Current Articles

2025, Volume 42,  Issue 2

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2025, 42(2)
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2025, 42(2): 1-2.
Abstract:
Effect of glycosylation modification on structure and functional properties of walnut peptides
LIAO Yanchao, LIU Yan, ZHANG Juncheng, MIN Weihong
2025, 42(2): 219-229. doi: 10.11833/j.issn.2095-0756.20240621
Abstract:
  Objective  This study aimed to explore the effects of the Maillard reaction between walnut peptides (WP) and carbohydrates under dry heat conditions on the structural modifications before and after the reaction. It also analyzed the functional characteristics such as antioxidant activity and thermal stability before and after the Maillard reaction, providing a theoretical basis for walnut peptides application in the food industry.   Method  The Maillard reaction between walnut peptides and arabinoxylan (AX) or xylo-oligosaccharides (XOS) was conducted using dry heat. The degree of grafting and the browning index were used to reflect the extent of glycosylation. The impacts of different carbohydrates on the molecular weight, microstructure, particle size, thermal stability, and antioxidant activity of walnut peptides were measured.   Result  Arabinoxylan was a high-molecular-weight polysaccharide mainly composed of arabinose and xylulose, while walnut peptides were primarily composed of peptide fragments less than 2 000 Da. After glycosylation with arabinoxylan, the content of oligopeptides increased, whereas it decreased when reacting with xylo-oligosaccharides. The average particle size of the Maillard products of walnut peptides decreased, while the total and free thiol contents increased, leading to a more disordered and loose structure. Furthermore, both thermal stability and antioxidant activity improved.   Conclusion  Glycosylation is beneficial for improving the structure and functional properties of walnut peptides, and can enhance the feasibility of their application in the food industry. [Ch, 7 fig. 2 tab. 45 ref.]
Detection of kinsenoside and it’s isomer, endogenous hormones in Anoectochilus roxburghii
LI Lulu, ZHU Zhibin, LI Shuikun, FANG Jieyun, BAI Yan, FANG Li, TOU Lingjuan, ZHOU Xiaojun, WANG Hongzhen
2025, 42(2): 230-238. doi: 10.11833/j.issn.2095-0756.20240435
Abstract:
  Objective  Kinsenoside is a characteristic active ingredient of Anoectochilus roxburghii, and it’s isomer is impurity that is extremely difficult to remove during kinsenoside preparation process.   Method  Kinsenoside and it’s isomer contents in whole plant, root, stem and leaf of ‘Jianye’, ‘Hongxia’, ‘Daye’, and ‘Xiaoye’ cultivars were detected using HPLC-ELSD, and their accumulation pattern were also analyzed. The contents of endogenous IAA, ABA, and SA were detected using HPLC-PDA, and correlation coefficient of kinsenoside and these hormones accumulation pattern were also analyzed using Pearson correlation analysis.   Result  Kinsenoside contents (2.84 to 3.81 mg·g−1) were varied in 4 cultivars of A. roxburghii, and that was the highest in ‘Daye’, moderate in ‘Xiaoye’ and ‘Jianye’, and the lowest in ‘Hongxia’. Kinsenoside accumulated predominantly in aerial parts, and it’s content was slighter higher than that in stem. Meanwhile, the content of it’s isomer were very low in all cultivars (0.14 to 0.50 mg·g−1) and it exclusively accumulated in root. Kinsenoside and it’s isomer simultaneously detected in the protocorm like bodies (PLBs) of ‘Hongxia’, and kinsenoside content was almost equal to that of the whole plant. Kinsenoside was detected in PLBs in ‘Jianye’, and it’s content was higher than that whole plant, while there is no it’s isomer was detected in PLBs of ‘Jianye’. Kinsenoside and IAA in a polar manner in the stem of all 4 cultivars were positive correlated. Meanwhile kinsenoside and SA accumulation pattern were positively correlated ‘Xiaoye’, ‘Hongxia’ and ‘Jianye’ cultivars. Kinsenoside accumulation pattern hanged with the IAA accumulation pattern after TIBA treatment. These results showed that kinsenoside biosynthesis may be regulated by endogenous IAA accumulation.   Conclusion  This study identified the distribution patterns of kinsenoside and it’s isomer in A. roxburghii. Kinsenoside specificity was distributed in the aboveground part, while the isomer was distributed in the roots. No isomer of kinsenoside was detected in PLBs of ‘Jianye’. The aboveground part or the PLBs with ‘Jianye’ can be used as a high quality drug source to produce high quality clematiside at low cost. There is a positive correlation between kinsenoside and the endogenous IAA accumulation, which either positively regulates the synthesis of kinsenoside, or can regulate the synthesis of kinsenoside by changing the endogenous IAA synthesis. [Ch, 3 fig. 4 tab. 31 ref.]
Differences in free amino acids during post-ripening process of Torreya grandis ‘Xi Fei’ and ‘Xiangya Fei’ seeds
CHENG Jiajie, CHEN Rong, YU Weiwu, CHEN Wenchao, HU Yuanyuan, ZHANG Zuying, SONG Lili
2025, 42(2): 239-248. doi: 10.11833/j.issn.2095-0756.20250169
Abstract:
  Objective  This study aims to investigate the changes in free amino acid content during post-ripening process of different Torreya grandis ‘Merrilii’ cultivars and the differences among cultivars, providing a scientific reference for quality assessment and germplasm innovation of T. grandis ‘Merrilii’ cultivars.   Method  The automatic amino acid analyzer was used to measure the free amino acid content in the seeds of ‘Xi Fei’ and ‘Xiangya Fei’ during post-ripening process. Combined with principal component analysis (PCA), the specific differences in total free amino acids, essential amino acids and flavor amino acids between the two cultivars during post-ripening process were systematically revealed.   Result  Fifteen common free amino acids were detected in both ‘Xi Fei’ and ‘Xiangya Fei’ seeds throughout the ripening process. Specifically, the total free amino acid content ranged from 673.11 to 1 102.36 µg·g−1 in ‘Xi Fei’ and from 881.77 to 1 068.93 µg·g−1 in ‘Xiangya Fei’. Notably, the contents of both essential and non-essential amino acids were significantly higher in ‘Xi Fei’ seeds compared to ‘Xiangya Fei’. PCA further highlighted the differences in major flavor amino acids between the two cultivars, with ‘Xi Fei’ exhibiting prominent aromatic amino acids, contributing to its aromatic character, while ‘Xiangya Fei’ showed significant umami amino acids, enhancing its delicious taste.   Conclusion  Considerable variations exist in the amino acid content and composition among different T. grandis ‘Merrilii’ cultivars. The ripening process not only increases the amino acid content and nutritional value of the seeds but also enhances the flavor characteristics of both cultivars, making them more distinctive in their own right. [Ch, 7 fig. 2 tab. 34 ref.]
Genome-wide identification of the polygalacturonase gene family in Rubus chingii and its roles in fruit development
SHEN Danwei, ZHU Ting, LI Meixin, JIANG Jingyong, SHI Yujie, LI Xiaobai, ZENG Wei, CHEN Zhen
2025, 42(2): 249-260. doi: 10.11833/j.issn.2095-0756.20240427
Abstract:
  Objective  The polygalacturonase (PG) gene family members of pectin hydrolase in Rubus chingii were identified and analyzed in this study, and the vital PG-coding genes during fruit development were screened, which could provide a theoretical reference for achieving the breeding goals to expand the fruit size or inprove fruit softening.   Method  Genome-wide identification and bioinformatics methods were used to identify the PG gene family members of R. chingii. Transcriptome sequencing and RT-qPCR were used to analyze expression patterns of PG genes during fruit developmental stages.   Result  A total of 47 RchPGs were predicted, which were unevenly distributed on 7 chromosomes. Phylogenetic relationships showed they could be divided into 6 clades (Clade A−D). Among these, 28 RchPGs proteins had integrated 4 domains, Ⅰ (SPNTDG), Ⅱ (GDDC), Ⅲ (CGPGHGISIGSLG), and Ⅳ (RIK), while 11 RchPGs missed domain Ⅲ. The result of the transcriptome sequencing showed that RchPG6, RchPG29, RchPG1, RchPG23 and RchPG12 involved in hydrolysis of cell wall for fruit expansion at earlier stages of fruit development. Oppositely, RchPG16, RchPG2, RchPG10 and RchPG38 were highly expressed at later stages and might be essential for fruit ripening and softening. In particular, the expression level (FPKM values from RNA-seq) of RchPG16 was dramatically increased at the red fruit stage, and the FPKM value was 2168.17 times higher than that at the immature big green (BGⅠ) stage, indicating that it played a significant role in fruit ripening and softening.   Conclusion  RchPG gene family in R. chingii were differentially expressed in different stages of fruit development to improve fruit expansion and softening. Among them, RchPG16 and RchPG28 genes may play a key role in the ripening and softening of R. chingii. [Ch, 8 fig. 1 tab. 32 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
2025, 42(2): 261-272. doi: 10.11833/j.issn.2095-0756.20240327
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 120.0 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.]
Cloning and analysis of tissue-specific expression patterns of ThMYBPAR gene in Tetrastigma hemsleyanum
WANG Ziyue, YANG Feng, WANG Hongyan, XING Qiaoyue, BAI Yan
2025, 42(2): 273-280. doi: 10.11833/j.issn.2095-0756.20240459
Abstract:
  Objective  Flavonoids are essential components that determine the quality of Tetrastigma hemsleyanum. This study aims to investigate the regulatory role of the ThMYBPAR gene in flavonoid biosynthesis in both the tuberous root and leaves of T. hemsleyanum, thereby providing a theoretical foundation for understanding the molecular mechanisms underlying quality formation in this plant species.   Method  The tuberous root and leaves of 3-year-old T. hemsleyanum plants were analyzed by determining their content of proanthocyanidins, total flavonoids, and antioxidant capacity. Primers were designed for the cloning of the ThMYBPAR gene. The sequence characteristics and evolutionary relationships of the ThMYBPAR protein were assessed through bioinformatics analysis. Additionally, the expression patterns of the ThMYBPAR gene in both tuberous root and leaves were examined using real time fluorescence quantitative PCR (RT-qPCR), alongside an investigation into the correlation between ThMYBPAR gene expression levels and flavonoid content.   Result  The content of total flavonoids and proanthocyanidins in the tuberous root were 0.55 and 1.77 g·L−1 respectively, which were significantly higher than those in the leaves (P<0.05). Moreover, the ABTS free radical scavenging rate of the tuberous root extract reached 90%, indicating notable differences in the quality of herbal material between the tuberous root and leaf samples. Previous transcriptomic analyses had demonstrated that the ThMYBPAR gene, which consisted of 888 bp and encoded a protein comprising 310 amino acids, showed a significant degree of similarity to the VvMYBPAR gene found in grapevines (Vitis vinifera). The protein contained distinctive DNA-binding functional domains, R2 and R3, and was classified within the R2R3-MYB transcription factor subfamily 5, with a preferential localization in the nucleus. RT-qPCR analysis revealed that the expression of the ThMYBPAR gene was primarily detected in the tubers of T. hemsleyanum, exhibiting a positive correlation with the content of total flavonoids and proanthocyanidins (P< 0.01).  Conclusion  The ThMYBPAR gene plays a crucial role in the regulation of proanthocyanidin synthesis in T. hemsleyanum. The differential expression levels of ThMYBPAR in the tuberous root and leaves may account for the observed variations in quality between these two plant parts. [Ch, 5 fig. 2 tab. 22 ref.]
Regional differentiation patterns of common functional traits of Salix matsudana in precipitation gradient zones
GUO Meimiao, ZHANG Bona, TANG Luyao, YE Linfeng, XIE Jiangbo, WANG Zhongyuan
2025, 42(2): 281-290. doi: 10.11833/j.issn.2095-0756.20240505
Abstract:
  Objective  The objective is to analyze the variation characteristics and driving factors of functional traits of Salix matsudana, a common species distributed along the precipitation gradient, and reveal the adaptation mechanism and potential of S. matsudana under climate change.  Method  From July to September 2021, taking the transect from southeast to northwest of China as its research platform, 10 sampling points were selected along the precipitation gradient in Xuancheng, Xinyang, Sanmenxia, Tongchuan, Qingyang, Wuzhong, Jinchang, Zhangye, Jiuquan, and Hami. The common species of S. matsudana was used as the target plant and 16 functional traits including leaf mass per area (ALM), Huber value (Hv), and maximum net photosynthetic rate per unit mass (Amass) were measured. One-way ANOVA and plant trait network were used to explore the variation characteristics and adaptation strategies of S. matsudana in the precipitation gradient. The main climatic factors driving trait variation were further revealed by hierarchical partitioning method.   Result  (1) There were regional differences in functional traits of S. matsudana. Amass, Hv and ALM all reached extreme values under moderate rainfall. Amass and Hv in semi-humid and semi-arid regions were significantly higher than those in humid and arid regions (P<0.05), while ALM was the opposite, significantly lower in semi-humid and semi-arid regions than in humid and arid regions (P<0.05). (2) S. matsudana exhibited higher resource utilization efficiency in semi-humid and semi-arid regions with more favorable conditions, where the average path length was shorter, and the average clustering coefficient and edge density were higher. The average path length in descending order was as follows: arid region (2.124), humid region (2.013), semi-humid region (1.838), and semi-arid region (1.681). The average clustering coefficient from high to low was semi-arid region (0.750), semi-humid region (0.700), arid region (0.576), and humid region (0.505). The semi-humid region had the highest edge density, which was 0.400, followed by the semi-arid region at 0.325. (3) The contribution rate of climatic factors to the variation of the overall functional traits of S. matsudana along precipitation gradient from high to low was as follows: mean annual precipitation (21.57%), photosynthetically active radiation during the growing season (19.73%), and mean temperature during the growing season (11.94%), totalling 53.24%.  Conclusion  Precipitation change is the main climatic factor driving the regional differentiation of functional traits of S. matsudana. [Ch, 4 fig. 3 tab. 40 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
2025, 42(2): 291-301. doi: 10.11833/j.issn.2095-0756.20240401
Abstract:
  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.]
Eco-hydrological effects of litter layer in typical plantations forests in central Yunnan
SONG Guocang, YAN Shilin, YU Fuke, MAO Chuanliang, YU Xiao, YANG Yao, HUANG Xinhui
2025, 42(2): 302-311. doi: 10.11833/j.issn.2095-0756.20240399
Abstract:
  Objective  Quantitatively evaluate the eco-hydrological effects of litter layer of typical plantations in central Yunnan, is aimed to provide theoretical basis for plantation water storage capacity and realizing forest ecosystem sustainable management.   Method  With 3 typical plantations (over-matured Eucalyptus benthamil, over-matured Pinus armandii, medium-aged E. benthamil) selected as the research objects, field investigation, indoor immersion experiment, water loss experiment and laboratory rainfall simulation experimental analysis was conducted of the eco-hydrological effects in plantation.   Result  (1) The total litter stocks range of typical plantations in central Yunnan is 13.07−16.84 t·hm−2, and over-matured P. armandii>medium-aged E. benthamil>over-matured E. benthamil. The total thickness of over-matured Eucalyptus benthamil in the 3 kinds of plantation forests was significantly greater than that of medium-aged E. benthamil. (2) The natural moisture content of litter in three types of plantations ranged from 42.28%−78.51%. Both indoor soaking experiments and artificial rainfall simulation tests demonstrated that the water-holding capacity of the litter, and over-matured P. armandii>medium-aged E. benthamil>over-matured E. benthamil. The impact of rainfall intensity on the litter's water-holding performance was not significant. (3) The cumulative water uptake (loss) of litter in each forest type was a logarithmic function with time, and the rate of water uptake (loss) was a power function with time. (4) The 3 typical stands water loss process of litter was a change process from rapid water loss to slow water loss and then to gradual non-water loss, which better reflected the water holding capacity of litter.   Conclusion  The results of laboratory rainfall simulation and litter indoor immersion experiments were consistent, the natural water content and water-holding (interception) performance of the over-matured E. benthamil are the minimum. Based on the water holding capacity and evaporation of litter of 3 typical plantations in central Yunnan, it is suggested that the area of over-matured E. benthamil forest should be appropriately reduced and the planting proportion of P. armandii should be increased from the aspect of water conservation. [Ch, 5 fig. 3 tab. 29 ref.]
Estimation of fine dead fuel load based on Random Forest Model
LIU Shihao, HU Wen, YANG Yanggu, YANG Shengnan, XU Yun, ZHANG Jiayang
2025, 42(2): 312-320. doi: 10.11833/j.issn.2095-0756.20240386
Abstract:
  Objective  The objective is to study the estimation method and spatial distribution of fine dead fuel load on the ground surface.   Method  Based on remote sensing data and field survey results, a Random Forest Model was employed to estimate the land surface fine dead fuel load in 172 standard plots of arboreal forests and bamboo forests in Anhua County, Hunan Province, and the importance of each factor in the estimation process was analyzed.   Result  (1) The Random Forest Model had high accuracy in estimating the surface fine dead fuel load. The determination coefficients (R²) on the training set and validation set were 0.930 and 0.724 respectively, and the root mean square errors were 0.2623 and 0.4166 t·hm−2 respectively, both of which passed the confidence test at 0.01 level. (2)There were significant differences in the importance of each factor in the estimation process, and the importance index ranking from the largest to the smallest was vegetation type factor (39.95%), stand factor (7.23%), terrain factor (3.91%) and spectral feature index factor (3.82%). (3) The surface fine dead fuel load in Anhua County was 1.18−6.19 t·hm−2, and the areas with high fuel load were mainly concentrated in Jiangnan Town, Tianzhuang Township, Malu Town, Yanxi Town, Le’an Town, Meicheng Town, and Taoxi Town.   Conclusion  The Random Forest Model can be well applied to estimate the surface fine dead fuel load, and can provide a reliable method for regional forest management and conservation, as well as for forest fire risk mitigation. [Ch, 4 fig. 2 tab. 30 ref.]
Community structure and species composition in Dachen Island
YANG Bairun, WU Jiang, GUAN Kaicheng, SHEN Weikang, HONG Xujie, WANG Jiang
2025, 42(2): 321-328. doi: 10.11833/j.issn.2095-0756.20240423
Abstract:
  Objective  This study, with an exploration of the structure and species composition of the plant community of Dachen Island and its relationships with soil factors, is aimed to provide a scientific basis for its maintenance and management.   Method  Based on the investigation of 15 plots (20 m × 20 m) on Dachen Island and combining with the method of Redundancy Analysis (RDA), a study was conducted of its species composition, diameter structure, community similarity and environmental factors.   Result  The Dachen Island community boasts a record of 34 species of woody plants, which belong to 26 families and 32 genera. The size-class distribution of species individuals was generally inverse J-shaped. The communities dominated by Casuarina equisetifolia had higher value of diversity indexes, while those dominated by Eurya japonica and Ficus erecta had lower value diversity indexes. The communities dominated by E. japonica and Dalbergia odorifera and those dominated by E. japonica and Clerodendrum trichotomum had the highest similarity coefficient, while the community dominated by F. erecta and those dominated by Clerodendrum trichotomum and Celtis sinensis had the lowest similarity coefficient. Furthermore, there was a negative correlation between soil total phosphorus content and community similarity coefficient whereas soil nitrate nitrogen, ammonium nitrogen, and available phosphorus showed a positive correlation with species diversity of communities.   Conclusion  The communities in Dachen Island are primarily dominated by Casuarina equisetifolia, E. japonica and F. erecta, and the soil total phosphorus had a close link with species composition. [Ch, 4 fig. 2 tab. 30 ref.]
Ecological niche and interspecific association of dominant tree species in a Machilus and Phoebe forest in Jiande, Zhejiang Province
HUANG Hao, WU Wenxiao, LÜ Jiangbo, XU Yonghong, FAN Jianzhong, WU Jiasen
2025, 42(2): 329-338. doi: 10.11833/j.issn.2095-0756.20240378
Abstract:
  Objective  The objective is to analyze the ecological niche and interspecific relationship of the Machilus and Phoebe forest in Jiande Forest Park, which is the largest existing natural Machilus and Phoebe forest in Asia, so as to provide theoretical basis for its protection, population restoration and near-nature management.   Method  Based on the survey data of 1 hm2 sample plot in July 2023, the ecological niche and interspecific association of 19 dominant tree species with important values≥1% were examined, including M. pauhoi, M. leptophylla, M. thunbergii, and P. sheareri, through species composition, niche breadth, niche overlap index, χ2 test, variance ratio method, interspecific association coefficient, and co-occurrence percentage.  Result  (1) M. pauhoi had the highest important value (23.44%), and was the constructive species of the community. The important values of M. leptophylla, M. thunbergii, and P. sheareri were 1.20%−1.80%, ranking after the 12th place. (2) In the sample plots, there was a high niche overlap between M. pauhoi and other dominant tree species, among which the ecological niche overlap value with M. leptophylla was as high as 0.87. The niche overlap values between M. leptophylla, M. thunbergii, P. sheareri, and other tree species were relatively small, ranging from 0.10 to 0.50. (3) There was a significant positive correlation (P<0.05) among the dominant trees in Machilus and Phoebe forest in Jiande. The χ2 test, interspecific association coefficient, and percentage of co-occurrence revealed that there was a strong correlation between M. pauhoi and 18 dominant tree species, while the correlation between M. leptophylla, M. thunbergii, and P. sheareri and the dominant tree species was weak. (4) Regression analysis showed that interspecific association coefficient, and percentage of co-occurrence of the main dominant tree species were significantly positively correlated with the ecological niche overlap value (P<0.01).   Conclusion  The species of Machilus and Phoebe forest in Jiande are relatively independently distributed and in the middle stage of succession, with loose interspecific relationship. Appropriate measures such as selective logging and understory replanting can be taken to achieve long-term stable growth of Machilus and Phoebe trees. [Ch, 4 fig. 2 tab. 33 ref.]
Physiological characteristics of Lagerstroemia indica flowers in opening process
CHEN Mengmeng, ZHAO Yu, BAI Mingzhu, YU Mengxin, GU Cuihua
2025, 42(2): 339-347. doi: 10.11833/j.issn.2095-0756.20240347
Abstract:
  Objective  The study of physiological characteristics of Lagerstroemia indica flowers during the opening process provides reference for further floral regulation.   Method  This study took the petals of L. indica in different periods of flower opening as experimental materials, and investigated the physiological and biochemical changes, including cell morphology change, cell relative water content, carbohydrate content and endogenous hormone content. The correlations between the indicators were analyzed by Pearson detection method.   Result  According to the phenological observation, the single flower opening process can be divided into 4 periods: tight bud stage (S1), flower bud expansion stage (S2), early blooming stage (S3) and full blooming stage (S4). Scanning electron microscope observation showed that the upper and lower epidermal cells of the petals gradually expanded during flower opening, and there were undulating, striped and radial patterns on the cell surface with the progress of flower opening, and the area of the lower epidermal cells was larger than the area of the upper epidermis in each stage. The relative water content of petals, sepals and the whole bract/whole flower showed an overall increasing trend, the total soluble sugar content also showed an overall increasing trend, and the starch content showed an increasing and then decreasing trend. Abscisic acid (ABA) content was relatively low and changed steadily, the content of auxin (IAA) and gibberellin (GA3) was low and the overall expression trend was different, the content of zeatin riboside (ZR) was higher and the change was larger, and the ratio of ZR/ABA was larger and the change was large. Correlation analysis showed highly significant positive correlation (P<0.01) between the 9 indicators, significant negative correlation (P<0.05) between starch content and sucrose content, and non-significant correlation between starch content and other indicators.   Conclusion  During the opening process of L. indica, accompanied by significant changes in the morphology of the upper and lower epidermal cells of the petals, increase in relative water content of floral cells, rise in carbohydrate content and dynamic adjustment of endogenous hormone content, these changes jointly promoted the normal opening of L. indica flowers. [Ch, 6 fig. 1 tab. 33 ref.]
Comprehensive targeted metabolomic analysis of fruit stalks in two species of Hovenia plants
YING Junhui, PAN Wenwen, ZHANG Hua, ZHOU Shengcai, LIN Yan, ZHANG Junhong, CHEN Shitong
2025, 42(2): 348-356. doi: 10.11833/j.issn.2095-0756.20240429
Abstract:
  Objective  This study aims to clarify the metabolite differences in the fruit stalks of Hovenia acerba and H. trichocarpavar var. robusta, and lays a foundation for the development and utilization of Hovenia plants.   Method  Through a comprehensive targeted metabolomics approach of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the differences in metabolites and metabolic pathways in the fruit stalks of H. acerba and H. trichocarpa var. robusta were analyzed.   Result  A total of 1810 metabolites were detected in the fruit stalks of the two Hovenia species, of which 782 metabolites showed significant differences (P<0.05). Compared with the fruit stalks of H. acerba, there were 378 up-regulated differential metabolites and 404 down-regulated differential metabolites in the fruit stalks of H. trichocarpa var. robusta, and the relative contents of tannin and quinone metabolites were significantly down-regulated. The differential metabolites in the fruit stalks of the two Hovenia species were primarily enriched in the biosynthetic pathways of phenylalanine compounds, flavonoids, and isoquinoline alkaloids. Among them, the extremely significant differential metabolites included alkaloid substances such as ligustroside, N-methylligustroside and methylcoclaurine, as well as flavonoids like naringin, naringin chalcone, and 2’, 3, 4, 4’, 6’-pentahydroxy chalcone.   Conclusion  There are significant differences in the metabolic profiles of the fruit stalks of the two Hovenia species under the same ecological conditions, especially the relative content of alkaloids and flavonoids with medicinal value and high sweetness. [Ch, 7 fig. 1 tab. 41 ref.]
Comprehensive evaluation of Solanum melongena cultivars
YING Xuebing, CHEN Pingmei, LI Luyao, WANG Hong, WU Haotian, ZHANG Yijun, ZHANG Xuerong, ZANG Yunxiang
2025, 42(2): 357-364. doi: 10.11833/j.issn.2095-0756.20240394
Abstract:
  Objective  In order to establish a suitable evaluation methods for eggplant resources, the agronomic characters and quality indexes of different eggplant cultivars are analyzed, which will provide a theoretical reference for rapid screening of germplasm resources and eggplant breeding.   Method  10 eggplant varieties ‘Zilong No.5’ ‘Zilong No.7’ ‘Liangzi No.7’ ‘Zheqie No.10’ ‘Hangqie No.716’ ‘Hangqie No.718’ ‘Z1’ ‘Z2’ ‘Z3’ ‘Hangqie No.2020’ were used to determine 16 indicators relevant with plant growth and fruit characteristics. The principal component analysis method was used for comprehensive evaluation.   Result  There were differences among different eggplant cultivars. Plant of ‘Z2’ was the highest. The highest plant breadth and stem diameter was found in ‘Zilong No. 7’ and ‘Hangqie No. 716’, respectively. For fruit length, ‘Z1’ was the longest, while ‘Zilong No. 7’ was the shortest. The highest and lowest chroma value was found in fruit of ‘Z1’ and ‘Z3’, respectively. The hardness of fruit peel and pulp for ‘Hangqie No. 716’ was significantly higher than those of the other 9 cultivars (P<0.05). The pericarp toughness of ‘Liangzi No. 7’ was significantly higher than others (P<0.05). Soluble sugar and protein contents of ‘Z2’ were the highest. Fruits of ‘Liangzi No. 7’ and ‘Zilong No. 5’ showed the highest levels of amino acid. Principal component analysis extracted a total of 5 principal components with a cumulative contribution rate of 87.126%.   Conclusion  A comprehensive evaluation model of eggplant was constructed by taking the eigenvalues corresponding to the five principal components and the ratio of single principal component to the extracted principal components. The best comprehensive score was found from ‘Liangzi No. 7’, while the worst was found from ‘Zilong No. 7’. [Ch, 1 fig. 6 tab. 29 ref.]
Chloroplast genome characteristics and molecular marker development of Pennisetum
JIANG Zhuanzhuan, CHEN Hong, BAO Hongyan, DAI Yutong
2025, 42(2): 365-372. doi: 10.11833/j.issn.2095-0756.20240371
Abstract:
  Objective  The objective is to analyze the chloroplast genome characteristics of 4 published plants in the genus Pennisetum, and to develop corresponding molecular markers. This will provide new insights into the evolutionary and phylogenetic relationships of Pennisetum.   Method  Bioinformatics methods were used to analyze the complete chloroplast genome sequences of 4 species of Pennisetum published in the NCBI database. The analysis included repeat sequences, codon preferences, polymorphisms, collinearity, and development of simple sequence repeat (SSR) molecular markers.   Result  The chloroplast genome length and GC content of the 4 species of Pennisetum were relatively similar, with a low degree of codon shift. Boundary expansion analysis indicated no significant contraction between different regions. Collinearity analysis showed strong inter-species collinearity among the 4 species of Pennisetum. Phylogenetic analysis based on chloroplast genome sequences revealed that P. flaccidum had the closest phylogenetic relationship with P. glaucum, P. purpureum, and P. alopecuroides. 5 pairs of SSR molecular markers had high practicality in plant species within the genus Pennisetum. Specifically, primer SSR2 was expressed in both P. flaccidium and P. alopecuroides; while primer SSR5 was specifically expressed in P. flaccidum. Additionally, SSR1, SSR3, and SSR4 showed high conservatism among all four species in this genus.   Conclusion  This study concludes that the chloroplast genomes of these 4 species are relatively conserved; furthermore, it confirms that genetic relationship between P. flaccidium is closest to those found in P. flaccidum, P. purpureum as well as P. alopecuroides. SSR2 molecular markers are specifically expressed in both P. flaccidium and P. alopecuroides, while SSR5 molecular markers are specifically expressed in P. flaccidum. [Ch, 7 fig. 2 tab. 28 ref.]
Nutrient release characteristics of bagged controlled-release fertilizer in Lei bamboo forest and its effect on bamboo shoot yield
ZHOU Dixuan, GUI Renyi, LEI Ji, WU Bin, DENG Shixin
2025, 42(2): 373-382. doi: 10.11833/j.issn.2095-0756.20240219
Abstract:
  Objective  Bag controlled release fertilizer has the characteristics of wrapping the fertilizer and controlling the nutrient release through biodegradable materials. The study of bag controlled release fertilizer for Lei bamboo (Phyllostachys violascens) forests was carried out in order to reduce the loss of fertilizers and improve the nutrient utilization rate, which in turn increased the yield of Lei bamboo shoots.   Method  12 experimental plots of Lei bamboo forest were randomly selected, and 4 treatments were set up, namely, bag controlled release fertilizer, spreading compound fertilizer, hole-applied compound fertilizer, and no fertilizer (the control) with each treatment replicated for 3 times. The differences in nutrient loss, fertilizer utilization, and bamboo shoot yield among different treatments were analyzed by determining the indexes such as ammonia volatilization, the changes of N, P, and K contents of runoff and seepage liquid, and the changes in the appearance and quality of bagged controlled-release fertilizer under different treatments.   Result  Bag controlled-release fertilizer significantly reduced soil ammonia volatilization as well as nutrients lost by runoff leakage, in which the cumulative ammonia volatilization of bag controlled release fertilizer treatments was reduced by 35.5% and 40.5% compared to sprinkled compound fertilizer and hole-applied compound fertilizer, respectively. The amount of total nitrogen, total phosphorus and total potassium in the soil leachate of bagged controlled-release fertilizers was reduced by 33.9%−40.3%, 41.3%−45.1% and 36.7%−39.7%, respectively, compared with that of sprinkler-applied fertilizers and hole-applied fertilizers. Bagged controlled-release fertilizers reduced the amount of total nitrogen and phosphorus in soil runoff liquid by 22.8% to 29.2% and 36.4% to 44.3%, respectively, compared to spreading fertilizers and hole-applied compound fertilizers. And the fertilizer efficacy period of bagged controlled-release fertilizer in Lei bamboo forest was about 5.0 months, and the time of complete release of fertilizer was 6.5 months. The release rate of bagged controlled-release fertilizer was slower in the early stage of application, and the rate of release reached the maximum in the 2nd−3rd month after the application of fertilizer. The apparent utilization rate of nitrogen, phosphorus and potassium in the bag controlled-release fertilizer treatment was greater than that in the spreading compound fertilizer treatment, in which the apparent utilization rate of nitrogen was increased by 27.7%, which was 2.9 times higher than that in the spreading compound fertilizer treatment. The shoot yield of bag controlled-release fertilizer treatment reached 14.74 t·hm−2, which was 62.1% and 25.8% higher than that of the control and spreading compound fertilizer treatment, respectively.   Conclusion  Bag-controlled release fertilizer effectively enhance the shoot yield of Lei bamboo and the efficiency of fertilizer utilization, while concurrently mitigating nutrient loss and environmental pollution. [Ch, 6 fig. 3 tab. 34 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
2025, 42(2): 383-392. doi: 10.11833/j.issn.2095-0756.20240358
Abstract:
  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.]
Preparation and properties optimization of veneer-PE laminated decorative panels
LIU Qiongyao, QU Xi, LIU Xiaoqian, FANG Lu, CHANG Liang
2025, 42(2): 393-401. doi: 10.11833/j.issn.2095-0756.20240345
Abstract:
  Objective  This study aims to prepare wooden decorative laminates-sheets made from polyethylene film (WDL) based on the laminated composite structure of high-pressure decorative laminates made from thermosetting resins impregnated sheets (HPL), which provides a theoretical basis for the preparation of aldehyde-free composite decorative panels with excellent performance.   Method  Polyethylene film and reconstituted decorative veneer were used as raw materials, and the five-layer structural WDL were prepared by hot pressing in the way of smooth-grain grouping. Box-Behnken Response Surface Analysis was used to study the impact of hot-pressing factors on the impregnation peeling performance and tensile strength of the smooth grain and to optimize the process parameters for the preparation of decorative panels.   Result  The impregnation peeling performance of WDL was affected greatly by hot-pressing temperature and hot-pressing time, while hot-pressing pressure had no significant effect on the impregnation peeling performance. The peeling length gradually decreased with the increase of hot-pressing temperature and hot-pressing time. Hot-pressing temperature and time, hot-pressing time and pressure also had significant interaction effects on the impregnation peeling performance of WDL. The tensile strength along the grain of WDL was mainly determined by the strength and thickness of the reconstituted decorative veneer, and the hot-pressing temperature also affected the tensile strength of WDL. Low temperature could result in inadequate cementation of the reconstituted decorative veneer and PE, and high temperature could lead to degradation of the hemicellulose in the veneer, all of which adversely affect the tensile strength along the grain of WDL. When the hot-pressing temperature was 160 ℃, the hot-pressing time was 109 s, and the hot-pressing pressure was 1 MPa, the impregnation peeling length of the decorative boards under these conditions reached 0 mm, and the tensile strength of the smooth grain reached 38.2 MPa, which was close to the prediction results of the optimization model.   Conclusion  A new type of veneer-PE laminated decorative panels is prepared, which has no formaldehyde release, and its water resistance meets the requirements of the TypeⅡ immersion peel test according to GB/T 17657−2022. It can meet the needs of general interior decoration field, and there is no need to add adhesive again in the post-finishing process, which is an upgraded product of HPL. [Ch, 8 fig. 3 tab. 27 ref.]
Preparation of bamboo carbon quantum dots and their application in fluorescence anti-counterfeiting
LIU Yan, LI Rongrong
2025, 42(2): 402-409. doi: 10.11833/j.issn.2095-0756.20240361
Abstract:
  Objective  The objective is to achieve a green method for the preparation of bamboo carbon quantum dots and to improve the utilization efficiency and added value of waste biomass materials.   Method  Fluorescent carbon quantum dots were prepared by a one-step hydrothermal method using bamboo waste materials (bamboo septa) as the initial carbon source and water as the solvent. The micro-morphology, chemical structure and optical properties of the carbon quantum dots of bamboo septa were characterized and analyzed by means of transmission electron microscopy, X-ray diffraction, infrared spectrometry, X-ray photoelectron spectroscopy, UV-visible photometry and fluorescence spectroscopy.   Result  The shape of the prepared carbon quantum dots had a near-circular shape, with a size distribution of 0−1.6 nm. The absolute fluorescence quantum yield was 6.85%, and they had excellent fluorescence properties, with a blue fluorescence under a 365 nm ultraviolet lamp.   Conclusion  The prepared carbon quantum dots aqueous solution is environmentally friendly and has good performance, which can be further optimized for application in the field of fluorescence anti-counterfeiting of wood materials such as furniture wood products and artificial boards. [Ch, 7 fig. 35 ref.]
Reviews
Biotic and abiotic mechanisms of the impact of forest restoration on soil N2O emissions
YANG Shengqiu, WANG Shaojun, XIA Jiahui, LI Rui, LUO Shuang, LAN Mengjie, GUO Xiaofei, XIE Lingling, WANG Zhengjun, XIAO Bo, GUO Zhipeng, ZHANG Ye
2025, 42(2): 410-421. doi: 10.11833/j.issn.2095-0756.20240375
Abstract:
Nitrous oxide (N2O) is the third most important greenhouse gas next to carbon dioxide and methane. Forest restoration may mediate the changes in plant-soil biological-physicochemical environment, and thereby significantly affect the dynamics of soil N2O emissions. It is of great scientific significance to explore the biotic and abiotic mechanisms of the impact of forest restoration on soil N2O emissions. In this study, four microbial pathways (autotrophic nitrification, heterotrophic nitrification, biological denitrification and nitrifying bacterial denitrification) of N2O produced from forest soil were reviewed. The regulation mechanisms of biotic factors (litter, root biomass, root exudates, soil microorganisms and animal communities) and abiotic factors (climate type, temperature, moisture, pH, carbon pool, as well as nitrogen, phosphorus and potassium pools) affecting soil N2O emissions during forest restoration were discussed. At present, research about the effect of forest restoration on soil N2O emissions mainly focuses on the analysis of single-factor mechanism, while there is a relative lack of research on the mechanism of multi-factor coupling in regulating the direction, intensity and dynamics of forest soil N2O emissions. Future research on the regulatory mechanism of greenhouse gas emissions from forest soil should focus on the synergistic direct or indirect effects of multiple factors of “plant-microbial-soil fauna-physicochemical environment” under the background of global climate change intensification, so as to provide key theoretical support for accurately predicting the impact of forest restoration on global climate change. [Ch, 91 ref.]
Research progress on classification, variation mechanism and application of plant leaf color mutants
ZHOU Xiawen, SHI Congguang, ZHOU Fangwei, XU Liang, YANG Shaozong, HE Qiuling
2025, 42(2): 422-432. doi: 10.11833/j.issn.2095-0756.20240397
Abstract:
Leaf color variation in plants is a common and easily recognized phenomenon in nature, which affects the photosynthetic efficiency of plants and leads to poor growth, so it was once considered to be an undesirable variation and gradually eliminated. But in recent years, social advancements and increased demand for ornamental landscaping have brought renewed attention to leaf color mutants. Leaf color mutants are generally regulated at the molecular level, resulting in abnormal chloroplast structure, inhibited photosynthesis, and abnormal pigment synthesis and metabolic pathways. Therefore, they serve as ideal materials for studying pigment metabolism, chloroplast development and differentiation, photosynthesis, and related pathways, and can also provide important information for variety improvement. This paper reviews the research progress of leaf color mutants in recent years, and clarifies that leaf color mutants in higher plants mainly come from natural mutation and artificial mutation. Leaf color mutants can be divided into several types based on color, such as yellowing, yellow green, green yellow, green white, albino, light green, white emerald, stripe and so on. According to the way of leaf color change, leaf color mutants can be divided into monochromatic mutation, variegated mutation and stage chlorosis. Its inheritance mode is generally divided into nuclear inheritance, cytoplasmic inheritance and nucleocytoplasmic interaction inheritance. Compared with normal green leaf plants, the net photosynthetic rate, stomatal conductance, transpiration rate of most leaf color mutants decrease, so does the utilization rate of carbon dioxide. Mutations in genes related to synthesis and metabolism of chlorophyll, carotenoids, and flavonoids (particularly anthocyanins), as well as genes involved in chloroplast differentiation and development, can explain the molecular mechanism underlying leaf color mutants. Leaf color mutants can be applied in landscaping and widely used in basic research and breeding as excellent experimental materials. The findings of this review can provide theoretical reference for further research on leaf color variation. [Ch, 112 ref.]