2021 Vol. 34, No. 3
2021, 34(3): -1--1.
[Abstract](1325) [FullText HTML] (1002) [PDF 99160KB](64) [Cited by] ()
2021, (3): 0-0.
[Abstract](1439) [FullText HTML] (890) [PDF 274KB](42) [Cited by] ()
Identification of Nitrate Transporter Gene Family PeNPFs and Their Expression Analysis in Phyllostachys edulis
2021, 34(3): 1-12. doi: 10.13275/j.cnki.lykxyj.2021.03.001
[Abstract](4409) [FullText HTML] (2187) [PDF 1390KB](87) [Cited by] ()
Objective To identify the members of nitrate transporter (NPF) gene family in moso bamboo (Phyllostachys edulis) and systematically analyze their molecular characteristics and expression patterns, in order to lay the foundation for in-depth study of the nitrate transport function of the NPF genes in Moso bamboo. Method Bioinformatics methods were used to identify NPF family gene members in the genome of Moso bamboo, a comprehensive analysis of acting elements in their promoters, gene structure, physical and chemical properties of their encoded proteins, conserved domains and systematic evolution was performed. The tissue specific expression of NPF genes in different tissues of Moso bamboo and their expression patterns after different abiotic stress and hormone treatments were analyzed using the existing transcriptome data. Result A total of 27 NPF genes (PeNPF1.1~PeNPF8.8) were identified in Moso bamboo, and their gene structure was found to be quite different. The number of intron was 2~5. The longest coding region was 2286 bp (PeNPF7.4) and the shortest was 1359 bp (PeNPF8.8). The regulatory element analysis showed that a variety of elements related to abiotic stresses such as cold and drought, as well as hormonal responses such as GA3 and NAA were identified in the promoter region of PeNPFs. The molecular weight of the proteins encoded by PeNPFs ranged from 49.56~82.08 kDa, with the isoelectric point (pI) of 5.17~9.85. Most PeNPFs were neutral or basic proteins with similar transmembrane structures. Phylogenetic analysis showed that PeNPFs were clustered into 7 subfamilies, and the numbers of members in each subfamily were 1, 3, 1, 6, 1, 7 and 8, respectively. Analysis of protein conserved motifs showed that there was a total of 10 conserved motifs in PeNPFs, of which motif 1, motif 2 and motif 4 were highly conserved motifs shared by all members. The expression profile heat map analysis based on transcriptome data demonstrated that the expression of PeNPFs had certain differences in different tissues such as leaves, inflorescences, roots, rhizomes and shoots, among which each member was detected in at least one tissue, and some members exhibited tissue-specific or constitutive expression. After cold and drought treatments, the expression of PeNPF5.3, PeNPF7.2, PeNPF7.3 and PeNPF8.7 showed significant down-regulation, which was consistent with the presence of cold and drought response regulatory elements in their promoter sequences. After GA3 and NAA treatments, PeNPF7.3 and PeNPF7.6 demonstrated opposite expression changes, while the expression trend of PeNPF7.1 was similar. Conclusion There are 27 members of NPF gene family in Moso bamboo, which can be divided into 7 subfamilies. The molecular characteristics and tissue expression specificity of each member in different subfamilies have certain differences, and the expression changes of some PeNPFs in response to abiotic stress and hormone treatments have reached the level of significant differences. These expression profiles suggest that PeNPFs might play different functions in the transport of nitrate in different tissues of bamboo and in the process of dealing with different environments. These findings could be references for understanding the biological functions of PeNPFs in Moso bamboo.
2021, 34(3): 13-22. doi: 10.13275/j.cnki.lykxyj.2021.03.002
[Abstract](5712) [FullText HTML] (3007) [PDF 1012KB](88) [Cited by] ()
Objective To assess the effects of climate change on forest and grass fire risk in Central Asia. Method An index was built to assess the wildfire risk in Central Asia based on wildfire possibility, vulnerability and exposure. The modified Nesterov index (MNI) was used to calculate the fire weather index of the region based on daily precipitation, mid-day temperature, and dew point. The authors used HadGEM2-ES global climate model with four scenarios (RCP2.6, RCP4.5, RCP6.0, and RCP8.5) to project the fire weather index of Central Asia. The vulnerability was calculated with burn probability and vegetation types. The authors also projected the exposure in the future with population and GDP distributions under three climate scenarios (SSP1, SSP2, and SSP3). A fire risk index was established by using analytic hierarchy process (AHP), which combined with possibility, vulnerability and exposure. Result The results showed that the areas with high and very high ratings on wildfire risk would account for 47.2% during 2021—2050, which increase by 16.9% over the baseline. The areas with high and very high risks would increase by 12.4%, 18.6%, 13.6%, and 20.4% under the RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios in 2021—2050, respectively. The wildfire risk would also increase during 2071—2099 period. The areas with high and very high risks would be 53.1%, which would be an increase of 22.9% compared with the baseline. It would increase by 11.1%, 22.4%, 24.6%, and 32.9% for RCP2.6, RCP4.5, RCP6.0, and RCP8.5 scenarios, respectively. Conclusion The areas with high and very high risk under the RCP2.6 scenario in 2021—2050 period will be larger than that of 2071—2099 period. While the areas with high and very high risk under the RCP4.5, RCP6.0, and RCP8.5 scenarios in 2071—2099 period will be less than that of2021—2050 period. The areas with high and very high risks will significantly increase in the future. The key areas for fire management should include the west grassland, mountain forests and shrubs in south.
Genome-wide Identification of PLD Gene Family of Populus trichocarpa and Its Responses to Salt Stress
2021, 34(3): 23-36. doi: 10.13275/j.cnki.lykxyj.2021.03.003
[Abstract](7278) [FullText HTML] (3599) [PDF 1279KB](105) [Cited by] ()
Objective To analyze the pressure of selection in the evolution of PLD gene family in the woody model plant Populus trichocarpa, the cis-acting elements in the promoter, the tissue expression characteristics, and the expression pattern under salt stress in order to provide references for mining the role of PtrPLD in abiotic stress. Method Using Arabidopsis PLD gene family protein sequence alignment to obtain the P. trichocarpa genome homologous gene, and then identify the PtrPLD gene after the conserved domain identification; using the software ClustalW and MEGA to perform the amino acid sequence alignment and systematic evolution analysis of the PtrPLD and AtPLD genes; using MEME, Plant-mPLoc, ExPasy and other software tools to analyze the characteristics of PtrPLD genes and encoded proteins; using Tbtools software to analyze homologous genes and Ka/Ks values; using Plantcare online tools to analyze the cis-acting elements in the promoter of PtrPLD; using Phytozome transcriptome database and qRT-PCR to analyze the PtrPLD tissue expression characteristics; and using qRT-PCR to analyze the PtrPLD response to salt stress in each tissue. Result The results show that the PtrPLD family can be divided into 2 subfamilies, C2-PLD and PX/PH-PLD, which containing 13 and 3 genes respectively. There are 7 pairs of paralogous genes and the Ka/Ks between them is far less than 1. The promoter region of PtrPLD family genes contains a large number of abiotic stress and hormone response elements, among which the PtrPLDδ4 promoter contains 20 elements. The PtrPLD family of encoded proteins all contain Motif 1-4, and the sequences on the same evolutionary branch of the evolutionary tree are highly conserved. Analysis of the expression characteristics showed that the PtrPLD family genes have specific expression in roots, stems and leaves, and most members are mainly expressed in the roots. Under NaCl stress, the expression level of PtrPLD family genes in the roots, stems and leaves showed a trend of up-down-up within 72 hours. Conclusion The results show that the PtrPLD family genes play an important role in the response of P. trichocarpa to salt stress. This study will promote the identification of the biological functions of PtrPLD family genes and the mining of genetic resources in response to abiotic stress.
2021, 34(3): 37-45. doi: 10.13275/j.cnki.lykxyj.2021.03.004
[Abstract](4392) [FullText HTML] (2355) [PDF 1321KB](63) [Cited by] ()
Objective To provide data in molecular-level for revealing the regulatory role of MlCYP734A6 in the growth and development of Musella lasiocarpa. Method The 3′ and 5′ RACE technology was used to clone the full length cDNA of MlCYP734A6 gene. The software of bioinformatics was used to analyze the nucleotides and protein sequence. Real-time PCR method was used to analyze the gene expression level in different types and tissues of Musella lasiocarpa. HPLC-MS/MS was used to detect the brassinolide content in different tissues. Result The full length cDNA of MlCYP734A6 is 1 584 bp, encoding 527 amino acids. The relative molecular mass of coding protein is 60 038.84 Da and the isoelectric point is 6.61. Sequence comparison and phylogenetic tree analysis showed that the amino acid sequence of MlCYP734A6 had the closest evolutionary relationship with the CYP734A6 protein of Musa acuminata subsp. malaccensis. Real-time PCR analysis showed that MlCYP734A6 could be detected in all tissues. The two tissues with the highest expression level were rachis and root tip, and the lowest expression level was in leaf. No significant correlation was found between the brassinolide content and the expression pattern of MlCYP734A6, and excessive brassinosteroids in RD05 was a possible cause of dwarfed phenotype. Conclusion The study indicated that MlCYP734A6 may participate in the metabolism of brassinosteroids, and balance the bioactive brassinosteroids content in Musella lasiocarpa. These results provide further theoretical support for the role of CYP734As in plant growth and development in the future.
2021, 34(3): 46-55. doi: 10.13275/j.cnki.lykxyj.2021.03.005
[Abstract](3442) [FullText HTML] (2504) [PDF 1239KB](49) [Cited by] ()
Objective To study the effects of plant/white rot fungi (WRF) inoculation on rhizosphere soil metabolome in root exudate of plants cultivated in PAH-contaminated soil. Method A pot experiment was conducted in greenhouse for bioremediation of PAH-contaminated soils and Salix viminalis L. was used as phytoremediation materials. Based on liquid chromatography-mass spectrometry (LC-MS) and metabolomics method, the test was focused on comparing the effect of inoculating Crucibulum laeve on metabolic profiling of rhizosphere PAH-contaminated soil of S. viminalis. Result Under POS and NEG mode, 881 and 823 compounds were detected and identified in metabolic profiling, respectively. Among them, 18 compounds were identified and assumed to be potential root exudates components. The component variety and content of rhizosphere metabolites were remarkably reduced by C. laeve inoculating, which including 16 root exudate components. Conclusion In this study, it is showed that inoculation with WRF can promote the uptake capability of roots to a broad spectrum of soil compounds. It is speculated that the response of plant roots to WRF stimulating leads to the improvement of PAHs phytoextraction capacity. This is of great significance for revealing the mechanism of plant/WRF combination remediation of PAH-contaminated soils.
Investigation on Host Range, Host Resistance Substances of Bacterial Bark Canker of Populus × euramericana
2021, 34(3): 56-63. doi: 10.13275/j.cnki.lykxyj.2021.03.006
[Abstract](2924) [FullText HTML] (1751) [PDF 628KB](24) [Cited by] ()
Objective This Research is to investigate the host range of bacterial canker of Populus × euramericana, the resistant varieties and its possible resistant substances. Method The host range of the pathogen and the resistant varieties were determined by field investigation and inoculation tests. The content of active substances in the bark of resistant and susceptible varieties was analyzed by HPLC. Result The host of bacterial pathogen of Populus × euramericana canker are Populus deltoides, Populus × euramericana and Salix matsudana. Zhonglin 46, 2025, 2001, 313, Zhonghe-1 and 16-09 were highly susceptible to the bark canker disease; Yukang 1 and 16-10 were highly resistant varieties, 131, 03-59, 02-212 and 03-34 were resistant varieties. Hybrid willows and Salix babylonica are resistant to the pathogen, and Salix × aureo-pendula can be affected, but do not cause serious disease. The HPLC analysis showed that the contents of catechol, benzoic acid and chlorogenic acid in the bark of resistant and highly susceptible poplar varieties were significantly different. The catechol and catechin increased when the hosts were infected by L. populi. Conclusion In this study, the host range of bacterial canker of Populus × euramericana were determined, and resistant and highly susceptible poplar varieties were screened, and the catechol and catechin are important compound for host to defense the pathogen infection. The results will be helpful to the control of the bacterial disease of poplar.
2021, 34(3): 64-71. doi: 10.13275/j.cnki.lykxyj.2021.03.007
[Abstract](3686) [FullText HTML] (2827) [PDF 702KB](92) [Cited by] ()
Objective To study the factors influencing the stand volume change of Chinese fir (Cunninghamia lanceolata) plantations under the context of climate change. Method Based on the long term spacing trails of Chinese fir plantations established in Weimin Forest Farm, Shaowu, Fujian Province, the authors modeled the stand volume growth in relation to stand variables (including planting density, stand basal area per hectare, number of trees per hectare, stand quadratic mean diameter, dominant height, age) and climatic factors (including mean annual temperature, mean warmest month temperature, mean coldest month temperature, mean annual precipitation, annual heat-moisture index, degree-days below 0℃, summer mean maximum temperature, winter mean minimum temperature, spring (March to May) mean temperature) based on Bayesian model averaging (BMA) and stepwise regression methods (SR). Result The stand volume of Chinese fir increased with the increase of stand basal area per hectare, stand quadratic mean diameter, stand dominant height, age, summer mean maximum temperature, spring mean temperature, and Degree-days below 0℃. The model determined by SR method was not in the top five models with the highest posterior probability selected by BMA, which indicated that the model uncertainty. In view of the posterior probability of a model, SR method had lower accuracy. Conclusion The stand volume of Chinese fir plantations is significantly affected by stand and climate factors. Compared with SR method, BMA method shows a better performance because of its considering the model uncertainty.
Diameter Distribution of Semi-natural Mixed Forest of Pinus massoniana and Broadleaved Trees Based on Stratification
2021, 34(3): 72-80. doi: 10.13275/j.cnki.lykxyj.2021.03.008
[Abstract](3469) [FullText HTML] (2192) [PDF 739KB](80) [Cited by] ()
Objective The diameter distribution of each storey (including the whole stand and sublayers) of semi-natural mixed forest of Pinus massoniana and broadleaved trees was studied to reveal the diameter distribution characteristics of the stand and provide data for their sustainable management. Method Based on 10 semi-natural mixed forests plots, the maximum light-receiving plane method was used to divide storey, and the Shapiro-Wilk test was used to measure the normality of the diameter distribution of each plot and storey; the skewness and kurtosis coefficients were used to describe the graphic characteristics of the diameter distribution. The diameter distributions of each plot and storey were fitted by three-parameter Weibull distribution and the Meyer negative exponential function, and the chi-square test was used to test the fitting effect, then the function with better fitting effects was selected to fit the distribution chart of each plot, and analyzed the distribution characteristics of the stand. Result There were five plots whose sublayer Ⅰ obeyed normal distribution, but for all sample plots, the diameter distribution of all the whole stand and the sublayer Ⅱ followed an inversed J shape were not obeying normal distribution. The skewness coefficient of all the whole stand and sublayers were positive value, the kurtosis coefficient of the whole stand of 7 plots were less than 0, and for most plots the skewness coefficient and the absolute value of the kurtosis coefficient of the whole stand were between that values of the sublayer Ⅰ and the sublayer Ⅱ. The Weibull distribution function has a good fitting effect on the whole stand and the sublayer Ⅰ. The pass rates of the chi-square test of the whole stand, the sublayer Ⅰ and the sublayer Ⅱ were 80%, 100%, and 70%, respectively. Meyer negative exponential function could fit the sublayer Ⅱ better, while the adaptability to the whole stand and the sublayer Ⅰ were poor, especially the pass rate of the sublayer Ⅰ was only 10%, but the pass rate of the sublayer Ⅱ reached 100%. Conclusion There are significant differences in the diameter distribution of the whole stand and each sublayer of the semi-natural mixed forest of P. massoniana and broadleaved trees, the diameter distribution of sublayer Ⅰ tends to be normal distribution while the whole stand and the sublayer Ⅱ are inverse J shaped and not obeying normal distribution. The diameter distribution from sublayer Ⅱ to sublayer Ⅰ shows a transition trend from negative exponential distribution to normal distribution. For all sample plots, the diameter distribution curves of each storey are right-skewed, and the curves of the whole stand of most sample plots are platykurtic. The Weibull distribution function has a good fitting effect on the whole stand and the sublayer Ⅰ, while the Meyer negative exponential function is suitable for fitting diameter distribution of sublayer Ⅱ.
Population Structure and Spatial Distribution Pattern of Kmeria septentrionalis an Endangered Species, in Karst Habitat
2021, 34(3): 81-87. doi: 10.13275/j.cnki.lykxyj.2021.03.009
[Abstract](3305) [FullText HTML] (2288) [PDF 802KB](57) [Cited by] ()
Objective Taking the natural regeneration population of endangered plant Kmeria septentrionalis in karst habitat as object to study the population regeneration structure, spatial distribution pattern and environmental impact factors. Method Point pattern and generalized mixed linear model were used to complete a linear fitting of the spatial distribution pattern and environmental impact factors of the regeneration population of K. septentrionalis. Result (1) The population structure of K. septentrionalis was in an inverted “J” type, the survival curve was close to Deevey-Ⅲ; the existence of a large number of young-aged seedlings indicated that the regeneration condition of K. septentrionalis population was good. (2) Except for the weak random distribution on a small scale, the other scales were in a clustered distribution. (3) The canopy density, soil moisture and rock exposure rate were the main factors affecting the spatial distribution of K. septentrionalis. Conclusion The condition of the regeneration population of K. septentrionalis in the study area is good, and the high-intensity spatial aggregation distribution is mainly the combined action of the seed biological characteristics and karst habitat.
Effects of Simulated Nitrogen Deposition on Litter Decomposition and Soil Microorganisms of Typical Subalpine Forests in Central Yunnan, China
2021, 34(3): 88-97. doi: 10.13275/j.cnki.lykxyj.2021.03.010
[Abstract](3581) [FullText HTML] (2604) [PDF 984KB](51) [Cited by] ()
Objective To study the relationship between litter decomposition and soil microbial characteristic under simulated nitrogen (N) deposition so as to provide references for studying the response mechanism of carbon and nitrogen cycles under N deposition in forest ecosystem. Method In this study, the litter of four typical subalpine forests (evergreen broadleaved forest, Pinus armandii forest, Quercus semicarpifolia forest, Pinus yunnanensis forest) in central Yunnan were taken as the research objects. From February 2018 to January 2019, through simulating the nitrogen deposition and in-situ decomposition experiments, the litter bag method was used to study the variations of litter carbon and nitrogen, soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and soil microbial quantity under different simulated N depositions. Four treatment levels of N deposition were applied, i.e., low nitrogen (LN, 5 g·m−2·a−1), medium nitrogen (MN, 15 g·m−2·a−1), high nitrogen (HN, 30 g·m−2·a−1) and the control (CK, 0 g·m−2·a−1). Result Under different N deposition treatments for one year, the C content in the litter of evergreen broadleaved forest and Quercus semicarpifolia forest increased significantly (0.40%～8.16%), while that of Pinus armandii forest and Pinus yunnanensis forest decreased by 2.67% under LN but increased by 4.09% under HN. The N content of litter of all these forests increased significantly (1.45%～69.01%), while the C/N ratio decreased significantly (0.34%～37.92%). Under the same N deposition, the soil microbial biomass decreased with the depth of soil layer, and the influence of N deposition on the vertical distribution pattern was not significant. The effect of N deposition on soil MBC and MBN in evergreen broadleaved forest and Quercus semicarpifolia forest was inhibited, and the effect of N deposition on Pinus armandii forest and Pinus yunnanensis forest was promoted with low N and inhibited with high N. The soil MBC/MBN ratio ranged from 5.31 to 11.26 in the four forests. The effects of N deposition on MBC/MBN ratio of different soil layers in different forests were different, but all of them was inhibited by high N treatment. Conclusion Litter decomposition in typical subalpine forests in central Yunnan is mainly affected by forest types, followed by N deposition. The soil microbial biomass and quantity are mainly affected by forest types, followed by soil depth, while the effect of N deposition is the smallest.
Comparison and Analysis of Diversified Intestinal Flora of Buzura suppressaria Larvae and Endophytes in Eucalyptus Leaves
2021, 34(3): 98-107. doi: 10.13275/j.cnki.lykxyj.2021.03.011
[Abstract](3524) [FullText HTML] (2257) [PDF 1001KB](45) [Cited by] ()
Objective This study is to investigate the diversified intestinal flora of Buzura suppressaria larvae and Eucalyptus leaves which are the major food of B. suppressaria, and to analyze the inner relationship between them. Method Illumina Miseq technology was applied to sequence the bacteria 16S rDNA and fungi ITS rDNA in the intestinal of the 5th instar larvae and Eucalyptus leaves. Both the diversity and abundance of the bacteria and fungi in the intestinal and Eucalyptus leaves were analyzed. Result The results of bioinformatics analysis showed that the bacteria populations in the intestinal tract of B. Suppressaria larvae were annotated into 6 phyla, 11 classes, 19 orders, 38 families and 43 genus, whereas the fungi populations were categorized into 8 phyla, 29 classes, 67 orders, 159 families and 257 genus. The Endophytic bacteria found in Eucalyptus leaves included 10 phyla, 19 classes, 26 orders, 54 families and 74 genus, and the fungi included 8 phyla, 31 classes, 79 orders, 171 families and 291 genus. The main pathogenic bacteria of Eucalyptus were found in both of the Eucalyptus leaves and the larvae intestinal tract, including the orders of Colletotrichum, Pseudomonas, Pseudocercospora, Aureobasidium, Septoria, Lasiodiplodia and Neofusicoccum. Conclusion The diversity and abundance of bacteria and fungi populations in the intestinal tract of B. suppressaria larvae were different from those of the Eucalyptus leaves, which had an important influence on the intestinal microbial community structure. The gnawing or fecal contact of B. suppressaria larvae carrying certain pathogens may be the cause of the pathogen infecting healthy Eucalyptus leaves.
Surface Fuel Loading of Pinus massoniana Forest in Different Succession Stages and Relevant Affecting Factors
2021, 34(3): 108-117. doi: 10.13275/j.cnki.lykxyj.2021.03.012
[Abstract](3213) [FullText HTML] (2262) [PDF 792KB](36) [Cited by] ()
Objective Based on the analysis of the variation characteristics of the fuel loading of Pinus massoniana forest in different succession stages, to determine the key factors affecting the surface fuel load. Method Taking pure P. massoniana forests with different age classes in Wuyishan National Park as the research object, alternative method of temporal and spatial was used to analyze the characteristics of different types of surface fuel loading and their relationship with terrain, stand, and meteorological factors. Result (1) With the succession of P. massoniana forest, the surface live fuel loading decreased, while the dead fuel loading and total fuel loading increased. The total fuel loading was mainly caused by 1 hour dead fuel loading. (2) The difference between young and mature P. massoniana stands was the most obvious. At the late stage of succession, the surface live fuel loading decreased by 47.21% and the surface dead fuel loading increased by 113%. (3) According to RDA ranking method, the surface fuel loading were closely related to terrain factors (such as altitude, slope position), stand factor (such as average branch-free bole height, average DBH, and canopy density) and meteorological factors (such as air temperature). (4) Linear regression analysis showed that different types of surface fuel loading had different influence factors, among which the average DBH had the greatest impact on the shrub fuel loading, the slope position had the greatest impact on the herb fuel and 1 hour dead fuel loading, the average clear bole height had the greatest impact on the 10 hour dead fuel and total fuel loading. Conclusion Surface fuel loading of P. massoniana forest are different in various succession stages and the influence factors vary with different types of surface fuel.
Morphological and Biomass Characteristics of Fargesia decurvata in Different Forest Types in Jinfo Mountain
2021, 34(3): 118-126. doi: 10.13275/j.cnki.lykxyj.2021.03.013
[Abstract](3441) [FullText HTML] (2206) [PDF 790KB](49) [Cited by] ()
Objective To study the growth and reproduction characteristics of Fargesia decurvata J. L. Lu under different forest types, and the trade-off characteristics of clonal reproduction and sexual reproduction of long-lived, one-time flowering bamboos. Method F. decurvata, the dominant species in shrub layer under three forest types, i.e. deciduous broad-leaved forest (De), evergreen deciduous broad-leaved mixed forest (De+Ev) and evergreen broad-leaved forest (Ev) was selected as experimental materials, to study the morphological plasticity, biomass accumulation and biomass distribution characteristics and reproductive characteristics in vegetative stage and ripening stage. Result (1) From vegetative stage to ripening stage, the amount of leaves decreased significantly in De and De+Ev, and there was no significant change in Ev. The length of the splitter, the amount of internode of the splitter, the mean diameter of the splitter, and the internode length of the splitter all decreased in De and De+Ev, and increased in Ev. During the ripening stage, the amount of spikelets in De was higher than that in De+Ev and Ev. (2) During the transition from vegetative growth to ripening stage, the leaf biomass accumulation and leaf biomass allocation of F. decurvata ramets in De and De+Ev decreased sharply, there was no significant change in the biomass of other components in this two types of forest; the biomass accumulation of each component in Ev increased significantly except for the leaves, and the biomass allocation increased significantly in the branches, and decreased in the leaves and roots; the stems and branches as supporting organs accounted for a large amount of biomass allocation in the three forest types. (3) During the vegetative growth stage, F. decurvata in the three forest types produced shoots for clonal growth, and the amount of bamboo shoots per unit area of De+Ev was significantly higher than Ev. However, no shoots were produced during the ripening stage, only seeds were produced, and the amount of bamboo seedlings per unit area of Ev was significantly lower than that of the other two forest types. The tissue density was significantly higher than that in vegetative growth stage. The seed setting rate and reproductive distribution of F. decurvata were very low. Conclusion The morphological characteristics, biomass accumulation and biomass allocation characteristics of F. decurvata population are different in various life history stages, and there are also differences among these forest types. There is an obvious trade-off between clonal growth and sexual reproduction, as sexual reproduction progresses, the clonal growth capacity will weaken and disappear.
2021, 34(3): 127-134. doi: 10.13275/j.cnki.lykxyj.2021.03.014
[Abstract](3241) [FullText HTML] (2257) [PDF 701KB](55) [Cited by] ()
Objective To explore the effects of thinning intensity on the growth of teak, on soil physicochemical properties and on enzyme activity. Method Taking 15 years old pure forest of teak (Tectona grandis) as trial object, four thinning intensity treatments, including low, moderate, heavy thinning and the control were set. The growth, soil properties and enzyme activities of teak plantation were measured 3.5 years after thinning, and the difference of these indexes with different intensity treatment was analyzed. Redundant analysis method (RDA) was used to study the relationship between tree growth, soil enzyme activity and soil property. Result The effects of thinning on soil physicochemical properties and enzyme activities were showed mainly in 0-20 cm soil layer. The soil moisture content of the surface soil increased and soil pH reduced after thinning. The contents of soil organic matter and alkali-hydrolyzed nitrogen was positively correlated with the intensity of thinning treatment, In 0-20 cm soil layer, the organic matter contents under moderate and heavy thinning increased by 18.2% and 19.0% compared with the control, and the alkali-hydrolyzed nitrogen content was respectively 15.7% and 16.6% higher than that of the control. The contents of total nitrogen and exchangeable calcium also increased after thinning. The activity of invertase and acid phosphatase in 0-20 cm soil layer was significantly enhanced by thinning, but there was no significant difference in urease and catalase contents. The average breast-height diameter and the volume of individual trees of teak plantation increased with the intensity of thinning treatment, and the stand basal area and volume were higher than those of the control. Under heavy thinning treatment, the annual increment of growth indexes of teak was the largest and significantly higher than that of the control, while both the individual volume and stand volume increment were higher than of the control by 80.0% and 90.2% respectively. There was a positive correlation between soil organic matter, available phosphorus and tree growth indexes. Soil water holding capacity, density and total porosity were the main environmental factors affecting soil enzyme activity. Conclusion Thinning can improve soil nutrient and water status, promotes the growth of teak, and the productivity of forest land can increase obviously. Thinning significantly enhances the C cycle-related invertase activity and increases the activity of N, P cycle-related enzymes. Total nitrogen, soil bulk density are the key factors affecting enzyme activity. The suitable thinning intensity of 15-year-old teak plantation is 40%-45%.
2021, 34(3): 135-144. doi: 10.13275/j.cnki.lykxyj.2021.03.015
[Abstract](3653) [FullText HTML] (2757) [PDF 828KB](43) [Cited by] ()
Objective To study the variation of leaf functional traits of different understory shrubs in Acacia mangium Willd. plantation, so as to provide references for species selection for regeneration of understory vegetation in mature plantation in southern China. Method In this paper, four understory shrubs, including Psychotria rubra (Lour.) Poir., Ilex asprella (Hook. et Arn.) Champ. ex Benth var.as, Evodia lepta (Spreng.), and Rhodomyrtus tomentosa (Ait.) Hassk. in a thirty-four-year reforested A. mangium plantation in Heshan City, Guangdong Province, were used to study the variation of leaf functional traits and try to clarify the adapting mechanisms of understory species to light environment in plantation. Result (1) The leaf mass per area (LMA) of R. tomentosa was the highest, with the value of 157.51 g·m-2, which was significantly higher than those of the other species, and the LMA of I. asprella was the smallest; the leaf N and P concentrations of E. lepta was the highest, but with the lowest N: P ratios; (2) Both the Chl a and Chl b contents in I. asprella leaves were significantly larger than those of the other species, and the leaf carotinoid content in I. asprella was lower than that of P. rubra, but higher than that of E. lepta and R. tomentosa; (3) The leaf soluble sugar and non-structural carbohydrates (NSC) of I. asprella was significantly higher than those of the other species, and the leaf starch concentration of I. asprella was also significantly larger than those of E. lepta and R. tomentosa, indicating that I. asprella can well adapt to the shade environment via storing relatively higher soluble sugar and starch. Conclusion Among the four understory plants, the lower LMA of I. asprella can be helpful to maintain the strong photosynthetic capacity. Also, the higher NSC in leaf of I. asprella can provide stable energy for adapting shade environment. Therefore, I. asprella can be a selective species for regeneration of understory in mature plantation in southern China.
Influence of Talaromyces aurantiacus on the Soil Phosphorus Fraction and Biomass of Moso Bamboo Seedling
2021, 34(3): 145-151. doi: 10.13275/j.cnki.lykxyj.2021.03.016
[Abstract](3208) [FullText HTML] (2264) [PDF 664KB](31) [Cited by] ()
Objective To explore the contribution of the phosphorus-solubilizing fungi Talaromyces aurantiacus JXBR04 to soil phosphorus bioavailability in growth promotion of Phyllostachys edulis. Method Greenhouse potting experiment was used to study the effect of the strain on the content of phosphorus bioavailability in the rhizosphere soil of Ph. edulis. The contents of available phosphorus, mineral nitrogen the activities of related soil enzymes in the soil were analyzed, and the growth-promoting effect on Ph. edulis by inoculating on JXBR04 was evaluated. Results Compared with the control, the application of JXBR04 significantly increased the content of HCl-P and CaCl2-P fraction, increased the activities of soil urease and catalase in the rhizosphere soil of Ph. edulis, while the content of enzyme-P, citric acid-P fraction, the activities of soil acid phosphatase and alkaline phosphatase were not affected. The content of soil available phosphorus and mineral nitrogen increased by 78.3% and 13.3%, respectively. The content of HCl-P and CaCl2-P in soil was significantly positively correlated with the content of available phosphorus in soil and the biomass of Ph. edulis, indicating that the application of JXBR04 significantly promoted the biomass of Ph. edulis. Conclusion The increase of available phosphorus in soil is driven mainly by the content of CaCl2-P and HCl-P fraction though inoculating on strain JXBR04, which can promote Ph. edulis to absorb and utilize the available phosphorus to increase biomass. This regulated process is not mediated by soil phosphatase.
2021, 34(3): 152-157. doi: 10.13275/j.cnki.lykxyj.2021.03.017
[Abstract](3117) [FullText HTML] (2519) [PDF 508KB](33) [Cited by] ()
Objective By testing Ormosia hosiei elite families to reveal the genetic variation of the growth and form-quality traits of O. hosiei families, and provide a reference for the breeding and directional cultivation of the superior materials of O. hosiei. Method 3-year O. hosiei elite family plantations were used to study the genetic variation and the correlation among traits. The experimental forests were established in 2017 at two sites (Longquan of Zhejiang Province and Fuzhou of Jiangxi Province). Result The genetic differences of the growth and shape traits of 3-year-old O. hosiei were significant (p < 0.01). The variation coefficient of the growth and form-quality traits of the two sites ranged between 23.3% and 65.1%. With the exception of stem straightness, the estimated values of all the other family heritability traits of O. hosiei were high, and the variation ranged between 0.36 to 0.83, subjected to moderate to strong genetic control. The estimated values of individual heritability of tree height (0.87) was higher than that of family heritability (0.83) in Longquan, Zhejiang, which was strongly controlled by heredity. The individual heritability of O. hosiei trees in both the two sites was lower than the family heritability, the variation of individual heritability was from 0.04 to 0.61, which was under moderate to weak genetic control. On the whole, the genetic correlation coefficient was greater than the phenotypic correlation coefficient. The O. hosiei family with higher height and larger basal diameter has more branches and thicker branches. The plants with higher stem straightness can be selected indirectly through the selection of ground diameter. Conclusion There are extremely significant genetic differences, and the range of variation is large. Most traits were controlled by moderate to strong inheritance. The fast-growing O. hosiei individuals have more branches and thicker branches, which is beneficial to the breeding of O. hosiei germplasm resources.
Study on Growth and Physiological Response Mechanism of Xanthoceras sorbifolia Bunge under Salt-alkali Stress
2021, 34(3): 158-165. doi: 10.13275/j.cnki.lykxyj.2021.03.018
[Abstract](3443) [FullText HTML] (2362) [PDF 847KB](60) [Cited by] ()
Objective To explore the physiological response mechanism of Xanthoceras sorbifolia Bunge under saline-alkali conditions, so as to provide reference for silviculture in saline-alkali land. Method The relative conductivity, the activity of proline and superoxide dismutase (SOD) were studied to observe the change of physiological indicators. The influences of different concentrations of NaCl (70, 140, 210, 280 mmol·L−1) and Na2CO3 (35, 70, 105, 140 mmol·L−1) on the growth and physiological characteristics of one-year-old X. sorbifolia seedlings were observed by pot experiment. Result With the increase of saline-alkali concentration, the relative conductivity, the contents of proline and soluble protein changed significantly. The experimental data was larger than that of control group under high concentrations stress. Compared with the CK, the content of malondialdehyde increased significantly after 12 days of treatment with 210 mmol·L−1 salt and 105 mmol·L−1 alkali, and reached a peak with the concentrations of NaCl and Na2CO3 were 280 mmol·L−1 and 105mmol·L−1 respectively. Moreover, the SOD activity continued to increase under the stress, while the activity increased and then declined with the strengthen of the treatment concentration. Additionally, Two-way ANOVA showed that the time duration and concentration had extremely significant correlated with relative conductivity and proline content (P < 0.01). Correlation analysis demonstrated that the five physiological indicators measured in the leaves of seedlings under salt-alkali stress had significant positive correlation (P < 0.05). Principal component analysis was also applied after standardization of all index data. A principal component with eigenvalue greater than 1 was extracted under two different salt treatments. The cumulative variance contribution rate under NaCl treatment reached 82.423%, and the cumulative variance contribution rate under Na2CO3 treatment was 77.725%. Conclusion Under salt and alkali stress, X. sorbifolia Bunge mainly protects the integrity of the cell membrane system by accumulating a large amount of osmotic adjustment substances and increasing the activity of antioxidant enzymes. In the antioxidant enzyme system, the activity of SOD is higher under low-concentration stress than that of control group. However, the enzyme activity is destroyed under high concentration stress, which shows an obvious phenomenon of threshold value.
Screening of Camellia oleifera Rootstock Genotypes Tolerant to Low Phosphorus and Identification of Indexes Tolerant to Phosphorus Deficiency
2021, 34(3): 166-173. doi: 10.13275/j.cnki.lykxyj.2021.03.019
[Abstract](2968) [FullText HTML] (2605) [PDF 632KB](23) [Cited by] ()
Objective To screen the rootstocks with high tolerance to low phosphorus and the key indexes which can be used to identify low phosphorus tolerance of Camellia oleifera through evaluating different cultivates rootstocks tolerant to the low phosphorus. Method The pot seedling experiment with normal-P (1 mmol·L−1) and low-P (0 mmol·L−1) was carried out. A total of twelve seedlings of C. oleifera genotypes were selected. Fourteen indexes of each seedling of C. oleifera, including biomass, leaf area, leaf morphology, root morphology, total phosphorus content and so on, were measured under two different treatments. The coefficient tolerant to low P was used to evaluate the low P resistance and distinguish index of the low P tolerance for C. oleifera using a regression model. Result Under low P stress, the biomass accumulation in the shoot and root of most C. oleifera cultivates was generally reduced, and the ratio of root to shoot and PUE was generally increased. The result of PCA analysis showed that the 14 indexes were transformed into 4 independent comprehensive indexes, and their cumulative contribution rate reached 90.398%. The 12 C. oleifera varieties were divided into three types by D-value clustering, among which GF20, CL3, 84-3 were clustered as a type of relatively intolerant to low P, W1, CL53, GX48 as the intermediate type, G8, CL4, W2, CL40, CL18, 83-4 as low P tolerance. The equation model of PA (Total phosphorus accumulation), SPC (Shoot phosphorus content), TRA (Total root surface area), LW (Leaf width), RPC (Root phosphorus content) was established by stepwise regression: D = -0.960 + 0.666PA + 0.341SPC + 0.379TRA + 0.460LW + 0.197RPC. Conclusion Low P will inhibit the growth and total P accumulation and increase the ratio of root to shoot and total PUE for C. oleifera. The cultivates of G8, CL4, W2, CL40, CL18, 83-4 should be considered as the relatively low P tolerance varieties. The total P accumulation, aboveground P content, total root surface area, leaf width and toot P content could be identified as indicators for C. oleifera tolerant to low phosphorus.
Temporal and Spatial Distribution Characteristics of Negative Air Ion in Platycladus orientalis Forest of Jiulong Mountain, Beijing
2021, 34(3): 174-179. doi: 10.13275/j.cnki.lykxyj.2021.03.020
[Abstract](3169) [FullText HTML] (2405) [PDF 1604KB](57) [Cited by] ()
Objective To investigate the distribution of negative air ion (NAI) concentration in Jiulong Mountain which locates in suburb of Beijing, and understand the role of forest vegetation in improving air quality. Method KEC-900 air ion detector was used to measure and record the NAI concentration at 11 plots of P. orientalis stand in Jiulong Mountain of Beijing according to day, month, altitude and aspect by the method of fixed observation. Result The diurnal variation of NAI concentration in Jiulong Mountain differed among seasons. The curves of diurnal variation of NAI concentration in spring and summer followed a single-peak type, and the spring and summer peak values appeared at 12: 00 and 14: 00. The curves of diurnal variation of NAI concentration in autumn and winter followed a double-peak type, and the peak values appeared at 8: 00 and 18: 00. The monthly average concentration of NAI was characterized by two peaks in May and October, with values of 691 ions per cm3 and 920 ions per cm3. The concentration of NAI rose at first and then decreased with the increase of altitude. When the altitude is higher than 450 m, the NAI concentration in the P. orientalis forest was greater than in the forest edge. In the P. orientalis forest locates in Sijiangou with the altitude of 140m, the NAI concentration on the sunny slope was slightly lower than that on the shaded slope (P > 0.05) in April, and the NAI concentration on the sunny slope was significantly higher than that on the shaded slope (P < 0.05) in August. Conclusion The NAI concentration in the P. orientalis forest of Jiulong Mountain have obvious spatial and temporal distribution characteristics, that is, the concentration of NAI shows "single peak type" or "double peak type" with time, and shows "single peak type" with altitude, and is affected by both the aspect and the time.
Effects of Stand Factors of Pinus tabulaeformis Stand on Damage of Matsucoccus sinensis in Bailongjiang Forest Area
2021, 34(3): 180-186. doi: 10.13275/j.cnki.lykxyj.2021.03.021
[Abstract](2955) [FullText HTML] (2047) [PDF 742KB](19) [Cited by] ()
Objective To study the effects of stand factors of Pinus tabulaeformis stand on the damage severity of Matsucoccus sinensis, so as to provide reference for the prevention and control of M. sinensis in Bailongjiang forest area. Method Pure P. tabulaeformis stands with relatively uniform age structure (about 25 years-old) were selected as the object in Bailongjiang forest area, and seven stand factors, including herb coverage, stand density, canopy density, tree height, height under branch, DBH and crown width, and the pest severity index of M. sinensis were investigated in the sample plots. The relationship between stand factors and pest severity index in the plot was analyzed. Result The results showed that six stand factors, i.e. herb coverage, stand density, tree height, height underbranch, DBH and crown width, had significant effect on the damage severity of pure P. tabulaeformis stand, but the canopy density showed less effect. Through multiple regression analysis and stepwise regression analysis, the key stand factors affecting the damage severity of M. sinensis were found to be herb coverage, stand density and height under branch. Herb coverage had a significant effect on the pest severity index of M. sinensis (P < 0.01). The correlation analysis showed that with the increase of herb coverage, the pest severity index decreased. The effect of stand density on the pest severity index of M. sinensis was very significant (P < 0.01), and the damage of low density stand (381~763 trees·hm−2) was aggravated by M. sinensis, the stand density (>763 trees·hm−2) of P. tabulaeformis stand was less damaged. There was a significant difference in the effect of height under branch on the pest severity index (P < 0.01), the stand with the height under branch of 3.5~4.4 m was seriously damaged by M. sinensis, while the stand with lower height under branch (1.1~3.5 m) was less damaged. Conclusion The stand factors of pure P. tabulaeformis stand are closely related to the occurrence and damage of M. sinensis, and the three stand factors (herb coverage, stand density and the height under branch) have the most significant effect on the occurrence and damage of M. sinensis. It is suggested that adjusting the stand factors, pruning and thinning are effective in preventing and controlling the damage of M. sinensis.
Isolation and Investigation on Properties of Nitrogen-fixing Bacteria from Rhizosphere of Broussonetia papyrifera Hybrid
2021, 34(3): 187-193. doi: 10.13275/j.cnki.lykxyj.2021.03.022
[Abstract](3989) [FullText HTML] (2613) [PDF 679KB](39) [Cited by] ()
Objective To obtain strains of nitrogen-fixing bacteria from Broussonetia papyrifera (Linnaeus) L’Héritier ex Ventenat hybrid and determine their functional characteristics. Method The Ashby medium was selected as separation condition to isolated nitrogen-fixing bacteria from the roots and rhizosphere soil of B. papyrifera hybrid in Tianshui, Lanzhou and Zhangye experimental areas of Gansu Province. In addition, identification and phylogenetic analysis were carried out on the isolated nitrogen-fixing bacteria. The nitrogenase activity, phosphorus solubility, properties of IAA-producing and inhibition of plant pathogenic fungi of each strain were determined at the same time. Entropy weight method was used for comprehensive evaluation of the features of the strains. Result A total of 10 nitrogen-fixing bacteria was isolated from the soil far from the rhizosphere and topsoil, which belonged to 8 genera, mostly Pseudoxanthomonas. Each strain showed nitrogenase activity, among which the nitrogenase activity of the strains TS4 and HP10 was greater than 180 IU·L−1. Only the strains TS4 and HTZ2 had certain phosphorus solubility. 8 strains could secrete IAA, among which the strain HTZ4 demonstrated the strongest secretion ability, with an IAA increment of 44.62 µg·mL−1. All strains showed no antagonistic effect on Botrytis cinerea Persoon, 7 strains showed inhibitory effects on at least two kinds of plant pathogens. The strains HTZ4, HTZ3, and HP5 showed the strongest inhibitory activities against Alternaria solani (Ellis et G. Martin) Sorauer, Fusarium oxysporum Schlecht and Fusarium solani (Martius) Sacco, respectively, with inhibition rates of 50.00%, 48.78% and 47.37%. To sum up, the strains with strong comprehensive properties were the strains TS4, HP5, ZY9, HTZ4 and HTZ5. Conclusion The results of this study can provide data and references for further developing nitrogen-fixing strains with excellent comprehensive performance, multifunctional nitrogen-fixing bacterial fertilizer for Broussonetia papyrifera hybrid, and promoting the yield of Broussonetia papyrifera hybrid in semi-arid area of Northwest China.
2021, 34(3): 194-200. doi: 10.13275/j.cnki.lykxyj.2021.03.023
[Abstract](3628) [FullText HTML] (2707) [PDF 709KB](41) [Cited by] ()
Objective To explore the optimal medium ratio at each stage of the tissue culture of Betula albo-sinensis, to establish the tissue culture system of B. albo-sinensis, and provide theoretical support for the studies on species selection of superior varieties, directional cultivation and genetic transformation of B. albo-sinensis. Method Using dormant buds of B. albo-sinensis as explants to study the optimal disinfection and sterilization method of explants, the effect of 6-BA and NAA concentrations on the germination of dormant buds and proliferation culture, and the effects of basic medium types, IBA and sucrose concentrations on the induction of adventitious root. Result The optimal tissue culture system of B. albo-sinensis established in this study is as follows. (1) Using B. albo-sinensis dormant buds as explants, and sterilized with 70% alcohol for 30 seconds and washed with sterile water for 3-4 times, then sterilized with 0.1% HgCl2 for 8 minutes and washed with sterile water for 5-6 times to obtain sterile materials. (2) The optimal medium for the germination of dormant buds is WPM basic medium with 1.5 mg·L−1 6-BA and 0.1 mg·L−1 NAA, the germination rate of explants is 83.33%. (3) The best proliferation culture is WPM adding 1.5 mg·L−1 6-BA and 0.02 mg·L−1 NAA, with a proliferation coefficient of 4.77 and a health index of 2.45. (4) The most suitable medium for adventitious root induction is WPM supplemented with 0.8 mg·L−1 IBA, the rooting rate is 100%, and the root health index is 2.61. All the media are supplemented with 30 g·L−1 sucrose and 7 g·L−1 agar. Conclusion With WPM as the basic medium and different concentrations of 6-BA, NAA and IBA added, the culture of B. albo-sinensis at all stages could be successfully carried out, and a complete regeneration system of organogenesis generation pathway is established. The transplant survival rate of regenerated plants is higher than 80%.