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).
Effects of Pb stress on physiology and main rhizosphere characteristics of Hydrangea macrophylla
SONG Yunjing, JIN Jing, ZHAO Bing
doi: 10.11833/j.issn.2095-0756.20240301
[Abstract](26) [HTML](5) [PDF](1)
Abstract:
  Objective  The objective is to explore the effects of different concentrations of lead (Pb) stress on the root growth physiology, root exudates and rhizosphere soil nutrient environment of Hydrangea macrophylla, and analyze its adaptation mechanism, provide a scientific basis to repair lead-contaminated soil.   Method  The effects of Pb [0 (the control), 500, 1 500, 2 500 mg·kg−1] stress on the growth and uptake of Pb, root oxidative damage, root antioxidant system, root osmotic regulatory substances and root exudates, soil physical and chemical properties, soil enzymes and rhizosphere Pb chemical morphology were studied by a pot experiment.   Result  Pb stress inhibited the growth of H. macrophylla, especially under 2 500 mg·kg−1 Pb treatment, the biomass decreased significantly by 23.7% compared with the control, but H. macrophylla had a certain tolerance to high concentrations of Pb. The oxidative damage caused by Pb stress on H. macrophylla was alleviated by increasing SOD and POD activities in the root, increasing GSH content and enhancing the antioxidant capacity. H. macrophylla also increased the content of osmotic regulatory substances. The soluble sugar content reached the maximum under 2 500 mg·kg−1 Pb treatment, while the proline content was opposite. The root could secrete fatty acids and amines to maintain cell structure, eliminate reactive oxygen species, and the increase of glycolic acid secretion promoted Pb absorption. Soil microecological environment was improved under Pb stress. The activities of sucrase and catalase in rhizosphere soil reached the maximum under the treatment of 2500 mg·kg−1 Pb, which effectively improved soil nutrients. With the increase of Pb concentration, rhizosphere pH value decreased and EC value increased, and the exchangeable ionic state and carbonate binding state of soil Pb accounted for 2.03% and 8.09% respectively, which increased the available state composition of Pb and was conducive to the absorption of Pb by H. macrophylla.   Conclusion  H. macrophylla has good adaptability to Pb, and can grow normally in soil with high concentration of Pb and improve the physical and chemical properties of soil. [Ch, 2 fig. 4 tab. 40 ref.]
Spatio-temporal evolution of habitat quality in Haikou from 2000 to 2020 based on InVEST model
ZHANG Juan, ZHAO Runjiang, LEI Jinrui, LIN Chuanxiang, WANG Zeyu, HUANG Jiajian
doi: 10.11833/j.issn.2095-0756.20240358
[Abstract](67) [HTML](12) [PDF](2)
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  Objective  This study is to analyze the habitat quality and its influencing factors in Haikou, so as to provide data support and scientific reference for ecological environment protection and urban construction.   Method  Based on the land use data of 2000, 2010 and 2020, InVEST model and the methods of land use transfer, habitat quality change rate and spatial statistical analysis were used to analyze the spatial-temporal dynamic changes in habitat degradation and habitat quality in Haikou, and summarize the influencing factors.   Result  ① From 2000 to 2020, forestland was the main type of land use in Haikou, accounting for 47.22%, 55.03%, and 48.75% of the total area in each period, followed by cropland. During the research period, the increase of built land area was the largest, with an increase of 230.37 km2, mainly transformed from forestland, cropland, and grassland. ②The change rate of habitat degradation degree was −1.77% from 2000 to 2010, and 12.20% from 2010 to 2020. The level of habitat degradation showed a spatial distribution pattern centered around the urban area and decreasing in circles. ③The overall habitat quality in Haikou was good. The proportion of areas with excellent habitat quality grades was around 50.00% in all stages, while the proportion of areas with poor grades increased from 5.33% in 2000 to 16.83% in 2020. The habitat quality level changed significantly and frequently in areas such as the urban-rural fringe in the central urban area of Haikou. During the research period, the habitat quality index of Haikou firstly increased and then decreased, and showed an overall decrease from 0.6880 to 0.6588.   Conclusion  From 2000 to 2020, the overall habitat quality in Haikou firstly increased and then decreased, which is closely related to the intensity of urban construction. Haikou should maintain the ecological priority and pay attention to ecological restoration of the main urban area, ecological infrastructure construction, and strengthen the protection and comprehensive management of the ecological system of the peripheral natural environment of the main urban area. [Ch, 5 fig. 7 tab. 25 ref.]
Niche and interspecific association of dominant species of woody plants in evergreen broad-leaved forest in Bailushan scenic area, Zhejiang Province
PAN Chenhao, TANG Weiping, HUANG Han, HU Hanwen, YE Jin, CHEN Shenglong, WU Jiasen
doi: 10.11833/j.issn.2095-0756.20240458
[Abstract](31) [HTML](9) [PDF](0)
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  Objective  The study is to explore the niche and interspecific association of dominant species of woody plants in the evergreen broad-leaved forest in Bailushan scenic area, Zhejiang Province and understand their relationship and succession characteristics, so as to provide reference for ecological restoration and biodiversity conservation of subtropical evergreen broad-leaved forests.  Method  Taking the dominant species of woody plants in the evergreen broad-leaved forest in the study area as the research object, a long-term fixed plot with an area of 1 hm² was established. Ecological niche analysis, variance ratio method (RV), χ2 test, Pearson correlation coefficient, and Spearman rank correlation coefficient were used to analyze the niche and interspecific relationship of dominant woody plant species with importance values greater than 1.00%.   Result  (1) Schima superba, Lithocarpus glaber, Quercu sphillyreoides, and Pinus massoniana were the constructive species of the community. Among them, S. superba had the highest importance value (VI=27.37%), Levins niche width (BL=20.95), and Shannon niche width (BS=3.11), while the other three species had importance values greater than 10%. The average BL and BS were 16.63 and 2.87, respectively. (2) The mean niche overlap index of dominant species was 0.39. Most species were relatively independent in resource utilization and interspecific competition was weak. S. superba, L. glaber, Q. sphillyreoides, and P. massoniana had high niche overlap (mean Oik=0.73), indicating a high degree of similarity in resource utilization. The niche overlap index of Castanopsis sclerophylla with these four species was relatively low (mean Oik=0.17), indicating the weakest competition. (3) The overall association of dominant species in the community showed a significant positive correlation (P<0.05). According to χ2 test, among the 153 pairs out of 18 dominant woody plant species, only 12 pairs showed significant associations (P<0.05), while 91.00% pairs were not significantly correlated. Similar results were observed in Pearson correlation and Spearman rank correlation tests, and 71.25% and 71.90% of species pairs were not significantly correlated. The positive and negative association ratio was greater than 1, indicating that species tended to distribute independently.   Conclusion  The community is in the middle to late stage of succession and has a relatively stable ecological state. In the management of evergreen broad-leaved forests in the early or middle stage of succession in central Zhejiang, it is recommended to moderately retain P. massoniana when regulating high-density stands and appropriately plant Q. sphillyreoides in forest gaps and edges to promote positive succession and enhance the stability of forest ecosystems. [Ch, 4 fig. 2 tab. 36 ref.]
Characterization and phylogenetic location analysis of chloroplast of the endangered plant Neotrichocolea bissetii
ZHU Mengfei, HU Yingfeng, SHI Xueqin
doi: 10.11833/j.issn.2095-0756.20240356
[Abstract](65) [HTML](17) [PDF](4)
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  Objective  Neotrichocolea bissetii, a vulnerable liverwort by International Union for Conservation of Nature (IUCN), is endemic to East Asia. This study aims to clarify the structure traits of chloroplast genome and phylogenetic status of N. bissetii, the results can provide theoretical reference for the species identification, resource conservation and systematic evolution of N. bissetii.   Method  DNA was extracted, sequenced and assembled from N. bissetii samples collected in the field. The chloroplast genome structure, repeat sequences and codon bias were analyzed. The phylogenetic relationship was constructed based on the chloroplast genome sequences of 19 bryophytes.   Result  The whole genome sequence of the chloroplast of N. bissetii was 118 423 bp, including a pair of reverse repeat regions (IR, 9 031 bp), a large single copy region (LSC, 80 837 bp) and a small single copy region (SSC, 19 524 bp). It contained 79 protein-coding genes, 8 rRNA and 36 tRNA. In addition, a total of 56 simple sequence repeats (SSR) were detected in the whole chloroplast genome, most of which were AT/AT dinucleotide sequences. Codon preference analysis showed that the codon preferred to ends in A/U. With the exception of a few variable regions, the IR boundary regions of the chloroplast genome of the N. bissetii were very conserved. Phylogenetic tree showed that this species was most closely related to Trichocoleopsis sacculata.   Conclusion  The chloroplast genome of N. bissetii is a typical tetrad structure and relatively conserved. Phylogenetic tree analysis indicates that N. bissetii and T. sacculata into a branch structure. [Ch, 5 fig. 3 tab. 32 ref.]
Ant diversity along gradient in the middle-western section of Tianshan Mountains in Xinjiang
NONG Zhengguo, XIONG Zhongping, XU Zhenghui, WANG Xubo, LIU Xia
doi: 10.11833/j.issn.2095-0756.20240244
[Abstract](47) [HTML](10) [PDF](0)
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  Objective  In order to reveal the diversity of ant species in different vertical zones in Tianshan Mountains, the ant community structure, relationship between species diversity and altitude and vegetation in the middle-western section of Tianshan Mountains were studied.   Method  Ant communities in four vertical zones were surveyed by plot sampling and searching methods. The sampling adequacy was tested by Estimate S 9.1.0, and the diversity indexes in different zones were calculated. The correlations between diversity indexes and altitude and vegetation characteristics were analyzed by SPSS 24.0, if the correlation between species diversity and elevation was significant, both linear and binomial models were used for fitting, the fitting was evaluated based on R2 value while the significance was tested.   Result  A total of 136 247 ants were collected, and 29 species belonging to 12 genera and 2 subfamilies were recognized. Tetramorium caespitum, Lasius niger and Formica fusca were the dominant species of the middle-western section of Tianshan Mountains in Xinjiang. Sampling adequacy analysis showed that the most of ant species were collected. The richness of ant species of the four vertical zones as follows: Dushanzi vertical zone (18 species) > Narathi vertical zone (14 species)> Kuqa vertical zone (13 species) > Ulastai vertical zone (10 species). Diversity analysis showed that the ant species diversity of the middle-western section of Tianshan Mountains generally decreased with the altitude increasing. The species number and diversity index of the four vertical zones were significantly negatively correlated with the altitude change. On the four vertical zones, the correlation significance between evenness index and altitude was not the same, the change trends of binomial and linear models also lacked regularity. There was no significant correlation between dominance index and elevation change, but the binomial model analysis of each vertical zone showed a trend of increasing firstly and then decreasing with the elevation increasing. Community similarity analysis found that the similarity coefficient of ant community was between 0.166 7 to 0.600 0 (average 0.289 0), which was at the medium dissimilarity level, and indicating significant differentiation among ant communities. Correlation analysis showed that the species number was significantly positively correlated with tree canopy density, while the correlation between other diversity indexes and vegetation characteristics was not significant.   Conclusion  Altitude significantly affected ant species diversity in this region, while slope, humidity and vegetation also play an important role. In the Tianshan area of Xinjiang,under the influence of multiple factors such as vegetation types mainly being grassland and shrubland, hot and dry climate, high altitude and large temperature difference, and the ecosystem in this region is relatively fragile, so the protection of biodiversity in this region should be strengthened. [Ch, 5 fig. 5 tab. 37 ref.]
Response of sap flow rate in Salix psammophila plantation to soil water supply and its influencing factors
SUN Kai, LIU Wenjuan, PEI Zhiyong, ZHANG Shiji, ZHU Xinyu, CHEN Hongwei, YANG Jianjun
doi: 10.11833/j.issn.2095-0756.20240359
[Abstract](59) [HTML](10) [PDF](0)
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  Objective  The objective is to analyze the dynamic variations in sap flow rate of Salix psammophila branches across various diameter classes and explore the water use control strategies of S. psammophila in response to soil water potential (Psw) and meteorological factors under the influence of rainfall during the growing season, so as to provide theoretical reference for understanding the water consumption characteristics of desert shrubs under seasonal drought.   Method  12 branches from 3 sample trees (including 4 diameter levels: 6−8 mm, 8−10 mm, 10−12 mm, and greater than 12 mm) were selected from the national germplasm resource bank of S. psammophila in Hobq Desert. From May to October 2023, sap flow system for small stems or branches was used to continuously monitor changes of sap flow, Psw and meteorological factors such as precipitation, air temperature and relative humidity. Principal components analysis and stepwise linear regression were used to analyze the response of sap flow to major meteorological factors and Psw at different depths before and after rainfall.   Result  (1) During the growing season, the daily variation of sap flow rate at different diameter levels of S. psammophila showed a “single peak” or “double peak” curve from May to August, while a “U” shaped curve was easy to appear in September to October, and the onset time of sap flow rate was gradually delayed. (2) The sap flow rate of S. psammophila with smaller diameter was significantly positively correlated with Psw in 20 and 40 cm soil layers (P<0.05), and was more directly influenced by Psw in 40 cm soil layer. There was a significant positive correlation between the flow rate of S. psammophila with larger diameter and Psw in 60 and 80 cm soil layer (P<0.05), and was more directly affected by Psw in 80 cm soil layer. (3) When the precipitation exceeded 10 mm, the sap flow rate of S. psammophila at different diameter levels showed a “multi peak” curve, and the daily cumulative flow decreased. The cumulative contribution rate of soil temperature, saturated vapor pressure deficit, relative air humidity, and air temperature to changes in sap flow rate before rainfall was 71%, and the cumulative contribution rate of Psw in 10 and 20 cm soil layers to changes in sap flow rate after rainfall was 63%.   Conclusion  The instantaneous variation and overall level of S. psammophila sap flow rate are affected by meteorological factors and soil water supply, respectively, indicating that the short-term and long-term flow characteristics of S. psammophila under seasonal drought have different responses to environmental factors. [Ch, 7 fig. 5 tab. 30 ref.]
Analysis of the structure and species composition of the forest communities in Yandang and Kuocang Mountains in Taizhou, Zhejiang Province, China
SHEN Weikang, WU Jiang, GUAN Kaicheng, YANG Bairun, HONG Xujie, WANG Jiang
doi: 10.11833/j.issn.2095-0756.20240416
[Abstract](47) [HTML](8) [PDF](2)
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  Objective  Taking the forest communities of Yandang and Kuocang Mountains in Taizhou as the research objects, this study focuses on the differences of forest community structure and species composition of 2 mountain systems and their causes, which provides technical support for understanding the changes of evergreen broad-leaved forests in Taizhou.  Method  Based on the survey of 11 plots in Yandang Mountain and 15 plots in Kuocang Mountain (20 m×20 m), species composition, diameter structure and their relationships with the environmental factors were analyzed using methods such as Redundancy Analysis (RDA).   Result  Forest communities of Yandang Mountain recorded 67 species of trees, belonging to 31 families and 46 genera while those of Kuocang Mountain recorded 89 species of trees, belonging to 38 families and 62 genera. Species having important values ≥1% in the forest communities of Yandang and Kuocang Mountains were Schima superba, Liquidambar formosana, Cinnamomum camphora, Cunninghamia lanceolata, Loropetalum chinense, Eurya rubiginosa, Cyclobalanopsis glauca, Castanopsis sclerophylla, Adina pilulifera, Eurya muricata, Styrax faberi. The important value of Schima superba in the forest communities of Kuocang Mountain was 27.37%, which was 16.80% higher than that in Yandang Mountain. Shannon-Wiener index and Pielou evenness index of the forest communities of Yandang Mountain were significantly higher than those of Kuocang Mountain (P<0.05). The total individual diameter distribution of species in 2 forest communities showed inverted J shapes. Total nitrogen, rock exposure rate, pH, soil total carbon and electrical conductivity were the main factors affecting the diversity indexes of forest communities of 2 mountains.   Conclusion  Shannon-Wiener index and Pielou evenness index of Yandang Mountain forest community were significantly higher than those of Kuocang Mountain forest communities. The main difference between 2 mountain forest communities is that the important value of Schima superba in Kuocang Mountain forest community is significantly higher than that in Yandang Mountain. [Ch, 3 fig. 3 tab. 42 ref.]
Characteristics and influencing factors of carbon density structure in Pinus massoniana forests with different afforestation years
WANG Bingyi, ZHANG Yong, WU Cuirong, WANG Zeng, FU Weijun
doi: 10.11833/j.issn.2095-0756.20240401
[Abstract](79) [HTML](18) [PDF](5)
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  Objective  The objective of this study is to interpret the carbon accumulation characteristics during the growth process of typical Pinus massoniana forests, and investigate the mechanism and potential of carbon sequestration in P. massoniana forests.   Method  Four different afforestation years (8, 12, 22, 38 years) of P. massoniana plantations with similar slopes and altitudes were selected in Laoshan Forest Farm, Qiandaohu Town, Chun’an County, Zhejiang Province. Multiple statistical methods combined with redundancy analysis and structural equation modeling were employed to analyze the carbon density characteristics of P. massoniana forests with different afforestation years and the main factors affecting their carbon density.   Result  The total biomass reached its maximum value at 38 years (mature forest), which was significantly higher than that of young and middle-aged forests (P<0.05). The biomass of the herb layer and litter layer reached their maximum values at 22 years of afforestation, with values of 13.74 and 5.24 t·hm−2, respectively. Carbon density of the tree layer increased with the increase of afforestation years, reaching a maximum value of 176.36 t·hm−2 at 38 years (mature forest). There were significant differences in soil carbon density among different ages of P. massoniana forests (P<0.05). The carbon density in the soil layers of 0−10 and 10−30 cm reached their maximum values at 38 years (mature forest), which were 38.60 and 57.13 t·hm−2, respectively. Redundancy analysis revealed that total potassium, available potassium, and slope direction were the main contributing factors to carbon density of P. massoniana forests, accounting for approximately 28.70%, 27.00%, and 9.90% of the carbon density of each component, respectively, and were crucial to overall carbon sequestration of soil and vegetation. The structural equation model demonstrated that bulk density, vegetation density, and total potassium content had significant effects on carbon density in P. massoniana forests.   Conclusion  The carbon density of P. massoniana forests is closely related to the years of afforestation, with mature P. massoniana forests exhibiting the highest capacity for carbon sequestration. Environmental factors and soil nutrient status are crucial for enhancing the carbon sequestration potential of P. massoniana forests. [Ch, 4 fig. 5 tab. 44 ref.]
Effects of different microbial strains on element release during weathering of basalt
YANG Pan, LUO Yubo, YANG Jiao, YUAN Si, LI Jianwu
doi: 10.11833/j.issn.2095-0756.20240381
[Abstract](42) [HTML](10) [PDF](2)
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  Objective  Analyze the effects of different microorganisms on the weathering and elemental release of basalt, to explore the role of microorganisms in the weathering process of basalt, and to provide a theoretical basis for microorganisms promoting basalt weathering.   Method  Different microbial strains (Bacillus mucilaginosus and Trichoderma asperellum) were selected to carry out simulation experiments on biological weathering of basalt. By means of elemental geochemical methods (elemental dissolution amount and rate) and mineral analytical methods (material composition), the effects of microorganisms on the release amount, release rate, and release capacity of Si, Ca, Al, Fe, and Mg elements from basalt were investigated, and preliminarily explored the release mechanisms.   Result  Microorganisms contributed to the weathering of basalt and the dissolution of elements, compared to the control group, the pH of the fungal and bacterial system solutions decreased by 1.46 and 0.88 units, respectively. Compared to the control group, the release amounts of Si, Ca, Al, Fe and Mg elements in basalt was significantly increased by 10.2, 2.6, 8.2, 92.9 and 9.9 times under the action of fungi, and it was significantly increased by 2.7, 1.2, 1.7, 19.7 and 3.2 times under bacterial action. The order of element release from basalt under the action of fungi and bacteria was same: Ca>Mg>Fe>Si>Al. Microorganisms create an acidic environment mainly by secreting organic acids or by complexing to promote the weathering of basalt and increase the rate of elemental dissolution.   Conclusion  Microorganisms can effectively increase the release and rate of elements during the weathering process of basalt, there are also differences among different strains. The release and rate of elements during the weathering process of basalt under the treatment of T. asperellum are higher than those under the treatment of B. mucilaginosus, indicating that fungi have a more significant role in accelerating the weathering process of basalt. [Ch, 6 fig. 41 ref.]
Effects of foliar microstructure characteristics of 13 evergreen shrubs on atmospheric particulate retention capacity in Zhengzhou City
HE Dan, YUAN Jiangqin, GAO Zhenfei, LI Chaomei, LEI Yakai, LIU Yiping, DONG Nalin
doi: 10.11833/j.issn.2095-0756.20240415
[Abstract](53) [HTML](14) [PDF](2)
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  Objective  The objective is to investigate the effects of leaf microstructure of garden plants on particle retention capacity, and provide theoretical basis for the selection of urbangarden tree species.   Method  13 evergreen shrubs, including Pyracantha fortuneana, Fatsia japonica and Nerium oleander were studied in Zhengzhou City, Henan Province. The retention of particles of different sizes [total suspended particulate matter (TSP), large particulate matter (PM>10), inhalable particulate matter (PM10) and fine particulate matter (PM2.5)] per unit leaf area was measured by graded membrane filtration method. The microstructure of leaf surface was observed by scanning electron microscopy and ultra depth microscope, and the relationship between particle retention capacity and leaf surface microstructure features was analyzed.   Result  (1) There were significant differences in the retention capacity of 13 evergreen shrubs with different particle sizes (P<0.05), and the strongest comprehensive dust-retention ability was found in P. fortuneana, F. japonica, and N. oleander, with a dust retention capacity per unit area of 2.59, 2.23 and 1.97 g·m−2, respectively, 3.58−4.70 times that of Mahonia fortunei and Nandina domestica, which had a weak dust retention capacity. (2) Particles tended to be distributed near the midrib and leaf tip. Observation of leaf surface microstructure revealed that there were various structures such as grooves, fuzz, and protrusions on the upper surface. Most of the stomata were located on the lower surface of the leaf. These structures synergistically affected the retention of particles in plants, and concurrently enhanced the roughness of leaf surfaces. The surface roughness in N. oleander leaves was the highest (4.53 μm), with regular semi-circular protrusions on the upper surface and large concave stomata on the lower surface, surrounded by hairy tissue to attach dust particles. (3) Correlation analysis indicated that leaf area, roughness, stomatal length were significantly positively correlated with the content of TSP, PM10 and PM2.5 retention per unit leaf area (P<0.05, P<0.01), and stomatal width and stomatal area were significantly positively correlated with PM10 and PM2.5 retention (P<0.05).   Conclusion  P. fortuneana, F. japonica, and N. oleander are recommended as excellent garden dust-retaining species in controlling air pollution in Zhengzhou City. [Ch, 5 fig. 3 tab. 35 ref.]
Genome-wide identification and tissue expression analysis of IGT gene family in soybean
CHEN Mengyao, HU Yiran, ZHENG Zhifu, PAN Tian
doi: 10.11833/j.issn.2095-0756.20240354
[Abstract](115) [HTML](15) [PDF](2)
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  Objective  This study aims to employ bioinformatics methods to perform a comprehensive genome-wide identification of the soybean IGT gene family and explore the potential functions of IGT gene family in soybean.   Method  Soybean cultivar Glycine max‘Tianlong 1’ was selected and GmIGTs were identified by BLASTP search of IGT protein domain. The evolutionary relationships, gene structure, conserved motifs, cis-acting elements, and collinearity relationships were analyzed by bioinformatics methods. The expression patterns of GmIGTs in different tissue parts were analyzed.  Result  A total of 17 GmIGT genes were identified and classified into 4 branches based on their phylogenetic relationships: TAC, IGT-like, DRO, and LAZY. Protein conserved motif analysis revealed that all IGT proteins contained Motif2. Chromosomal localization and collinearity analysis showed that GmIGT genes were unevenly distributed on 11 chromosomes, and segmental duplication might have played a significant role in the expansion of GmIGT gene. Cis-acting element analysis indicated that GmIGT expression might be associated with light response, physiological response, plant hormone response and stress. RT-qPCR analysis demonstrated that GmIGT gene had obvious tissue-specific expression characteristics. Among them, GmIGT5 exhibited relatively high expression levels in all tissues, while GmIGT4 and GmIGT10 were highly expressed in stems and petioles.   Conclusion  GmIGT gene may play a potential role in shaping soybean plant architecture, and GmIGT4 and GmIGT10 may be the core genes involved in this process. [Ch, 9 fig. 2 tab. 23 ref.]
The impact of stand structure and soil nutrients on herbaceous diversity in natural secondary Betula platyphylla forests in eastern Qinghai Province
LI Rui, ZOU Xingchen, CHENG Chang, SHI Zhengyang, PENG Xiaojing, LIU Jingwen, LIU Qianqian, HE Kangning
doi: 10.11833/j.issn.2095-0756.20240383
[Abstract](67) [HTML](11) [PDF](2)
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  Objective  This study is to explore the dominant factors in stand structure and soil nutrients that affect the understory herbaceous diversity of natural secondary Betula platyphylla forest, so as to provide theoretical basis for optimizing the stand structure and improving herbaceous diversity of natural secondary B. platyphylla forest in Qinghai Province.   Method  Taking the natural secondary B. platyphylla forest in Baoku Forest Farm of Datong County, Qinghai Province as the research object, 20 standard plots (24 m×24 m) were selected by typical sampling method. The effects of multiple factors (stand spatial structure, stand non-spatial structure, and soil nutrient) on herbaceous diversity were investigated by correlation analysis and redundancy analysis.   Result  (1) A total of 47 species of herbaceous plants belonging to 41 genera and 24 families were found under the B. platyphylla forest, among which Lolium perenne, Fragaria vesca, Polygonum viviparum, Galium bungei and Geranium wilfordii were the dominant species, with mean important values of 19.52%, 18.91%, 10.53%, 6.95% and 5.27%, respectively. (2) Redundancy analysis showed that openness, mean DBH, and size ratio could explain 44.1%, 16.8% and 8.2% of the variation patterns in herbaceous diversity, respectively, and were the main stand factors affecting herbaceous diversity. Alkali-hydrolyzed nitrogen and available potassium could explain 7.9% and 7.6% of herbaceous diversity pattern, respectively, and were the main soil nutrient factors.   Conclusion  Both stand structure and soil nutrients significantly affect understory herbaceous diversity. The overall level of understory herbaceous diversity can be improved by adjusting stand spatial structure, optimizing stand competition and improving soil fertility. [Ch, 2 fig. 4 tab. 37 ref.]
Niche and interspecific connectivity of dominant species of woody plants in evergreen broad-leaved forest of Jinzifeng National Forest Park
LI Kun, HU Zhaogui, ZHANG Maofu, GAN Yanling, LI Suchun, LIU Fang, LIN Haiping
doi: 10.11833/j.issn.2095-0756.20240307
[Abstract](100) [HTML](15) [PDF](1)
Abstract:
  Objective  This study explore the ecological niche and interspecific association of the dominant species of woody plants in evergreen broad-leaved forest in Jinzifeng National Forest Park, Zhejiang Province, in order to provide a reference for ecological restoration and biodiversity conservation of subtropical evergreen broad-leaved forest.   Method  Niche composition, niche width, niche overlap index, niche similarity coefficient, variance ratio method, \begin{document}$ {X}^{2} $\end{document} test, Pearson correlation coefficient, and Spearman rank correlation coefficient were used to study the niche and interspecific association of 21 dominant species of woody plants with important values ≥1%.   Result  (1) There were 113 species of woody plants belonging to 31 families and 62 genera in the evergreen broad-leaved forest community in Jinzifeng National Forest Park, including Fagaceae, Rosaceae, Lauraceae, and Ericaceae. (2) The importance values and niche widths of Schima superba, Castanopsis eyrei and Pinus taiwanensis were larger. They were established species in this community, and had higher niche overlap values and niche similarity coefficients with other dominant species of woody plants. The niche overlap values and niche similarity coefficients of 21 dominant species of woody plants were mainly concentrated in the range of 0.10 − 0.50. (3) The dominant species of evergreen broad-leaved forest woody plants in Jinzifeng National Forest Park showed a significant positive association. Among 210 species pairs, 112 species pairs showed no significant positive association, 49 species pairs showed no significant negative association, only 2 species pairs showed extremely significant positive association (P<0.01) , 8 species pairs showed significant positive association (P<0.05) , 39 species pairs showed no association. Spearman rank correlation test and Pearson correlation test showed no significant association. Species pairs accounted for 81.4% and 80.0%, respectively. The interspecific association was weak, with positive and negative association ratios greater than 1. (4) The regression analysis of Pearson correlation coefficient and niche overlap values of dominant tree species showed a extremely significant positive correlation (P<0.01).   Conclusion  The evergreen broad-leaved forest community in Jinzifeng National Forest Park is in the middle stage of succession, and the competition among species is gradually balanced. [Ch, 3 fig. 5 fig. 34 ref.]
Response of JrGA3ox gene expression to growth and drought stress in Juglans regia
ZHENG Lin, WANG Fengmin, FAN Tingting, WANG Ketao, HU Hengkang, HUANG Jianqin, ZHANG Qixiang
doi: 10.11833/j.issn.2095-0756.20240327
[Abstract](95) [HTML](24) [PDF](5)
Abstract:
  Objective  The objective is to study the gibberellin oxidase JrGA3ox gene, which is of great significance for improvement, growth and development, and drought resistance of Juglans regia varieties.   Method  J. regia wild-type (WT), JrGA3ox overexpression (OE) and interference (RNAi) plants were used as experimental materials. Drought treatment with 5% PEG 8000 volume fraction was simulated to investigate the plant phenotype, physiological and biochemical indexes and expression level of drought resistance gene under drought stress, and clarify the drought resistance mechanism of JrGA3ox gene.   Result  (1) Real-time fluorescent quantitative PCR verification showed that the expression level of JrGA3ox gene in OE plants and RNAi plants were 120 and 0.3 times that of WT plants, respectively. (2) Plant growth phenotype analysis showed that plant height and internode length of OE plants were significantly higher than those of WT plants, while those of RNAi plants were significantly lower than those of WT plants (P<0.05). (3) Compared with WT plants, under drought stress for 0−28 days, RNAi plants showed better growth, while OE plants showed weaker growth. (4) Stomatal opening and chlorophyll mass fraction decreased gradually with the extension of drought stress time. Stomatal opening of RNAi plants were significantly lower than that of WT plants (P<0.05), while stomatal opening of OE plants were significantly higher than that of WT plants. The chlorophyll mass fraction of RNAi plants were always significantly higher than that of OE plants and WT plants (P<0.05). (5) After drought stress, the mass molar concentration of reactive oxygen species and malondialdehyde in OE plants were significantly higher than that in WT plants, while that in RNAi plants were significantly lower than that in WT plants (P<0.05). (6) The activity of antioxidant enzymes and expression level of related resistance genes firstly increased and then decreased during the stress process, reaching their maximum value at 14 days of drought stress, and those in RNAi plants were significantly higher than those in WT plants, while those in OE plants were significantly lower than those in WT plants (P<0.05).   Conclusion  JrGA3ox gene in J. regia can positively regulate plant height and internode length, and negatively regulate stomatal opening, photosynthesis, antioxidant enzyme activity of plants, thus improving plant drought resistance. [Ch.10 fig. 1 tab. 28 ref.]
Screening and identification of ERF transcription factors of B2 subgroup involved in regulating lycopene β-cyclase gene LCYB in Osmanthus fragrans
LI Li, PANG Tianhong, FU Jianxin, ZHANG Chao
doi: 10.11833/j.issn.2095-0756.20240316
[Abstract](102) [HTML](16) [PDF](7)
Abstract:
  Objective  This study aims to screen and identify ERF transcription factors of B2 subgroup involved in regulating lycopene β-cyclase OfLCYB gene of Osmanthus fragrans.   Method  ‘Yanhong Gui’, a cultivar of O. fragrans, was used as the material to screen OfERF genes of B2 subgroup from the O. fragrans transcriptome database. Bioinformatic analysis, real-time quantitative PCR (RT-qPCR) and yeast one-hybridization were used to analyze the sequence and expression characteristics of the OfERF gene and its binding to the OfLCYB gene promoter.   Result  The promoter of the OfLCYB gene contained two ATCTA cis-acting elements. Four OfERF genes of B2 subgroup were screened based on the O. fragrans transcriptome database, all of which contained an AP2 conserved structural domain. The RT-qPCR results showed that the expression levels of OfERF72a and OfERF72b genes gradually decreased with the flowering process, and were significantly negatively correlated with the expression of OfLCYB gene, with P values of 0.0338 and 0.0296, respectively. The results of yeast one-hybridization proved that there was a physical binding between OfERF72b and the OfLCYB promoter.   Conclusion  OfERF72b may participate in the metabolism of carotenoid in O. fragrans by regulating the transcription of OfLCYB. [Ch, 7 fig. 3 tab. 25 ref.]
Floral substances and daytime release rhythms of 3 Chimonanthus species
HU Guiting, YANG Liyuan, REN Guangbing, ZHAO Hongbo
doi: 10.11833/j.issn.2095-0756.20240266
[Abstract](106) [HTML](19) [PDF](0)
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  Objective  Flower fragrance is an important characteristic of ornamental plants, which is very crucial for plants reproduction. This study aims to reveal the biosynthesis and release mechanism of floral substances in Chimonanthus, and to provide a solid theoretical basis for the utilization and development of Chimonanthus resources.   Method  Headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) were used to identify and analyze floral substances of 3 Chimonanthus species, including C. praecox, C. salicifolius and C. nitens.   Result  A total of 44 floral substances were identified in 3 Chimonanthus species, among which 19, 23 and 18 substances were identified in C. praecox, C. salicifolius and C. nitens respectively. The floral substances of alcohols and esters were the highest in C. praecox, while the content of alkenes was the highest in the floral substances of C. salicifolius and C. nitens. The daytime release rhythms of floral substances in 3 Chimonanthus species were different. The floral substances of C. salicifolius and C. nitens in the morning, noon and afternoon were different, but the floral substances of C. praecox changed little. Phylogenetic analysis showed that C. salicifolius and C. nitens were more closely related than C. praecox.   Conclusion  The floral substances of C. salicifolius and C. nitens are similar, which caters to the phylogenetic relationship between them. In view of the special low-temperature flowering environment of C. praecox, the interaction between pollination insects and floral fragrance may be the reason for the uniqueness of floral substances. [Ch, 3 fig. 3 tab. 35 ref.]
Genetic variation of seed traits and SSR markers in femal Torreya grandis
LI Keyu, CHEN Rong, LIU Lian, CAI Xiaojun, JIANG Zhengchu, XIE Qiandan, YU Chenliang, YU Weiwu
doi: 10.11833/j.issn.2095-0756.20240254
[Abstract](124) [HTML](30) [PDF](1)
Abstract:
  Objective  This study is to investigate the seed traits of female Torreya grandis, analyze the genetic variation of the population based on SSR primers, and compare the differences in seed phenotype, quality, and genetic diversity between and within populations of T. grandis.   Method  Female T. grandis from Fuyang, Shengzhou, Lin’an, Jiande in Zhejiang Province and Mount Huangshan in Anhui Province were used as materials to compare the phenotypic traits of T. grandis leaves and seeds through variance analysis and principal component analysis. The genetic diversity of T. grandis was compared by SSR molecular markers using female T. grandis from Fuyang, Shengzhou, Lin’an, Chun’an and Mount Huangshan as raw materials.   Result  Analysis of seed traits revealed that there were significant individual differences (P<0.01) in 8 indicators: leaf quality, leaf shape index, seed mass, seed shape index, seed weight, kernel shape index, seed coat thickness, and shell thickness between and within populations. The relative fat content and soluble sugar content also showed extremely significant differences among populations (P<0.01), with fat content ranging from 29.36% to 42.35%, indicating rich variation in T. grandis seed appearance and kernel quality. SSR primer analysis showed that the mean Nei’s genetic diversity index (H) was 0.400, the mean Shannon’s information index (I) was 0.650, and the mean polymorphic information content (PIC) was 0.400. Chun’an population exhibited the highest genetic diversity (H=0.410, I=0.658), while Shengzhou population showed the lowest (H=0.369, I=0.565). 92% of the total genetic variation existed within the population.   Conclusion  There are genetic variations in the phenotype and quality of T. grandis between and within populations. The genetic diversity of Chun’an population is the highest, and the genetic variation within the population is greater than that between populations. [Ch, 2 fig. 11 tab. 26 ref.]
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2024, 41(6).  
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2024, 41(6): 1-2.  
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Intra-annual growth and its response to climatic factors in four ring-porous wood species
XU Junliang, HOU Jiayu, WU Tong, ZHAI Lexin, LUO Pengfei, WEI Miao, ZHANG Yiping
2024, 41(6): 1105-1113.   doi: 10.11833/j.issn.2095-0756.20240574
[Abstract](187) [HTML](59) [PDF](7)
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  Objective  The radial growth dynamics of xylem is considered one of the indicators of sensitivity to environmental change. Investigating the xylem formation is crucial to elucidate the relationship between trees growth and the climate.   Method  Microcore sampling and paraffin sections technology were used to monitor the intra-annual growth dynamics of xylem formation. We collected the microcores of Catalpa bungei, Cinnamomum camphora, Fraxinus chinensis and Koelreuteria paniculata every 7−10 d, and Gompertz model was used to fit the modeled value of cumulative radial growth.   Result  (1) Cambial activity began in early March and ended in mid-October. The duration of cambial activity was shortest for C. bungei [(189.0±14.6) d], and longest for C. camphora [(216.0±17.4) d]. (2) Four species finished the xylem differentiation in early November, and their maximum growth rate occurred in the middle of May. However, the widths of cumulative radial growth showed great variations among four ring-porous species which were from (5 807.0±2 192.9) μm for F. chinensis to (8 276.0±1 744.2) μm for C. bungei. (3) Additionally, temperature may be the main climatic factor influence the radial growth in study area. Both air temperature and surface ground temperature had a significantly positive correlation on the xylem growth increment for four ring-porous wood species (P<0.01). The positive correlation between precipitation and xylem growth was only in C. camphora (P<0.05). It may explained by the smallest diameter and area of vessel of C. camphora, which led to the trees were more sensitive to precipitation.   Conclusion  The radial growth of the four tree species in the local area is highly significantly positively correlated with air temperature. The response of the C. camphora plants to climatic factors is stronger than the other three ring-porous porous tree species. [Ch, 5 fig. 4 tab. 52 ref.]
Effects of precipitation pattern change on non-structural carbohydrates in different organs of Cunninghamia lanceolata seedlings
FU Xiaobin, CHEN Qi, LIU Yuanqiu, DUAN Tianze, WANG Lixing, PAN Yanle, KANG Wangchao, DENG Wenping
2024, 41(6): 1114-1123.   doi: 10.11833/j.issn.2095-0756.20240253
[Abstract](144) [HTML](50) [PDF](6)
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  Objective  Frequent droughts caused by global temperature rise and precipitation pattern change have significant impacts on forest ecosystems, so information of plant water utilization and adaptation during and after droughts is crucial.   Method  The seedlings of Cunninghamia lanceolata were used as test material. A two-factor controlled experiment with 4 precipitation amount and 2 precipitation intervals gradients was set to investigate the response of non-structural carbohydrates (NSC) and related fractions content in different organs that suffer different precipitation amount and intervals.   Result  With the decrease of precipitation, NSC content of the seedlings showed an overall trend of firstly increasing and then decreasing in absorbing roots, transport roots, branches and leaves, and continuous decreasing in branches and trunks. C. lanceolata seedlings increased NSC content in transport roots, absorbing roots, leaves and branches, while hydrolyzed and converted the starch from the absorbing roots to soluble sugars to regulate intracellular water potentials; soluble sugars content showed an overall trend of continuous decreasing in transport roots and trunks, and an overall trend of firstly increasing and then decreasing in absorbing roots, leaves and branches; starch content of all organs showed an overall trend of firstly increasing and then decreasing. When precipitation was too low, C. lanceolata seedlings would consume NSC to preferentially meet the survival needs of absorbing roots, which led to a significant decrease of NSC content in transport roots, branches and twigs (P<0.05). When precipitation intervals increased, NSC content in leaves and transport roots of the seedlings increased significantly (P<0.05); soluble sugar content of leaves decreased significantly (P<0.05), and soluble sugar content of transported roots increased significantly (P<0.05).   Conclusion  To improve the survival of C. lanceolata plantation forests under changes in precipitation patterns, soil water content should be maintained at more than 50% of the average monthly precipitation in the local multi-year dry season, and watering intervals can be extended in areas with higher precipitation. [Ch, 3 fig. 1 tab. 51 ref.]
Age effect on biomass distribution pattern and optimization of allometric growth equation in Eucalyptus urophylla×E. grandis plantations
CAO Haoyang, DU Apeng, XU Yuxing, ZHU Wankuan, HUANG Runxia, LIU Yusheng, WANG Zhichao
2024, 41(6): 1124-1133.   doi: 10.11833/j.issn.2095-0756.20240180
[Abstract](236) [HTML](60) [PDF](9)
Abstract:
  Objective  This study aims to analyze the biomass distribution pattern of Eucalyptus plantations at different ages, so as to provide theoretical basis and data support for accurate assessment of carbon storage and carbon sink in China’s Eucalyptus industry.  Method  Eucalyptus urophylla×E. grandis plantation in Leizhou Peninsula was taken as the research object. The whole-plant harvesting method was used to measure the biomass of various organs in 57 trees aged 1, 2, 3, 6 and 10. Using diameter at breast height (DBH), height (H), and diameter at breast height-tree height (DBH 2 H and DBHH) as independent variables, allometric growth models for organ biomass, aboveground biomass, and total biomass without and with age variables were established, respectively, to screen for the optimal model.   Result  The biomass of different parts of E. urophylla×E. grandis increased with age, but the proportion of each organ to the total biomass varied with age. The proportion of stem biomass increased with age, from 45.21% at 1 year old to 68.25% at 10 years old, whereas the proportion of branch and leaf biomass decreased with forest age, from 19.43% and 16.31% at 1 year old to 10.51% and 2.91% at 10 years old , respectively. The proportion of root biomass first increased from 19.05% at 1 year old to 25.21% at 3 years old, and then gradually decreased to 18.33% at 10 years old. The root to shoot ratio of E. urophylla×E. grandis ranged from 0.16 to 0.39. In selecting the optimal model for biomass of various organs, the model with DBH as the independent variable (without age variable) had better predictions for root biomass and total biomass than other models. The model with DBH 2 H plus age as independent variables had the best predictions for leaf biomass and aboveground biomass. The model with DBH, H, and age as independent variables had the best predictions for branch biomass. Regarding the prediction accuracy for stem biomass, there was no significant difference between the prediction models with DBHH and DBH 2 H plus age as independent variables, and both models could predict stem biomass well.   Conclusion  Forest age has significant impacts on the biomass allocation ratio of various organs in E. urophylla×E. grandis plantations. The prediction accuracy of branch, leaf, and aboveground biomass in E. urophylla×E. grandis plantations significantly improves if forest age is included in the allometric growth model. [Ch, 2 fig. 4 tab. 45 ref.]
Health evaluation of Populus euphratica forest in Dali Yabuyi Oasis in the hinterland of the desert
CUI Chuandeng, SHI Qingdong, LI Xiang, SHI Haobo, WAN Yanbo, LI Dinghao
2024, 41(6): 1134-1141.   doi: 10.11833/j.issn.2095-0756.20240148
[Abstract](111) [HTML](33) [PDF](5)
Abstract:
  Objective  The widespread degradation of Populous euphratica forests seriously threatens the ecological security of oases in arid zones. Therefore, mapping the health of P. euphratica forests is important for their sustainable management.   Method  The P. euphratica forests in Dali Yabuyi Oasis in the desert hinterland were taken as the object, and based on the field survey of 68 typical sample plots in the region, 17 indexes were selected from the aspects of forest productivity, forest community structure and habitat factors, and the health evaluation index system and health evaluation model applicable to the P. euphratica forests in the region were constructed by using the principal component analysis and the cluster analysis method, the forest health indexes were calculated, and the health of the P. euphratica forests in the region was comprehensively evaluated.   Result  (1) The overall forest health of oasis P. euphratica forests was poor, with 29.4% in an unhealthy state, 33.8% in a medium-healthy state, 30.9% in a sub-healthy state, and 5.9% in a healthy state. Groundwater burial depth, total nitrogen, depression, Simpson index, and Shannon-Wiener index were the main factors affecting forest health. (2) In the P. euphratica forests of Dali Yabuyi Oasis, the forest health index of deep groundwater burial depth is significantly lower than that of shallow and medium groundwater burial depth (P<0.05), and the forest health level is relatively low. Shallow groundwater burial depths have relatively high levels of forest health. Overall, the forest health indices of different groundwater depths: shallow groundwater depth (0.65)>medium groundwater depth (0.45)>deep groundwater depth (0). (3) Among the P. euphratica forests in different regions of the oasis, the forest health index of the P. euphratica forests in the north is significantly lower than that in the center and south, and the forest health level is relatively low. Forest health is relatively high in the south. Overall, the forest health index showed an increasing trend from the north, center to the south, and the forest health index in different regions: south (0.61)>center (0.58)>north (−0.01).   Conclusion  The overall health level of P. euphratica forests in the oasis is poor, the shallower the water table is, the higher the health index of P. euphratica forests is, and the health index shows a decreasing trend from the south, the center to the north in different regions. [Ch, 2 fig. 2 tab. 29 ref.]
Study on the population density and activity rhythm of wild boar in Longyou County, Zhejiang, China
LI Yuying, CHEN Xiangxiang, YING Yishan, YI Lixiao, ZHU Lihong, YING Jianping, LIN Xiaoyue, ZHANG Min
2024, 41(6): 1142-1149.   doi: 10.11833/j.issn.2095-0756.20240170
[Abstract](224) [HTML](37) [PDF](169)
Abstract:
  Objective  By investigating the population density and activity rhythm of wild boar (Sus scrofa) in Longyou County of Zhejiang Province, this study is aimed to research the accurate countermeasures for wild boar prevention and control, and to provide exemplary monitoring and evaluation work from theory and practice to methodological application at the county level.  Method  Firstly, with the employment of infrared camera technology, a total of 1 308 independent and valid photographs were obtained from January 2021 to August 2023. Then the population density was estimated using a random encounter model, and the activity rhythm of the wild boar in the studied area was also investigated using the kernel density estimation method.  Result  The population density of wild boar in Longyou County ranged from 0.957 to 1.291 per square kilometer, with the total estimated population size of 417 to 563. The number of wild boar decreased from the southern mountainous areas, the northern mountainous areas to the central regions. In terms of habitat selection, the wild boar population preferred coniferous forests (relative abundance index IRA=38.45%), mixed coniferous and broad-leaved forests (IRA=24.39%), and the elevation range of 1 100 to 1 300 m (IRA=57.25%). High population density was observed at 17:00 in all four seasons. The daily activity rhythms were similar in spring and winter, exhibiting an unimodal pattern. When come to summer, the daily activity rhythm was bimodal, with the main peaks occurring around sunrise and sunset. There was no significant fluctuation of daily activity rhythm in autumn and the population exhibited a highly significant seasonal migration along the altitudinal gradient (P<0.01).  Conclusion  The distribution of wild boars in Longyou County exhibits significant spatial heterogeneity, and their activity rhythms are deeply influenced by the factors of altitude and season. This study provides direct scientific evidence for the formulation of wild boar control policies in Longyou County and will serve as a reference for estimating population density as well as studying the activity rhythms of wild boar at the county level. [Ch, 2 fig. 4 tab. 29 ref.]
Response of dehydrin JrDHN gene in walnut to drought stress
ZHANG Yuhang, ZHANG Manman, MA Yuhang, WANG Ketao, HU Hengkang, HUANG Jianqin, ZHANG Qixiang
2024, 41(6): 1150-1159.   doi: 10.11833/j.issn.2095-0756.20240282
[Abstract](2) [PDF](0)
Abstract:
  Objective  This purpose was to investigate the physiological and molecular responses, as well as the molecular mechanisms, of Juglans hindsii×J. regia overexpressing line JrDHN during drought stress, to provide theoretical basis for breeding drought-resistant J. regia (walnut) cultivars.   Method  Healthy overexpressing walnut JrDHN were subjected to drought stress at different time points. The response of the overexpressing JrDHN line to drought stress was observed from various aspects including phenotype, antioxidant enzyme activity, and reactive oxygen species content. Quantitative PCR was conducted to analyze the expression levels of drought-related genes MYB, ADH, and CAM in plant tissues, exploring the molecular mechanism by which overexpression of JrDHN gene affects plant drought resistance.   Result  The results confirmed the overexpression of JrDHN gene in walnut seedlings, with expression levels in JrDHN1, 2, 3 being 2.55, 1.72, and 1.49 times higher than the WT respectively. Phenotypic traits of the overexpressing JrDHN line were superior to WT after 1−4 weeks of drought treatment, with significantly lower stomatal aperture in the overexpressing JrDHN line compared to WT after 2 weeks of drought treatment. The activities of antioxidant enzymes (SOD, POD, CAT) showed an initial increase followed by a decrease trend, reaching maximum values at 2 weeks, with SOD and POD activities in JrDHN1 significantly higher than WT (P<0.01), and CAT activity showing significant difference (P<0.05). Chlorophyll content reached its minimum after 4 weeks of drought treatment, with significantly higher levels in the overexpressing JrDHN line compared to WT. Levels of MDA, H2O2, and O2·− increased gradually with prolonged drought stress, reaching maximum values at 4 weeks, with significantly lower levels in JrDHN1 compared to WT. Expression levels of drought-related genes MYB, ADH, CAM showed an initial increase followed by a decrease trend, with significantly higher levels in the overexpressing JrDHN line compared to WT after 2 weeks.   Conclusion  The overexpressing JrDHN transgenic walnut seedlings exhibited superior phenotype, photosynthetic capacity, and antioxidant capacity under PEG-simulated drought stress compared to WT. Overexpression of JrDHN gene in walnut seedlings effectively enhanced the activity of antioxidant enzyme system, scavenged reactive oxygen species, reduced cell damage, thereby improving plant drought resistance. [Ch, 8 fig. 1 tab. 34 ref.]
Effects of abiotic stress treatments on the transcriptional activity of transposable element-derived TUCP in Phyllostachys edulis
ZHU Bailiang, DING Yiqian, ZHOU Mingbing
2024, 41(6): 1160-1169.   doi: 10.11833/j.issn.2095-0756.20240195
[Abstract](149) [HTML](32) [PDF](2)
Abstract:
  Objective  Transposable elements (TE), an essential component of eukaryotic genomes are prone to activation under stress when they account for over 63% of the Phyllostachys edulis genome. This study, with an analysis of the expression patterns of transcripts of uncertain coding potential (TUCP) from transposable elements under abiotic stress, is aimed to provide insights into the molecular mechanisms of TEs in stress resistance in Ph. edulis.   Method  First, bioinformatics techniques were employed to investigate the transcriptional characteristics and patterns of TE-TUCPs, and neighboring genes in Ph. edulis under 4 stress treatments: low temperature, high temperature, high salinity, and UV irradiation. Then the reliability of the differentially expressed TE-TUCPs, data derived from the transcriptome was validated using RT-qPCR.   Result  A total of 57 627 TE-TUCPs were identified from the transcripts of Ph. edulis under 4 stress treatments. These TE-TUCPs exhibited specific expression patterns in response to different abiotic stresses. High temperature, high salinity, and UV irradiation promoted differential expression of genes neighboring TE-TUCPs with transcriptional activity, whereas low temperature suppressed such differential expression.   Conclusion  TE-TUCPs were primarily derived from the Ty1/Copia and Ty3/Gypsy superfamilies. The expression potential of genes and that of nearby TE-TUCPs were mutually inhibitory and the transcription of TE-TUCPs was regulated by abiotic stress to modulate the expression of neighboring genes in response to stress. [Ch, 7 fig. 2 tab. 44 ref.]
Genetic analysis of kernel oil content and related traits in complete diallel progenies of Camellia oleifera
WANG Anni, WANG Kailiang, CHAI Jingyu, ZHONG Huiqi, TENG Jianhua, ZHANG Lei, YU Wenxian, LIN Ping
2024, 41(6): 1170-1179.   doi: 10.11833/j.issn.2095-0756.20230603
[Abstract](93) [HTML](15) [PDF](3)
Abstract:
  Objective  The objective is to study the genetic variation patterns of oil-related traits in complete diallel progenies of Camellia oleifera, and to provide basis for parental selection in cross breeding.   Method  5×5 complete diallel hybridization (no self-crossbreeding) was carried out with 5 excellent clones of C. oleifera as parents, and the oil content, lignin, cellulose and hemicellulose contents of 20 hybrid families were determined. The correlation among traits was analyzed, the general combining ability of parents and the specific combining ability of hybrid combinations were determined, and the genetic variation rules among traits were analyzed.   Result  The kernel oil content of 20 families ranged from 252.30 to 537.08 mg·g−1, the lignin content was from 49.64 to 222.20 mg·g−1, the cellulose content was from 42.11 to 130.43 mg·g−1, and the hemicellulose content was from 3.72 to 111.96 mg·g−1. There were significant differences in oil, lignin, cellulose and hemicellulose contents of kernels among 20 families (P<0.01), and there were significant correlations (P<0.01) among the 4 traits. The correlation coefficient between oil content and lignin content was the highest (−0.47). Except for the specific combining ability of lignin content and reciprocal cross effect of oil content, the general combining ability, specific combining ability and reciprocal cross effect of the parents were significantly different (P<0.01) in the 4 traits. Oil and hemicellulose contents of kernels were jointly controlled by additive and dominant effect, and dominant variance was greater than additive variance. The lignin content was mainly affected by additive effect and the cellulose content was mainly controlled by dominant effect. The broad-sense heritability of the 4 traits ranged from 7.86% to 14.03%, and the narrow-sense heritability was 0 to 14.03%, all of which were strongly influenced by environmental factors.   Conclusion  Based on the analysis of combining ability, 2 excellent parents ‘Changlin No. 4’ and ‘Changlin No. 40’, as well as 2 excellent combinations ‘Changlin No. 40’× ‘Changlin No. 95’ and ‘Changlin No. 4’בChanglin No. 53’ are selected. [Ch, 8 tab. 35 ref.]
Cloning and expression analysis of RcF3H in Rubus chingii
YING Yuxin, CHEN Junyu, YAO Lingtiao, XU Zhangting, YU Zhenming, KAI Guoyin
2024, 41(6): 1180-1188.   doi: 10.11833/j.issn.2095-0756.20240326
[Abstract](153) [PDF](8)
Abstract:
  Objective  Flavanone 3-hydroxylase (F3H) is a key enzyme in the synthesis of plant flavonoids. This study aims to investigate the relationship between RcF3H gene and flavonoid metabolism in Rubus chingii and analyze its biological function, so as to provide reference for further exploring the mechanism of RcF3H in the process of flavonoid accumulation in R. chingii.   Method  RcF3H gene was cloned from R. chingii, and bioinformatics analysis was performed, including physicochemical properties, homology comparison, phylogenetic tree and promoter cis-acting elements. At the same time, this study detected the expression level of RcF3H gene in different tissues, fruit growth period and exogenous methyl jasmonate (MeJA) induction.   Result  RcF3H gene, belonging to the 2-oxoglutarate-dependent dioxygenase superfamily, was located on the first chromosome, and its fragment length was 1098 bp. RcF3H gene consisted of 1 exon and encoded 365 amino acids. RcF3H belonged to the hydrophilic stable protein. Subcellular localization predicted that the protein was located in the cytoplasm. The secondary and tertiary structure of RcF3H was mainly composed of α-helix and irregular curl, which had the closest genetic relationship with dicotyledons such as Rubus coreanus and Arabidopsis thaliana. Analysis of promoter cis-acting elements showed that the promoter region of RcF3H gene contained multiple cis-acting elements, and its function mainly focused on responding to hormones and stress. RcF3H gene was highly expressed in fruits, and had obvious tissue specificity. In addition, the expression of RcF3H gene in different ripening stages of fruits was consistent with the accumulation of flavonoids, and the expression increased under the treatment of 100 μmol·L−1 MeJA. These results suggested that RcF3H gene is the key enzyme to promoting flavonoid synthesis.   Conclusion  RcF3H gene responds to MeJA stimulation and may act as a positive regulator of flavonoid biosynthesis in R. chingii, affecting flavonoid accumulation. [Ch, 8 fig. 2 tab. 28 ref.]
Effects of natural vegetation restoration after logging on soil organic carbon and its active components in Pinus massoniana secondary forests
HU Ao, ZHAO Yihui, WU Jilai, WU Yanping, LI Tongxin, YAN Yibo, YE Jianfeng, WANG Yixiang
2024, 41(6): 1189-1200.   doi: 10.11833/j.issn.2095-0756.20240264
[Abstract](165) [HTML](30) [PDF](4)
Abstract:
  Objective  The objective is to study the distribution characteristics of soil organic carbon (SOC) and its active components in Pinus massoniana forest affected by pine wilt disease, so as to reveal the influence mechanism of natural vegetation restoration after logging on soil carbon sink in P. massoniana secondary forest and provide scientific support for organic carbon pool management.  Method  From March to June 2023, in Yuhang District and Lin’an District of Hangzhou City, the undamaged P. massoniana forest was used as the control (ck), four vegetation restoration types were set up by using the space substitution time survey method: moderate logging restoration for 5 a (ML5), moderate logging restoration for 15 a (ML15), heavy logging restoration for 5 a (HL5) and heavy logging restoration for 15 a (HL15) to compare the variation characteristics of SOC, readily oxidizable carbon (ROC), particulate organic carbon (POC), microbial biomass carbon (MBC) and water-soluble organic carbon (WSOC) in different soil layers ( 0−10, 10−20, 20−40 cm ) of P. massoniana secondary forest under natural recovery after different logging intensities, and their relationship with soil physicochemical properties was analyzed to explore their mechanisms.   Result  (1) The content of SOC and its active components in each soil layer ranking from high to low were SOC, ROC, POC, MBC and WSOC, and the content decreased accordingly with the deepening of soil layer. The highest SOC content was 33.53 g·kg−1 in 0−10 cm soil layer of ML15, and the lowest WSOC content was 136.55 mg·kg−1 in 20−40 cm soil layer of ck. (2) Under the same logging intensity, the content of active organic carbon in soil of P. massoniana secondary forest increased with the increase of natural recovery years, among which the content of POC in each soil layer changed the most, and the content of POC in each soil layer of 15 a was over 2.6 times higher than that in each soil layer of 5 a. (3) The content of active organic carbon component in 0−10 cm soil layer of ML15 was the highest, and was significantly higher than that in ck (P<0.05 ). (4) The results of correlation analysis showed that there were significant positive correlations among active organic carbon components in soil and between active organic carbon components and \begin{document}${\mathrm{NO}}_3^- $\end{document}-N and NH4 + -N ( P<0.05 ).  Conclusion  Moderate logging has a significant promoting effect on SOC and its active components in P. massoniana secondary forest. The longer the natural recovery time of vegetation, the more favorable it is to increase the content of soil active organic carbon components. Moderate logging of P. massoniana pure forests and their natural recovery can promote soil carbon pool accumulation. [Ch, 3 fig. 3 tab. 46 ref.]
Effect of thinning restoration on enzyme activity and enzyme stoichiometry in the topsoil of oak-pine mixed forest
TAN Rui, YU Shuiqiang, LI Yu, WANG Xiangfu, XU Xinying, LI Yuanhui, WANG Weifeng
2024, 41(6): 1201-1210.   doi: 10.11833/j.issn.2095-0756.20240185
[Abstract](78) [HTML](13) [PDF](2)
Abstract:
  Objective  This study, with an investigation of the effects of different recovery periods after thinning on soil physical-chemical proprieties and extracellular enzyme activities in oak-pine mixed forests in the Qinling Mountains, is aimed to better understand the nutrient cycling processes under thinning treatments, providing basis for developing programs of sustainable forest management and exploring better ecological restoration measures.   Method  First, pace-for-time substitution was employed to explore the effects of thinning restoration process (5 and 13 years, no thinning as the control) on soil physical-chemical proprieties and enzyme activity changes in the surface layer at 0−10 cm depth. Then the enzyme stoichiometric ratios and enzyme vectors were calculated for each treatment.   Result  (1) The total phosphorus, microbial biomass carbon, and microbial biomass nitrogen contents in the soil increased significantly, whereas the inorganic nitrogen content decreased in the 13-year restoration (P<0.05) and the soil pH increased in the 5-year and 13-year restorations; following a 13-year restoration, the soil organic carbon content progressively recovered to pre-thinning levels after declining dramatically in the 5-year restoration (P<0.05). (2) Thinning significantly increased the activity of β-glucosidase (BG), while decreasing the activities of β-xylosidase (BX), nitrogen acquiring enzyme (NAG+LAP), and acid phosphatase (AcP) (P<0.05); after the 13-year restoration, the activities of phenol oxidase (POX) and peroxidase (PER) showed a decreasing tendency during the initial stage of thinning (5 years treatment) and then reverted to pre-thinning values. (3) In the 13-year restoration, thinning significantly increased the soil enzyme carbon-nitrogen ratio (EC/N), soil enzyme carbon-phosphorus ratio (EC/P) and vector length value (P<0.05) whereas the EC/P and soil enzyme nitrogen-phosphorus ratio (EN/P) increased significantly and the vector angle value decreased in the 5-year restoration (P<0.05).   Conclusion  Soil nutrients, organic carbon, and oxidase activities showed a recovery trend with the thinning recovery stage with the soil pH being a key factor affecting soil enzyme activity and the change of enzyme vectors. Thinning decreases the phosphorus limitations of soil microorganisms during the initial stage of recovery, but it has little effect on the phosphorus and carbon limitation in the later stage of recovery. [Ch, 3 fig. 4 tab. 41 ref.]
Effects of stand density on biomass and soil physico-chemical properties of Pinus tabuliformis forest in the loess area of western Shanxi
JIA Yajie, YANG Jianying, ZHANG Jianjun, HU Yawei, ZHANG Ben, ZHAO Jiongchang, LI Yang, TANG Peng
2024, 41(6): 1211-1221.   doi: 10.11833/j.issn.2095-0756.20240571
[Abstract](175) [HTML](59) [PDF](2)
Abstract:
  Objective  This study is in order to explore the effects of stand density on biomass and soil physicochemical properties in Pinus tabuliformis forests, for high-quality development and performance of the ecological service function.   Method  A 30-year-old P. tabuliformis forest in Caijiachuan watershed, Jixian County, Shanxi Province, was used as the research object, and the standard wood method was used to measure the biomass of individual plants and the overall biomass of the sample plots under the conditions of different densities, and the soil physicochemical properties were determined, so as to analyze the effects of stand density on the biomass of P. tabuliformis forest and soil physicochemical properties, and to determine their relationship by redundancy analysis (RDA) and Spearman’s correlation analysis.   Result  (1) The differences in stand biomass and total tree biomass between different densities were significant (P<0.05), and with the increase of stand density, stand biomass gradually decreased, and the total tree biomass had a peak at a density of 1 750 plants·hm−2; (2) The physicochemical properties of soil in forests of different densities differed significantly (P<0.05), with soil porosity being the highest at 1 750 plants·hm−2, reaching 52.38%, soil moisture content being the highest at 2 750 plants·hm−2, reaching 13.84%, and soil fertility being the best at a density of 1 750 plants·hm−2; (3) RDA and Spearman’s correlation analyses revealed that total soil porosity, organic carbon and quick-acting phosphorus were all highly significantly correlated with arbor biomass in the sample plots (P<0.01), and below-ground biomass was significantly affected by soil water content (P<0.05).   Conclusion  The stand density should be maintained at 1750 plants·hm−2 for the purpose of sequestering carbon and releasing oxygen and maintaining maximum productivity, and for the purpose of increasing the carbon sink capacity of the soil and improving fertility, and at 1 750−2 750 plants·hm−2 for the purpose of retaining soil and water and improving soil water retention properties. [Ch, 4 fig. 5 tab. 40 ref.]
Effect of iron-modified biochars on soil nutrients and bioavailability of As and Pb
MAO Haonan, YANG Xing, LU Kouping, WU Jiasen, WANG Hailong
2024, 41(6): 1222-1232.   doi: 10.11833/j.issn.2095-0756.20240171
[Abstract](170) [HTML](38) [PDF](2)
Abstract:
  Objective  To investigate the effects of raw and iron-modified biochar on the nutrient content and bioavailability of arsenic (As) and lead (Pb) in con-contaminated agricultural soil.   Method  An experiment using rice potted in soil mixed with 2% raw Ficus microcarpa biochar (FMB) and Polyferric Sulfate (iron)-modified biochar (Fe-FMB) was conducted, no biochar soil as control. Soil nutrient availability, soil enzyme activity, rice biomass and As and Pb concentrations in various plant organs at different growth stages were measured. The bioavailable As and Pb in the soil were determined using the NH4H2PO4 and DTPA extraction methods, respectively.   Result  The results indicated that, compared to the control, Fe-FMB significantly enhanced the availability of nutrients such as phosphorus (P) and silicon (Si) in the soil and significantly altered the distribution of Si forms in the soil (P<0.05), primarily increasing the content of amorphous silicon (by 25.2%) and iron-manganese oxidized silicon (by 11.1%). Fe-FMB was more effective in immobilizing soil As (P<0.05), reducing it by 37.9% compared to the control, while original biochar (FMB) was more effective for soil Pb immobilization, reducing it by 24.9%. Application of Fe-FMB led to a 67.2% reduction in As content in rice grains as compared to the control. Furthermore, Fe-FMB significantly increased the activities of leucine aminopeptidase, acid phosphatase, and catalase (P<0.05), with maximum increases of 121.1%, 99.1%, and 33.2%, respectively. Pearson correlation analysis showed that soil enzyme activity was significantly related to pH and As availability (P<0.05), indicating that biochar application can regulate soil enzyme activity by influencing soil pH and As bioavailability.   Conclusion  While F. microcarpa biochar is effective in remediating soils contaminated with Pb only, it is not suitable for the treatment of soils co-contaminated with As and Pb. On the other hand, iron-modified biochar shows a better prospect for remediating soils co-contaminated with As and Pb. [Ch, 8 fig. 2 tab. 36 ref.]
Removal effect of ecological ditches on agricultural non-point source pollutants in Zhejiang Province
YANG Xubin, SHAO Jianjun, YING Shanshan, ZHU Yiyang, JIANG Peikun
2024, 41(6): 1233-1241.   doi: 10.11833/j.issn.2095-0756.20240212
[Abstract](135) [HTML](22) [PDF](5)
Abstract:
  Objective  This study is to comprehensively evaluate the role of ecological ditches in the blocking process of agricultural non-point source pollution and scientifically assess the effect of ecological ditches on pollutant removal.   Method  6 ecological ditches in Tonglu, Lin’an, Jiande, Dongyang, Yiwu, and Zhuji in Zhejiang Province were selected for water quality monitoring. The removal rates of major agricultural non-point source pollution by ecological ditches were calculated, including total nitrogen (TN), ammonium nitrogen (\begin{document}${\mathrm{NH}}_4^+ $\end{document}-N), total phosphorus (TP), and chemical oxygen demand (COD), and the impact of ditch construction composition on the removal of agricultural non-point source pollution was analyzed.   Result  The average removal rates of TN, \begin{document}${\mathrm{NH}}_4^+ $\end{document}-N, TP, and COD in the 6 ditches were 18.31%, 38.74%, 13.49%, and 23.97%, respectively, among which the removal effect of \begin{document}${\mathrm{NH}}_4^+ $\end{document}-N was better. The slope roughness of Yiwu ditch and Tonglu ditch was increased by ecological slope construction. The contact area between water flow and slope was increased by narrow ditch width and the retention time of water flow was prolonged. The removal effect of TN and \begin{document}${\mathrm{NH}}_4^+ $\end{document}-N was relatively high, and the relationship was linear with the inflow load (P<0.05). The plant density in Zhuji ditch was high, showing good TP removal effect. The number of denitrification phosphorus removal devices had a good positive correlation with TN, \begin{document}${\mathrm{NH}}_4^+ $\end{document}-N, TP, and COD (P<0.05), which was a key factor for ecological ditches to intercept agricultural non-point source pollution.   Conclusion  The water purification function of ecological ditches in Zhejiang Province can be strengthened by constructing ecological slopes, installing denitrification phosphorus removal devices, and increasing plant density. [Ch, 4 fig. 2 tab. 34 ref.]
Effects of nitrogen application on nitrogen, phosphorus and potassium absorption and alkaloid accumulation in Fritillaria hupehensis
JIANG Li, GUO Kunyuan, CHEN Gang, CHENG Weishun, LUO Xi, WANG Suping, HUANG Xiang, DU Lei, ZHANG Guiyou, HONG Juan
2024, 41(6): 1242-1251.   doi: 10.11833/j.issn.2095-0756.20240217
[Abstract](93) [HTML](35) [PDF](1)
Abstract:
  Objective  This study aims to analyze the annual variation of the concentration and accumulation of nitrogen, phosphorus, and potassium in Fritillaria hupehensis bulbs, and explore the impacts of different nitrogen dosages on the accumulation of dry matter and alkaloids of F. hupehensis, so as to provide scientific basis for rational fertilization of F. hupehensis.   Method  F. hupehensis obtained from Xintang township, Enshi City, Hubei Province was used as the material. Under the conditions of 102.4 kg·hm−2 phosphorus pentoxide and 86.4 kg·hm−2 potassium oxide for both phosphorus and potassium fertilizers, 4 nitrogen fertilizer treatments were set up: no nitrogen fertilizer (N0), 58.0 kg·hm−2 nitrogen fertilizer (N1), 116.0 kg·hm−2 nitrogen fertilizer (N2), and 174.0 kg·hm−2 nitrogen fertilizer (N3). Samples were collected at seedling, flowering and harvest stages to determine the concentration of nitrogen, phosphorus, potassium and various alkaloids in the bulbs of F. hupehensis at different growth stages.   Result  The accumulation of dry matter, nitrogen, phosphorus, potassium, total alkaloid, verticine, verticinone, peimissine and hupehenine in F. hupehensis bulbs significantly increased with increasing nitrogen application (P<0.05), and all reached their peak at a nitrogen fertilizer application of 116.0 kg·hm−2. With the increase of nitrogen application, potassium to phosphorus ratio in F. hupehensis bulbs was less than 3.4 at seedling stage, while that during the flowering and harvesting periods was more than 3.4. Throughout the entire growth period, nitrogen to phosphorus ratio in F. hupehensis bulbs was less than 14.0, and nitrogen to potassium ratio was less than 2.1. During the seedling and harvest stages, the concentration of total alkaloid, verticine, verticinone, and hupehenine in F. hupehensis bulbs all decreased with increasing nitrogen application. During the flowering period, the concentration of verticine, verticinone and peimissine in F. hupehensis bulbs showed an increasing trend with the increase in nitrogen application. When the nitrogen fertilizer application amount was 116.0 kg·hm−2, the peak accumulation of total alkaloid, verticine, verticinone, hupehenine and peimissine in F. hupehensis bulbs were 56.50, 4.20, 12.73, 1.66, and 3.68 mg·plant−1, respectively. When the same amount of nitrogen fertilizer was applied, with the extension of growth period, except for peimissine, the concentration of all other alkaloids was the highest during the harvest period and the lowest during the flowering period. When the nitrogen fertilizer application amount was 116.0 kg·hm−2, the accumulation rate of verticine, verticinone and peimissine in bulbs decreased from flowering to harvest stage. The dry matter accumulation rate was relatively fast from seedling to flowering stage, and the accumulation ability of total alkaloids in the bulb during the flowering to harvest period was strong.   Conclusion  The amount of nitrogen fertilizer significantly affects the yield and quality of F. hupehensis. Excessive application of nitrogen fertilizer is not conducive to the accumulation of dry matter and alkaloids in bulbs. The accumulation of dry matter and alkaloids in bulbs of F. hupehensis at different growth stages is a dynamic process. Yield increase is predominant at vegetative growth stage, while alkaloids accumulation is dominant at productive growth stage. [Ch, 4 fig. 2 tab. 28 ref.]
Effect of dominant weeds on wheat growth characteristics under different planting densities and fertilization treatments
RONG Yizhong, GAO Junjie, CHENG Shushi, ZHANG Zhen, ZHANG Li
2024, 41(6): 1252-1260.   doi: 10.11833/j.issn.2095-0756.20240193
[Abstract](84) [HTML](15) [PDF](3)
Abstract:
  Objective  This study, with an investigation of the effects of planting density, fertilization, and neighboring weed species identity on wheat growth, is aimed to provide scientific guidance for wheat cultivation.   Method  With wheat (Triticum aestivum) and two dominant weed species [wild oat (Avena fatua) and barnyard grass (Echinochloa crus-galli)] selected as target species, a competition experiment was conducted between pairs of wheat and weeds, by setting four planting densities (4, 8, 12 and 16 plants·pot−1), four wheat-weed planting ratios (25%∶75%, 50%∶50%, 75%∶25% and 100%∶0), as well as with or without nitrogen addition. After growing for about six months, the total biomass, plant height, leaf and root functional traits of wheat were measured.   Result  (1) In monoculture or mixtures with weed species, individual wheat’s biomass decreased with the increase of planting density and the proportion of wheat (P<0.05) (i.e., the occurrence of negative density dependence). (2) For individual wheat plants grown in monoculture, fertilization significantly increased their biomass and leaf area (P<0.05) while for those grown in mixture with wild oats or barnyard grass, fertilization had the trend to increase the biomass, root length and root surface area, which did not depend on weed species identity. (3) The interaction effects of planting density, proportion, and fertilization significantly affected wheat root length and area, but demonstrated no effects on other traits.   Conclusion  Fertilization enhanced wheat’s aboveground traits in monoculture and belowground traits in mixed cropping, with consistent negative density dependence in both systems. This indicates that agricultural management outcomes are influenced by weed interactions. [Ch, 4 fig. 1 tab. 38 ref.]
Impact and evaluation of different drying methods on the quality of Prunus mume flowers
CHEN Yingzhi, KONG En, LU Xinke, WANG Yiguang, DONG Bin, ZHAO Hongbo
2024, 41(6): 1261-1273.   doi: 10.11833/j.issn.2095-0756.20240256
[Abstract](159) [HTML](42) [PDF](4)
Abstract:
  Objective  The impact of different drying methods on the quality of dried Prunus mume flowers is to be studied and evaluated, so as to provide reference for maintaining the quality of dried P. mume flowers in drying process.   Method  4 different drying methods (hot air drying, microwave drying, compound drying and vacuum freeze-drying) were used to treat 8 P. mume flower cultivars (‘Dongfang Zhusha’ ‘Guhong Zhusha’ ‘Xiaohong Gongfen’ ‘Fenpi Gongfen’ ‘Fentai Yudie’ ‘Yueguang Yudie’ ‘Jiuguang Lve’ and ‘Suyu Lv’). Color difference, antioxidant capacity, and total flavonoid content were used as evaluation indicators to compare the impact of different drying methods on the quality of P. mume flowers. The entropy weight-coefficient of variation method was used for combined weighting to calculate the comprehensive score. The evaluation model was verified by the weighted proximation ideal solution sorting method and the optimal drying method was obtained.   Result  The color difference and shrinkage rate treated with vacuum freeze-drying were the smallest, less than 33.09 and 28.7%, respectively, and the total flavonoids, anthocyanins, and total chlorogenic acid mass fractions of the samples were the highest. The soluble protein mass fraction and antioxidant capacity of the materials treated with vacuum freezing and composite drying methods were the highest. The retention rate of volatile substances was the highest after composite drying, exceeding 50%. The comprehensive scores ranking from high to low was vacuum freeze-drying group, composite drying group, hot air drying group, and microwave drying group.  Conclusion  The mass fraction of active ingredients is the highest after vacuum freeze-drying, followed by composite drying. The quality of P. mume flowers is the best after vacuum freeze-drying and composite drying, which can be used for high-quality processing and mass production. [Ch, 8 fig. 6 tab. 29 ref.]
Fabrication and controlled release characteristics of whey protein-alginate dialdehyde microcapsule
YANG Ye, WU Shaping, WANG Kaijun, WU Changling, LIU Xingquan, WU Fenghua, WANG Peng
2024, 41(6): 1274-1282.   doi: 10.11833/j.issn.2095-0756.20240243
[Abstract](113) [HTML](15) [PDF](130)
Abstract:
  Objective  This study used whey protein (WPI) and alginate dialdehyde (ADA) to prepare WPI-ADA copolymer microcapsules, and the interactions between WPI and ADA and their effects on the controlled release of curcumin in the microcapsules were investigated to provide a theoretical basis for the development of the encapsulation system of curcumin.   Method  WPI-ADA copolymers were prepared using a wet-heat method, and the interaction between WPI and ADA was explored through analysis of grafting degree, browning intensity, and infrared spectroscopy. The effects of different proportions of copolymers on the emulsion were studied in terms of particle size, zeta potential, and rheological properties. The influence of copolymers on microcapsules was investigated using X-ray diffraction, thermogravimetric analysis, and the release characteristics of curcumin.   Result  The results indicated that the optimum mass ratio of WPI and ADA for preparing microcapsules was 1∶3. Grafting degree, browning intensity and Fourier transform infrared spectroscopy (FTIR) analyses confirmed the formation of conjugates. Driven by covalent binding, the particle size of WPI-ADA emulsion decreased from 415.4 nm to 325.9 nm, and the microcapsule encapsulation efficiency increased from 83.9% to 95.4%. Additionally, WPI-ADA copolymer microcapsules exhibited good thermal stability. In vitro simulated digestion experiments demonstrated that WPI-ADA copolymer microcapsules exhibited certain controlled release capabilities, extending the time for maximum curcumin release from 12 hours to 24 hours in simulated gastric fluid and intestinal fluid.   Conclusion  Under covalent interaction, WPI-ADA copolymers can improve the physicochemical properties and curcumin release properties of microcapsules, and can be used to modify the microcapsule system and the delivery of hydrophobic active substances. [Ch, 8 fig. 1 tab. 27 ref.]
Spatiotemporal evolution and regulation strategies of ecological risks in green space landscape in the water network area of southern Jiangsu
HUANG Xiaojie, DING Jinhua, WANG Daqing
2024, 41(6): 1283-1292.   doi: 10.11833/j.issn.2095-0756.20240169
[Abstract](137) [HTML](30) [PDF](3)
Abstract:
  Objective  This study aims to discuss the ecological risks caused by landscape fragmentation and habitat quality decline in green space in the water network area of southern Jiangsu Province under the background of rapid urbanization.   Method  Taking Kunshan City as an example, the land use data from 2000, 2010 and 2020 were selected, and the landscape pattern index was used to construct a landscape ecological risk assessment model. The spatiotemporal evolution characteristics of landscape ecological risks in green space of Kunshan City from 2000 to 2020 were analyzed, and green space control zones were defined based on the characteristics of landscape ecological risk level transfer and change.  Result  (1) From 2000 to 2020, the total area of green space in Kunshan City showed a continuous reduction trend, with a significant decrease in cultivated land, a total reduction of 20 203.11 hm2, accounting for 21.70%. The water area first slightly increased and then continued to decrease, with an overall decrease of 3813.66 hm2. The proportion of forest land and grassland was relatively small and stable. The area transfer matrix between land types of green space mainly showed a shift from arable land to construction land, reflecting the increasing interference degree of green space by artificial construction. (2) There were certain changes in the distribution of landscape ecological risks, mainly manifested as a shift from low risk level to higher risk level. The proportion of the highest and high risk areas increased by 8.10% and 6.61%, respectively, while the area of low and the lowest risk areas decreased by 8.25% and 9.73%, respectively. (3) Based on the characteristics of landscape ecological risk level transfer and change, the study area was divided into three types of control zones: key restoration zone, coordinated buffer zone and optimal utilization zone.  Conclusion  The landscape ecological risk of green space in Kunshan City shows an upward trend. There is a correlation between the transformation of green space land use type and landscape ecological risk, reflecting the increasing ecological pressure of green space under human construction activities. Green space zoning regulation strategies based on the spatiotemporal evolution characteristics of risks are proposed in this study. [Ch, 4 fig. 5 tab. 28 ref.]
Spatiotemporal variation and driving factors of normalized difference vegetation index (NDVI) in Yan’an City
LAN Mengyao, ZHOU Dezhi, GUAN Yinghui
2024, 41(6): 1293-1302.   doi: 10.11833/j.issn.2095-0756.20230610
[Abstract](48) [HTML](11) [PDF](1)
Abstract:
  Objective  Vegetation is a principal component of terrestrial ecosystems. This study intends to investigate the spatiotemporal variation in regional vegetation coverage, and quantify the relative contributions of climate change and human activities, which can provide scientific support for future ecological environment construction and sustainable development of the region.   Method  Based on the MODIS-normalized difference vegetation index (NDVI) dataset and meteorological data of Yan’an City from 2001 to 2020, Mann-Kendall trend analysis, partial correlation analysis and residual analysis were employed to investigate the response of NDVI to climate change and human activities.   Result  (1) From 2001 to 2020, the annual mean NDVI value in Yan’an City was 0.69, indicating a significant upward trend, with a spatial distribution pattern of high in the south and low in the north. (2) The impact of temperature and precipitation on NDVI varied significantly at different temporal scales. At the annual scale, NDVI was influenced more by precipitation than temperature. At the seasonal scale, NDVI in spring was influenced by both temperature and precipitation, while precipitation in summer had a greater impact on NDVI. In autumn and winter, the correlation between NDVI and temperature and precipitation was not significant in most regions. (3) The overall NDVI exhibited a trend of improvement, with 83.27% of the area showing significant improvement. (4) The impact of climate change and human activities on vegetation had a dual effect, with 91.26% of the area affected by both factors. The relative contributions of the two to vegetation change were 17.81% and 82.19%, respectively.   Conclusion  The overall vegetation in Yan’an City demonstrates a positive trend, and compared to climatic factors, human activities have a stronger driving effect on NDVI changes. [Ch, 7 fig. 3 tab. 28 ref.]
Impact of industrial organization models on the value realization of non-timber forest products
WANG Danting, ZHU Zhen, YANG Hong, SHEN Yueqin
2024, 41(6): 1303-1312.   doi: 10.11833/j.issn.2095-0756.20240297
[Abstract](90) [HTML](24) [PDF](64)
Abstract:
  Objective  This study aims to explore the impact of various industrial organization models on the value realization of non-timber forest products and their mechanism of action, and to clarify effective pathways for the value realization of material-based ecological products.   Method  Based on the survey data of 811 farming households from 7 counties (cities) in Zhejiang Province in 2022, this study empirically analyzed the impact of different industrial organization models on the value realization of non-timber forest products, as well as the role of regional public brands in this process.   Result  Both horizontal cooperation (cooperative + farmer) and vertical collaboration (company + farmer) models had significant positive effects on the value realization of non-timber forest products. Mechanism verification showed that regional public brands played a mediating role in the value realization process of non-timber forest products by industrial organizations. Heterogeneity tests revealed that the premium effect of non-timber forest products sold by farmers with small operation scale and through the Internet was more significant.   Conclusion  Industrial organizations can facilitate the value realization of non-timber forest products by promoting farmers’ participation in regional public brands. Therefore, it is suggested that while improving the organization degree of farmers, it is necessary to strengthen the construction of regional public brand and optimize sales channels. [Ch, 6 tab. 35 ref.]
Review
Research progress on plant physiological morphology and light response mechanism in shaded environments
LIU Pei, WU Yufen, WANG Xiaofeng, WU Wenhui, GAO Yanhui, CHEN Donghong, SI Jinping, LI Cong
2024, 41(6): 1313-1322.   doi: 10.11833/j.issn.2095-0756.20240187
[Abstract](339) [HTML](44) [PDF](43)
Abstract:
Light is a crucial environmental factor affecting plant growth and development. It is of great scientific significance and application value to enhance plant yield and quality in agricultural production by improving its photosynthetic efficiency. In dense plant communities, lower plants receive less light energy due to the coverage of upper vegetation, so lower plants need to compete for more light energy to maintain growth. Plants have two strategies to obtain more light energy: shade avoidance syndrome (SAS) and shade tolerance response (STR). Research on SAS is relatively thorough, but there is a lack of in-depth research on STR. This paper provides an overview of how sunny plants adapt to lower light level by extending hypocotyl, petioles, stems and other physiological morphological changes in shaded environments. At the same time, shade tolerant plants respond to limited light conditions by exhibiting shade resistance characteristics such as promoting carbon acquisition, low phenotypic plasticity ability and improving stress resistance. Combined with the mechanism of shade avoidance response of sunny plants in response to low light environment through the interaction between hormones and light signaling pathways, the shade tolerance response mechanism of shade tolerant plants in shaded environments is studied, which involves both activating antagonistic factors to inhibit shade avoidance syndrome and improving the transcription activity of shade tolerance response genes to enhance low light adaptability. This review provides reference for research on the mechanism of different plants responding to low light environments, and proposes effective ways to improve the efficiency of plant light energy utilization, cultivate crop varieties with high light efficiency, and construct efficient forest ecosystems. [Ch, 3 fig. 61 ref.]
Total Contents
Total Contents
2024, (6): 1323-1323.  
[Abstract](1) [HTML](1) [PDF](0)
Abstract:

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

Tel:0571-63732749

E-mail:zlxb@zafu.edu.cn

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