2022 Vol. 35, No. 2
2022, 35(2): 0-0.
[Abstract](1080) [FullText HTML] (700) [PDF 3213KB](74) [Cited by] ()
2022, 35(2): 0-1.
[Abstract](1085) [FullText HTML] (699) [PDF 276KB](63) [Cited by] ()
2022, 35(2): 1-8. doi: 10.13275/j.cnki.lykxyj.2022.02.001
[Abstract](2966) [FullText HTML] (1598) [PDF 793KB](141) [Cited by] ()
Objective To explore the latitudinal variations of soil organic carbon (C), total nitrogen (N) and total phosphorus (P) and their ecological stoichiometry in Pinus massoniana (Lamb.) plantations of subtropical China. Method Soil samples of 0-20 cm layer were collected from the pure plantations in eight sites ranging from southeast to northwest to determine the contents of soil organic C, total N and total P. The variations of soil C-N-P contents and their ecological stoichiometry along the latitudinal gradient were explored by regression analysis. The relationships of climatic factors (mean annual temperature, MAT and mean annual precipitation, MAP), stand characteristics (age, density and DBH) and soil key properties (pH value and clay content) with soil C-N-P contents and stoichiometry were examined by Pearson’s correlation analysis and redundancy analysis. Besides, the relative contribution rates of these environmental factors to the variations in soil C-N-P contents and stoichiometry were analyzed using the variation partitioning analysis. Result The average contents of soil organic C, total N and total P were 16.02, 1.22, and 0.35 g·kg-1, respectively; and the average ratios of soil C:N, C:P and N:P were 14.18, 47.01, and 3.59, respectively. Both soil organic C and total N decreased significantly (P<0.01) with increasing latitude, while no obvious spatial pattern of total P was found. Soil C:N significantly increased (P<0.05) while soil C:P and N:P decreased (P<0.01) over latitude. The soil organic C and total N were significantly positively correlated with MAT, MAP, and diameter at breast height (DBH) (P<0.05), but negatively correlated with soil pH value (P<0.05). The soil C:P and N:P were significantly positively correlated with MAT, MAP, DBH, and soil clay content (P<0.05), while negatively correlated with stand age (P<0.05). Climatic factors, stand characteristics and soil key properties totally explained 63.8% of latitudinal variations in soil organic C, total N, total P and soil C:N, C:P, N:P, with characteristics of climatic factors (46.3%) > stand characteristics (43.3%) > soil properties (35.5%). Conclusion Soil C:N, C:P and N:P in P. massoniana (Lamb.) plantations follows obvious latitudinal patterns, which are driven by MAT, MAP, stand age, stand density, DBH, soil pH value, and soil clay content. Importantly, the interaction effects of these environmental factors are greater than the single effects.
Dynamic Variation of Growth Traits in Open-pollinated Families of Quercus acutissima Superior Tree and Selection of Superior Families Among Three Sites
2022, 35(2): 9-18. doi: 10.13275/j.cnki.lykxyj.2022.02.002
[Abstract](2919) [FullText HTML] (1582) [PDF 1032KB](72) [Cited by] ()
Objective To study the genetic variation of growth traits in superior open-pollinated families of Quercus acutissima with the increase of stand age, and to select the superior families for Q. acutissima plantation cultivation. Method Eighteen superior tree open-pollination families coming from Rongshui of Guangxi Zhuang Autonomous Region were planted in 3 test sites (Yongfeng of Jiangxi Province, Kaihua of Zhejiang Province and Chuzhou of Anhui Province). The variation in tree growth among the families and the dynamic changes of above-ground biomass of individual tree (AGB) with stand age were investigated. The stability of growth traits was evaluated using the AMMI model, and then the superior families were selected. Result The tree height, diameter at breast (or ground) height, and the AGB significantly differed among the 3 test sites. The AGB of Q. acutissima trees was significantly affected by the site, family, and family × site. The site had the greatest impact on growth variation, followed by family and family × site. The growth performance of 1-3 years old and 6-11 years old families had great difference among test sites. Based on the AGB at the 11st year, the superior families in Yongfeng were M11, M9 and M15, their genetic gain was 4.08%-7.45%; the superior families in the Kaihua were M16 and M2, their genetic gain was 28.01%-37.02%; the superior families in the Chuzhou were M17, M1 and M18, their genetic gain was 15.05%-30.29%. According to growth performance and stability analysis, it was showed that the families M18 and M20 were suitable for cultivation at all the 3 test sites. The average biomass of the AGB was 31.38 kg, and the average Dg(e) was 0.88. Conclusion The growth of superior open-pollinated families of Q. acutissima will be affected by the interaction of site and family, and some superior families were selected for Q. acutissima plantation cultivation.
Study on Effectiveness of Crop Tree Management for Individual Tree Growth in Spruce-Fir Coniferous-Broadleaved Mixed Forest
2022, 35(2): 19-27. doi: 10.13275/j.cnki.lykxyj.2022.02.003
[Abstract](2739) [FullText HTML] (1352) [PDF 769KB](105) [Cited by] ()
Objective The aim of this study is to explore the effect of crop tree management on the growth of individual trees in coniferous-broadleaved mixed forest, and provide technical support for the ecological restoration and succession of coniferous-broadleaved mixed forest community and forest quality precision improvement. Method The spruce-fir coniferous-broadleaved mixed forest in Wangqing Forestry Bureau of Jilin Province was selected as the research object. Variance analysis was applied to analyze the influence on DBH increment and volume increment caused by crop tree management and the control group, as well as by the different number of free-to-growth (FTG), according to different diameter classes and tree species. Result (1) Compared with the control, the increment of DBH and volume of crop trees of different diameter classes under crop tree management were significantly different, except for the crop trees of diameter class III. With the increase of diameter class, the growth promotion effect of crop trees decreased significantly. (2) Crop tree management did not significantly improve or inhibit the growth of crop trees of pioneer tree species. However, it could significantly promote the growth of crop trees of climax and associated tree species, especially for the climax tree species. (3) With the increase of free-to-growth space, the growth of crop trees of different diameter classes increased, but the difference of volume increment of diameter class III was not significant. The growth of DBH reached the maximum in FTG4 and the growth of volume reached the maximum in FTG3. Compared with before management, at least two directions of free-to-growth space needed to be released to significantly promote the growth of the crop tree. (4) Tilia amurensis was suitable for 2-3 growth directions, Abies nephrolepis was suitable for 2-4 growth directions, Pinus koraiensis and Picea schrenkiana were suitable for 3-4 growth directions. Conclusion Crop tree management can significantly promote the growth of crop tree, and is conducive to community restoration and succession. The crop tree management of spruce-fir coniferous-broadleaved mixed forest should focus on small and medium-sized trees, followed by the large-sized trees. 2-4 directions of free-to-growth space should be released according to the suitability of different tree species.
2022, 35(2): 28-36. doi: 10.13275/j.cnki.lykxyj.2022.02.004
[Abstract](3126) [FullText HTML] (1472) [PDF 877KB](51) [Cited by] ()
Objective Based canopy height model (CHM) to automatically delineate the forest sub-compartments of forest resources management inventory similar to the manual delineation. Method Supported by tree species derived from hyperspectral image, the CHM generated from airborne LiDAR data was used for multi-resolution segmentation and optimization. First, the segmentation was applied on 1 m resolution CHM to obtain the over-segmentation results. Then 1 m resolution CHM was down sampled to 5 m resolution and segmented to get the under-segmentation results. By combining and optimizing these two results, the final sub-compartment delineation was obtained. The manual sub-compartments, the sub-compartments delineated based on 0.1 m spatial resolution Digital Orthophoto Map (DOM) and the Logging sub-compartments were used as reference data. The Ultimate Measurement Accuracy (UMA) rule was used to validate the accuracy of boundary drawing of stand segmentation results in its consistency with the reference sub-compartments. The UMA has 8 indexes, which are Roundness, Compactness, Shape index, Radius of smallest enclosing ellipse, Elliptic fit, P2A etc. And the Intersection Over Union (IOU) ratio was also introduced to quantify the consistency between the automatic segments and reference sub-compartments. The explained variance of mean height and mean DBH was calculated using the field data to validate the internal consistency and external variability accuracy of automatic segments. Result The automatic segments were similar to that of the reference sub-compartments in shape, area and other characteristics of UMA, and were most similar to the manual sub-compartments. The proportions of automatic segments whose IOU ratio was more than 70% with manual sub-compartments, the DOM sub-compartments and the Logging sub-compartments were 46%, 37%, and 43%, respectively. The proportions of automatic segments whose IOU ratio more than 50% were 61%, 54%, and 55%. The explained variances of mean DBH and mean height of automatically delineated sub-compartments were 97% and 98%, indicating the high internal consistency and distinct differences with adjacent sub-compartments of automatic sub-compartments. The explained variances of mean canopy height was 84.81%, which was 1.77% higher than that of the manual sub-compartments. Conclusion The sub-compartments automatically delineated by multi-scale segmentation method with CHM and tree species derived from hyperspectral image have obvious advantages in terms of internal consistency and boundary accuracy, and are more consistent with the distribution of trees at sub-compartments boundaries. This method saves time, increases efficiency, and increases the accuracy of forest sub-compartment delineation, which can support forest delicacy management planning.
2022, 35(2): 37-44. doi: 10.13275/j.cnki.lykxyj.2022.02.005
[Abstract](2774) [FullText HTML] (1805) [PDF 1220KB](83) [Cited by] ()
Objective To provide theoretical support for exploring the regulatory function of WOX4b gene in walnut adventitious rooting. Method Using the cDNA of Juglans regia ‘Linzaoxiang’ as template, the full-length CDS of JrWOX4b was cloned. The multiple sequence alignments and evolution analysis were applied by using bioinformatics technology to analyze its molecular characteristics. The fusion expression vector of JrWOX4b and yellow fluorescent protein (YFP) tag were constructed for subcellular localization analysis. After completing the genetic transformation and phenotype analysis of Populus alba × P. glandulosa, the function of this gene was determined. Result The CDS of JrWOX4b is 678 bp in length, encoding 226 amino acids, and molecular weight is 25.42 KDa. The results of multiple alignment and phylogenetic analysis of the amino acid sequences showed that walnut JrWOX4b has the closest genetic relationship with the homologous protein of Carya illinoensis, followed by Quercus lobata, while has the farthest genetic relationship with Panicum miliaceum and Brachypodium distachyon. Phenotypic analysis of JrWOX4b overexpression plants showed that both the transgenic and control plants grew normally. However, under the same culture conditions, JrWOX4b could significantly increase the number of adventitious roots. The number of adventitious roots of 2-week-old overexpression plants is 3～4 times that of the control plants, and the length of adventitious roots is 1/2 of that of control plants. Conclusion JrWOX4b, the member of WOX gene family, was successfully cloned from walnut, and its overexpression can significantly promote the number of adventitious roots. The results provide theoretical support for the research on adventitious root regulation mechanism, and also provide excellent genetic resources for the rapid propagation of other difficult-to-root plant species.
Characterization of Differentially Expressed Genes in Root Tips of Poplar Under Different Nitrogen Forms
2022, 35(2): 45-55. doi: 10.13275/j.cnki.lykxyj.2022.02.006
[Abstract](2722) [FullText HTML] (1696) [PDF 1138KB](48) [Cited by] ()
Objective To understand the molecular regulation mechanism of Populus × canescens root tips in response to different nitrogen forms. Method High-throughput transcriptome sequencing technology was used to screen and analyze the differentially expressed genes in poplar root tips under nitrate or ammonium treatments. At the same time, the effects of differently expressed genes on the growth and development process of poplar root tips were analyzed and described, which provides a scientific basis for the subsequent development of new poplar germplasm with high nitrogen absorption and utilization. The root tips of P. × canescens were treated with 0.5 mmol·L−1nitrate (NO3−) and 0.5 mmol·L−1 ammonium (NH4 + ) for 10 days, and transcriptome sequencing and bioinformatics analysis were performed on the root tips of the plants. Result The root length under nitrate treatment was almost twice that under ammonium treatment. 2207 differentially expressed genes were identified from the root tip transcriptome library of poplar treated with two nitrogen forms. Fifty GO functional clusters and 20 KEGG pathways were obtained by means of differential gene GO and KEGG functional clustering analysis, respectively. Furthermore, 36 differentially expressed genes related to nitrogen metabolism pathway, biosynthesis of various amino acids and metabolic process were screened by MapMan analysis. Analysis of the regulatory network of these differential gene interactions showed that nitrate reductase (Potri.005G172400) gene played an important role in affecting root tip growth and development by responding to different nitrogen forms. Conclusion Differentially expressed genes of poplar root tips under different nitrogen form treatments were obtained. The functions of the differentially expressed genes were analyzed, which may help to understand the molecular mechanism of poplar root tip growth and development process by responding to different nitrogen forms.
Study on Safety of Grafted and Self-rooted Seedlings of 4-year-old Transgenic Populus tomentosa in Trial Plots
2022, 35(2): 56-66. doi: 10.13275/j.cnki.lykxyj.2022.02.007
[Abstract](2701) [FullText HTML] (1674) [PDF 1183KB](27) [Cited by] ()
Objective To study the safety of transgenic Populus tomentosa with AhDREB1 gene from self-rooted seedlings planted in Binhai of Tianjin and transgenic seedlings planted in Yanshan of Hebei in order to evaluate the possible impact of transgenic Populus tomentosa on the environment. Method PCR amplification and electrophoresis were used to detect the genomic DNA of the 4-year-old transgenic P. tomentosa, soil DNA, root DNA of grafted seedlings from Yanshan and the genomic DNA of resistant microorganisms in Binhai. The amount of rhizosphere microorganisms in the soil of Binhai trial plot was monitored continuously (March, April and May). The degradation time of different organs (new shoots, perennial branches, new root tips, perennial lateral roots, new young leaves and old leaves) at different growth stages of transgenic P. tomentosa plants were measured in Binhai and Yanshan trial plots under simulated natural conditions. The allelopathic test was conducted to determine whether the transgenic leaves of P. tomentosa had any effect on the growth of Brassica pekinensis seeds. Result The electrophoretic results showed that exogenous genes stably existed in the genome of transgenic P. tomentosa, and no target gene fragment was found in soil DNA, root stock DNA of Yanshan grafted seedlings and DNA samples of resistant microorganisms. There was no significant difference in the amount of culturable microorganisms in the rhizosphere soil between non-transgenic plants and transgenic plants in Binhai. Exogenous genes were degraded in the litter of transgenic P. tomentosa after 2 months, whether it fell on the weed surface, soil surface or buried in soil. The allelopathic results showed that there was no significant difference between the non-transgenic plants and the transgenic plants on the growth of the hypocotyl and radicle of Brassica pekinensis seed. Conclusion No effect of transgenic P. tomentosa on the surrounding environment is found after 4 years of planting in the trial plot .
Effect of Fractal Characteristics of Soil Structure on Macropores in Different Succession Forest Communities in Mid-subtropical Region
2022, 35(2): 67-77. doi: 10.13275/j.cnki.lykxyj.2022.02.008
[Abstract](2046) [FullText HTML] (1304) [PDF 922KB](25) [Cited by] ()
Objective To study the structural fractal characteristics of different successional forest communities in the middle subtropical zone and its influences on soil macropores, so as to provide data support. Method The Pinus yunnanensis forest in the early succession, the P. yunnanensis-broadleaved mixed forest in the middle of succession and succession top evergreen broadleaved forest were chosen as the research objects in Mopanshan Mountain, central Yunnan. The methods of dyeing combined with image morphology analysis were adopted to analyze the fractal characteristics of soil and its influences on macropores. Result The number of macropores and total porosity in the vertical section generally decreased with the deepening of soil layer, while the number of horizontal pores decreased with the increase of radius. The order of porosity among different forests was P. yunnanensis and broadleaved mixed forest > evergreen broadleaved forest > P. yunnanensis forest. The pore surface density (Mz) decreased monotonously with the increase of soil depth, and the pore complexity (Dz) showed the opposite trend. The Dz of evergreen-broadleaved forest was the largest (2.006), while P. yunnanensis forest was the smallest (1.595), indicating the higher the community level, the more complex the structure, and the greater the distortion and variation of macropores. Soil fractal characteristics proved that the soil structure of evergreen broadleaved forest was better than that of the other two communities. The soil structure decreased with the increase of depth. The correlation analysis revealed that there existed a positive correlation between Mz and agglomerate fractal dimension (P < 0.01), while DZ had a negative correlation with soil mechanical fractal dimension (P < 0.05). The contents of different diameter aggregated and agglomerate fractal dimension had remarkably effects on soil pore surface density. Conclusion The soil macropores and structure will be greatly improved with the succession process, and the soil structure stability of the top succession community is the best. The research results could provide reference for reducing soil moisture and nutrient loss, thus improving the ecological service function of forest communities.
Leaf Color Diversity and the Change of Physiological Characteristics of Quercus spp. During the Discoloration Period in Autumn
2022, 35(2): 78-88. doi: 10.13275/j.cnki.lykxyj.2022.02.009
[Abstract](2562) [FullText HTML] (1583) [PDF 1195KB](52) [Cited by] ()
Objective To study the change of physiological characteristics changes of Quercus spp. during the discoloration period and found the relationship between leaf color diversity and physiological changes. Method 4-year-old seedlings of Sect. Lobatae (Quercus texana, Q. shumardii, Q. phellos, Q. laurifolia and Q. pagoda) and Sect. Quercus (Q. lyrata, Q. michauxii and Q. fabri) were used to measure chromatic aberration parameters (L*, a*, and b*), pigment, soluble sugar, C, N and P contents during the leaf senescence stage. Result During the autumn, the leaf senescence period, the variation range of L* value was small and stable. The values of a* and b*, chlorophyll and carotenoid contents decreased whereas the anthocyanin content increased gradually. The leaf N and P contents decreased gradually in the senescing leaves, but the contents of soluble sugar in leaves increased. The a* value showed significantly positive correlations with anthocyanin and soluble sugar content, C:N ratio and C:P ratio; and negative correlations with chlorophyll, carotenoid, N and P content. In general, the leaf color of Sect. Lobatae was redder than that of Sect. Quercus, while there were significant differences among species in terms of leaf color and leaf color retention period. Due to the different magnitude of variation in each index of each species, the leaf color of Quercus spp. changed from green to yellow-red, crimson, bright red or brown in the late stage of leaf discoloration. The leaf color of Q. texana was the reddest in autumn and the red leaves occurred the longest. Conclusion Usually, the leaf color of Sect. Lobatae will change earlier than that of Sect. Quercus. In the early stages, the variation of parameters is very small. After, the leaf color of Quercus spp. is mostly affected by chlorophyll and carotenoids break down and anthocyanins will synthesize quickly. The N and P contents will gradually decrease, and the utilization rate increase significantly.
2022, 35(2): 89-96. doi: 10.13275/j.cnki.lykxyj.2022.02.010
[Abstract](2217) [FullText HTML] (1355) [PDF 900KB](34) [Cited by] ()
Objective The humus layer moisture is one of the environmental characteristics of a forest. It is significant to explore the long-term dynamics of the humus layer moisture and the underlying regulatory mechanisms for understanding the water conservation function of a forest ecosystem and the changes of the forest environment. Method In this study, we focused on the zonal climax forest in lower subtropical China, i.e., the monsoon evergreen broad-leaved forest which was strictly protected in Dinghushan National Nature Reserve. Based on the unified standards for the construction and monitoring of forest plots by Chinese Ecosystem Research Network, long-term observation of humus layer moisture in the monsoon evergreen broad-leaved forest was conducted from 2005 to 2018. This study aims at exploring the long-term dynamic of humus layers moisture and its regulatory mechanisms. Result During 2005 to 2018, the average annual precipitation of Dinghushan was 1 975.6 mm, the average annual temperature was 22.3 ℃, the rainfall was abundant and the heat input was stable throughout the year, presenting warm wet summers and cool dry winters. The average standing mass of humus layer was 126.0 g·m−2, which was slightly higher in the dry seasons (130.3 g·m−2) than in the wet seasons (121.6 g·m−2). The average annual humus layer moisture was 89.5%. The mean humus layer moisture in wet seasons (103.2%) was obviously higher than that in dry seasons (75.8%), and the variation coefficient in the wet seasons (19.6%) was significantly lower than that in the dry seasons (35.9%). Compared with the change of soil water storage (0-15 cm) in the same period, the variation coefficient of humus layer moisture (30.1%) was significantly higher than that of the soil water storage (11.6%), indicating that humus layer was more sensitive to the change of external environment. Further analysis showed that the precipitation, air relative humidity, evaporation, vapor pressure deficit and soil water storage had profound effects on the dynamic of humus layer moisture, especially the air relative humidity in the wet seasons and the air relative humidity and precipitation in the dry seasons had the dominant effects, respectively. Conclusion The humus layer moisture in monsoon evergreen broad-leaved forest in Dinghushan is relatively high. It plays an important role in stabilizing the internal environment of forest ecosystem and indicating the change of regional environment.
2022, 35(2): 97-103. doi: 10.13275/j.cnki.lykxyj.2022.02.011
[Abstract](3315) [FullText HTML] (1366) [PDF 854KB](39) [Cited by] ()
Objective To obtain the key NAC genes involving in regulating the root growth and development of yew trees. Method Basing on the full-length transcriptome data of Taxus × media, bioinformatics methods were used to identify NAC transcription factors. The protein structure and gene tissue expression profile of the selected NAC genes were also analyzed. Result A total of 44 NAC transcription factors were identified, which have typical conserved NAC domains at the N-terminal, and most of the members contain 5 conserved structural functional subdomains. Phylogenetic tree analysis showed that 44 T. × media NAC (TmNAC) proteins were clustered into 7 subfamilies of Arabidopsis. Sequence structure analysis indicated that the tertiary structures of the TmNAC proteins were similar, but the structures of the representative member of different subfamily also showed obvious differences. The expression results showed that TmNAC15, 16, 18, 21, 22, 29, 39, 40, 41, and 44 had higher expression level in roots than stems and needles. Conclusion In this study, 44 TmNAC transcription factors were identified from T. × media and they were clustered into 7 subfamilies. Among them, TmNAC21, 22, 39, 40, and 44 may be involved in the root growth and development progresses of yew trees.
Soil Enzyme Activity Related to Nitrogen Cycling in Chinese Fir (Cunninghamia lanceolata) Plantation with Different Stand Age
2022, 35(2): 104-111. doi: 10.13275/j.cnki.lykxyj.2022.02.012
[Abstract](2727) [FullText HTML] (1225) [PDF 807KB](67) [Cited by] ()
Objective To study the variation of soil nitrogen (N)-cycling enzyme activities and rhizosphere effect during the development of Chinese fir (Cunninghamia lanceolata) plantation and its driving factors. Method Rhizosphere and non-rhizosphere soils were collected from Chinese fir plantation with the ages of 7, 15, 24 and 34. The enzyme activities regulating soil nitrogen cycling (β-glucosidase (BG), acetyl-β-D-glucosaminidase (NAG), proteolytic enzyme (PRO), urease (URE), leucine aminopeptidase (LAP) and nitrate reductase (NR)) were measured. Redundancy analysis (RDA) and Pearson correlation were conducted to explore the relationship between soil nitrogen-cycling enzyme activities and the soil physico-chemical properties. Result Forest age and rhizosphere had significant effects on soil N-cycling enzyme activities (P<0.05). The enzyme activities regulating soil nitrogen cycling in the non-rhizosphere soil decreased at first and then increased with the increase of forest age. The activities of BG, NAG, PRO, URE and LAP in rhizosphere soil were significantly higher than those in non-rhizosphere soil (P<0.05). The difference of NR activity between rhizosphere and non-rhizosphere soil varied with forest age. The NR activity in rhizosphere soil was significantly higher than that of non-rhizosphere soil in 15- and 24-years-old Chinese fir plantations (P<0.01). The rhizosphere effects of soil NR activities in 15-years-old Chinese fir plantation were significantly higher than those in 7-years-old and 34-years-old Chinese fir plantations (P<0.05). The key factors regulating soil N-cycling enzyme activities in rhizosphere and non-rhizosphere soil were C/N and ammonium nitrogen content. Conclusion Soil N-cycling enzyme activities was the lowest in middle-age Chinese fir plantations in mid-subtropical China, indicating that nitrogen may still be one of the main limiting factors in the fast-growing stage of Chinese fir plantations. In the future, we should focus on the middle-age Chinese fir plantation, so as to meet the nitrogen demand of Chinese fir and achieve the purpose of sustainable management.
2022, 35(2): 112-117. doi: 10.13275/j.cnki.lykxyj.2022.02.013
[Abstract](2025) [FullText HTML] (1410) [PDF 663KB](35) [Cited by] ()
Objective To select highly pathogenic strain of Beauveria bassiana against Hippotiscus dorsalis nymph, so as to support the biological control of H. dorsalis. Method The entomopathogenic fungi were isolated from muscardine cadaver of H. dorsalis with the tissue isolation approach. The species identification was conducted based on morphological method combined with DNA barcoding. The virulence of B. bassiana isolates was evaluated by bioassay. Result In the study, seven strains of entomopathogenic fungi were isolated from the muscardine cadaver of H. dorsalis. The morphological characteristics, cultural characteristics and ITS rDNA sequences of all isolates were consistent with those of B. bassiana, so these isolates were identified as B. bassiana. The results of bioassay in the laboratory showed that, when the conidia concentration was 108 conidia·mL−1, the LT50 of LYC10, LYC11, LYC15 and LYC4 strains were 5.04 days, 5.45 days, 6.17 days and 14.03 days, respectively. In the field, the LC50 of LYC11 strain was 2.43 × 104 conidia·mL−1. Conclusion In the study, seven strains of B. bassiana were isolated from H. dorsalis. It is showed the pathogenicity of different strains is different, and the pathogenicity of LYC10 strains is the strongest. The cumulative mortality of LYC11 strain in bamboo forest is lower than that measured in the laboratory.
2022, 35(2): 118-128. doi: 10.13275/j.cnki.lykxyj.2022.02.014
[Abstract](2297) [FullText HTML] (1621) [PDF 1283KB](45) [Cited by] ()
Objective To understand the relationship between leaf biomass and radial growth of Larix olgensis in Xiaoxing'anling Mountains. Method The relationship between leaf biomass and radial growth at individual tree level and at different direction interval of individual tree was studied based on pipe model theory, and the correlation between crown distribution and radial growth was analyzed. Result Leaf biomass was significantly and positively correlated with stem diameter, basal area and sapwood area at breast height and height to crown base, as well as basal area growth in recent 1 , 2 , 3 and 5 years, and the leaf biomass model using breast height basal area as a predictor had the best fitting effect. The leaf biomass in different direction interval of a single tree was significantly positively correlated with the stem radius and basal area at the corresponding DBH and the height to crown base, and the growth of basal area in recent 1, 2, 3 and 5 years. Conclusion When estimating the leaf biomass per tree, the basal area of breast height is the best predictor. The leaf biomass of different direction interval in a individual tree is significantly and positively correlated with the stem radius, basal area and basal area growth of corresponding directions, and there is a certain correlation between crown displacement and pith eccentricity.
Molecular Cloning and Expression Analysis of Transcription Factor Gene CoSOC1-like in Camellia oleifera
2022, 35(2): 129-139. doi: 10.13275/j.cnki.lykxyj.2022.02.015
[Abstract](2941) [FullText HTML] (1705) [PDF 1052KB](47) [Cited by] ()
Objective To clone the homologous gene of SOC1 from Camellia oleifera (CoSOC1-like) and to analyze its sequence structure, expression pattern and protein evolution. Method Total RNA was extracted from the young leaves of three-years-old C. oleifera, and the CoSOC1-like gene was cloned by using RT-PCR technology and RACE (rapid amplification of cDNA ends) technology. The sequence and expression pattern of CoSOC1-like were analyzed using the bioinformatic tools and fluorescence quantitative PCR, respectively. The subcellular localization and evolution of CoSOC1-like protein were analyzed using the method of gene transient expression and MEGA7 software, respectively. Result The full length cDNA of CoSOC1-like contained 654 bases, encoding 217 amino acids, and the relative molecular weight was 24.958 kD and the isoelectric point was 6.8. The Genbank accession number of CoSOC1-like is MT036382. The CoSOC1-like protein had the structure of MADS-box family transcription factors of plant type Ⅱ, and there was a SOC1 MOTIF in C-domain. The CoSOC1-like protein had 31 phosphorylative loci in its amino acid sequence, and its tertiary structure based on secondary structure had obvious active sites, and the transient expression of CoSOC1-like gene showed the CoSOC1-like protein located in nuclear, which was consistent with the nuclear localization characteristics of transcription factors. The phylogenetic analysis showed that the CoSOC1-like protein was clustered in the same evolutionary branch with SOC1-like protein of Camellia sinensis. Fluorescence quantitative PCR analysis showed that the CoSOC1-like gene could be detected in all organs, and there was a maximal relative expression level in flower buds of C. oleifera. Conclusion The CoSOC1-like gene may play an important role in the flower bud differentiation, and participate in the growth and development of other organs such as root, stem, leaf and seed of C. oleifera.
Identification and Biological Activity of a New Virus of Micromelalopha sieversi (Staudinger) (Lepidoptera: Notodontidae)
2022, 35(2): 140-147. doi: 10.13275/j.cnki.lykxyj.2022.02.016
[Abstract](2169) [FullText HTML] (1432) [PDF 715KB](30) [Cited by] ()
Objective To identify a new viral strain of baculovirus which have high virulence against Micromelalopha sieversi (Staudinger). Method The ultrastructure and biological activity of this virus were study to determine its biological control potential. Result The ultrastructure showed that the occlusion bodies of the virus mainly consisted of ellipse, with an average size of 0.43 × 0.21 μm and the inclusion bodies embedded a single rod-shaped virion. It had the structural features of a granulovirus named as Micromelalopha sieversi granulovirus (MisiGV). Biologic activity assays showed that MisiGV is highly virulent in the 3rd instar larvae of M. troglodyta, with an LC50 of 2.37 × 105 OBs·mL−1. The LT50 of the virus increased with the decreasing of virus concentration. When the virus concentration were 1.2 × 107, 4.0 × 106, 4.0 × 105, 1.2 × 105 and 4.0 × 104 OBs·mL−1, the LT50 values were 7.55, 11.61, 14.69, 16.06 and 17.62 days, respectively. The susceptibility of larvae at different instar to different MisiGV concentrations indicated that the younger larvae of M. troglodyta were more susceptible to virus than the older larvae, and the speed of larval death depended on the age and virus concentration. Generally, at 4.0 × 106 OBs·mL−1, the highest cumulative mortality of 2nd and 4th instar larvae were 90.00% and 50.58%, respectively, whereas the times required to kill 50% of the 2nd and 4th instars were approximately 6.81 days and 12.89 days. At 4.0 × 104 OBs·mL−1, the highest cumulative mortality of 2nd and 4th instar larvae were 83.33% and 36.67%, the LT50 values were approximately 11.91 days and 25.65 days. In addition, after different concentration of MisiGV inoculation, the pupation and emergence rate of surviving larvae were significantly lower than that of the control. However, no significant difference on the emergence rate was observed at 4.0 × 104 OBs·mL−1 MisiGV concentration. Conclusion A new virus-MisiGV is reported. This virus-MisiGV is a biological control factor with development potential and application prospects.
2022, 35(2): 148-153. doi: 10.13275/j.cnki.lykxyj.2022.02.017
[Abstract](2445) [FullText HTML] (1788) [PDF 1140KB](61) [Cited by] ()
Objective To analyze the gallery structure and boring characteristics of Monochamus alternatus in Pinus densiflora and P. thunbergii in order to further understand the bio-ecological characters of M. alternatus in the hidden life process and benefit the application of natural enemy insects, pathogenic microorganisms, and injection drugs to control it. Method During the overwintering period, the gallery structure of M. alternatus in P. densiflora and P. thunbergii were systematically dissected. The gallery length, blocked frass length, internal diameter of entrance holes and pupal chambers, moisture content of frass, relative orientation between entrance holes and emergence holes were measured and the relationships between body size of larvae and host species and boring characteristics were analyzed. Result The galleries in both trees were U-shaped, single, not got through each other, blocked at the end of the entrance hole, and most of emergence holes were above the entrance holes. The boring characters of M. alternatus showed little correlation with individual body size and tree species. Conclusion The hidden and boring characteristics of M. alternatus in xylem are relatively regular, which is less affected by the host species. Its gallery is U-shaped, and part of that is blocked by the mixture of frass and fece.
Recognition of Visual and Olfactory Signal Functions in Hebomoia glaucippe Adults During Their Foraging and Courtship
2022, 35(2): 154-162. doi: 10.13275/j.cnki.lykxyj.2022.02.018
[Abstract](2317) [FullText HTML] (1496) [PDF 916KB](28) [Cited by] ()
Objective To study the mechanism of visual and olfactory signal utilization in the foraging and courtship of Hebomoia glaucippe. Method The attractive effects of different colors of flowers and artificial flowers sprayed with honey water and artificial models on H. glaucippe were verified by behavioral studies. Result In the odorless attractive experiment of 7 different colors of artificial flowers, the male and female butterflies showed an obvious color tendency towards long-wavelength red (620-750 nm). The total number of visits to flowers by the male and female butterflies was 259, 151 and 108 respectively. After spraying honey water on the artificial flowers, the male and female butterflies visited the flowers for 583 times, 305 times and 278 times respectively. In the case of using honey water only, the total number of female and male butterfly visits was only 10, in which the numbers of female and male butterfly visit were 8 and 2 respectively. Compared to the odor group and color groups, the butterfly visiting times of color + odor group increased by 58.3 and 2.25 times, respectively. During the courtship, the chasing of the model by the H. glaucippe was inconsistent with the chasing law of the natural population. The visit to the scentless specimen model was significantly lower than that of the natural population (P<0.05). There were differences in the colors and patterns of the wings of female and male butterflies. Conclusion H. glaucippe butterfly is mainly visual and supplemented by olfaction when foraging, and it has obvious preference for color vision. Both vision and olfaction participate in courtship recognition during courtship, using visual signals for initial spouse recognition, and then precise recognition through olfactory signals.
Interspecific Association of Shrub Species in Burned Site of Picea asperata-Abies fabri Forest on the Northern Slope of Dieshan Mountains
2022, 35(2): 163-170. doi: 10.13275/j.cnki.lykxyj.2022.02.019
[Abstract](2382) [FullText HTML] (1626) [PDF 789KB](37) [Cited by] ()
Objective To reveal the interspecific association of shrub species in the burned area of Picea asperata-Abies fabri forest on the north slope of Dieshan mountains, the northeastern margin of Qinghai -Tibetan Plateau. Method Based on the field survey data, the interspecific association of 17 shrub species in the burned area was studied by using variance ratio method (VR), chi-square (χ2) test, association coefficient (AC) and Jaccard similarity coefficient (PC) with 2 × 2 contingency table. Result The VR value of overall association was equal to 0.93; χ2 test showed that 9 species pairs reached extremely significant positive association, 2 species pairs reached significant association, 125 species pairs showed no significant association; there were 27 species pairs with the AC value of [0.6, 1], 9 species pairs with the AC value of [0.2, 0.6), 40 species pairs with the AC value of [−0.2, 0.2), 13 species pairs with the AC value of [−0.6, −0.2）, and 47 species pairs with the AC value of [−1, −0.6); the value of Jaccard was similar, there were 17 pairs with PC value of [0.57, 1], 12 pairs with PC value of [0.29, 0.57) and 107 pairs with PC value of [0, 0.29). The results obtained by each research method were basically similar, but there were some differences among the test methods. Conclusion The correlation among the pairs is not strong, few species pairs are significant or extremely significant, and the overall association among species in the community shows no significantly negative trends. The results show that the interspecific association of shrub species is not strong and the community stability is not high. The interspecific association of shrub species is mainly affected by plant biological characteristics, ecological adaptability and human activities, soil, climate, competition and allelopathy.
Relationship between Soil Enzyme Activities and Physicochemical Properties in Mangrove Wetland of Qinglan Port
2022, 35(2): 171-179. doi: 10.13275/j.cnki.lykxyj.2022.02.020
[Abstract](2490) [FullText HTML] (1668) [PDF 1052KB](29) [Cited by] ()
Objective To analyze the soil quality of different mangrove communities in Qinglan Port wetland at the aspect of soil enzyme activity, so as to benefit the mangrove wetland soil carbon sink monitoring and ecological restoration in Hainan Province. Method Soil enzyme activities soil microbial biomass carbon and nitrogen content and physicochemical properties of five mangrove communities were analyzed. Result (1) The lowest contents of microbial biomass carbon and nitrogen and microbial entropy of carbon in the soil surface were found in the Lumnitzera racemosa community, which were significantly lower than that of the individual communities. However, the soil microbial entropy of nitrogen had no significant differences among different community types. (2) The soil enzyme activities in the surface layer of wetland in each community type were basically in the order of sucrase > phosphatase > catalase > urease. There were significant differences among different community types. The activities of urease, phosphatase and catalase in Ceriops tagal community were the highest, which were significantly higher than those in B. sexangula and R. apiculata communities. The catalase activity of C. tagal community was the highest, which was significantly higher than that of B. sexangula and R. apiculata communities. The sucrase activity was the highest in Sonneratia alba community, which was significantly higher than that in B. sexangula and R. apiculata communities. (3) The soil urease activity was significantly positively correlated with water content (SWC), organic carbon (SOC), microbial biomass carbon (MBC), total nitrogen (TN), total phosphorus (TP), total potassium (TK) and total reducing substances (RS). The phosphatase activity was significantly positively correlated with soil SWC, MBC, microbial biomass nitrogen (MBN) and RS, and significantly positively correlated with TN and TK. The catalase activity was significantly positively correlated with SWC, SOC, MBC and TN. The sucrase activity was significantly positively correlated with SWC, SOC, MBC, TN and MBN. (4) The results of redundancy analysis showed that SWC, MBC and RS were the main factors affecting the soil enzyme activities of mangrove communities in Qinglan Port. Conclusion Soil enzyme activity can be used to characterize the soil quality of mangrove wetland in Qinglan Port.
Nutrient Characteristics and Physiological Adaptation of Phyllostachys glauca at Different Habitats in Limestone Mountains
2022, 35(2): 180-186. doi: 10.13275/j.cnki.lykxyj.2022.02.021
[Abstract](2055) [FullText HTML] (1260) [PDF 865KB](24) [Cited by] ()
Objective To study the nutrient distribution and low P adaptive mechanism of Phyllostachys glauca McClure in the soil of limestone mountain which is highly heterogeneous and the nutrient distribution is uneven. Method The N and P contents in leaf, branch, culm, stump, rhizome and root of Ph. glauca were measured and analyzed at different soil habitats (continuous soil, semi-continuous soil, and sporadic soil) in the limestone mountain of northwest Jiangxi Province. Result (1) With the increase of rock coverage, the total N content of soil increased, but the total P content was low in all the three habitats. (2) The N content of Ph. glauca increased with the increase of rock coverage, and reached the highest value in sporadic soil habitat. Conversely, the P content decreased with the increase of rock coverage. The ratio of N:P content of plants increased sharply with the greatest degree of P deficiency in sporadic soil habitat, but the ratio of N:P content of leaf remained relatively stable. With the increase of rock coverage, the N content in each component of Ph. glauca showed a slowly increasing trend, while the P content showed a decreasing trend, and all plant components except leaf decreased significantly. (3) The distribution pattern of N and P changed with the increase of the rock coverage. No difference was observed on the proportion of N among the three habitats (except the rhizome). The P distribution of leaf in semi-continuous soil and sporadic soil was significantly higher than that in continuous soil, but in semi-continuous soil the P distribution proportion of culm was significantly lower than that in continuous soil. Conclusion The N and P content in Ph. glauca are positively correlated to soil N and P supply. In the case of sufficient supply of soil N and insufficient supply of soil P, this bamboo species will enrich the scarce nutrients (P) to leaf by adjusting its interior distribution pattern, and then ensure the photosynthetic needs of leaf to maintain plant growth and improve the adaptability under soil stress.
Hydrological Effects of the Humus Layer of Pure Forest of Populus davidiana and Betula platyphylla in Southern Section of Daxing'anling Mountains, Inner Mongolia, China
2022, 35(2): 187-193. doi: 10.13275/j.cnki.lykxyj.2022.02.022
[Abstract](1748) [FullText HTML] (871) [PDF 713KB](22) [Cited by] ()
Objective To study the stock volume of humus layer and its water conservation effect of typical stand in Saihanwula National Nature Reserve, where a lot of tree died under drought stress caused by climate warming and drying. Method Nine plots were selected for each of the pure forests of Populus davidiana and Betula platyphylla. The biomass of humus layer and the water holding capacity of humus layer of the two forests was determined using indoor soaking method. Result The results showed that: (1) Under the same canopy density, the total biomass of humus layer of P. davidiana forest was 12.41 t·hm−2, higher than that of B. platyphylla forest (10.97 t·hm−2). (2) The maximum water holding capacities of the humus layer of both the forest was 26.85 and 26.77 t·hm−2, and the corresponding effective storage capacities were 11.96 and 11.07t·hm−2, showing the similar water-holding effect. (3) The relationship between dynamic water holding capacity of humus layer and the soaking time followed a logarithmic function, and the relationship between the water absorption rate and soaking time followed a power function. Conclusion This study carried out in the southern section of the Daxing'anling Mountains shows that the humus layer biomass of pure forest of P. davidiana is slightly larger than that of the pure forest of B. platyphylla, but the water holding capacity of humus layer of both the two forests is similar.
Selection of Reference Genes for Real-time Quantitative PCR in Clerodendrum trichotomum Thunb. Leaves
2022, 35(2): 194-202. doi: 10.13275/j.cnki.lykxyj.2022.02.023
[Abstract](2614) [FullText HTML] (1635) [PDF 852KB](26) [Cited by] ()
Objective To select the stable internal reference genes by real-time PCR (qRT-PCR) under different abiotic stress conditions in Clerodendrum trichotomum leaves. Method Based on previous transcriptome data, 17 reference genes were selected under different abiotic stresses (salt, drought and heat) for C. trichotomum. Four reference gene analysis software i.e. GeNorm, NormFinder, BestKeeper and ReFinder were used to select the optimal internal reference gene, to select the genes for Na + /H + Exchanger1 (ClNHX1) and to verify the stability of internal reference genes elected. Result Genes RPL and AP-2 were the most stable under salt stress; MDH and AP-2 were the most stable under drought stress; UBCE2 and ACT were the most stable under heat stress. For abiotic treatments, AP-2 and UBCE2 were the most stable reference genes. Conclusion AP-2 and UBCE2 can be used as internal reference genes for gene quantification in abiotic stress studies of C. trichotomum leaves. This study can provide reliable normalization for gene expression analysis and ensured more accurate data for further molecular mechanism research in C. trichotomum.