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2021, 34(5): -1--1.
2021, 34(5): 0-0.
Response of Stem Radial Growth of Eucalyptus urophylla × E. grandis to Planting Density Based on Transcriptome Analysis
CHEN Mo, HE Sha-e, CHEN Shao-xiong, OUYANG Lin-nan, ZHANG Cheng, ZHANG Wei-yao
2021, 34(5): 1-12. doi: 10.13275/j.cnki.lykxyj.2021.005.001
Objective To identify the key genes of secondary xylem development response to planting density for a well understanding of molecular mechanism of planting density affecting radial growth of eucalypts. Method By a combination of PacBio Iso-Seq and RNA-Seq analysis, the differentially expressed transcriptomes of xylem cells in Eucalyptus urophylla × E. grandis were identified under high and low planting densities. The tissues expression profiles of these key genes were analyzed via qRT-PCR. Result A total of 45 490 non-redundant full-length transcripts and 443 transcripts differentially expressed in xylem cells were obtained under high and low planting densities, and 60 transcripts encoding regulatory factors were obtained. Under low planting density, the diameters of trees increased significantly. The PXL2 and its interactional genes CUL1, T15D22.7 related to cell division, the MYB46, C3H14 with their downstream genes CesAs and LACs related to secondary wall regulation were preferentially expressed in the xylem cells. These genes might play key roles in the regulation of diameter growth under different densities. In addition, the NAC86 homologous genes involved in sieve element development and the inhibitor PTL homologous genes with dual functions in cambial cell proliferation and xylem differentiation were also up-regulated. They could promote the xylem development, which were different from the functions in herbaceous plants. The results of tissue expression analysis showed that PXL2, CUL1, T15D22.7, NAC86 and PTL were predominantly expressed in phloem and xylem, whereas MYB46, C3H14, CesA and LAC17 were predominantly expressed in xylem. Conclusion In this study, the candidate genes of xylem development related to planting density are identified and a model of molecular regulatory network that how the planting density affects radial growth of E. urophylla × E. grandis is proposed, which will benefit the intensive study of the molecular mechanism under different planting densities affecting radial growth for trees.
Variation in Fruit Traits of Eucommia ulmoides Germplasm Resources and Their Comprehensive Evaluation
DU Qing-xin, QING Jun, LIU Pan-feng, WANG Lu, DU Lan-ying, HE Feng, DU Hong-yan
2021, 34(5): 13-23. doi: 10.13275/j.cnki.lykxyj.2021.005.002
Objective To provide theoretical basis and genetic materials for breeding and utilization of Eucommia ulmoides. Method Based on 331 E. ulmoides germplasm resources from 18 provinces of China, correlation analysis, cluster analysis and principal component analysis were conducted for evaluating and selecting superior germplasms with 19 fruit traits. Result The coefficient of variation of fruit traits was 4.64%-25.79% and the average coefficient of variation was 12.65%. Large variations were found in 100-fruit pericarp wrapping seed kernel weight (25.79%), 100-seed kernel weight (22.32%) and seed volume index (19.53%), while the linolenic acid (4.64%), oleic acid (5.78%) and fruit type index (8.04%) kept relatively stable. The diversity index ranged from 1.6572 to 2.0947, with an average of 2.0234. The 100-fruit weight showed a significant positive correlation with fruit volume index and 100-seed kernel weight, E. ulmoides rubber content significantly and positively correlated to 100-fruit pericarp wrapping seed kernel weight and fruit lateral diameter, while significantly and negatively correlated with crude fat content. Cluster analysis divided the germplasm resources into three groups: small (Ⅰ), medium (Ⅱ), and large (Ⅲ), different types of germplasms were preliminarily defined. Based on principal component analysis, the cumulative contribution rate of the first seven principal components were accounted for 85.169%, ten superior germplasms were selected for evaluation of oil, rubber and comprehensive utilization. Conclusion E. ulmoides germplasm shows high variation. The yield index has the largest variation, represented by 100-fruit pericarp wrapping seed kernel weight and 100-seed kernel weight, which provides possibility for the selection of superior germplasms. The optimal germplasms selected for different purpose provides an excellent germplasm basis for the breeding and comprehensive utilization of E. ulmoides.
Seed Dispersal Pattern and Progeny Genetic Diversity of Casuarina equisetifolia
LI Zhen, ZHANG Yong, WEI Yong-cheng, MENG Jing-xiang, ZHONG Chong-lu
2021, 34(5): 24-31. doi: 10.13275/j.cnki.lykxyj.2021.005.003
Objective To reveal the seed dispersal pattern and compare the genetic diversity differences among natural regeneration population (progeny population), maternal population and seedling plantation population of Casuarina equisetifolia, and to provide reference data for artificially promoting natural regeneration of C. equisetifolia seedling plantation. Method Paternity analysis software Cervus 3.0 was used to determine the maternal parents of individuals in regeneration population, and to compare the genetic diversity of the three kinds of C. equisetifolia populations based on genotype data of progeny and candidate maternal parents obtained from 11 polymorphic SSR loci. Result (1) Totally 137 alleles (Na) were detected from 367 individual samples of maternal and progeny populations using 11 SSR markers, and the number of alleles per SSR locus varied from 6 to 24, with an average effective alleles (Ne) number of 4.95. The average expected heterozygosity (He), observed heterozygosity (Ho) and polymorphism information (PIC) were 0.75, 0.77 and 0.72 respectively. All the loci were categorized as moderate-high polymorphic loci. (2) At 80% confidence interval, the female parents of 148 progeny which accounted for 72.20% of the total progeny number were identified using genotype data obtained from 11 SSR markers. The seed effective dispersal distance of C. equisetifolia ranged from 10 m to130 m, with the mean dispersal distance of 71 m, which belongs to short-distance dispersal. The female parents were mainly concentrated in the northeast and east of the sampling plots, and their contribution to progeny reached up to 75.00%. (3) For the purpose of determining an even sample number, the genotype data of 84 individual samples were extracted respectively from the three populations for genetic diversity comparison. The results showed that the natural regeneration population presented slightly lower genetic diversity than the other two populations, but it still possessed relatively high genetic diversity based on its genetic parameters. Conclusion The seed dispersal of C. equisetifolia is of a short-distance dispersal, and the natural regeneration population can also maintain a high genetic diversity, which provides reference data for artificially promoting the natural regeneration of the seedling plantation of C. equisetifolia in coastal shelterbelts of Southern China.
Variation of Growth Dominance in Thinned Chinese Fir Stands with Different Planting Densities
WANG Han-chen, ZHANG Xiong-qing, ZHANG Jian-guo, QU Yan-cheng, JIANG Li
2021, 34(5): 32-38. doi: 10.13275/j.cnki.lykxyj.2021.005.004
Objective The thinned Chinese fir (Cunninghamia lanceolata) stands with different planting densities were used to explore the variation of growth dominance under different thinning treatments, so as to provide management strategies for cultivation and management of Chinese fir. Method The data for this study were sampled from Chinese fir plantation in Nianzhu Forest Farm, Fenxi city, Jiangxi Province. The linear mixed effect model was used to illustrate the growth dominance in relation to age, accumulated thinning intensity, living number of trees per hectare and the interaction of these variables. Result The growth dominance increased with accumulated thinning intensity, age, and living number of trees per hectare before or after the thinning. The negative value of growth dominance was not observed during the last observation. When the stands had the same living number of trees per hectare, the growth dominance increased with accumulated thinning intensity. Conclusion The sparse planting density and sparse density management make the growth dominance closer to the value 0, which is beneficial for balanced growth of all sized trees, and increasing the yield of larger trees. The dense planting density and sparse density management can not only harvest smaller trees, but also increase the growth dominance and promote the growth of larger trees with the increase of accumulated thinning intensity, as a result of harvesting the large size trees.
Identification of NLP Transcription Factors of Phyllostachys edulis and Their Expression Patterns in Response to Nitrogen
YUAN Ting-ting, ZHU Cheng-lei, LI Zi-yang, SONG Xin-zhang, GAO Zhi-min
2021, 34(5): 39-48. doi: 10.13275/j.cnki.lykxyj.2021.005.005
Objective To identify the NLP family members in moso bamboo (Phyllostachys edulis) and lay a foundation for further study on the molecular regulation mechanism of these NLPs. Method The molecular characteristics of the NLP members in moso bamboo were identified and analyzed comprehensively by bioinformatics methods, and the expression patterns of the NLPs in response to nitrogen were detected by quantitative real-time PCR (qPCR). Result Ten NLP members (PeNLP1~PeNLP10) were identified from moso bamboo. The length of PeNLPs ranged from 714 aa to 963 aa, with the molecular weight of 77.41~105.08 kDa, and the theoretical isoelectric point ranged from 5.36 to 6.25. The prediction of subcellular localization showed that all PeNLPs were located in the nucleus except PeNLP9 in the chloroplast. Phylogenetic analysis showed that PeNLPs could be divided into 3 groups with 4, 2 and 4 members, respectively. All PeNLPs contained 4 introns, and there were some differences in the size and position of introns among different members. There were 6 collinear gene pairs in PeNLPs and 9 collinear gene pairs between PeNLPs and OsNLPs, and their Ka/Ks were all less than 1.0, indicating that they had undergone purification selection in evolution. Tissue specific analysis showed that some PeNLPs expressed in tissue-specific manner, while some PeNLPs expressed constitutively. The expression of PeNLPs was induced by nitrogen starvation, and that of PeNLP1 was significantly up-regulated within 1 hour, while those of other 5 PeNLPs were significantly down-regulated (p < 0.01). After 72 hours of nitrogen starvation, the seedlings were resupplied with nitrogen, and the expression levels of all PeNLPs were significantly up-regulated (p < 0.05 or p < 0.01) within 24 hours. Conclusion There are 10 members of NLP family identified in moso bamboo. There are some differences in molecular characteristics and tissue expression specificity of each member. The expression of PeNLPs can respond to nitrogen starvation rapidly, and it is significantly up-regulated in the process of nitrogen resupply after nitrogen starvation.
Comparative Study on Wood Characteristics of Cunninghamia lanceolata from Different Provenances
YAN Yao, LI Bing-jun, HE Zong-ming, LIU Yu-hui, LI Ming, YU Xin-tuo, MA Xiang-qing
2021, 34(5): 49-57. doi: 10.13275/j.cnki.lykxyj.2021.005.006
Objective The study aims at comparing the differences of wood characteristics of Chinese fir (Cunninghamia lanceolata) plantations from different provenances and analyzing their geographical variation regularity, so as to screen the better Chinese fir provenance. Method The first provenance test plantation of Chinese fir planted in 1958 was selected as the research object. Through investigating the growth of Chinese fir from different provenances, the intermediate trees were determined. The wood density, tracheid morphology, dry shrinkage, wet swelling, shear strength parallel to grain, compression strength parallel to grain, bending modulus of elasticity, bending capacity, impact property and hardness were determined and compared. The wood properties were evaluated by cluster analysis and principal component analysis. Result Significant differences were found in wood characteristics among nine provenances of Chinese fir (P < 0.05). The dry shrinkage and wet swelling of wood increased with latitude, but there was no significant geographical variation regularity in other wood characteristics. The wood density of Anhui Xiuning provenance was significantly higher than that of other provenances (P < 0.05). The rank order of the tracheid length-width ratio is as follows: Guangdong Yu'nan provenance > Zhejiang Jinhua provenance > Fujian Nanping provenance > Sichuan Pengxian provenance > Sichuan Lushan provenance > Hubei Zhuxi provenance > Hunan Huitong provenance > Anhui Xiuning provenance > Guizhou Jianhe provenance. The ratio of tangential to radial shrinkage of Anhui Xiuning provenance and volume shrinkage coefficients of Guizhou Jianhe provenance were the lowest. The bending modulus of elasticity and bending capacity of Fujian Nanping provenance were the highest. The impact property and shear strength parallel to grain of Anhui Xiuning provenance were the highest. The compression strength parallel to the grain of Guangdong Yu'nan provenance was the highest, while the hardness of wood from Sichuan Lushan provenance was higher than that of other provenances. A significant correlation between wood characteristics index and wood density was significantly correlated with some wood characteristics index. According to the difference of wood properties of different provenances, nine provenances of Chinese fir were clustered into three categories: category I included Fujian Nanping provenance, Guangdong Yu'nan provenance, Sichuan Lushan provenance and Anhui Xiuning provenance, category II included Sichuan Pengxian provenance, Zhejiang Jinhua provenance, Hubei Zhuxi provenance and Hunan Huitong provenance, category III included the Guizhou Jianhe provenance. Using comprehensive analysis, the rank order for wood properties of the nine provenances is as follows: Anhui Xiuning provenance > Sichuan Lushan provenance > Fujian Nanping provenance > Guangdong Yu'nan provenance > Sichuan Pengxian provenance > Zhejiang Jinhua provenance > Hubei Zhuxi > Hunan Huitong provenance > Guizhou Jianhe provenance. Conclusion Geographical provenance has an essential influence on wood properties of Chinese fir to a certain extent.
Effects of Valsa sordida Infection on Photosynthetic Characteristics and Carbon-Water Metabolism in Populus alba var. pyramidalis
LI Jin-xin, ZHANG Yi-nan, MIAO Rui-fen, XING Jun-chao, LI Min, SHEN Wan-na, WANG Li, ZHAO Jia-ping
2021, 34(5): 58-68. doi: 10.13275/j.cnki.lykxyj.2021.005.007
Objective The photosynthetic response and water metabolism characteristics of P. alba var. pyramidalis leaves were studied, and the correlation between photosynthesis and water metabolism of poplar under pathogen infection was discussed in this study, so as to provide theoretical and experimental basis for the occurrence and control of the poplar Valsa canker disease. Method Using a girdling-inoculation system, we evaluated gas-exchange and chlorophyll fluorescence characteristics, concentrations of non-structural carbohydrates in root and midday water potential of one-year poplar saplings with Valsa canker disease, and analyzed the relationship between transpiration rate, midday water potential and stomatal conductance, vapor pressure deficit. Result Compared with girdle control, Valsa canker significantly reduced the net photosynthetic rate (62.45% to 91.05%), stomatal conductance (64.19% to 87.43%), the maximum photochemical efficiency (19.13% to 42.79%), actual photochemical efficiency (4.04% to 69.93%) and electron transport rate (52.58% to 68.03%); also decreased the maximum net photosynthetic rate (76.94%), light saturation point (40.40%) and apparent quantum efficiency (46.09%), and increased dark respiration rate (82.14%) and light compensation point (242.42%). Valsa canker infection significantly decreased soluble sugar (35.06% to 44.50%, 20-30 day) and starch content (35.77% to 58.39%, 10-30 day) in roots. The fungi inhibited leaf transpiration rate (57.36% to 80.49%), water use efficiency (24.92% to 70.55%), and increased water vapor pressure deficit (13.59% to 33.65%) and midday water potential (39.74%, 20 day). The results of correlation analysis showed that transpiration rate was positively correlated with stomatal conductance and negatively correlated with water vapor pressure deficit, and there was no linear relationship between midday water potential and stomatal conductance and water vapor pressure deficit. Stomatal closure caused by Valsa canker infection was not related to leaf water status. Conclusion The main reasons for the decrease of net photosynthetic rate of poplar leaves were that leaf light energy conversion, photosynthetic electron transport and light energy utilization were hindered. Valsa infection did not cause water stress, even had some improvement. And had an important effect on the carbon accumulation of host roots, leading to the content of non-structural carbohydrates in roots was always at the initial level of infection.
Method and Application of Forest Fire Risk Assessment on Forest Stand Scale
ZONG Xue-zheng, TIAN Xiao-rui, LIU Chang
2021, 34(5): 69-78. doi: 10.13275/j.cnki.lykxyj.2021.005.008
Objective To study the forest fire risk assessment based on the burn probability, fire behavior, and potential fire impact. Method The Burn-P3 model was used to simulate the burn probability, potentialfire intensity, fire spread, and fire type in the Jiulongshan Forest Farm. The fire impact was calculated from ecology importance, vulnerability, and protection level of each forest stand. The exposure indicated the impacts of fire on urban and water resources. The forest fire risk assessment system on forest farm scale was established by using analytic hierarchy process (AHP). Result The results showed that the average burn probability was 0.0351 for the forest stand area, and the areas with high and very high burn probability accounted for 10.3% and 6.0%, respectively. The fire types are surface fire and intermitted crown fire. The average fire intensity and rate of spread were 2140.9 kW/m2 and 3.7 m/min, respectively. The areas with high and very high fire behavior index accounted for 17.8% and 14.0%, respectively. Conclusion The ecological value and potential fire impact of the forests are relative high and the fire risk assessment will be helpful to enhance the fire management. The fire risk assessment shows that the areas with high and very high fire danger rating account for 31.8%. The deciduous coniferous forest and mixed forest in west, north, and south parts of the farm show the higher fire risk, fire management activities should be strengthened for the purpose of risk mitigation.
Expression of SPL-like Gene LaSPL2 and LaSPL3 in Japanese Larch (Larix leptolepis) During Somatic Embryogenesis
FAN Yan-ru, LAN Qian, HAN Su-ying, QI Li-wang, ZHANG Li-feng
2021, 34(5): 79-87. doi: 10.13275/j.cnki.lykxyj.2021.005.009
Objective To reveal LaSPL2 and LaSPL3 function during somatic embryogenesis, based on their molecular characteristics and expression patterns. Method The full-length cDNA sequences of LaSPL2 and LaSPL3 were obtained by homologous cloning and RACE techniques. The amino acid sequences for known SPL family proteins were aligned using the ClustalX 2.1 software. The full-length protein sequence alignment was used to construct a phylogenetic tree according to the neighbor-joining method of the MEGAX program. Subcellular localization was performed by transient expression system of tobacco. The expression patterns of LaSPL2 and LaSPL3 during somatic embryogenesis were detected by qRT-PCR. Result In this study, two SPL homologous genes, LaSPL2 and LaSPL3, were isolated from Japanese larch, which encoded 532 amino acids and 191 amino acids respectively. Further analyses revealed that LaSPL2 and LaSPL3 mRNA were targeted by miR156. The deduced amino acid sequences of the LaSPL2 and LaSPL3 harbored a highly conserved SBP domain. A transient expression analysis of the LaSPLs-GFP fusion proteins in tobacco leaf epidermal cells revealed that the LaSPL2 and LaSPL3 proteins were localized in the nucleus. Moreover, the expression of LaSPL2 and LaSPL3 was down regulated by ABA during the early stage of somatic embryogenesis. With the further development of somatic embryos, the expression levels of LaSPL2 and LaSPL3 peaked at 10 and 14 days, respectively. Subsequently, with the maturation of somatic embryos, their transcription levels decreased gradually to the lowest level at 42 days. Conclusion The effects of ABA removal on the expression of LaSPL2 and LaSPL3 indicate that ABA might be the main factor in their down-regulation during the early stage of somatic embryogenesis. Furthermore, the expression of LaSPL2 and LaSPL3 will reach the peak at the early stage of somatic embryogenesis, implying it might encode an important regulator of early embryonic pattern formation. The sequence analysis and expression patterns of LaSPL2 and LaSPL3 indicated that they may be regulated by miR156 during somatic embryogenesis and play an important role in the maturation of somatic embryos.
Growth Difference and Early Evaluation and Selection of Young Picea abies Clones in Western Hubei
GAO Ben-wang, OUYANG Fang-qun, GAO Han, LI Wei, LEI Hua, TIAN Kai-chun, QI Song, WANG Jun-hui
2021, 34(5): 88-94. doi: 10.13275/j.cnki.lykxyj.2021.005.010
Objective To select and breed elite trees for local quality reforestation by evaluating the genetic architecture of growth and branch relevant traits from 378 9-year-old Picea abies clones. Method P. abies clones were established using a completely random block design. The genetic variation of height, diameter at breast height, crown width, stem increment of the current year, number of branch in the first round were analyzed to select elite clones using EXCEL and package lme4. Result The results showed that the clones and the interaction effects between clones and block significantly affected the height, diameter at breast height, crown width, stem increment, and branch of P. abies. The genetic and phenotypic variation coefficient were 10.02%~20.38% and 31.36% ~48.36%. The repeatablilty of height, diameter at breast height, crown width, stem increment, branch and volume were 0.59~0.71. The phenotypic correlation and genetic correlation coefficients of height, stem increment, diameter at breast height, and crown width were 0.72 to 0.95, which were all significantly correlated to each other. 30 elite clones were chosen by tree height genetic value with the selected ratio 7.94%. The genetic gain of the height were 26.38%. Conclusion The height, stem increment, diameter at breast height, branches, and crown width of 378 P. abies clones have significant variation among clones, and are affected by the interactive effect between clones and environment. The clones also have obvious interaction with site, indicating that the most suitable clones should be selected according to site when implementing clonal forestry. 30 elite clones with good growth performance are chosen by their genetic values of tree height which may be used in the promotion and application of P. abies asexual reproduction.
Simulation of Operation for Forest Management Based on Body Action Interaction
ZHU Nian-fu, ZHANG Huai-qing, CUI Zhe-yu, YANG Ting-dong, WANG Lin-long, LIU Hua
2021, 34(5): 95-103. doi: 10.13275/j.cnki.lykxyj.2021.005.011
Objective In view of the complex and diverse types of forest management operations, this paper aims at solving the problems of poor interactivity, lack of natural and realistic interactive experience, and the difficulties to deal with frequent operations, and developing a set of interactive methods of forest management measures based on body action. Method A forest simulation scene based on the immersive virtual reality and visual simulation system CAVE2 was constructed as the interactive object, the management measures with strong interaction on the user side such as logging, pruning and replanting were selected, the limb movements in the operation process of forest management measures were analyzed, and the relative distance and angle changes between the management tools and users in the simulation scene were mapped with the limb actions. The interaction model of body movement was constructed to realize the implementation of limb action control management measures and the simulation of forest management. Result The interactive model of body movement constructed in this study was correctly mapped into forest management measures. The success rate of single operation was 86%, and the good rate of interactive evaluation was 91%. The combination of body movement and management tools facilitates the expansion of interactive demand of forest management simulation. Conclusion The simulation of forest management operation based on body action interaction can visually and intuitively show the operation process of forest management measures, which is helpful for the user's to further understand the forest management and improve the level of forest management assistant decision.
Effects of Stand Structure on Natural Regeneration of Quercus mongolica Forest in Mountainous Area of Eastern Liaoning Province
DONG Li-li, LIU Hong-min, ZHAO Ji-chuan, GAO Ying-xu, WANG Cheng-cheng, FAN Jun-gang
2021, 34(5): 104-110. doi: 10.13275/j.cnki.lykxyj.2021.005.012
Objective The relationship between stand structure and undergrowth regeneration seedling was discussed to provide theoretical basis for artificial promotion of natural regeneration. Method Several Q. mongolica forests in mountainous area of eastern Liaoning province were taken as the research objects, the fitting model and Pearson correlation analysis were used, and the effect of stand spatial structure on natural regeneration of Q. mongolica was studied. Result (1) The forest stand base area had a significant effect on seedling density. With the increase of stand base area, the seedling density showed an increasing trend. When the base area reached 31 m2·hm−2, the increase of seedling density gradually slowed down. (2) There was a significant negative correlation between stand base area and seedling base diameter and seedling height (P < 0.05). (3) The relationship between stand competition index and density and seedling density was typical parabola. Compared with density, the effect of competition index on seedling density was more significant. (4) The spatial structure of stand had a significant effect on the species diversity of regenerated seedlings, the higher the degree of mixing, the more complex the vertical structure, and the higher the diversity of regeneration seedling species and Shannon-wiener. (5) Multivariate stepwise regression analysis showed that the main variables influencing the total regeneration density were stand basal area, crowding and competition index. Conclusion Adjusting stand basal area, crowding and competition index are the effective ways to promote the natural regeneration and improve the species diversity of Q. mongolica forest.
Fire Performance Evaluation of Ten Main Afforestation Species in Mountainous Areas Around Xining, Qinghai Province
LI Hai-jia, ZHENG Shu-xia, SHAN Xiao-xiao, MA Yu-lin, SONG Zheng, REN Fei
2021, 34(5): 111-118. doi: 10.13275/j.cnki.lykxyj.2021.005.013
Objective To study the physicochemical properties and combustion characteristics of common tree species in Qinghai, and to evaluate the fire resistance of local tree species, so as to provide references for the selection of fire-resistant tree species in Qinghai. Method The fire-resistance indexes of 10 tree species were divided into fire-resistance factor fa and combustion performance factor fb (including the extrinsic factor fb1 and the intrinsic factor fb2) by factor analysis. Through Pearson correlation analysis and partial correlation analysis, the relationship between the 9 physicochemical properties of the 10 tree species and the fire prevention factors was obtained. Finally, the fire-resistant performance of the 10 tree species was ranked by comprehensive analysis. Result (1) There was a significant negative correlation between fb2 and the moisture content of leaves, between the burning point of bark and branches, and between fa, fb2 and the calorific value of leaves. (2) The results of partial correlation analysis showed that the moisture content of leaves had a significant negative correlation with fb2, and the fb2 had a significant negative correlation with fa. (3) The ranking similarity of fire performance of tree species based on the comprehensive values of combustion test and fire performance was 64%. Conclusion The comprehensive fire-resistance evaluation model of the 10 tree species is established, and the order of fire-resistance is obtained based on different weight systems as Atriplex canescens > Armeniaca sibirica > Rosa xanthina> Caragana korshinskii > Syringa oblata Lindl. > Elaeagnus angustifolia > Hippophaerha mnoides > Amygdalus triloba > Sabina vulgaris > Picea crassifolia. The results are of practical application and popularization to the fire-resistance of tree species in Xining and its surrounding areas.
Study of Foliar Fertilizer-B Absorption and Distribution in Poplar Saplings Using 10B Tracer
FU Xiao-xia, PENG Jun-dong, LENG Jing, CAI Xue, XIONG Ling-jun, OU Yong-bin
2021, 34(5): 119-124. doi: 10.13275/j.cnki.lykxyj.2021.005.014
Objective The absorption, distribution and re-translocation of foliar boron fertilizer in poplar under different boron conditions were analyzed, in order to provide clues for the cultivation and management of poplar plantation. Method Populus alba var. pyramidalis Bunge saplings were sand cultured in greenhouse. Different concentrations of boric acid were added to the nutrient solution, and the lower mature leaves were fed with 10B-rich boric acid (H310BO3). The growth of poplar was recorded, and the boron content in different parts was determined. Result (1) Under sand culture condition with low boron concentration, the biomass and boron accumulation of plants decreased significantly, the boron concentration in upper leaves significantly decreased, and the proportion of boron allocated to young leaves significantly decreased also. (2) Application of foliar boron fertilizer (LB + F) could supplement the boron concentration in upper leaves, and reduce the changes of biomass and boron accumulation to a certain extent. Most of boron absorbed from foliar fertilizer was retained in the fertilized leaves, while 31.68%, 5.27% and 1.06% of absorbed foliar boron can be re-translocated to young leaves, roots, and stems. (3) In relative to normal boron concentration, application of foliar boron fertilizer (NB + F) could increase boron concentration in stem, but had no significant effect on boron concentration of roots and leaves and the biomass in different parts. Compared with LB + F, NB + F plant absorbed much less boron from foliar fertilizer, which was only 15.6% of the former. Conclusion Boron deficiency will result in a reduced boron allocation to young leaves in poplar, thus affects plant growth. The boron fertilizer absorbed by mature leaves could be re-translocated to other parts of the plant, especially the young leaves. The negative effect of rhizosphere boron deficiency on plant growth can be compensated by applying foliar boron fertilizer.
Interspecific Relationship of Primary Coastal Plant Communities in Pingtan Island
WANG Wei-yao, ZHENG Xin-xuan, WU Ya-hua, LI Yan-lin, GUAN Shi-min, NI Rong-wei, HUANG Liu-jing
2021, 34(5): 125-134. doi: 10.13275/j.cnki.lykxyj.2021.005.015
Objective To analyze the interspecific relationship of primary coastal plant communities in Pingtan Island and further understand the structural characteristics and coexistence mechanism of coastal plant communities. Method Based on community survey, the interspecific association and correlation analysis of dominant species (importance value ny) of plant community in four typical habitat types (bedrock shrub, hilly shrub, sandy meadow and bedrock grass) in Pingtan Island were carried out by the variance ratio method (VR), in Pingtan Island were carried out by the variance ratio method (lysis of dominant specie(CCA sorting), and the ecological species groups were divided. Result The coastal plant communities of the four habitats were significantly positively correlated (VR > 1, W > χ20.05(N)), and the community was relatively stable as a whole. The association and correlation between most species pairs were not significant (P > 0.05), and the interspecific independence was strong. Overall positive and negative association and correlation ratio was greater than 1, showing a positive association and positive correlation trend. Conclusion Spearman rank correlation coefficient test has higher significance rate of interspecific correlation and higher sensitivity than χpearman rank correlation coefficient test has higher significance racan be divided into 4 ecological species groups according to the results of R language CCA sorting and interspecific correlation analysis. These 4 groups correspond to 4 habitats. In the restoration and protection of native coastal vegetation in Pingtan Island, the interspecific relationship and environmental adaptability of species should be fully considered, and the appropriate ecological species groups should be selected for planting. In the bedrock habitat with high soil salinity, the ecological species group I: Peucedanum japonicum, Crepidiastrum lanceolatum, Vitex trifolia, etc. The ecological species group II is suitable for planting in the low mountains and hills with large soil volume, high altitude and high rock exposure rate: Eurya emarginata, Elaeagnus pungens, Ficus pumila, etc. On the coastline of sandy soil with low soil salinity and loose soil, ecological species group III is selected for planting: Oenothera drummondii, Calystegia soldanella, Glehnia littoralis, etc. In the soil with relatively high water content, ecological species IV is selected for planting: Berchemia sinica, Heteropappus ciliosus, Lycoris radiata, etc.
Cloning and Expression Pattern of Sensory Neuron Membrane Protein Genes of Tropidothorax elegans
SONG Yue-qin, BAI Xiao-jun, CHEN Qing-xiao, LÜ Qi-hui, Sun Hui-zhong
2021, 34(5): 135-141. doi: 10.13275/j.cnki.lykxyj.2021.005.016
Objective To study the sensory neuron membrane proteins (SNMPs) in Tropidothorax elegans. Method The SNMP genes were cloned by PCR, and the expression of these genes were analyzed by fluorescence quantitative PCR. Result Two SNMPs genes of T. elegans, named as TeleSNMP1 and TeleSNMP2, were cloned and identified for the first time by RT-PCR. Sequence analysis showed that the TeleSNMP1 encoding area was 1 497 bp in length, encoding 498 aa. The TeleSNMP2 encoding area was 1 686 bp in length, encoding 561 aa. The isoelectric points of these two genes were 8.26 and 7.05, respectively. Homology analysis showed that the consistency of SNMPs genes in insects of the same order was high, while the consistency of different order was low, and the sequence consistency between TeleSNMP1 and TeleSNMP2 was extremely low. The evolutionary tree results also showed that the evolutionary relationship of SNMPs genes in insects of the same order was rather close. Quantitative real-time PCR showed that TeleSNMP1 was antennae-biased, whereas TeleSNMP2 was expressed in female and male antennae but was also expressed in nonantennal tissues. Conclusion The results provide a useful reference for future studies on the function of the T. elegans SNMPs gene.
Effects of Phosphorus Addition and Inoculation of Mycorrhizal Fungi on the Growth and Phosphorus Utilization of Masson Pine Container Seedlings from Different Families
HUANG Sheng-yi, WU Tong-gui, CHU Xiu-li, WANG Bin, WANG Xiu-hua, ZHANG Dong-bei, ZHOU Zhi-chun
2021, 34(5): 142-151. doi: 10.13275/j.cnki.lykxyj.2021.005.017
Objective To study the differences of growth and phosphorus absorption and utilization of second-generation families of masson pine (Pinus massoniana) container seedlings with different genetic background under the interaction of different phosphorus addition amount and inoculation of mycorrhizal fungi so as to provide guidance for precise cultivation of high-quality P. massoniana container seedlings,. Method Three second-generation families of P. massoniana with different genetic backgrounds were used as materials to observe and analyze the differences in growth and phosphorus utilization of different families of P. massoniana under two phosphorus addition levels (low P: 50 g·m−3 substrate, high P: 900 g·m−3 substrate) in two plots inoculated with mycorrhizal fungi and without inoculation. Result The results showed that phosphorus addition promoted the growth, P content and P uptake in all organs of P. massoniana container seedlings from three families. The seeding height, caliper, whole plant dry matter, whole plant P content and P uptake of container seedlings with high P level were 8.70%, 21.73%, 61.62%, 30.25% and 112.08% higher than those with low P level, while the height-diameter ratio and root-shoot ratio were 10.62% and 19.82% lower. After inoculation, the seedling height, caliper, whole plant dry matter and whole plant P uptake increased by 2.34%, 6.40%, 20.69% and 18.08%, while the height-diameter ratio, root-shoot ratio and whole plant P content decreased by 4.09%, 3.87% and 3.23% respectively. Mycorrhizal fungi could reduce the differences of caliper and root-shoot ratio among different phosphorus addition levels, and the growth differences among families. The interaction of phosphorus addition and mycorrhizal fungi significantly promoted the P uptake of container seedlings stem and root, and mycorrhizal fungi promoted the growth of P. massoniana container seedlings more significantly at high P levels. The growth responses of different families to different phosphorus addition and mycorrhizal treatments were different. The effect of phosphorus addition on family No. 15 was the most significant, and that of mycorrhizal inoculation on family No. 53 was the most significant. Family No.37 was more balanced. Conclusion The effect of phosphorus addition is more obvious than that of families and mycorrhizal treatments. In order to further improve the cultivation level of P. massoniana container seedlings, reasonable fertilization should be carried out according to the different responses of three families to phosphorus fertilizer, and the P utilization efficiency can be improved by inoculating mycorrhizal fungi.
Sphaerolecanium prunastri (Hemiptera: Coccoidea: Coccidae), A New Pest in Wild Fruit Forests, Xinjiang
WANG Yu-li, LYU Zhao-zhi, LINGHU Wei, GAO Gui-zhen
2021, 34(5): 152-158. doi: 10.13275/j.cnki.lykxyj.2021.005.018
Objective Sphaerolecanium prunastri (Boyer de Fonscolombe) broke out in wild fruit forests in Xinjiang, which caused great harm to the survival of wild apricot and the ecological environment of wild fruit forests. This paper tries to clarify the biological characteristics of S. prunastri in order to provide a scientific basis for the prevention and control of S. prunastri in wild apricot forest in Xinjiang, China. Method From June 2019 to June 2020, the morphological characteristics, life history and habits of S. prunastri were studied by laboratory observation and field survey in Gongliu and Xinyuan counties in Xinjiang, China. Result S. prunastri was sexual dimorphism insect. The female adult was hemispherical and the male has wings. S. prunastri had one generation a year and overwintered as second instar nymphs mainly on the branches. The overwintering mortality was more than 65%. The female adult laid 527 eggs averagely. The estimated lower developmental threshold was 9.50 ℃, and effective accumulated temperature of 81.17 degree-day were required for development from the egg to first instar. The female to male ratio was 1.02: 1. There was no significant difference in the number of S. prunastri in the four directions of the wild apricot tree crown. S. prunastri was mainly distributed on the shade side of three-year-old branches. Conclusion The best time for prevention and control of S. prunastri in Xinjiang wild fruit forests is the post-hibernant and the enlargement period of 2nd-instar overwintering nymphs (late March to late April) and the dispersal period of 1st-instar nymphs (early to middle June). It is suggested to carry out comprehensive control of S. prunastri in this period.
Species Composition and Diversity of Betula alnoides Natural Forests at Dehong Prefecture, Yunnan Province
LUO Dan, WANG Chun-sheng, DAO Bao-hui, ZHAO Zhi-gang, GUO Jun-jie, ZENG Jie
2021, 34(5): 159-167. doi: 10.13275/j.cnki.lykxyj.2021.005.019
Objective Species composition and diversity characteristics of Betula alnoides natural forests were investigated to provide evidences for biodiversity conservation of B. alnoides natural forests as well as close-to-nature management of B. alnoides plantation. Method Plots with total areas of 10, 000 m2 and 5, 000 m2 were set up to investigate the species diversity in the forests at Pailuo Mountain, Ruili (PLS) and Huatao Ridge, Mangshi (HTL), Dehong Prefecture, Yunnan Province, respectively. The former stand was naturally regenerated after clear-cutting in 1958, while the other was naturally regenerated on abandoned land after slash-and burn cultivation in 1967. The Simpson index, Shannon-Wiener index and Pielou evenness index were used to analyze the species composition and diversity of tree, shrub and herb layers. The diameter class distributions were analyzed for the whole stand and the main tree species with importance value above 5.00%. Result There was no absolute dominant species in PLS stand, and the most important species in PLS was Machilus pingii (14.76%) and B. alnoides (9.55%). The species with the largest important value in HTL stands was B. alnoides (26.47%), which was absolutely dominant in the stand. The species richness (except herb layer), Simpson dominance index, Shannon-Wiener diversity index and Pielou evenness index in each layer of PLS stand were higher than those of HTL stands, but the species dominance was lower in PLS stands. The species distribution was more evenly distributed in PLS stand. Simpson dominance index, Shannon-Wiener diversity index and Pielou evenness index were the highest in shrub layer, while the highest species richness was observed in tree layer. The diameter-class structures of both the stands were inverted J-shaped, and the main tree species with important value above 5.00% were concentrated in the middle and small sized classes except B. alnoides which was in large and middle-sized classes. Conclusion The PLS stand is much closer to late succession stage than HTL stand, and they all belong to stable coenotypes. These findings could provide evidences and technical support for conservation of B. alnoides natural forest and close-to-nature transformation and management of B. alnoides pure plantation.
Influence of IAA and NAA on Cutting Propagation of Dalbergia odorifera
XU Shan-shan, LIU Xiao-jin, XU Da-ping, HONG Zhou, GUO Jun-yu, YANG Zeng-jiang
2021, 34(5): 168-176. doi: 10.13275/j.cnki.lykxyj.2021.005.020
Objective To identify the influence of IAA and NAA on the rooting and shooting ability of Dalbergia odorifera, and provide theoretical and technical support for the rapid propagation and cultivation of D. odorifera. Method Semi-lignified branches from 2-year-old D. odorifera seedlings were collected as the propagation materials. An orthogonal experiment was designed according to the concentrations of IAA and NAA and the soaking time. The effects of 16 treatments on rooting and shooting parameters of D. odorifera were investigated 80 days after cutting, and the subordinate function values method and principal component analysis were applied to comprehensively evaluate the rooting effects. Result The concentrations of IAA and NAA, the soaking time, the interaction between IAA and NAA concentration, and the interactions between IAA concentration and soaking time showed great impacts on rooting percentage, and statistical differences were also observed in terms of length of roots, amount of roots, surface and volume of root system. Under certain concentration range, the rooting percentage increased as the concentration of IAA increased, while decreased as the concentration of NAA increased. The principal component analysis and subordinate function values were used to comprehensively evaluated the cutting propagation performance. It is showed that the corresponding rooting percentages of the top 4 treatments were 96.10%, 97.66%, 96.10% and 96.88%, respectively. Conclusion Considering the rooting percentage, root and shoot development synthetically, it is suggested to apply 500 mg·L−1 IAA + 750 mg·L−1 NAA + 1-minute soaking or 750 mg·L−1 IAA + 750 mg·L−1 NAA + 10-second soaking or 250 mg·L−1 IAA + 1-minute soaking or 500 mg·L−1 IAA + 500 mg·L−1 NAA + 10-second soaking in production practice to carry out cutting propagation of D. odorifera.
Analysis of Codon Usage in the Chloroplast Genome of Cypripedium calceolus
DING Rui, HU Bing, ZONG Xiao-yan, HAN Chen-yang, ZHANG Li-jie, CHEN Xu-hui
2021, 34(5): 177-185. doi: 10.13275/j.cnki.lykxyj.2021.005.021
Objective To analyze the codon usage bias of Cypripedium calceolus chloroplast genome, and identify the main factors influencing codon usage bias of this species in order to provide reference for the chloroplast genomics research of Orchidaceae species. Method Downloading the complete chloroplast genome sequence of C. calceolus and screening the protein coding sequences, the EMBOSS online program was used to calculate the GC content of each gene and codon, and the software CondonW was used to calculate the length of amino acid (LAA), effective number of codon (ENC), relative synonymous codon usage (RSCU), frequency of optimal codons (FOP) and the acid base content of the third nucleoside of each gene codon. The software SPSS was used to analyze the correlation among each index, and software Origin was used to plot. Result The third codon position of C. calceolus chloroplast genome sequence was rich in A and T, and the GC3 content was only 29%. The ENC values varied from 37.92 to 61.00, indicating a relatively weak codon usage bias. The correlation between the number of effective codons and GC3 showed an extremely significant level. There were 34 codons with relative synonymous codon usage greater than 1 and 29 codons ending with A and U. Analysis of neutral plot, ENC-plot and PR2-plot showed that the preference of C. calceolus chloroplast genome codons was mainly influenced by natural selection. Correspondence analysis showed a similar pattern of codon usage bias of the genes encoding photosynthetic system proteins, while other types of genes were quite different. Sixteen codons were finally determined as the optimal codons. Conclusion This study confirms that natural selection is the main factor affecting codon usage bias of C. calceolus chloroplast genome. The optimal codon of this species is screened. The results can provide a reference for the phylogeny and chloroplast genome codon evolution of Orchidaceae.
Identification of the Pathogen Causing Anthracnose on Ailanthus altissima in Henan Province, China
WANG Shu-he, ZHANG Jia-zheng, HE Jin-he
2021, 34(5): 186-192. doi: 10.13275/j.cnki.lykxyj.2021.005.022
Objective The aim of the study is to identify the pathogen causing leaf anthracnose on Ailanthus altissima in the Tianchishan National Forest Park in Songxian County of He'nan Province, China, so as to provide references for the prevention and control of the disease. Method Pathogenic fungi were isolated from diseased leaves of A. altissima using tissue isolation methods. The isolates were purified in potato dextrose agar (PDA) by single spore culture. Species identifications for the pathogens causing anthracnose on A. altissima were carried out using morphological characterization, phylogenetic analysis, and pathogenicity assays. Result A total of 11 Colletotrichum spp. isolates were recovered from the samples by tissue isolation methods. Colonies were white to gray in color with cottony mycelia and darker underneath on PDA, conidia cylindrical, hyaline, smooth-walled, aseptate. Two representative isolates (CH-1 and CH-3) were selected for pathogenicity tests and phylogenetic analyses. Both the isolates CH-1 and CH-3 were able to infect A. altissima in wounded inoculations. A multi-locus phylogeny was established based on five genomic loci ITS, ACT, TUB2, CHS-1 and GAPDH. The phylogenetic tree showed that the isolates CH-1 and CH-3 from A. altissima clustered into a clade with high confidence (bootstrap value, BP=99%), together with Colletotrichum fructicola. Conclusion Based upon morphological characteristics and multi-locus phylogenetic analysis, the isolates CH-1 and CH-3 were identified as C. fructicola. This study represents the first report of C. fructicola on A. altissima in China.