental strain. Oral immunization of mice with LM10403sΔtatD provided 80% protection against L. monocytogenes parental strain infection. Chao1 and Observed species indices showed that the difference between ck and LM10403sΔtatD group was not significant, but LM10403s and LM10403sCΔtatD group were significantly lower compared to ck group (P<0.05). At the phylum level, the relative abundance of the Firmicutes in LM10403sΔtatD group was higher than that in LM10403s and LM10403sCΔtatD group, and at the genus level, the relative abundance of the genus, Lactobacillus in LM10403sΔtatD group was higher than that in LM10403s and LM10403sCΔtatD group functional prediction analysis showed that LM10403s group in signaling pathways including cellular processes, environmental information processing, and metabolism was more enriched than the LM10403sΔtatD group.   Conclusion  The deletion of tatD gene reduced the virulence of L. monocytogenes and had animmuno protective effects while infection of the tatD gene deletion mutant strain in mice reduced the effect on intestinal flora dysbiosis and increased the beneficial bacteria. [Ch, 6 fig. 1 tab. 21 ref.]
Microstructure and humidity response of polyethylene glycol/cellulose nanocrystal composite liquid crystal films
XU Yunzhe, CHEN Yifan, LIN Xinyi, FANG Xinye, WU Qiang
2024, 41(1): 169-175.   doi: 10.11833/j.issn.2095-0756.20230236
[Abstract](171) [HTML](44) [PDF](22)
Abstract:
  Objective  Cellulose nanocrystalline (CNC) liquid crystal film, as a kind of photonic crystal with special optical properties, has a promising prospect in the fields of anti-counterfeiting technology, photoelectric functional materials and humidity responsive functional materials. This study, with an exploration of the influence of polyethylene glycol (PEG) on the humidity response of CNC liquid crystal films, is aimed to explain its response mechanism to provide a theoretical basis for the development of low-cost, reusable and highly sensitive PEG/CNC composite film humidity sensors.   Method  The chiral nematic photonic liquid crystal films with humidity response were prepared by evaporation-induced self-assembly of PEG/CNC suspension, and the effects of PEG content on the microstructure, color evolution, mechanical properties and humidity response of the PEG/CNC films were investigated. Then, the cyclic properties of PEG/CNC liquid crystal films under different humidity conditions were studied.  Result  For pure CNC film system, with the increase of CNC content from 3% to 7%, the pitch of CNC liquid crystal film decreased, and the maximum wavelength of reflected light shifted from 596.5 nm to 511.0 nm. For PEG/CNC films, with the increase of PEG content, the pitch of PEG/CNC composite liquid crystal film decreased from 394.0 nm to 244.0 nm while the maximum wavelength of reflected light moved from 613.5 nm to 350.5 nm. The toughness increased first and then decreased, the optimal PEG addition amount was 5%, the breaking energy was 31.9 J·m−2 which was 138% higher than that of pure CNC film. After 5 hygroscopic and dehumidifying experiments, the PEG/CNC film showed good humidity response repeatability with the change rate of the equilibrium wavelength being lower than 0.6%.  Conclusion  An iridescent photonic PEG/CNC liquid crystal film for humidity sensing were prepared, and it was found that PEG can regulate the structural colour by modulate the pitch of the composite film. [Ch, 6 fig. 25 ref.]
Surface defect detection technology of wood-based panel based on image segmentation and deep learning
YANG Fan, YANG Bokai, LI Rongrong
2024, 41(1): 176-182.   doi: 10.11833/j.issn.2095-0756.20230280
[Abstract](243) [HTML](100) [PDF](27)
Abstract:
  Objective  Aiming at the problems of low detection efficiency, low accuracy and digital storage of detection results in the manual detection of surface defects of panel furniture parts, a surface defect detection method of veneer wood-based panel based on image segmentation and deep learning algorithm was proposed.   Method  The defect data set was constructed by the artificial panel images collected by industrial cameras. The global threshold and local dynamic threshold algorithms were used to segment surface defects and image interceptions. The ReLU6 nonlinear activation function was replaced by ReLU function, and the method of reciprocal residual structure was introduced to optimize the MobileNetv 2 deep learning network, and the defect identification and classification were carried out.   Result  The accuracy of the algorithm for the detection of edge breakage and scratch defects on the surface of the veneer panel is 93.1% and 97.5%, and the recall rate is 95.3% and 97.6%, respectively. The average detection time of a single sheet is 163 ms.   Conclusion  The method has high precision and stability, which can solve the problems of low accuracy and low efficiency of traditional manual detection methods, and provide a new idea for automatic detection of surface defects of furniture panels. [Ch, 6 fig. 3 tab. 21 ref.]
Courses, characteristics and motivations of spatial and temporal evolution of national forest cities in China
LIN Zhouyu, HAN Renjie, LI Jian
2024, 41(1): 183-191.   doi: 10.11833/j.issn.2095-0756.20230248
[Abstract](192) [HTML](64) [PDF](123)
Abstract:
  Objective  This study, with an analysis of the courses, characteristics, and motivations of the spatiotemporal evolution of 219 national forest cities, is aimed to countermeasures and suggestions for the current imbalance in the spatial distribution of national forest cities so as to promote the coordinated development of China’s ecological, economic, and social systems.   Method  First, development stages and construction concepts of national forest cities were determined from the macro perspective of China’s social and economic development with an analysis of the literature and the survey of history. Then, kernel density estimation, Gini coefficient, and standard deviation ellipse were employed to analyze the spatial evolution characteristics of national forest cities. At last, an exploration was conducted of the factors affecting the space-time evolution of national forest cities with the employment of overlay analysis, matrix analysis and SPSS.   Result  (1) The macro development stage can be summarized into three stages, namely basic exploration, system standardization, and rapid development whereas the construction concepts were featured with three changes: from fragmentation to integration, from transition to natural wind and from green to live. (2) In terms of the evolution of spatial quantity, administrative regions covered five levels, the quantity distribution was highly consistent with the “Hu Huanyong Line”, and the number of gathering centers had increased. (3) The evolution of spatial situation was featured with agglomeration, directionality and linkage, displaying the linkage development mode of “breakthrough on the point, connection on the line and expansion on the whole”.   Conclusion  In terms of administrative power, the government provides support and guidance for the construction of national forest cities through policy regulation and concept upgrading; the natural binding force and social driving force determine whether the city has the necessary conditions to develop into a high-quality and low-cost national forest city, and determine the quantity distribution and spatial evolution trend of them whereas the urban transformation force provides a starting point for the upgrading of national forest cities in accordance with the needs of the masses. This study has also put forward the countermeasures and suggestions to promote the balanced development of national forest cities on the basis of motivation analysis. [Ch, 4 fig. 4 tab. 22 ref.]
Application of multi-objective programming method in forest park management regionalization
LI Qiwei, ZHANG Xiuqing, Geriletu, GUO Xinxin, YANG Yin, WU Minjun, SHI Jiuxi
2024, 41(1): 192-201.   doi: 10.11833/j.issn.2095-0756.20230274
[Abstract](129) [HTML](20) [PDF](15)
Abstract:
  Objective  This study, on the basis of landscape resource evaluation and multi-objective planning, is aimed to carry out the optimization of forest park functional zoning so as to provide technical support for future work.   Method  Taking Da’anding Forest Park as an example, an evaluation was conducted of the eco-resilience, visual sensitivity and landscape beauty of each landscape unit. The results were then, through linear transformation, translated into the suitability of four management countermeasures namely, key protection, maintaining the status quo, local regulation and construction and reconstruction. Finally, the multi-objective planning method (VMP) was used to investigate the optimal management countermeasures for each landscape unit.   Result  (1) The evaluation index system of ecological landscape quality of forest parks was established with eco-resilience, visual sensitivity and landscape beauty as the core suggesting that the overall level of ecological resilience and visual sensitivity of Da’anding Forest Park was high, but regional differences were large. The scenic beauty was high, but the regional differences were small. (2) A linear transformation model of attribute index management countermeasure suitability was proposed to realize the transformation from multi index evaluation results to the suitability of park functional zoning. (3) The multi-objective programming method was used to seek for the optimal solution for the management of 20 landscape units in the study area, with the optimization results highly coupled with the actual landscape situation. (4) Of the five multi-objective planning methods, the ideal point method, the objective planning method and the fuzzy planning method belonged to one group whereas the efficacy function method and the maximum minimum method belonged to the other group, with the fuzzy programming method showing the best balance and thus recommended in practice and the internal planning results of the two groups are basically the same, with slight differences in between.   Conclusion  The results obtained from the research on the evaluation of the ecological landscape quality of forest parks were converted into attribute index-countermeasure suitability, the optimal solution of management countermeasures was achieved at the global and landscape unit levels by using multi-objective planning, and the results were highly coupled with the actual situation. Besides, of five common multi-objective planning methods, ideal point method, objective planning method and fuzzy planning method performed well, with the performance of the fuzzy planning method being the best. [Ch, 4 fig. 3 tab. 28 ref.]
Multi-scenario simulation and prediction of blue-green spatial pattern in the southern Jiangsu water network area
DING Jinhua, SUN Qi
2024, 41(1): 202-210.   doi: 10.11833/j.issn.2095-0756.20220741
[Abstract](69) [HTML](29) [PDF](8)
Abstract:
  Objective  The objective is to simulate and predict the multi-scenario development trend of the blue-green spatial pattern in the southern Jiangsu water network area, and explore scenario plans to promote sustainable development in the region.  Method  Taking the southern Wujiang District of Suzhou City, Jiangsu Province as sampling area, three scenarios were set up: natural development, ecological protection priority, and urban development priority. Based on CA-Markov model, a multi-scenario simulation analysis was conducted to simulate and analyze the changing trend of the blue-green spatial pattern in 2030. Morphological spatial pattern analysis (MSPA) and landscape connectivity evaluation were used to interpret the ecological structure and characteristics of the blue-green spatial landscape.   Result  There were significant differences in the scale and pattern of the blue-green space under different development scenarios. Under the priority scenario of natural development and urban development, the area of the blue-green space showed an accelerated reduction trend, with a reduction of 3 626.37 and 7 145.74 hm2 respectively. The shape types of the core area and pore of the blue-green space changed sharply in the negative direction, resulting in an increase in fragmentation and a decrease in connectivity in the blue-green space. Compared with the priority scenarios of natural development and urban development, the priority scenario of ecological protection increased the area of the blue-green space by 2 904.30 and 6 423.67 hm2, and the core area of the blue-green space and other morphological types increased significantly, with a significant reduction in porosity, a reduction in the fragmentation of the blue-green space, and an increase in connectivity.  Conclusion  The priority scenarios of natural development and urban development have a negative impact on the blue-green space in the water network area, and the priority scenario of ecological protection has a significant effect on maintaining the stability of the area and pattern of the blue-green space and improving its connectivity. [Ch, 4 fig. 4 tab. 23 ref.]
Review
Response of high nitrogen-loaded forest ecosystem to decreasing atmospheric nitrogen deposition: a review
SHEN Fangfang, WANG Binyu, YAO Bida, MO Mingmin, LIAO Yingchun, FANG Huanying, ZOU Xianhua, LIU Wenfei, YUAN Yinghong, FAN Houbao
2024, 41(1): 211-222.   doi: 10.11833/j.issn.2095-0756.20230380
[Abstract](79) [HTML](16) [PDF](12)
Abstract:
Atmospheric nitrogen (N) deposition is a global threat to biodiversity and ecosystem function. Since emission controls, N deposition has decreased or stabilized in European and North America, and China began to be stabilized in 2010. The future trajectory of N deposition may differ by regions. In this study, literature retrieval and extensive analytic methods were used to analyze N deposition recovery. The reaction of the forest ecosystem’ s soil (acidification and solution chemistry), structure (vegetation-microbial diversity), and function (productivity and carbon sequestration) to decreasing N deposition was studied. Soil solution chemistry (e.g., nitrate and ammonium concentrations, etc.) may responded very rapidly to reducing N input, whereas plant species composition, soil microbial communities, and soil processes may be slow in recovery. When N deposition is controlled, soil acidification can be reduced, and tree growth can be promoted. It is also possible that the vitality of plant may still deteriorating and soil acidity persists due to high rate of atmospheric N deposition. Restoration of plant diversity may face potential barriers to recovery and maintain eutrophication in the short term, but it supports the rise of species in a nutrient-poor. The response of forest ecosystem restoration to emission reduction strategies is delayed. The legacy of earlier N deposition result in a slow recovery, but recovery is simply a matter of time. Therefore, recovery from high N loads is a long and sluggish process, and further emission reduction efforts is still needed in the future. [Ch, 94 ref.]

Bimonthly, Start in 1984

Supervisor:Department of Education of Zhejiang Province

Sponsor:Zhejiang A&F University

Editor-in-Chief:SHEN Xi

Editor:Editorial Department of Journal of Zhejiang A&F University

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E-mail:zlxb@zafu.edu.cn

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