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2022, 35(4): 1-1.
2022, 35(4): 1-2.
Genetic Analysis on Multiple-year Growth Traits and Their Correlations with Wood Properties in Eucalyptus urophylla × E. tereticornis crosses
QIU Yan, WENG Qi-jie, LI Mei, CHEN Sheng-kan, ZHOU Chang-pin, LI Fa-gen, GAN Si-ming
2022, 35(4): 1-8. doi: 10.13275/j.cnki.lykxyj.2022.004.001
Objective To understand the genetic mechanism underlying multiple-year growth in Eucalyptus urophylla × E. tereticornis crosses and provide reliable support for determining the early selection age in large-diameter-timber variety breeding. Method For 13- and 16-year-old tree height, breast-high diameter and volume of 59 crosses derived from an incomplete factorial mating between 10 E. urophylla females and 10 E. tereticornis males, a mixed linear model was used to estimate the variance components of female, male, and female × male interaction effects and calculate the narrow-sense heritability. Phenotypic and additive genetic correlations with earlier growth and 10-year-old wood properties were also analyzed. Genetic correlations and principal components regression (PCR) analysis were used to estimate early selection age for growth traits. Result Overall growth of crosses at ages 13 and 16 was better than the maternal open-pollinated families, and there were one cross and 47 individuals qualified for the large-diameter-timber criterion ≥28 cm. For all the three growth traits at both ages, the variance components of female, male, and female × male interaction were all significant, only significant for volume, and only significant for 13-year-old height, respectively. It indicated that the effect of female was larger than male. Narrow-sense heritability ranged from 0.17 to 0.23, being moderate to low levels of genetic control. Phenotypic and additive genetic correlations of 16-year-old height, diameter and volume with earlier (age of 0.5, 1.5, 2.5, 4, 7.5,10 and 13 years) counterparts were all positively significant except for 1.5-year-old volume, and the additive genetic correlations for 2.5 and higher years were notably stable. PCR analysis showed that 2.5-year-old growth could explain 73.9%, 71.9% and 66.2% of phenotypic variation in 16-year-old height, diameter and volume, respectively. Growth traits at both ages were significantly genetically correlated with 10-year-old wood basic density (positive) and lignin content (negative, except H16). Conclusion Certain degree of growth heterosis is present at ages 13 and 16 in E. urophylla × E. tereticornis crosses, indicating the potential of selection for large-diameter-timber varieties. Female effects on growth are consistently significant while male effect on volume is significant, demonstrating the necessity of selection of female and male parents in hybrid breeding. Both significant correlations between 16-year-old and earlier growth and around 70.0% of 16-year-old phenotypic variation explained by 2.5-year-old growth suggested the practical age of early selection at 2.5 years. Significant correlations of growth with 10-year-old wood basic density and lignin content imply the feasibility of indirect selection.
Community Composition and Differentiation of Endophytic Mycobiota in Chestnut Fruits
LV Xing, DOU Gui-ming, WANG Hui-hua, LI Ru-hua, JIANG Ze-ping, LI Zhi-peng, YAN Dong-hui
2022, 35(4): 9-22. doi: 10.13275/j.cnki.lykxyj.2022.004.002
Objective Exploring the composition and diversity of the fruit endophytic fungi community is the basis for understanding the functions and mechanisms of fruit healthy microbiome. Method The diversity and composition of endophytic fungal communities in healthy fruit and its kernel (cotyledon) and shell (including seedcoat) parts of six chestnut cultivars were analyzed using high-throughput sequencing technology and traditional tissue isolation methods. Result A total of 3,229,205 high-quality sequences were generated from 36 samples of fruits and 2 tissues of six cultivars, and 1,557 fungal OTUs were annotated, belonging to 10 phyla, 38 classes, 97 orders, 203 families, and 350 genera. In chestnut fruit, Ascomycota (average relative abundance 80.40%) had the highest abundance, followed by Basidiomycota (average relative abundance 7.70%), and the dominant class were Sordariomycetes (average relative abundance 43.00%) and Saccharomycetes (average relative abundance 15.10%). The shared fungal taxa among species was enriched in Dothideomycetes with abundance >90%. Among chestnut fruit varieties, Ascomycota was also the most abundant group in each variety, with a relative abundance of 57.96%~90.15%, followed by Basidiomycota(3.28%~23.71%); At the class level, the dominant groups changed. The relative abundance of Saccharomycetes fungi (39.21%) was the highest in Maobanhong varieties, while Sordariomycetes fungi were the most abundant group (29.47%~59.56%) among the other five chestnut cultivars. Among the fruit tissues, the kernel tissue had higher unique fungal diversities than the shell, and the unique dominant groups of kernel tissue were all Basidiomycetes, especially the Russulales of Tremellomycetes. LEfSe analysis showed that there were significant differences in community composition or populations in the shell and kernel tissue, with Fusarium, Metschnikowia, Meyerozyma, and Debaryomyces fungi having significant dominance in kernel tissue. A total of 2346 effective strains were obtained by artificial culturable method, which belonged to Ascomycetes, Basidiomycetes and Mucoromycota. Except for yeasts that need special medium to be screened, the dominant fungal groups on fruits and tissues obtained by artificial culturing methods were similar to the results of high-throughput sequencing technology in terms of community composition and abundance. Conclusion Chestnut fruit has abundant endophytic fungal community composition and population diversity dominated by Sordariomycetes and Saccharomycetes, but the community-building species are mainly from Dothieomycetes. The endophytic fungal community composition is significantly different among chestnut fruit cultivars. Chestnut kernel has a richer diversity of exclusive endophytic fungi than shell part. There is a obvious differentiation on the composition of endophytic fungal community between chestnut kernel and shell tissue. This paper is the first systematic report on the compositional structure of endophytic fungi microbiota in chestnut fruit, which provides a basis for using chestnut healthy microbiome to prevent and control fruit diseases and to understand the nut fruit microbiome.
Leaf and Fine Root Functional Traits Response of 10-Year-Old Cunninghamia lanceolate Plantations to Soil Phosphorus Addition
ZHANG Yun, SONG Chong-lin, CHEN Jian, SHI Zuo-min, XIAO Wen-fa, ZHAO Guang-dong, YUAN Xiao-ping, WU Jian-guo
2022, 35(4): 23-32. doi: 10.13275/j.cnki.lykxyj.2022.004.003
Objective To reveal the response of leave and fine root functional traits of 10-year-old Cunninghamia lanceolate plantation to soil phosphorus (P) addition so as to provide scientific basis for its productivity improvement. Method Six treatment of P0 (control), P1, P2, P3, P4 and P5 were set up in the 10-year-old C. lanceolate plantations. Soil P addition amount was 0, 60, 120, 180, 240 and 300 kg·hm−2·a−1 respectively, and simulated P deposition experiment was carried out for three years to analyze changes of functional traits, phenotypic plasticity index (PI), coefficient of variation (CV) and the correlation between functional traits including leaf area (LA), specific leaf area (SLA), leaf tissue density (LTD), leaf dry matter content (LDMC), specific root length (SRL), specific root surface area (SRA), root tissue density (RTD). Result In the condition of soil P limitation, with the increase of P addition amount, LA, SLA, SRL and SRA of C. lanceolate increased firstly and then decreased, whereas LTDLDMCRTD decreased firstly and then increased. Under different soil P addition treatments, the average PI values of leave and fine root functional traits of C. lanceolate were 0.21 and 0.16 respectively; The range of CV was 3.9%-15.9%, which showed a weak variation; The LTD of C. lanceolate was negatively correlated with LA and SLA under P0 and P2 treatments (P < 0.01), and LTD was positively correlated with LDMC under P1 treatment (P < 0.05). SLA was positively correlated with LA under P0 and P3 treatment (P < 0.05), and SLA was negatively correlated with LDMC under P4 treatment (P < 0.01). The SRL of C. lanceolate was positively correlated with SRA under P0, P3, P4, and P5 treatments, and SRL was negatively correlated with RTD under P3 and P4 treatments (P < 0.01); RTD was negatively correlated with SRA under P0, P2, P3, P4, and P5 treatments (P < 0.01). Conclusion Cunninghaia lanceolata developed a survival strategy to cope with changes in soil P content by coordinating the coupling correlation between leaf and fine root functional traits. This research showed that appropriate P addition (P2, P3) was beneficial to soil nutrient absorption and growth of 10-year-old Chinese fir plantation.
Identification and Genetic Diversity Analysis of Olive Cultivars in Longnan Based on Phenotype and SSR Markers
XU Yue, HUANG Lan, LI Jin-hua, DENG Yu, ZHANG Jian-guo, ZENG Yan-fei
2022, 35(4): 33-43. doi: 10.13275/j.cnki.lykxyj.2022.004.004
Objective This study accurately identified the existing varieties and calculated genetic diversity in Longnan City, Gansu Province, which was the main olive producing area in China, and provided a reference for the introduction, domestication, breeding and utilization of olive germplasm resources in China. Method Identification and genetic diversity were analyzed for 110 individuals of 83 olive varieties collected from Longnan city using 13 SSR markers, and phenotypic diversity was analyzed with indicators such as leaf, fruit, and stone for 90 individuals of 68 varieties. And the clustering of varieties based on phenotypes was compared with that based on SSR markers. Result The phenotypic diversity indices for olive varieties from Longnan were 1.83 for quantitative traits and 0.79 for quality traits, respectively; SSR markers identified 78 different genotypes for all olives analyzed, with an observed heterozygosity of 0.683 and an expected heterozygosity of 0.754, respectively; all varieties could be divided into three groups, and the grouping of varieties were more or less related with their origin; most of the varieties bred and selected in China were closer to those originated from Italy; compared with those in the phenotypic-based cluster tree, different individuals of the same variety were more inclined to cluster together in the tree based on SSR genotypes. Conclusion In Longnan, 78 varieties with different genotypes were identified based on SSR markers, which shows a higher accuracy in variety identification and a clear kinship among varieties than that based on phenotypes. The phenotypic diversity and genetic diversity of olive in Longnan are high, and the introduced varieties are mainly from the western and central Mediterranean countries. Whereas the varieties bred and selected previously in China are more similar to varieties originated from Italy. To diversifying olive germplasm in Longnan, more varieties should be introduced and bred with varieties from different countries.
Genomic Characteristics and Population Genetic Variation of Dalbergia cultrata Graham ex Benth in China
LIU Yu, ZHENG Yong-qi, LI Chang-hong, LIN Fu-rong, HUANG Ping
2022, 35(4): 44-53. doi: 10.13275/j.cnki.lykxyj.2022.004.005
Objective To analyze the characterization of Dalberiga cultrata genome, and develop a set of high polymorphic SSR molecular markers for assessment of genetic variation of wild population. Method Next Generation Sequencing (NGS) was performed to evaluate the characteristic of genome, and MISA was used to mine candidate genomic SSR loci from the assembled data. The franking primers of candidate SSR loci were designed by Primer Premier v 5.0, and screened by polyacrylamide gel electrophoresis (PAGE). The polymorphic and population genetic analysis was performed by capillary electrophoresis (CE). Result The genome size of D. cultrata was about 706.92 Mb and the heterozygosity was about 1.26%. The rate of repetitive sequence was 55.74%. A total of 27 polymorphic SSR loci were screened and117 alleles were amplified on 27 SSR loci. The value of the polymorphism information content (PIC) varied from 0.149 to 0.803. The population genetic analysis showed the mean expected heterozygosity (He) and the coefficient of genetic differentiation (FST) was 0.504 and 0.034, respectively. AMOVA analysis revealed the genetic variation within the populations (96.54%) was much higher than that among the populations (3.46%). Conclusion The genome of D. cultrata belongs to high heterozygosity and highly repetitive complex genome, which provides important basic data to make a fine assembly strategy. A set of novel genomic SSR markers shows good polymorphism, and stability. Moderate genetic diversity and low genetic differentiation of wild populations of D. cultrata are revealed by SSR markers. This study would facilitate to conserve and assess wild germplasms of D. cultrata.
Variation Characteristics of Anthocyanin in Hybrids between Camellia azalea and Camellia japonica 'Meili'
YANG Mei-ying, LI Jian-bin, ZHANG Ying, LI Xin-lei, LIU Xin-kai, ZHONG Nai-sheng, LI Yan-ling
2022, 35(4): 54-62. doi: 10.13275/j.cnki.lykxyj.2022.004.006
Objective The object of this study was to determine anthocyanin components and contents in petals from Camellia azalea, C. japonica 'Meili' and their hybrids, and reveal variation regulation of main anthocyanin components and content, that will provide the scientific basis for breeding and utilization of camellias with high anthocyanin content. Method Anthocyanin components and contents of C. azalea, C. japonica 'Meili' and thirty-five hybrids were measured by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) and aultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Result Fourteen anthocyanin components were detected in C. azalea and the hybrids, eight of which were main anthocyanin components with high content, including cyanidin-3-O-(2-O-β-xylosyl)-β-galactoside (Cy3GaX), cyanidin-3-O-β-galactoside (Cy3Ga), cyanidin-3-O-(2-O-β-xylosyl)-β-glucoside (Cy3GX), cyanidin-3-O-β-glucoside(Cy3G), cyanidin-3-O-(6-O-(E)-p-coumaroyl)-β-galactoside(Cy3GaEpC), cyanidin-3-O-(2-O-β-xylosyl-6-O-(E)-p-coumaroyl)-β-galactoside (Cy3GaEpCX), cyanidin-3-O-(2-O-β-xylosyl-6-O-(E)-p-coumaroyl)-β-glucoside (Cy3GEpCX) and cyanidin-3-O-(6-O-(E)-p-coumaroyl)-β-glucoside (Cy3GEpC). The total amount of eight main anthocyanin of C.azalea was higher than that of C. japonica 'Meili', and that of hybrids have larger variation. The contents of Cy3GX and Cy3GaX in hybrids were lower than that of C. azalea, and contents of Cy3GEpCX and Cy3GaEpCX in hybrids were higher than that of C. azalea. The contents of Cy3G, Cy3Ga, Cy3GEpC and Cy3GaEpC in hybrids were basically in the middle of the parents. Conclusion The contents of anthocyanins with 2-O-β-xylosyl is higher than that of corresponding anthocyanins without 2-O-β-xylosyl, and the contents of anthocyanins with glucoside is higher than that of corresponding anthocyanins with galactoside. The main anthocyanin components of C. azalea are Cy3GX and Cy3GaX, and those of C. japonica 'Meili' are Cy3GEpC and Cy3G. The main components of hybrids are Cy3GX and Cy3GEpCX, followed by Cy3G and Cy3GEpC. Anthocyanins with 2-O-β-xylosyl in hybrids originate from C. azalea, and the proportion of anthocyanins with 2-O-β-xylosyl is higher than that of corresponding anthocyanins without 2-O-β-xylosyl, that indicates anthocyanins with 2-O-β-xylosyl has stronger genetic ability.
Interspecific distant hybrid incompatibility cytology and its physiological mechanis in Paeonia suffruticosa Andr.
ZHANG Xiang-yu, JIA Wen-qing, HE Song-lin, QIU Yong-jie, WANG Qiao-jian, HU Huan, SHI Lai-kun, LIU Hui-chao
2022, 35(4): 63-71. doi: 10.13275/j.cnki.lykxyj.2022.004.007
Objective To clarify the cytological and physiological mechanism of the incompatibility of distant hybridization between peony species, and provide theoretical and experimental basis for distant hybridization of peony. Method Using P. ostii ‘Feng Dan’ as the female parent and Paeonia baokangensis Z. L. Dai et T. Hong sp. Nov. as the male parent, the compatibility of distant hybridization and pollination was studied for exploring the relationship between the changes of pistils protect enzyme activity, soluble substance content and endogenous hormone content after pollination, pollens germination and pollen tubes growth. Result The results showed that the cytology of Paeonia baokangensis Z. L. Dai et T. Hong sp. Nov. and P. ostii ‘Feng Dan’ distant hybridization was poor as a result of slow pollens germination, corpus callosum deposition in pollen tubes, severe twisting and entanglement, disordered growth and branching, and only part of the pollens could pass through the style to the ovary. After pollination, the rapid increase of SOD activity was beneficial to pollens stigma recognition and pollen tubes growth; The rapid increase of MDA content was not conducive to the elongation and growth of pollen tubes in distant hybridization; Distant hybrid pistils had higher soluble protein and soluble sugar content than selfed pistils, which is manifested by enhanced stigma recognition and pistils rejection; The content of IAA in selfed pistils was significantly higher than that of distant hybridization, high levels of IAA, GA3 and IPA were helpful for pollens germination and pollen tubes growth; The ABA content of distant hybrid pistils was significantly higher than that of selfed pistils, high levels of ABA and JA showed an inhibitory effect on the growth of pollen tubes, induced the deposition of callosum, and the pollen tubes twisted and twisted to grow disorderly. Conclusion Pre-fertilization barriers exist in distant hybridization of P. ostii ‘Feng Dan’ and Paeonia baokangensis, which is closely related to the changes of enzyme activity in the pistil, the dynamic changes of endogenous hormone content and the content of soluble substances.
Genetic Structure and Association Analysis with Agronomic Traits of F1 Hybrids of Chestnut
JIANG Xi-bing, ZHANG Ping-sheng, ZHANG Dong-bei, WU Ren-chao, WU Jian, WU Cong-lian, LAI Jun-sheng, GONG Bang-chu
2022, 35(4): 72-83. doi: 10.13275/j.cnki.lykxyj.2022.004.008
Objective To analyze the natural allelic variation which controls agronomic characters and obtain the associated SSR loci of chestnut for supporting molecular marker assisted selection and efficient breeding. Method A total of 235 chestnut hybrid progeny populations covering 9 cross combinations were used to analyze the genetic structure and linkage disequilibrium(LD)of the populations. And association analysis of 32 highly polymorphic SSR markers with 25 agronomic traits were conducted. Result There was a certain linkage disequilibrium in 496 loci of 32 SSR markers when P < 0.05, among which 74 loci had a higher level of linkage disequilibrium than the others, accounting for 14.92% of the total marker pairs. However, when P < 0.01, the overall level of LD among the 32 SSR loci was low. Genetic structure analysis results showed that when K=4, the Delta K value approximated the maximum. The F1 mixed population was divided into four sub-populations, and the distribution of offspring in each sub-population showed a certain degree of genetic differentiation, with an average degree of mixing of 0.120. In the GLM model, up to 28 SSR loci were significantly associated with 24 agronomic traits, and the associated SSR loci ranged from 1 to 22 for each trait, with interpretation rates ranging from 4.65% to 24.02%. In the MLM model, 26 SSR loci were significantly associated with 23 traits, and the interpretation rates ranged from 5.04% to 24.02%. Based on the correlation analysis results of the two models, 15 SSR markers were associated with 3 growth traits, 14 SSR markers were associated with 3 branch traits, and 26 SSR markers were associated with 18 leaf phenotype and photosynthetic physiological traits. Conclusion 15 SSR markers including ICMA017s are highly correlated with 13 agronomic traits, and the interpretation rates of markers for traits are more than 10.00%. In addition, there is a phenomenon that the same marker is highly correlated with multiple traits and the same trait is highly correlated with multiple markers.
Effects of Gap Size on Regeneration Dynamics of Larix principis-rupprechtii Forest
ZHANG Yu, WEI Xi, LIANG Wen-jun, LIU Zi-qi, LI Fu-ming, ZHAO Yi, FENG Yong-han
2022, 35(4): 84-92. doi: 10.13275/j.cnki.lykxyj.2022.004.009
Objective To explore the natural regeneration in Larix principis-rupprechtii plantation in Guandi Mountain, and explore the effect of gap size on regeneration. Methods In this study, the density, growth status and spatial distribution of seedlings of Larix principis-rupprechtii under different gap sizes were investigated. The K2 function point pattern analysis was performed for exploring spatial pattern of seedlings under different gap sizes. Results (1) The regeneration density and growth indices of Larix principis-rupprechtii were positively correlated with the increase of gap area (P < 0.05). Gap size had the most significant effect on sapling growth indexes (base diameter, height and age). The maximum mean values of growth indexes mostly appeared in gap grade I (20~50 m2), and the maximum mean values of seedlings and saplings density appeared in gap grade II (50~100 m2) and III (100~150 m2), respectively. (2) Saplings mostly distributed in the canopy projection area and canopy gap edge, and gradually distributed in the center of the gap. (3) In the gap of Larix principis-rupprechtii, most of the saplings were aggregated and distributed in small scale, and few saplings were evenly distributed. Conclusion Gap size has a significant effect on regeneration of Larix principis-rupprechtii. Gap grade I (20~50 m2) is conducive to seedling establishment and germination. In addition, the gap area could be enlarged to grade II (50~100 m2) by human disturbance to promote seedling survival and sapling growth.
Eddy Covariance Applicability and Carbon Flux Variation Characteristics of Coniferous and Broad-leaved Mixed Forests in Jinyun Mountain
WANG Song-nian, WANG Yun-qi, WANG Kai, FENG Yin-cheng, WANG Jie-shuai
2022, 35(4): 93-102. doi: 10.13275/j.cnki.lykxyj.2022.004.010
Objective To provide helpful insights into forest management and sustainable forestry development, the applicability of eddy covariance method in the coniferous and broad-leaved mixed forest in Jinyun Mountain was explored and the carbon source or sink of the coniferous and broad-leaved mixed forest ecosystem was clarified. Method Used the eddy covariance observation method(EC) to obtain the carbon flux monitoring data of the coniferous and broad-leaved mixed forest in Jinyun Mountain from 2019.11 to 2020.10. Through turbulence data quality evaluation, energy closure and flux footprint analysis, the applicability of the eddy covariance to the underlying surface was verified. The changes of carbon flux in the ecosystem were analyzed, and the carbon source or sink in the study area were evaluated. Results During the study period, the turbulence data quality check of sensible heat flux(H), latent heat flux(LE) and carbon flux(Fc) was good, and the proportions of high-quality data were 77%, 61% and 62% respectively. During the growing season(April-October), the upper-layer energy closure rate was 0.82, and the lower-layer energy closure rate was 0.73. The direction of the high flux contribution area was consistent with the main wind direction (northeast)The. During the study period, the annual carbon sequestration of the ecosystem was 887.40 g·m−2. The monthly average daily changes and seasonal average daily changes were mostly bimodal, and the cumulative change of Fc was −826.2 g·m−2 in the growing season and −61.2 g·m−2 in the non-growing season. The main environmental factors affecting carbon flux were photosunthetically active radiation and wind speed, and R2 was 0.75 and 0.43, respectively. Conclusion The EC had good applicability in the monitoring process of the Jinyun Mountain coniferous and broad-leaved mixed forest ecosystem, and flux monitoring data are creadible, and flux quality check is evaluated well. During the study period, the ecosystem is in the process of carbon sink,and the carbon sink capacity in the growing season is significantly higher than that in the non-growing season. Photosynthetically active radiation and wind speed are the main environmental factors affecting carbon flux changes.
Forest Type Classification Based on Multi-temporal Sentinel-2A/B Imagery Using U-Net Model
YANG Dan, LI Chong-gui, LI Bin
2022, 35(4): 103-111. doi: 10.13275/j.cnki.lykxyj.2022.004.011
Objective To explore the classification effect of deep learning models on forest vegetation using multi-temporal Sentinel-2A/B images. Method In this study, based on the multi-temporal Sentinel-2A/B images and Digital Elevation Model (DEM) in Mengjiagang Forest Farm in Heilongjiang Province, the JM distance of each forest category was used to determine the best single-phase. The characteristics of multi-temporal vegetation index and red edge index (DVI, mNDVI, CIred-edge, NDre1) were analyzed. Support vector machine and optimized U-Net model were used to carry out classification experiments on single-phase + DEM and single-phase + DEM + multi-temporal vegetation index respectively. Result (1) On the basis of single-phase + DEM, when adding multi-phase vegetation index, the accuracy of U-Net model was 76.37%, which was 5.7% higher than that of single-phase + DEM; (2) The accuracy of U-Net model was higher than that of support vector machine. In addition, the deep learning U-Net model could avoid the "salt and pepper" phenomenon, and the classification results were more delicate. Conclusion Based on multi-temporal Sentinel-2A/B images, the vegetation index and red edge index time series characteristics are constructed, and the U-Net model can improve the classification accuracy of forest types to a certain extent.
Variation and Selection of Phenotypic Traits of Acer triforum Propagules from Different Producing Areas
SUN An-ran, ZHANG Ming, PANG Zhong-yi, YU Hai-yang, XIE Ying, ZHANG Shi-kai, ZHAO Xi-yang
2022, 35(4): 112-122. doi: 10.13275/j.cnki.lykxyj.2022.004.012
Objective To elucidate the variation pattern of the propagules phenotypic characters of Acer triflorum from different origins in Northeast China, and provide the basis for genetic resource conservation and selection breeding of Acer triflorum. Method Acer triflorum propagules from four producing areas of Heilongjiang, Liaoning and Jilin were used to determine the phenotype and vigor of the propagules. Result The results of variance analysis showed that, except the ratio of length to width of key fruit (P = 0.787), the differences of other traits among origins were extremely significant (P < 0.01). There were significant differences in phenotypic characters of Acer triflorum among different producing areas. Correlation analysis of each character showed that fruit length was positively correlated with fruit width, samara length, bears mark, wing length and shell percentage (P < 0.05, 0.368≤r≤0.421), and seed viability wasnegativly correlated withsamara length and shell rate (r = −0.897, r = −0.507, P < 0.01). Correlation analysis between the propagules of Acer triflorum and environmental factors showed that the samara length, samara width, fruit thickness and wing length were negatively correlated with altitude (−0.556≤r≤−0.529, P < 0.05). Fruit length, fruit width and 1000-seed weight were negatively correlated with altitude (−0.456≤r≤−0.380, P < 0.05). Shell rate was negatively correlated with annual mean temperature (r = −0.549, P < 0.05), whereas seed viability was positively correlated with annual mean temperature (r = 0.516, P < 0.05). The comprehensive evaluation value of P2 origin was higher than the others, with realistic gain 2.83%-22.08%. The realistic gain of 6 excellent families was 1.13%-78.65% based on the 20% selection rate. Conclusion There are abundant differences in phenotypic traits of Acer trifolium, which is mainly affected by two environmental factors: altitude and average annual temperature. According to the comprehensive evaluation of multiple characters, preliminarily selected P2 origin and 6 families including 19, 12, 6, 22, 27, 28 are excellent materials.
Annual Tree Diameter Growth Model of Chinese fir Plantations Including Different Stand Density Indices
JIANG Li, ZHANG Xiong-qing, Duan Ai-guo, ZHANG Jian-guo
2022, 35(4): 123-129. doi: 10.13275/j.cnki.lykxyj.2022.004.013
Objective To analyze the application value of stand density index in tree diameter growth model for accurate management of stand density. Method Based on the 28 years continuous observation data of the spacing trials of Chinese fir (Cunninghamia lanceolata) plantation in Shaowu, Fujian Province, the annual tree growth model was developed through variable rate method using seven density indices respectively. Also the model without stand density index was developed for comparing. Result All the eight models performed well, with R2 values more than 0.96. The models including the stand density indices were better than the model without stand density index. Among all the models with density indices, the model including stand density index (SDI) has the highest R2 value, followed by the model with stand basal area Ba and SD density index. Conclusion The model including SDI density index performed the best, which provides insights into density management in reason for Chinese fir plantations.
Identification and Expression Analysis of the HD-Zip I Subfamily Genes in Mulberry
HU Jing-tao, LI Ya-njie, DUAN Yan-yan, RUAN Yu, GU Xin, XIAO Guo-sheng
2022, 35(4): 130-142. doi: 10.13275/j.cnki.lykxyj.2022.004.014
Objective The aims of this study were to investigate the gene structure and phylogenetic of the mulberry (Morus alba L.) HD-Zip I subfamily members, clarify the tissue-specific expression of these genes in different organs, and reveal the expression level of the family genes under ABA and abiotic stress. Method Identification of putative HD-Zip I subfamily genes from MorusDB and bioinformatics analysis were performed. The evolutionary tree was constructed based on the multiple sequence alignment of the Arabidopsis and mulberry. RNA-seq data was used to analyze the tissue-specific expression of mulberry HD-Zip I genes. The transcription level of the family genes under hormone and abiotic stress was detected by qRT-PCR. Result A total of 14 HD-Zip I genes were identified in the mulberry genome. These members could be divided into six classes by phylogenetic tree. Members in the same class were similar in the gene structure and protein motifs. The expression level of both MnHD-Zip 2 and MnHD-Zip 6 were high in root, branch, winter bud, male flower, and leaf according to the RNA-seq data. All the MnHD-Zip I gene except MnHD-Zip 8, MnHD-Zip 9, MnHD-Zip 11, MnHD-Zip 12, and MnHD-Zip 13 were inhibited by ABA. The result of qRT-PCR showed that all the mulberry HD-Zip I genes could be induced by the abiotic stresses. Conclusion The β clades genes that were highly expressed in most of the organs were observably induced by the NaCl and dehydration. These results indicates that genes from the β clades of MnHD-Zip I play important roles in the development and stress response. In addition, MnHD-Zip 8 and MnHD-Zip 12 were dramatically up regulated by waterlogging, NaCl and dehydration, which indicates that these genes have essential roles in stress regulation of mulberry.
Differential Analysis of Anther Embryogenesis between Different Genotypes of Hevea brasiliensis
GU Xiao-Chuan, PENG Su-Na, DAI Xue-Mei, ZHOU Quan-Nan, SUN Xiao-Long, GUI Ming-Chun, HUANG Hua-Sun, HUA Yu-Wei, HUANG Tian-Dai, ZHANG Yuan-Yuan
2022, 35(4): 143-152. doi: 10.13275/j.cnki.lykxyj.2022.004.015
Objective Clarifying the effect of genotype on rubber tree somatic embryogenesis and combining with pedigree analysis to classify and group will provide a theoretical basis for accurately optimizing the somatic embryogenesis system of rubber trees. Method The genetic relationship between the 32 main rubber tree cultivars and their parents preserved in China National Rubber Tree Germplasm Repository was clarified through pedigree analysis. The two mediums with high somatic embryo induction rate in multiple cultivars in the previous experiment were used to induce callus and further induce somatic embryogenesis with anthers as explants. Finally, the induction rate of somatic embryos based on genetic relationship was analyzed. Result The pedigree analysis of 32 rubber tree cultivars showed that 7 cultivars were primary clones including PR107, GT1, PB86, Tjirl, Haiken1, Tianren31-45, and Hekou3-11. Twenty-three of the remaining 25 cultivars are genetically related to 1-3 of the above 7 cultivars. It is clear that the source of parents of rubber tree cultivars in China is narrow. Combining pedigree and somatic embryogenesis analysis showed that the somatic embryogenesis ability of rubber tree cultivars is closely related to the parental source, and the parental somatic embryogenesis ability determines the somatic embryogenesis ability of its offspring cultivars. When both parents are recalcitrant to somatic embryogenesis, most of their hybrid progeny are recalcitrant. When one of the parents has high somatic embryogenesis efficiency, even if the other parent is recalcitrant, most of its hybrid offspring have high somatic embryogenesis efficiency. However, the frequency of somatic embryogenesis varies significantly among these offspring, and there is a phenomenon of super-parental, which indicates that the rubber tree somatic embryogenesis is controlled by the participation of multiple genes. GT1, Tianren31-45, 93-114, RRIM513, and other parent-derived cultivars have low somatic embryo induction rate (e.g., Yunyan77-2, Yunyan77-4, Yunyan73-46, Baoting1-285, Zhanshi32713, and Reyan217), and PB86, RRIM600, Reyan88-13, and, Haiken1 and other parent-derived cultivars have high somatic embryo induction rate (e.g., Dafeng95, Haiken2, Reyan917, Reyan73397, Reyan879, Reyan918, Xuyu3, and Xuyu141-2). Conclusion There are obvious genotypic differences in rubber tree somatic embryogenesis, and this difference can be heritable. According to the somatic embryo induction efficiency and genetic relationship, analyzing and grouping 32 main rubber tree cultivars and their parents provide a way to optimize the somatic embryogenesis of rubber tree cultivars by genotype grouping.
Characteristics of Soil Nitrogen-Fixing Bacteria Community of Typical Forest Stands at Haituo Mountain, Beijing
SHI Ce, NIE Li-shui, WEI Yi-fan, ZHU Lin, YANG Hao, ZHANG Run-zhe, NIE Hao-liang, WANG Jiang, BO Hui-juan
2022, 35(4): 153-161. doi: 10.13275/j.cnki.lykxyj.2022.004.016
Objective To provide theoretical evidence relating to forest soil nitrogen circulation and forest vegetation restoration in warm temperate forests, the diversity, composition of soil nitrogen-fixing bacteria community and their relations with soil properties were studied in four different forest types in Songshan National Nature Reserve of Beijing. Method Four typical forest stands (Pinus tabuliformis Carriere (Pt), Pine-poplar mixed (Mix), Quercus mongolica Fisch (Qm) and Juglans mandshurica Maxim (Jm)) were selected with three replicate plots (20 m × 20 m). Soil samples of 0~20 cm soil layer were collected from each plot to analyze soil properties. In this study, real-time quantitative PCR and High-throughput sequencing were used to study the diversity and composition of soil nitrogen-fixing bacteria. Pearson’s correlation analysis and redundancy analysis (RDA) were used to examine the soil properties factors driving the community structure and diversity of the soil nitrogen-fixing bacteria. Result A total of 4 phyla, 6 classes, 13 orders, 16 families and 29 genera were detected from the soil samples. There were significant differences in the α diversity of soil nitrogen-fixing bacteria in the four forest types with Pt > Mix > Jm > Qm. β-diversity analysis showed that the inter-group differences of soil nitrogen-fixing bacteria communities of the four forest types were greater than the intra-group differences.. Proteobacteria was the dominant phylum. Bradyhizobium, Azohydromonas and Skermanella were the dominant genera in all soil samples. Redundancy analysis (RDA) showed that soil properties could explain 65.48% of the variation of soil nitrogen-fixing bacteria community. Soil organic matter and total nitrogen were the main factors affecting the structure and diversity of the soil nitrogen-fixing bacteria community. Conclusion There are abundant soil nitrogen-fixing bacteria resources in Haituo Mountain. There are significant differences in soil properties, soil nitrogen-fixing bacteria diversity and community structure under different forest stands. Soil organic matter and total nitrogen are the main soil properties factors that significantly affect the soil nitrogen-fixing bacteria in Haituo Mountains.
Spatial Heterogeneity and Reasonable Sample Sizes of Soil Bulk Density on A Larch Plantation Hillslope in Liupan Mountains
DENG Jia-nan, LIU Fan, LIU Ze-bin, GUO Jian-bin, WANG Yan-hui
2022, 35(4): 162-169. doi: 10.13275/j.cnki.lykxyj.2022.004.017
Objective Clarifying the spatial heterogeneity of soil bulk density on forest slopes and quantifying its reasonable sample sizes are of great significance for accurately understanding the runoff mechanism on hillslopes. Method Combining traditional statistics and geostatistics methods, the spatial heterogeneity of soil bulk density in 0~100 cm soil layer on a Larix gmelinii var. principis-rupprechtii (Mayr) Pilg. plantation hillslope in Liupan Mountains was analyzed. The minimum sampling sizes of soil bulk density under 95% confidence level and 10% error were quantified using Monte Carlo simulation sampling method. Result The soil bulk density in 100 cm soil depth on the hillslope varied from 0.99~1.48 g·cm−3. As the soil layer deepened, the soil bulk density gradually increased. Traditional statistics showed that the soil bulk density in 0~20 cm soil layer had weak variation, while other soil layers had moderate variation. The spatial heterogeneity of rock fragment on the slope was the main factor leading to the spatial variation of soil bulk density in different soil layers. Geostatistics showed that the spatial structure of soil bulk density in each soil layer was moderate spatial autocorrelation. The difference in the spatial variation of soil bulk density among different soil depths leaded to the differences in the minimum sampling size in varied soil depths. In the 95% confidence interval, if estimation accuracy of the soil bulk density in 100 cm soil layer was controlled to be within 10% error, at least 10 sampling points should be made. Conclusion There is a large spatial variation in soil bulk density on forest hillslope, and the reasonable sample size depends on the degree of spatial variation in soil bulk density. In the future, reasonable and efficient sampling strategies should be developed based on the relationship between the spatial variation of soil bulk density and the reasonable sampling sizes.
Effects of Nitrogen Addition on the Soil Phoshorus Fractions in Subtropical Pinus taiwanensis Forests
LIN Qiao-yu, ZENG Quan-xin, YUAN Xiao-chun, CUI Ju-yan, XIE Huan, LIN Hui-ying, LI Wei-peng, YANG Qing-bo, CHEN Yue-min
2022, 35(4): 170-178. doi: 10.13275/j.cnki.lykxyj.2022.004.018
Objective To investigate the changes in soil phosphorus (P) fractions in Pinus taiwanensis forest under nitrogen (N) deposition, and further explore the driving factors of P fractions changes for providing scientific basis for how Pinus taiwanensis forest adapts to the continuous aggravation of nitrogen deposition in the future. Method Soil P fractions, microbial biomass, acid phosphomonoesterase activity (ACP), phosphodiesterase enzyme activity (Phosphodiesterase enzyme, PD), and soil phospholipid fatty acids were detected in a short-term N-addition experiment in a Pinus taiwanensis forest on Daiyun Mountain, Fujian Province, China. Result There were significant effects of high N addition on the content of moderately labile P and stable P at 0−10 cm depth, whereas insignificant effects on the content of labile P, microbial biomass, ACP, PD, and community composition. In addition, low nitrogen supplementation significantly decreased the ratio of gram-positive bacteria to gram-negative bacteria in 10−20 cm soil layer (p < 0.05). In general, the variation trend of P fractions in the 10−20 cm soil layer was consistent with that in the 0−10 cm soil layer, but the change was not significant. However, N addition significantly decreased the content of microbial biomass P, and significantly increased ACP, PD activity and microbial biomass N/microbial biomass P. In addition, low N addition significantly decreased the ratio of gram-positive bacteria to gram-negative bacteria in 10−20 cm depth (p < 0.05). Redundancy analysis showed that soluble organic carbon and arbuscular mycorrhizal fungi key factors affecting changes in soil P fractions. Conclusion Short-term N addition maintains the soil P availability by promoting P transformation (e.g. the mineralization of moderate labile P), which is helpful for understanding the maintenance mechanism of soil P availability and productivity in P-poor ecosystems under short-term nitrogen deposition.
Leaf δ13C of the Main Afforestation Tree Species in Horqin Sandy Land
YU Feng-yuan, ZHANG Jin-xin, SUN Yi-rong, SONG Li-ning
2022, 35(4): 179-187. doi: 10.13275/j.cnki.lykxyj.2022.004.019
Objective Determining the water use characteristics of different afforestation tree species would supply a theoretical basis for the selection of tree species in vegetation restoration and reconstruction in semiarid and arid sandy lands. Method Leaf δ13C values of Pinus sylvestris var. mongolica, Populus × xiaozhuanica, Pinus tabuliformis, and Ulmus pumila trees in the south edge of the Horqin Sandy Land were measured together with monitoring soil water content at different depths to compare their water use efficiency (indicative of leaf δ13C) during the growing season, and the effect of hydrothermal factors on the water use efficiency was discussed. Result The leaf δ13C values of P. sylvestris var. mongolica, P. tabuliformis, and U. pumila trees decreased with seasons, whereas the leaf δ13C values of P. × xiaozhuanica firstly increased and then declined during the measurement period. In addition, the mean leaf δ13C value was higher in P. sylvestris var. mongolica trees (−26.92‰ ± 0.11‰) than in P. × xiaozhuanica (−27.40 ‰± 0.10‰) and P. tabuliformis (−27.57 ‰± 0.14‰) trees, whereas the mean leaf δ13C value was higher in P. × xiaozhuanica and P. tabuliformis trees than in U. pumila trees (−29.23 ‰± 0.17‰). The responses of the leaf δ13C monthly values to hydrothermal factors varied with tree species. There were no significant relationships between leaf δ13C monthly values and hydrothermal factors for P. sylvestris var. mongolica and U. pumila trees, whereas a significant negative relationship between monthly change in leaf δ13C and precipitation, air temperature, or relative humidity was observed for P. tabuliformis trees. However, a significant positive relationship between leaf δ13C monthly change values and air temperature was found for P. × xiaozhuanica trees. Conclusion The water use efficiency is the highest in P. sylvestris var. mongolica trees, followed by P. × xiaozhuanica and P. tabuliformis trees and the lowest value in U. pumila trees. In addition, water use efficiency for different tree species is not only related to biological characteristics but also related to the degree of influence by hydrothermal factors.
Fruit and Seed Phenotypic Diversity of Two Species of Diospyras spp. in Dabie Mountains
YANG Xu, XU Yang, GONG Bang-chu, XIE Qi-jun
2022, 35(4): 188-196. doi: 10.13275/j.cnki.lykxyj.2022.004.020
Objective To support comprehensive utilization and genetic improvement for two species of Diospyros spp. in Dabie Mountains, the phenotypic diversity within and among the populations was studied . Method Fruit and seed morphological properties of 11 Luotiantianshi persimmon (D. kaki) and wild persimmon (D. kaki var. silvestris) population were measured and analyzed. Result (1)The maximum value of fruit weight of Luotiantianshi persimmon’s phenotypic traits was 1.42 times the minimum value, and the maximum value of seed mass was 4.07 times the minimum value. The maximum value of fruit shape index of wide persimmon’s phenotypic traits was 1.48 times the minimum value and the maximum of seed mass was 5.53 times the minimum value. The average value of variation coefficient of Luotiantianshi persimmon and wild persimmon was 13.78% and 22.15%, respectively. and the Shannon index was 1.80 and 2.04, respectively. The variation level of wild persimmon was significant higher than Luotiantianshi persimmon. (2) The among-population variation (24.30%) of Luotiantianshi persimmon was much larger than the within-population variation (17.07%) ; and the mean phenotypic differentiation coefficient was 33.23%. While the within - population variation 48.75%) of wild persimmon was much larger than the among-population variation (6.69%); and the mean phenotypic differentiation coefficient was 73.13% which indicated that considerable differentiation was existed between population of wild permmison phenotype. Conclusion Luotiantianshi persimmon has the modest phenotypic diversity and the degree of phenotypic variation is slight and stable. In addition, there is low level of population differentiation. Within-population variation is the main source of variation. Wild persimmon has relatively higher phenotypic diversity level differentiation potential. Among all phenotypic traits, fruit weight, seed number, and evolutionary potential are high. In a conclusion, these two kinds of persimmon have different responsiveness to complex habitats.
Identification and Pathogenicity of Neofusicoccum occulatum the Agent Shoot Blight of Platycladus orientalis in Shandong Province, China
LIU Zai-zhe, QI Yu-kun, LV Juan, ZHANG Yu-jiao, ZHANG Wei, LIU Yun, FU Cui-cui, LIU Yin, LIU Bao-you, WANG Qing-hai
2022, 35(4): 197-204. doi: 10.13275/j.cnki.lykxyj.2022.004.021
Objective The pathogens causing shoot blight of Platycladus orientalis (L.) Franco in the Jinan Forest Farm, Shandong province were identified to provide a basis for the prevention and control of the disease. Method The pathogens were isolated from the lesion borders of P. orientalis by tissue isolation, and the pure cultures were obtained by monosporic isolation. The isolated strains were identified by combining morphological and polygenic phylogenetic analysis (ITS, TEF-1α, TUB2). Result Colonies were initially white, flattened with tufts of white mycelium. After 14 days, mycelium turned to be dark gray-green and dark brown on the back. Conidia are hyaline, unicellular, fusiform, ellipsoid, and cymbiform, ovoid. Three representative isolates (CBL-02, CLB-03, and CBCB-02) were used for pathogenicity tests and phylogenetic analyses. All the isolates tested could cause similar symptoms on the P. orientalis. The multilocus phylogenetic tree was generated using the maximum parsimony method based on 3 genomic loci ITS, TEF-1α, and TUB2. In the maximum likelihood phylogenetic tree, all test isolates were clustered in N. occulatum clade with 89% bootstrap support. Based on the multi-gene phylogeny and morphology, all test isolates were identified as N. occulatum Sakalidis, M. L., Burgess, T. I. Conclusion It is clear that N. occulatum is the pathogenic bacteria causing shoot blight of P. orientalis, and P. orientalis in Jinan City, Shandong Province.