• 中国中文核心期刊
  • 中国科学引文数据库(CSCD)核心库来源期刊
  • 中国科技论文统计源期刊(CJCR)
  • 第二届国家期刊奖提名奖

2021 Vol. 34, No. 2

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2021, 34(2): -1--1.
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2021, (2): 0-0.
Abstract:
Construction of Phenotypic Core Collection of Populus deltoides
CHEN Cun, DING Chang-jun, HUANG Qin-jun, LI Zheng-hong, ZHANG Jing, LIU Ning, LI Bo, SU Xiao-hua
2021, 34(2): 1-11. doi: 10.13275/j.cnki.lykxyj.2021.02.001
Abstract:
Objective To analyze the phenotypic and physiological characteristics of different groups of P. deltoides, and to compare the effectiveness and representativeness of the phenotypic core collection constructed by different sampling strategies. Method Based on the results of population structure analysis of phenotypic and physiological traits analyzed in previous studies, the P. deltoides resources were grouped, and 21 phenotypic and physiological characters of different groups were analyzed by multiple comparison. The Euclidean distance between clones was calculated, and the individuals of each group were clustered by the method of intergroup connection. The clones were screened by random sampling, deviation degree sampling, locus priority sampling and trait frequency sampling strategies, respectively. The best sampling strategy was selected by comparing and analyzing the diversity of core collection constructed by different sampling strategies. On the basis of the phenotypic core collection, the optimized core collection was constructed by making the phenotypic retention ratio (RPR) reaching 100.00%. The representativeness and validity of core collections were evaluated by comparing the mean, variance, range, coefficient of variation and RPR between the core and the original collections. Result The height growth, leaf number and leaf nutrient characters of the individuals of the provenance ‘Was’ were higher. The roots of the clones of provenances ‘Iow’ and ‘Que’ were developed. The stem growth, leaf morphology and single leaf growth of the clones of provenances ‘Mis’, ‘Lou’ and ‘Ten’ were prominent. The phenotypic core collection constructed by the strategy of character frequency sampling represented the diversity information of the original collection with the least collection. The effectiveness of the core collection was better than that constructed by the strategy of random sampling, deviation degree sampling and site priority sampling. Finally, the phenotypic core collection consisting of 27 clones was constructed, with the sampling ratio of 10.47%. The mean difference percentage (MD), variance difference percentage (VD), range coincidence rate (CR), coefficient of variation coincidence rate (VR) and RPR were 0.00%, 80.95%, 100.00%, 148.94% and 90.85%, respectively. On the basis of core collection, 5 individuals were added to construct phenotype optimized core collection, so that the RPR reached 100.00%, and MD, VD, CR and VR were 0.00%, 71.43%, 100.00% and 142.19%, respectively. The results of PCoA analysis showed that the phenotypic core collection and the optimized core collection were well representative. Conclusion There are significant differences in root, stem and leaf growth traits among different groups of P. deltoides germplasm resources. Through the strategy of character frequency sampling, the core collection of phenotype and the optimization of core collection of P. deltoides could retain the diversity of the original collection, greatly reduce the size and redundancy of the collection, and improve the variation level. The results could provide scientific basis for the conservation, management and utilization of P. deltoides germplasm resources.
Altitude and Interannual Dynamics of Soil pH Value and Cation Contents in Water-level-fluctuating Vegetation Zone in Three Gorges Reservoir Area
WANG Li-jun, CHENG Rui-mei, XIAO Wen-fa, YANG Shao, SHEN Ya-fei, GUO Yan, LEI Lei, ZENG Li-xiong
2021, 34(2): 12-23. doi: 10.13275/j.cnki.lykxyj.2021.02.002
Abstract:
Objective To investigate the soil pH value and metal element content in different altitudes (145~155 m, 155~165 m, and 165~175 m) of the Three Gorges Reservoir area and to master the dynamics over the past decade (2008-2018), so as to provide data for the subsection monitoring and control, as well as the prediction of soil environmental quality evolution in Three Gorges Reservoir area. Method According to the operation Scheduling of the Three Gorges Reservoir area, three secondary shrub sample lands with similar habitat types were selected in the typical fluctuation zone, and the pH value and metal element content in the soil (0-20 cm) at different altitudes were measured to analyze the differences and variations at different elevations and years in 2008, 2009, 2012, 2014, 2015, 2016 and 2018. Result (1) With the periodic fluctuation of water level, the annual changes of soil pH value, potassium, calcium and magnesium contents in the fluctuation zone showed a trend of fluctuating increase, and the contents of iron, manganese and zinc showed a trend of fluctuating decrease, while the contents of sodium showed a trend of decreasing year by year from 2008 to 2018. (2) At different altitudes in each year, the soil pH value and K content showed a pattern of 145~155 m > 155~165 m > 165~175 m, the Fe and Mn contents followed the pattern of 145~155 m < 155~165 m < 165~175 m, the Ca content was relatively abundant in the area of 145~155 m, while the Na, Mg and Zn contents showed no significant difference among different altitudes. By 2018, the soils in the 145~155 m and 155~165 m elevations had developed from acidic to alkaline, and the 165~175 m elevations from acidic to neutral. (3) Correlation analysis and regression analysis showed that the soil pH value was closely related to the content of metal elements. There was a significant positive correlation between soil pH value and the contents of potassium, calcium and magnesium (p < 0.01), and a significant negative correlation between the contents of manganese, zinc, sodium (p < 0.01) and iron (p < 0.05). Conclusion During the period of water level fluctuation for 10 times, the soil pH value and metal element content in different elevation sections of the fluctuation zone changed in varying degrees. It shows that periodic flooding is the main factor affecting the soil properties in the fluctuation zone, and elevation and soil pH value are the important factors affecting the content of metal elements. These conclusion could provide references for the prediction of the evolution trend of soil quality in different elevations of the fluctuation zone in the Three Gorges Reservoir area.
The Change of Soil Carbon Stabilization and Carbon Management Index in Different Mixed Plantations of Castanopsis hystrix in Subtropical Area of South China
WANG Ren-jie, JIANG Yi, WANG Yong, LIU Ting-wei, TANG Jing-ru, LIU Xiong-sheng, HUANG Rong-lin
2021, 34(2): 24-31. doi: 10.13275/j.cnki.lykxyj.2021.02.003
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Objective To study the soil organic carbon pool of different plantations of Castanopsis hystrix mixed forest and its stability in order to provide reference for the evaluation of carbon balance process and the selection of mixed models of C. hystrix mixed plantations in subtropics of south China. Method The C. hystrix pure forest (HC), C. hystrix + Pinus elliottii mixed forest (HS), C. hystrix + Michelia macclurei mixed forest (HH), C. hystrix + Mytilaria laosensis mixed forest (HM) were used as trial objects in this study, and the changes of soil organic carbon (SOC), easily oxidizable carbon (EOC), particle organic carbon (POC), dissolved organic carbon (DOC), microbial biomass carbon (MBC)and carbon pool management index (CMI) of different mixed plantations were analyzed. Result The contents of SOC, EOC, POC, DOC, and MBC decreased with the increase of soil depth in the four kinds of mixed plantations. SOC had a significant positive correlation with EOC, POC, and MBC (P<0.01), and the correlation coefficient between SOC and POC was the largest. The order of SOC content was HM>HH> HS>HC among different stands, and the change of 0-20 cm soil layer was consistent with that of the whole stand (0-40 cm soil layer). The change of CMI in 20-40 cm soil layer was consistent with that of the whole stand, and the order was HM>HH>HC>HS. Conclusion The contents of SOC, EOC, POC, DOC and MBC are mainly affected by the surface soil, CMI is mainly affected by the subsoil, and the POC content is most closely related with SOC in the four mixed plantations. The C. hystrix broadleaved mixed forests can improve soil fertility and soil quality, and the broadleaved mixed model of HM has the highest soil carbon pool quality, with the increase of organic carbon and activated carbon, it also contributes to the accumulation of inert carbon and the stability of carbon pool.
Study on Vegetation Restoration Characteristics of Daxing’anling Burned Area Based on EVI
WANG Bing, ZHANG Jin-yu, MENG Meng, ZHANG Qiu-liang
2021, 34(2): 32-41. doi: 10.13275/j.cnki.lykxyj.2021.02.004
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Objective Using Landsat images to study the identification and vegetation restoration of burned areas based on dNBR (difference Normalized Burned Ratio) and EVI (Enhanced Vegetation Index). Method Taking the 1987 forest fire happened in the northern region of Daxing’an Mountain as the research background, based on land classification and dNBR values, the burned areas were identified and extracted by K-means method, and were classified into light, moderate and severe fire intensity area; and then, based on the EVI values of the burned areas, the vegetation restoration characteristics in the burned area from 1987 to 2019 were analyzed by using the methods of one-way linear regression, Mann-Kendall and Theil-Sen median, so as to explore the vegetation restoration process of burned areas in Daxing'an Mountains. Result Based on dNBR, the total burned area was 1291.68 hm2, and the proportions of light, moderate and severe burned area were 45.70%, 32.16% and 22.14%, respectively. The severe burned area was distributed in the center of the burned area, and the fire intensity gradually decreased from the center to the outside. The impact of forest fire on EVI was obvious, the EVI values of light, moderate and severe burned area decreased by 30.0%, 48.3% and 68.8%, respectively. After the forest fire, the EVI values of burned areas gradually increased with the vegetation recovery, and their differences with the controlled area were gradually reduced. The recovery rates of EVI on different burned forest lands were severe > moderate > light, and the EVI value of shrub grassland was the same as that of the controlled area 2 years after the forest fire. During the process of vegetation restoration in the burned area, the EVI mutation points of forest land were less than that of shrub grassland, EVI mutation points of light burned area were less than those of severe and moderate burned area, and the mutation time of controlled area were all lagged behind that of burned area. Conclusion dNBR can be used to extract the burned area and fire intensity. The EVI values of burned area decreased obviously because of the fire, and the decreasing degree increased with the increase of fire intensity. In the process of vegetation restoration, the EVI values of the burned are increased gradually; the light and moderate burned forest land recovered to normal vegetation state 6−8 years after the fire, and the severe burned area returned to normal vegetation state about 14 years after the fire, while the burned shrub grassland recovered to normal 2 years after the fire. The ecosystem in the burned area is fragile and vulnerable to environmental conditions. Therefore, the fire intensity and natural environment are the main factors affecting the vegetation restoration of the burned area in Daxing'an Mountains. The results can provide some data support for vegetation restoration and management in Daxing'an Mountains.
Effects of Nitrogen Deposition on Soil Organic Carbon and Soil Microbial Communities in a Natural Castanopsis carlesii Forest
LIU Chun-hua, WU Dong-mei, LIU Yu-hui, CHEN Hui, SHEN Bao-gui, JANG Zong-kai, LIU Xiao-fei
2021, 34(2): 42-49. doi: 10.13275/j.cnki.lykxyj.2021.02.005
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Objective To study the effects of N deposition on soil organic carbon and microbial community structure in subtropical evergreen broadleaved natural forest, in order to better understand the response of forest ecosystem to future N deposition and develop effective mitigation strategies. Method An N addition experiment was designed to evaluate the effect of N deposition on soil carbon (C) and soil microbial communities in a natural Castanopsis carlesii forest in subtropical China. In this study, randomized block design was adopted with three-levels of N addition, viz. control (CK, 0 kg·hm−2·a−1), low N (LN, 40 kg·hm−2·a−1) and high N (HN, 80 kg·hm−2·a−1). Result Compared with the CK, the total microbial biomass examined by phospholipid fatty acid analysis (PLFA) were insignificantly increased in LN and HN treatment. The SOC concentration in LN treatment was 27.4% higher than that in CK treatment in 0-10 cm depth, while no significant effect being observed in HN. There were no significant effects of N addition on SOC concentration at the 10-20 cm soil depth in both LN and HN treatment. LN treatment significantly increased the total biomass and the biomass of each microbial component, while there was no significant effect in HN treatment at the 0-10 cm soil depth. Correlation analysis and random forest model analysis showed that increased dissolved organic carbon (DOC) concentration, total nitrogen (TN) concentration, C/N ratio and the increase of total microbial biomass under N deposition are the key factors driving soil organic C accumulation. Principal component analysis showed that N deposition significantly changed the microbial community at the 0-10 cm soil depth while not in the 10-20 cm depth. Conclusion Short term elevated atmospheric N inputs can increase forest soil C storage by increasing DOC concentration and microbial biomass in subtropical natural forest, while the long-term effects of N deposition on soil C sequestration remains unknown.
Effects of Simulated Nitrogen Deposition on Soil Enzyme Activity in Subalpine Forests in Central Yunnan, China
ZHENG Xing-rui, WANG Ke-qin, SONG Ya-li, ZHANG Zhuan-min, ZHANG Yu-jian, PAN Yu
2021, 34(2): 50-62. doi: 10.13275/j.cnki.lykxyj.2021.02.006
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Objective To study the effects of simulated N deposition on soil enzyme activity in different forest types. Method Pinus yunnanensis forest, Quercus semecarpifolia forest, Pinus armandii forest and evergreen broadleaved forest were used as the research objects in the typical forests at Mopan mountain, central Yunnan. From January to December, 2018, four N treatments including CK (0 g N m−2·a−1), low N (LN, 5 g N m−2·a−1), medium N (MN, 15 g N m−2·a−1) and high N (HN, 30 g N m−2·a−1) were set to determine the activities of invertase, amylase, urease, asparaginase, acid phosphatase, protease, catalase and polyphenol oxidase in different soil layers (0~5 cm, 5~10 cm and 10~20 cm) of the four forest areas at different N levels. Result The results showed that the effect of soil depth on the activity of the eight soil enzyme in these forests was lower in 10~20 cm soil than in 5~10 cm soil, with a maximum decrease of 76.8%. The activities of catalase in evergreen broadleaved forest and P. yunnanensis forest and polyphenol oxidase in Q. semecarpifolia forest and P. yunnanensis forest were inhibited in 0~5 cm soil layer, and the lowest activity was only 15.4% of that in the soil layer of 5~10 cm. The N level had a significant effect on soil enzyme activity. LN significantly inhibited the activity of invertase and amylase in Q. semecarpifolia forest. N treatment had no significant effect on urease and protease activity. LN treatment significantly increased the activity of asparaginase and acid phosphatase in soil layer 0~10 cm except evergreen broadleaved forest. The N treatment inhibited the soil catalase activity in P. armandii forest and the soil polyphenol oxidase activity in each forest, and promoted the soil catalase activity in Q. semecarpifolia forest and P. yunnanensis forest. Forest type had significant effects on soil invertase, amylase, urease, asparaginase, acid phosphatase, protease, catalase and polyphenol oxidase (P < 0.01). Conclusion Forest type and soil depth are important factors affecting the differentiation of soil invertase, amylase, urease, asparaginase, acid phosphatase, protease and catalase activity under N sedimentation. Soil polyphenol oxidase activity is sensitive to N sedimentation but not to forest type. Among the eight soil enzymes, asparaginase is the most sensitive to the interaction among soil depths, N application level and forest type.
Mark Second-order Characteristics of Broadleaved Korean Pine Forest
CHEN Ming-hui, ZHAO Zhong-hua, HUI Gang-ying, SONG Zi-long, WU Xiang-ju
2021, 34(2): 63-71. doi: 10.13275/j.cnki.lykxyj.2021.02.007
Abstract:
Objective To analyze the second-order characteristics of broadleaved Korean pine (Pinus koraiensis) forest in order to provide references for their protection, restoration and structural optimization. Method Taking four types of broadleaved Korean pine forests in Jiaohe of Jilin Province as examples, the single variable double correlation function and second-order characteristic functions of mark double correlation function, mark variation function, mark differentiation, mark mingling were used to analyze the tree species and size differentiation characteristics. Result The distribution patterns of these broadleaved Korean pine forests were significantly different. The distribution patterns of Juglans mandshurica-Abies holophylla-Pinus koraiensis forest (plot A), Fraxinus koraiensis-Pinus koraiensis forest (plot C) and Juglans mandshurica-Acer koraiensis-Pinus koraiensis forest (plot D) showed a significant cluster distribution on a certain scale, while those of Juglans mandshurica- Fraxinus koraiensis-Pinus koraiensis forest (plot B) followed the random distribution. Within the range of r, the DBH of tree mark tended to be smaller than the average DBH and the spatial autocorrelation was positive, especially in the scale of r = 0~8 m and r = 13~33 m. The mark DBH of plot B and plot D showed significant aggregation characteristics of similar size trees on the scale of r = 4~6 m and r = 0~12 m, respectively, while the plot C showed different sizes trees aggregation distribution on the scale of r = 0~5 m. The tree species distribution of the four types of broadleaved Korean pine forests belonged to completely random distribution, but there was the phenomenon of the same species aggregation on a certain scale. The scale ranges of the same species aggregation of plot A, plot B, plot C and plot D were r = 0~10 m, r = 0~25 m, r = 0~12 m and r = 0~8 m respectively. Conclusion The mark second-order characteristics of different types of broadleaved Korean pine forests showed significant difference, which is related to different development stages and degree of broadleaved Korean pine forest. The mark second-order characteristics further refine the differentiation characteristics of tree species and tree size on different scales, which has certain significance for broadleaved Korean pine forest management.
Dynamic Characteristics of Stand Density Measure of Chinese Fir (Cunninghamia lanceolata) Plantations with Different Improved Varieties and Initial Planting Densities
LI Xiao-yan, DUAN Ai-guo, ZHANG Jian-guo, ZHAO Shi-rong, FENG Sui-qi
2021, 34(2): 72-80. doi: 10.13275/j.cnki.lykxyj.2021.02.008
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Objective To study the dynamic characteristics of stand density measures of Cunninghamia lanceolata plantation at different improved varieties and initial planting densities in order to select the appropriate density index and provide a basis for density management of Cunninghamia lanceolata plantation. Method Based on 8-year positioning observation data of interactive test forest, the dynamic characteristics of three stand density measures, including crown competition factor (CCF), stand density index (SDI), ratio of dominant height to nutrient area (Z), with different improved varieties and initial planting densities and the linear regression analysis between the three stand density measures and initial planting density and stand age were analyzed. Result The law of dynamic changes of the three stand density measures were consistent with age with same improved variety and different initial planting densities, which increased with age. Under lower initial planting density, the slope of the fitting line of stand density measures was small, and became larger with the increase of initial planting density. The results showed that the higher the initial planting density, the stronger the competition intensity. Under same stand age, all the density measures increased with the initial planting density. There were quite significant differences among planting densities. Under the same initial planting density and different improved varieties, the improved varieties had no significant effect on the three stand density measures, and there was no interaction between the improved varieties and initial planting densities. Conclusion The three stand density measures can reflect density information to some extent. In the density ranging from 5000 to 6 667 trees·hm−2, the difference is not significant among initial planting densities in CCF and SDI, and it is difficult to reflect the difference between densities in this range. But the difference among densities reaches a significant level in Z in the whole density range. The Z can show the difference at different densities clearly, and has a larger applicable density, with no parameter and easy calculation. Therefore, it can be well applied to growth modeling and density management in Chinese fir plantation.
Diameter Growth Model Using Spatial Structure Parameters of Natural Larix gmelinii Stand in Daxing'anling Mountains, Northeast China
LYU Yuan-hang, YI Li-qi, WANG Ru-lin, LIU Zhao-gang, DONG Ling-bo
2021, 34(2): 81-91. doi: 10.13275/j.cnki.lykxyj.2021.02.009
Abstract:
Objective To study the effects of stand spatial structure on individual diameter growth of natural Larix gmelinii stand so as to provide reference and support for the effective recovery of secondary forests in the region. Method Based on 50 sample trees of L. gmelinii collected from the secondary forests in Pangu Forest Farm of Tahe Forestry Bureau, eight commonly used forest growth models were compared and evaluated using NLS function in S-Plus software, and the best basic model was determined. Then, the effects of commonly used stand factors, individual tree factors, species diversity, and stand spatial structure on the diameter growth were quantified using the parameterized method. Finally, the optimal mixed-effect model of growth for L. gmelinii trees were developed using NLME function, and the goodness-of-fit of different models were systematically evaluated. Result Mitscherlich equation was proved to be the optimal basic model of diameter growth for natural L. gmelinii stand, in which the coefficient of determination (Ra2) of the function was 0.6285. The parameter a highly related with the DBH of individual trees, and the mean tree height, the mingling and the uniform of the stand, while the parameter b mainly related with the mean DBH and the competition index of stand. The generalized diameter growth model could improve the value of Ra2 by about 31% (Ra2 = 0.8264) when comparing with the basic model. However, the technique of mixed-effect model could further improve the value of Ra2 by about 17% (Ra2 = 0.9710) when the random parameters (a1), heteroscedasticity function (varPower), and autocorrelation structure (corGaussian) were introduced. The results of 5-fold cross-validation showed that the coefficient of determination, average absolute error and root mean square of the estimated mixed-effect model were 0.9838, 0.56 cm and 0.72 cm respectively, indicating the outstanding prediction accuracy of the model. The simulation results showed that the amount of diameter growth increased significantly with the increase of the DBH of individual tree, the mingling and the uniform values (the closer to 0.5, the better), but decreased dramatically with the increases of the average DBH, the average tree height, and the Heygi's competition index. The corresponding amount of diameter growth would be: +0.45 cm, +3.62 cm, +4.71 cm, −0.34 cm, −0.21 cm and −0.73 cm, respectively, if the value of each variable increased by ten percent, however it highly depended on the stand characteristics and growth stages. Conclusion The levels of stand uniform and competition will affect the diameter growth of natural Larix gmelinii stand significantly, thus decreasing the competition levels of forest and creating (or maintaining) the random distributions and higher mingling degrees of the trees by appropriately cutting are highly recommended for the forest management in the near future.
Expansion and Expression Analysis of PtMAP65 Gene Family in Populus trichocarpa
XUE Li, LIU Xiao-xia, LUO Ying, LYU Zhong-rui, ZHANG Jian-guo, RAO Guo-dong
2021, 34(2): 92-101. doi: 10.13275/j.cnki.lykxyj.2021.02.010
Abstract:
Objective To study the expansion and expression of the MAP65 gene family members by using Populus trichocarpa, a model forest plant, as research material. Method Using BLASTP to identify the members of PtMAP65 gene family based on Phytozome database, and using tools such as Prot-Param, Plant-mPLoc, LocTree3, Wolfsort, MAGA7.0, GSDS, MEME, MCScanX, TBtools, BioEdit Sequence Alignment Editor, DnaSP5 and plantCARE to analyze the physical and chemical properties, predict subcellular locations, construct a phylogenetic tree, draw a gene structure diagram, analyze conserved domains, gene duplication events and promoter elements; and analyze the expression of PtMAP65 gene family members in different tissues based on gene chip data. Result Nine MAP65 genes were identified by BLASTP comparison. Phylogenetic analysis showed that the plant MAP65 gene family can be divided into 5 groups, and each group had a similar gene structure and conserved domain. The results of collinearity analysis and Ka and Ks analysis of the P. trichocarpa genome indicated that there were six pairs of segmental duplication genes in the PtMAP65 gene family, and the duplication genes were subject to strong purification selection in the evolutionary process. Analysis of the expression data showed that PtMAP65 gene family members had different expression patterns in different tissues, suggesting their functional divergence. Cis-acting element analysis of the promoter showed that PtMAP65s promoter had more light response and hormone response elements than stress response, growth and development elements. Conclusion Segmental duplication is a main force driving the evolution and expansion of PtMAP65 gene family, and it is speculated that there has been functional divergence among the PtMAP65 gene family members.
Analysis on Codon Bias of PmDXR Gene in Pinus massoniana Lamb.
ZHU Ling-zhi, ZHU Pei-huang, LI Rong, CHEN Yu, JI Kong shu
2021, 34(2): 102-113. doi: 10.13275/j.cnki.lykxyj.2021.02.011
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Objective To analyze the codon bias of PmDXR gene in Pinus massoniana in order to provide a theoretical basis for the subsequent functional verification and genetic transformation of PmDXR gene. Method The codon bias of DXR gene of P. massoniana and other 37 species was analyzed by CodonW, EMBOSS and SPSS online program. Neutral analysis, PR2-plot analysis and ENC-plot analysis were conducted to speculate the main factors for the formation of DXR gene codon bias. Then the codon frequency of the PmDXR gene of P. massoniana were compared with those of the 4 model organisms’ genome codon usage bias. Result The results showed that the codon bias level of PmDXR was low and biased toward the synonymous codons with A or T. The DXR codon bias analysis of different species showed that different species had different codon preference patterns, and gymnosperms DXR genes had stronger codon preference than angiosperm. The CDS sequences and RSCU cluster analysis showed that the preference of PmDXR gene was similar to other gymnosperms. Neutral analysis, PR2-plot analysis and ENC-plot analysis results indicated that the codon bias of DXR gene was mainly affected by natural selection. The codon usage frequency comparison and analysis showed that eukaryotic expression system of yeast was more suitable for heterologous expression of PmDXR gene in the selection of heterologous transforming receptors. The model plants Arabidopsis thaliana and Nicotiana tabacum can be used as genetic transformation receptors for PmDXR gene, but N. tabacum is the most ideal genetic transformation receptor. Conclusion This study initially revealed the codon preference of the PmDXR gene, the results provides an important guidance for the subsequent gene function verification, and also provides a scientific basis for the study of molecular evolution of P. massoniana.
Variation of Growth and Form-quality Traits of Cornus hongkongensis Family from Different Seed Sources
XIAO De-qing, SHEN Bin, LUO Qian-qian, XU Zhao-you, JIN Lin-fang, ZHOU Zhi-chun
2021, 34(2): 114-121. doi: 10.13275/j.cnki.lykxyj.2021.02.012
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Objective Young elite families of Cornus hongkongensis were tested, in order to reveal the genetic variation of the growth and form-quality traits of C. hongkongensis families from different seed sources, and provide a theoretical basis for the exploration and utilization of C. hongkongensis germplasm resources. Method 3-year-old C. hongkongensis elite families from different seed sources were used to study the genetic variation of growth and form-quality traits among the seed sources and the families from the same seed source. In addition, the correlation between traits was studied, the principal component analysis and cluster analysis were performed based on 9 traits. The experimental forest was established in 2016 at Longquan of Zhejiang Province. Result Significant differences were observed in traits of C. hongkongensis families among the seed sources and the families from the same seed source. Among them, the traits with the largest and smallest coefficient of variation were maxi-branch length (38.78%) and tree height (21.53%), respectively. The variation coefficient of growth traits range was between 21.53% and 26.66%, and the variation coefficient of growth traits was generally lower than that of form-quality traits. The variation of traits within the families from the same seed source (26.61%) was greater than the variation among seed sources (18.86%). The C. hongkongensis family with higher height, larger basal diameter and crown width had more branches and thicker branches. The more branches, the larger the branching angle and the smaller the crown width, the higher the straightness of the trunk. The 9 traits were integrated into 3 principal components, and their cumulative contribution rate could reach 82.636%. Tree height, maxi-branch length and stem straightness were the main distinguishing traits of growth and form-quality traits respectively. The 92 C. hongkongensis families tested were grouped into two categories. Type Ⅰ includes 56 families, which from 6 seed sources, i.e. Guangfeng of Jiangxi, Shangyou of Jiangxi, Longnan of Jiangxi, Datian of Fujian, Wuping of Fujian and Xingshan of Hubei. Type Ⅱ includes 36 families, which from 5 seed sources, i.e. Longquan of Zhejiang, Nanyue of Hu’nan, Yuanzhou of Jiangxi, Fenyi of Jiangxi and Yanping of Fujian. Conclusion There are significant variation of the traits of C. hongkongensis among the seed sources and families from same seed sources. Tree height, crown width and maxi-branch length, stem straightness, etc., are the major variation factors. Fast-growing families have the characteristics of more branches and thicker branches. The families tested are divided into two categories. The families included in Type Ⅰ are most from the seed sources in the southern geographically, with the main characteristics of tall form, compact plant-type, thick branches and fast-growing. The families included in Type Ⅱ are most from the seed sources in the northern geographically, with the main characteristics of spreading branches, high straightness of stem and slow-growing.
Endosphere Bacterial Diversity within Mixed Forest of Pinus densiflora Infected by Different Incidences of Sphaeropsis sapinea
XIE Xian, LIANG Jun, ZHU Yan-peng, SHI Liang, GAO Yan, ZHANG Ming, CHENG Yuan, ZHANG Xing-yao
2021, 34(2): 122-130. doi: 10.13275/j.cnki.lykxyj.2021.02.013
Abstract:
Objective To reveal the endosphere bacterial diversity and community structure of needle leaves of Pinus densiflora under different disease levels. Method High-throughput sequencing technology was used to sequence the v3-v4 region of the bacterial 16s rRNA gene, to determine the diversity and community structure of endophytic bacteria of P. densiflora under different disease levels. Result There were 388 587 effective bacterial sequences in needle leaves of coniferous-broadleaved mixed forests, totaling 679 OTUs, belonging to 28 phylum, 69 classes and 205 genera. There were 336 600 effective sequences of bacteria in needle leaves of coniferous mixed forests, totaling 656 OTUs, belonging to 29 phylum, 65 classes and 190 genera. In the coniferous-broadleaved mixed forests and coniferous mixed forests, the endophytic bacterial diversity of the asymptomatic needles of P. densiflora was higher than that of the infected needles. The predominant genera of endophytic bacteria in the asymptomatic needles were Massilia, Endobacter, Bryocella and Sphingomonas, and the relative abundance of Lactobacillus, Bryocella, Endobacter, Methylobacterium and Singulisphaera increased in infected needles, while Massilia and Sphingomonas decreased. The bacteria in coniferous needles with severe infection were distinguished from that in symptomatic coniferous needles and light infected needles. Conclusion The infection of S. sapinea affects the abundance of endophytic bacteria. The endophytic bacteria of the two type of mixed forests are consistent with the trend of the effects of S. sapinea, and the endophytic bacterial diversity in needles of P. densiflora is decreased gradually with the level of blight in the mixed forests.
Physiological Response of Five Varieties of Ornamental Phyllostachys praecox ‘Prevernalis’ to Low Temperature Stress
YANG Zhen-ya, ZHAO Jian-cheng, YUAN Jin-ling, WANG Bo, LI Qin, ZHOU Ben-zhi
2021, 34(2): 131-140. doi: 10.13275/j.cnki.lykxyj.2021.02.014
Abstract:
Objective To observe the effects of cold stress on the physiology indicators of Phyllostachys praecox ‘Prevernalis’, in order to study the cold tolerance mechanism of five varieties of ornamental Ph. praecox ‘Prevernalis’ to cold stress. Method The relative conductivity, antioxidant enzyme activity (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)), soluble protein content, malondialdehyde content and proline content in leaves of Ph. praecox ‘Prevernalis’ treated at different temperatures (0, −5, −10, −15, −20, −25, and −30℃) for 24 hours were measured. The semi-lethal temperature (LT50) of the five varieties was obtained by fitting the Logistic equation, and the correlation between physiological parameters and temperature as well as the cold resistance of the five varieties were investigated by principal component analysis (PCA) and redundancy analysis (RDA). Results All the relative conductivity curves of the five varieties were similar to S curve. The LT50 of the five varieties showed an increasing order of Ph. praecox cv. Linanensis (−18.73℃) < Ph. praecox ‘Xiyewutouleizhu’ (−17.09℃) < Ph. praecox f. Notata (−16.98℃) < Ph. praecox f. Chrysoderma (−16.82℃) < Ph. praecox f. Viridisulcata (−14.57℃). The antioxidant enzyme activity, soluble protein content, MDA content and proline content of the five varieties increased and then decreased with the decrease of temperature. The component matrix of soluble protein content and proline content was higher in the principal component 1. The activity of SOD and POD was higher in the principal component 2. Conclusion The cold tolerance of the five varieties showed a decreasing order of Ph. praecox cv. Linanensis > Ph. praecox ‘Xiyewutouleizhu’ > Ph. praecox f. Chrysoderma > Ph. praecox f. Notata > Ph. praecox f. Viridisulcata. The osmotic regulatory substances (soluble protein and proline) and antioxidant enzyme (SOD and POD) play major roles in the cold tolerance of Ph. praecox ‘Prevernalis’.
Effects of Continuous Flooding Stress on Photosynthetic Characteristics and Physiological and Biochemical Characteristics of Pinus elliottii
GUO Yan, SHEN Ya-fei, CHENG Rui-mei, XIAO Wen-fa, YANG Shao, WANG Li-jun
2021, 34(2): 141-148. doi: 10.13275/j.cnki.lykxyj.2021.02.015
Abstract:
Objective To study the effects of continuous flooding on leaf photosynthetic characteristics and physiological and biochemical characteristics of young plant. Method The Zigui section of the Three Gorges Reservoir riparian zone is affected by the water level operation of winter storage and summer discharge, forming a "drought-flooding-drought" water level fluctuation model, which makes the ecological environment of the riparian zone facing severe challenges. In this study, two-year-old Pinus elliottii seedlings were divided into six groups (including two control groups) with different initial drought and then flooding treatments and to study the effects of a simulated five-month winter flooding stress on photosynthetic characteristics and physiological and biochemical characteristics of seedling leaves after 45 days of drought stress. Result The results showed that with the increase of flooding time, the net photosynthetic rate of Group 1 (initially under mild drought stress and then root-flooded) and Group 2 (initially under mild drought stress and then full-flooded) showed a "decline-gentle" trend, but the net photosynthetic rate of Group 3 (initially under moderate drought stress and then root-flooded) and Group 4 (initially under moderate drought stress and then full-flooded) showed a downward trend. After 60 days, the net photosynthetic rate was lower than that of the former. After 150 days of flooding, the net photosynthetic rate of P. elliottii decreased by 30.9%, 33.0%, 51.9% and 62.3% respectively compared with the original values. Meanwhile, water flooding significantly reduced the stomatal conductance and transpiration rate. By comparing the relationship between Ci and Ls, it is concluded that the decrease of net photosynthetic rate of P. elliottii was mainly determined by stomatal factors in the early stage, and non-stomatal factors in the later stage. The content of soluble protein in root-flooded groups was mostly not significantly different from that in the control group during the flooding stage, while the content of soluble protein in leaves of P. elliottii in full-flooded group increased significantly at the early stage (60 days before flooding), but decreased gradually at the later stage. At 45 to 60 days of flooding, the activity of SOD in P. elliottii needles were significantly higher than those in the control group. The MDA content of P. elliottii leaves in different flooding conditions was not significantly different from that of the control groups within 30 days before flooding, but after 60 days of flooding, the MDA content of P. elliottii leaves increased significantly and gradually stabilized to a certain level. Conclusion These results can provide reference for the selection of suitable species and vegetation restoration and reconstruction in Three Gorges Reservoir riparian zone.
Stoichiometric Characteristics of Carbon, Nitrogen, Phosphorus and Potassium in Organs of Coniferous-broadleaved Mixed Forest in Northern Guangdong
ZHANG Tian-lin, QIU Zhi-jun, WU Zhong-min, CHEN Zhi-hong, HU Hui, ZHOU Guang-yi, ZHAO Hou-ben, LI Zhao-jia, CAI Zhang-lin
2021, 34(2): 149-157. doi: 10.13275/j.cnki.lykxyj.2021.02.016
Abstract:
Objective To fully understand the ecological stoichiometry of carbon (C), nitrogen (N), phosphorus (P), and potassium (K), in different organs of mixed forest in northern Guangdong and to reveal the nutrient balance mechanism and environmental adaptation mechanism of different organs of trees in the mixed forest in the southern subtropical in northern Guangdong. Method Five tree species, i.e. Schima superba, Choerospondias axillaris, Castanopsis carlesii, Cunninghamia lanceolata and Pinus massoniana in Xiaoliukeng-Qingzhangshan provincial nature reserve in Nanxiong County of Guangdong Province, were used as the trial materials to compare the distribution patterns and ecological stoichiometry characteristics of these species, and the correlation between the contents of these elements and the stoichiometric ratio of different organs. Result The results demonstrated that the contents of the four elements were the highest in leaf, the lowest in stem, and the medium in root and branch. The C:N, C:P and C:K showed the highest in stem, the lowest in leaf, and the medium in root and branch. The average C, N, P and K contents in leaf of the five tree species were 512.04, 14.29, 0.74 and 10.30 mg·g−1, respectively. The contents of N, P and K in leaf were significantly different from those in other organs (P < 0.05). Correlation analysis showed that trees had a complex internal coordination mechanism. Conclusion The content of C in each organ of coniferous-broadleaved mixed forest in northern Guangdong is relatively high, but the contents of N, P and K are scarce, and the growth of trees is mainly restricted by phosphorus. Castanopsis carlesii, Choerospondias axillaris, and Cunninghamia lanceolata have higher utilization ability of P element, and Choerospondias axillaris has a better nutrient distribution pattern, which is conducive to maintaining the dominant position in the competition.
Study on Spatial Distribution Dynamic Characteristics of Soil Seed Bank of Pinus densata Forest in Gongbu Nature Reserve, Tibet
GAO Tan, LI Zhao-qing, LU Jie, LI Jiang-rong, ZHENG Wei-lie
2021, 34(2): 158-165. doi: 10.13275/j.cnki.lykxyj.2021.02.017
Abstract:
Objective To understand the present situation of the soil seed bank of a Pinus densata forest for the purpose of protecting and managing the P. densata forest. Method In this study, the P. densata forests in different locations of Gongbu Nature Reserve were used as research objects. The spatial distribution pattern of P. densata soil seed bank was systematically studied by combining field survey sampling and laboratory test analysis. Result (1) In term of seed density of P. densata soil seed bank, no significant defference was found in different periods in the four directions of east, south, west and north (P > 0.05). However, with the sampling time, the seed density of P. densata soil seed bank in Dongjiu sample plot showed a decreasing trend, while with the sampling time, the seed density of P. densata soil seed bank Nyingchi sample plot and the Birity Mountain sample plot increased at initial and then decreased. (2) With the increase of the horizontal distance from the parent tree, the seed density gradually becomed smaller, i.e., 1 m > 3 m > 5 m, showing a distinct distribution trend of the near mother tree. The seed bank density of P. densata soil in different periods showed the Birity Mountain > the Nyingchi > the Dongjiu. (3) With the increase of soil depth, the amount of seed gradually decreased, and amng the total amount of seeds, above 89% was distributed in the litter layer and 0-2 cm soil layer. (4) In general, the seed density of the soil seed bank of P. densata forests increased with the elevation. However, as far as the Dongjiu and the Nyingchi sample plots were concerned, it followed a pattern of half-mountain < top and foot of the mountain, showing a "V" shape. (5) Most of the infesting seeds was found in the soil seed bank, accounting for more than 35% of the total seed. With the sampling time last, the amount of mouldy seeds increased gradually, the proportion of intact seeds decreased, and the amount of viable seeds was very few, which accounted for only 1.43% of the total seed, and 73.38% of the viable seeds ware stored in the litter. Conclusion There is no significant difference in the distribution of P. densata soil seed bank in different orientations at different times, but there are obvious distributions at different distances from the parent tree and different soil depths, which are mainly formed by the joint influence of the characteristics of the seeds and the external wind. With the sampling time changes, the amount of mouldy seeds increases, relating mainly to the high humidity and rainy climate in Gongbu Nature Reserve.
Community Composition and Stand Spatial Structure of Liriodendron chinense Natural Forest
XUE Wei-xing, GUO Qiu-ju, AI Xun-ru, YAO Lan, ZHU Jiang, HUANG Yang-xiang, LI Wei-yi, LUO Xi, LIU Yi
2021, 34(2): 166-173. doi: 10.13275/j.cnki.lykxyj.2021.02.018
Abstract:
Objective Taking Liriodendron chinense natural forest in Hefeng county, Enshi Tujia and Miao Autonomous Prefecture, Hubei Province as the research object, to analyze the species composition and stand space structure were analyzed, and describe the forest structure characteristics of L. chinense. Method Forty L. chinense plots of 20 m × 20 m were established in two typical distribution areas, respectively, each tree in the plots was positioned and measured. The Winkelmass software and R 3.5.1 were used to calculate the uniform angle index (W), dominance (U), mingling (M) and crowding degree (C) for trees with DBH ≥ 5 cm, the distribution of univariate distribution, the bivariate distribution and quadrivariate distribution characteristics were presented and analyzed. Result There were a total of 251 species in the L. chinense community, including 88 species of trees, 61 species of shrubs, 77 species of herbs and 25 species of woody lianas, belonging to 172 genera of 76 families. L. chinense population was the dominant population in the community, but the dominance was not obvious. The uniform angle index of the L. chinense natural forest was 0.566, and the overall distribution was slightly aggregated. The tree growth was in a neutral state (U = 0.508), the tree species were in a highly mixed state (M = 0.742), the stand density was high, and the mean crowding degree was 0.865. The uniform angle index had a certain influence on the dominance, mingling and crowding degree, and the mixing state and stand density were mutually promoting. Conclusion The species of L. chinense natural forest in the study area are highly mixed and estimated during the middle and late stage of natural forest succession. The competition relationships between individual trees should be adjusted in the process of forest management, in order to maintain the stability and sustainable development of the forest structure. It is necessary to reduce the phenomenon of the aggregation of same species, to selectively remove individual trees at absolute disadvantage and weak mixed degree, so as to improve the forest environment, and promote natural regeneration.
Scietific Notes
Phenotypic Variation Analysis of Quercus acutissima Natural Population Seeds
LYU Feng, XIE Xiao-man, HAN Biao, QIAO Jie, DONG Xin, WU Dan, LU Lu, LI Wen-qing
2021, 34(2): 174-179. doi: 10.13275/j.cnki.lykxyj.2021.02.019
Abstract:
Objective To reveal the variation and regularity of Quercus acutissima seeds and provide references for the conservation and genetic improvement of Q. acutissima germplasm resources. Method Variance analysis, cluster analysis and correlation analysis were used to analyze and compare the phenotypic traits of Q. acutissima seeds from seven natural populations. Result Significant differences were found in the length, width, aspect ratio, surface area, volume and thousand-grain quality of Q. acutissima seeds among and within groups. The coefficient of variation of each trait ranged from 10.34% to 28.18%, and the average phenotypic differentiation coefficient was 78.84%, indicating that inter-population variation is the main source of variation. The phenotypic traits showed extremely significant correlations; using hierarchical clustering. The seven groups could be divided into two groups. Conclusion There are abundant phenotypic variations in Q. acutissima seeds among and within these populations, and the result of cluster analysis showed no obvious correlation with the geographical distribution of each population. This study can provide a theoretical basis for the protection and utilization of diversified Q. acutissima germplasm resources.
Sensilla Ultrastructure of Antennae and Mouthparts of the First Instar Larvae of Dastarcus helophoroides (Coleoptera: Bothrideridae)
HAN Xiao, DUAN Yan-li, LI Xiu-fen, WANG Zhi-yong, ZHANG Yi-nan, QIAO Lu-qin
2021, 34(2): 180-184. doi: 10.13275/j.cnki.lykxyj.2021.02.020
Abstract:
Objective To determine the type, distribution and quantity of sensilla on antennae and mouthparts of the first instar larvae of Dastarcus helophoroides. Method The first instar larvae of D. helophoroides were selected within 12 h of hatching. After pretreatment, field emission scanning electron microscopy (FESEM) was used to observe sensilla. Result The head of the first instar larvae of D. helophoroides consisted of a pair of antenna, a pair of mandible, a pair of maxilla and a pair of labium. The antennae are filamentous, consisting of scape, pedicel and flagellum. A Bohm’s bristle was distributed on the scape, one sensilla pit basiconica, one sensilla basiconica Ⅰ and three sensilla basiconica Ⅱ were distributed on the pedicel. None of the sensilla was distributed on the flagellum. The mouthparts were prognathous and chewing-lapping type, there were one sensilla trichodea and one Bohm’s bristle on the mandible. The labium had nine digitiform sensilla and the maxilla has six digitiform sensilla. Conclusion Antenna and mouthpart of the first instar larvae of D. helophoroides have five types of sensilla, a total of 23, including physical sensilla and chemical sensilla. The digitiformsensilla are distributed in clusters, the other sensilla shows a scattered distribution.
Primary Study on Causes and Associated Pathogens for Chestnut Leaf Scorch
REN Fei, DONG Wei, SHI Sheng-qing, WANG Hui-hua, DOU Gui-ming, YAN Dong-Hui
2021, 34(2): 185-192. doi: 10.13275/j.cnki.lykxyj.2021.02.021
Abstract:
Objective To investigate and analyze leaf scorch of Castanea mollissima occurred in the main chestnut producing areas in Hebei Province. Method Combined the investigation of the symptoms in the forest, the isolation of microbes from the symptomatic leaf tissue, the confirmation of Koch's law in vitro leaves and potted seedlings, with the management measures of orchard and the environmental factors, the causes of disease were analyzed and discussed. Result The disease rate of orchard trees was 20%–50%, the disease rate of individual tree leaves can be up to 100%, the main symptom of individual leaf was dry leaf margin and interveinal tissue. No pathogen was found in the forest symptomatic tissues and microscopic examination. A total of 102 strains were isolated and purified from symptomatic tissues, all of which were fungi, belonging to 10 families, 12 genera and 15 species with Alternaria alternata as the most abundant. The inoculation test showed that Ophiognomonia setacea and Coniothyrium pyrinum could induce the browning of leaf tissue of Chinese chestnut. However, the symptom was significantly different from that of chestnut forest leaf scorch. Conclusion Two pathogens, O. setacea and Coniothyrium Pyrinum, were newly found and verified to be pathogenic to Chinese chestnut leaves, causing chestnut tree leaf spots, which were different with the leaf scorch symptoms in chestnut observed. Currently, leaf scorches in trees are ordinarily connected with environmental and physical factors which influenced tree growth with global warming, extreme weather, pollution, inadequate silviculture and control pests/diseases managements. Therefore, integrating non-infection to investigate causes of the leaf scorch of Castanea mollissima occurred in Hebei Province is strongly proposed in order to effectively prevent and control the disease as soon as possible.