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Study of Foliar Fertilizer-B Absorption and Distribution in Poplar Saplings Using 10B Tracer
FU Xiao-xia, PENG Jun-dong, LENG Jing, CAI Xue, XIONG Ling-jun, OU Yong-bin
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.014
Objective The absorption, distribution and re-translocation of foliar boron fertilizer in poplar under different boron conditions were analyzed, in order to provide clues for the cultivation and management of poplar plantation. Method Populus alba var. pyramidalis Bunge saplings were sand cultured in greenhouse. Different concentrations of boric acid were added to the nutrient solution, and the lower mature leaves were fed with 10B-rich boric acid (H310BO3). The growth of poplar was recorded, and the boron content in different parts was determined. Result (1) Under sand culture condition with low boron concentration, the biomass and boron accumulation of plants decreased significantly, the boron concentration in upper leaves significantly decreased, and the proportion of boron allocated to young leaves significantly decreased also. (2) Application of foliar boron fertilizer (LB + F) could supplement the boron concentration in upper leaves, and reduce the changes of biomass and boron accumulation to a certain extent. Most of boron absorbed from foliar fertilizer was retained in the fertilized leaves, while 31.68%, 5.27% and 1.06% of absorbed foliar boron can be re-translocated to young leaves, roots, and stems. (3) In relative to normal boron concentration, application of foliar boron fertilizer (NB + F) could increase boron concentration in stem, but had no significant effect on boron concentration of roots and leaves and the biomass in different parts. Compared with LB + F, NB + F plant absorbed much less boron from foliar fertilizer, which was only 15.6% of the former. Conclusion Boron deficiency will result in a reduced boron allocation to young leaves in poplar, thus affects plant growth. The boron fertilizer absorbed by mature leaves could be re-translocated to other parts of the plant, especially the young leaves. The negative effect of rhizosphere boron deficiency on plant growth can be compensated by applying foliar boron fertilizer.
Fire Performance Evaluation of Ten Main Afforestation Species in Mountainous Areas Around Xining, Qinghai Province
LI Hai-jia, ZHENG Shu-xia, SHAN Xiao-xiao, MA Yu-lin, SONG Zheng, REN Fei
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.013
Objective To study the physicochemical properties and combustion characteristics of common tree species in Qinghai, and to evaluate the fire resistance of local tree species, so as to provide references for the selection of fire-resistant tree species in Qinghai. Method The fire-resistance indexes of 10 tree species were divided into fire-resistance factor fa and combustion performance factor fb (including the extrinsic factor fb1 and the intrinsic factor fb2) by factor analysis. Through Pearson correlation analysis and partial correlation analysis, the relationship between the 9 physicochemical properties of the 10 tree species and the fire prevention factors was obtained. Finally, the fire-resistant performance of the 10 tree species was ranked by comprehensive analysis. Result (1) There was a significant negative correlation between fb2 and the moisture content of leaves, between the burning point of bark and branches, and between fa, fb2 and the calorific value of leaves. (2) The results of partial correlation analysis showed that the moisture content of leaves had a significant negative correlation with fb2, and the fb2 had a significant negative correlation with fa. (3) The ranking similarity of fire performance of tree species based on the comprehensive values of combustion test and fire performance was 64%. Conclusion The comprehensive fire-resistance evaluation model of the 10 tree species is established, and the order of fire-resistance is obtained based on different weight systems as Atriplex canescens > Armeniaca sibirica > Rosa xanthina> Caragana korshinskii > Syringa oblata Lindl. > Elaeagnus angustifolia > Hippophaerha mnoides > Amygdalus triloba > Sabina vulgaris > Picea crassifolia. The results are of practical application and popularization to the fire-resistance of tree species in Xining and its surrounding areas.
Effects of Stand Structure on Natural Regeneration of Quercus mongolica Forest in Mountainous Area of Eastern Liaoning Province
DONG Li-li, LIU Hong-min, ZHAO Ji-chuan, GAO Ying-xu, WANG Cheng-cheng, FAN Jun-gang
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.012
Objective The relationship between stand structure and undergrowth regeneration seedling was discussed to provide theoretical basis for artificial promotion of natural regeneration. Method Several Q. mongolica forests in mountainous area of eastern Liaoning province were taken as the research objects, the fitting model and Pearson correlation analysis were used, and the effect of stand spatial structure on natural regeneration of Q. mongolica was studied. Result (1) The forest stand base area had a significant effect on seedling density. With the increase of stand base area, the seedling density showed an increasing trend. When the base area reached 31 m2·hm−2, the increase of seedling density gradually slowed down. (2) There was a significant negative correlation between stand base area and seedling base diameter and seedling height (P < 0.05). (3) The relationship between stand competition index and density and seedling density was typical parabola. Compared with density, the effect of competition index on seedling density was more significant. (4) The spatial structure of stand had a significant effect on the species diversity of regenerated seedlings, the higher the degree of mixing, the more complex the vertical structure, and the higher the diversity of regeneration seedling species and Shannon-wiener. (5) Multivariate stepwise regression analysis showed that the main variables influencing the total regeneration density were stand basal area, crowding and competition index. Conclusion Adjusting stand basal area, crowding and competition index are the effective ways to promote the natural regeneration and improve the species diversity of Q. mongolica forest.
Variation in Fruit Traits of Eucommia ulmoides Germplasm Resources and Their Comprehensive Evaluation
DU Qing-xin, QING Jun, LIU Pan-feng, WANG Lu, DU Lan-ying, HE Feng, DU Hong-yan
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.002
Objective To provide theoretical basis and genetic materials for breeding and utilization of Eucommia ulmoides. Method Based on 331 E. ulmoides germplasm resources from 18 provinces of China, correlation analysis, cluster analysis and principal component analysis were conducted for evaluating and selecting superior germplasms with 19 fruit traits. Result The coefficient of variation of fruit traits was 4.64%-25.79% and the average coefficient of variation was 12.65%. Large variations were found in 100-fruit pericarp wrapping seed kernel weight (25.79%), 100-seed kernel weight (22.32%) and seed volume index (19.53%), while the linolenic acid (4.64%), oleic acid (5.78%) and fruit type index (8.04%) kept relatively stable. The diversity index ranged from 1.6572 to 2.0947, with an average of 2.0234. The 100-fruit weight showed a significant positive correlation with fruit volume index and 100-seed kernel weight, E. ulmoides rubber content significantly and positively correlated to 100-fruit pericarp wrapping seed kernel weight and fruit lateral diameter, while significantly and negatively correlated with crude fat content. Cluster analysis divided the germplasm resources into three groups: small (Ⅰ), medium (Ⅱ), and large (Ⅲ), different types of germplasms were preliminarily defined. Based on principal component analysis, the cumulative contribution rate of the first seven principal components were accounted for 85.169%, ten superior germplasms were selected for evaluation of oil, rubber and comprehensive utilization. Conclusion E. ulmoides germplasm shows high variation. The yield index has the largest variation, represented by 100-fruit pericarp wrapping seed kernel weight and 100-seed kernel weight, which provides possibility for the selection of superior germplasms. The optimal germplasms selected for different purpose provides an excellent germplasm basis for the breeding and comprehensive utilization of E. ulmoides.
Influence of IAA and NAA on Cutting Propagation of Dalbergia odorifera
XU Shan-shan, LIU Xiao-jin, XU Da-ping, HONG Zhou, GUO Jun-yu, YANG Zeng-jiang
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.020
Objective To identify the influence of IAA and NAA on the rooting and shooting ability of Dalbergia odorifera, and provide theoretical and technical support for the rapid propagation and cultivation of D. odorifera. Method Semi-lignified branches from 2-year-old D. odorifera seedlings were collected as the propagation materials. An orthogonal experiment was designed according to the concentrations of IAA and NAA and the soaking time. The effects of 16 treatments on rooting and shooting parameters of D. odorifera were investigated 80 days after cutting, and the subordinate function values method and principal component analysis were applied to comprehensively evaluate the rooting effects. Result The concentrations of IAA and NAA, the soaking time, the interaction between IAA and NAA concentration, and the interactions between IAA concentration and soaking time showed great impacts on rooting percentage, and statistical differences were also observed in terms of length of roots, amount of roots, surface and volume of root system. Under certain concentration range, the rooting percentage increased as the concentration of IAA increased, while decreased as the concentration of NAA increased. The principal component analysis and subordinate function values were used to comprehensively evaluated the cutting propagation performance. It is showed that the corresponding rooting percentages of the top 4 treatments were 96.10%, 97.66%, 96.10% and 96.88%, respectively. Conclusion Considering the rooting percentage, root and shoot development synthetically, it is suggested to apply 500 mg·L−1 IAA + 750 mg·L−1 NAA + 1-minute soaking or 750 mg·L−1 IAA + 750 mg·L−1 NAA + 10-second soaking or 250 mg·L−1 IAA + 1-minute soaking or 500 mg·L−1 IAA + 500 mg·L−1 NAA + 10-second soaking in production practice to carry out cutting propagation of D. odorifera.
Simulation of Operation for Forest Management Based on Body Action Interaction
ZHU Nian-fu, ZHANG Huai-qing, CUI Zhe-yu, YANG Ting-dong, WANG Lin-long, LIU Hua
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.011
Objective In view of the complex and diverse types of forest management operations, this paper aims at solving the problems of poor interactivity, lack of natural and realistic interactive experience, and the difficulties to deal with frequent operations, and developing a set of interactive methods of forest management measures based on body action. Method A forest simulation scene based on the immersive virtual reality and visual simulation system CAVE2 was constructed as the interactive object, the management measures with strong interaction on the user side such as logging, pruning and replanting were selected, the limb movements in the operation process of forest management measures were analyzed, and the relative distance and angle changes between the management tools and users in the simulation scene were mapped with the limb actions. The interaction model of body movement was constructed to realize the implementation of limb action control management measures and the simulation of forest management. Result The interactive model of body movement constructed in this study was correctly mapped into forest management measures. The success rate of single operation was 86%, and the good rate of interactive evaluation was 91%. The combination of body movement and management tools facilitates the expansion of interactive demand of forest management simulation. Conclusion The simulation of forest management operation based on body action interaction can visually and intuitively show the operation process of forest management measures, which is helpful for the user's to further understand the forest management and improve the level of forest management assistant decision.
Growth Difference and Early Evaluation and Selection of Young Picea abies Clones in Western Hubei
GAO Ben-wang, OUYANG Fang-qun, GAO Han, LI Wei, LEI Hua, TIAN Kai-chun, QI Song, WANG Jun-hui
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.010
Objective To select and breed elite trees for local quality reforestation by evaluating the genetic architecture of growth and branch relevant traits from 378 9-year-old Picea abies clones. Method P. abies clones were established using a completely random block design. The genetic variation of height, diameter at breast height, crown width, stem increment of the current year, number of branch in the first round were analyzed to select elite clones using EXCEL and package lme4. Result The results showed that the clones and the interaction effects between clones and block significantly affected the height, diameter at breast height, crown width, stem increment, and branch of P. abies. The genetic and phenotypic variation coefficient were 10.02%~20.38% and 31.36% ~48.36%. The repeatablilty of height, diameter at breast height, crown width, stem increment, branch and volume were 0.59~0.71. The phenotypic correlation and genetic correlation coefficients of height, stem increment, diameter at breast height, and crown width were 0.72 to 0.95, which were all significantly correlated to each other. 30 elite clones were chosen by tree height genetic value with the selected ratio 7.94%. The genetic gain of the height were 26.38%. Conclusion The height, stem increment, diameter at breast height, branches, and crown width of 378 P. abies clones have significant variation among clones, and are affected by the interactive effect between clones and environment. The clones also have obvious interaction with site, indicating that the most suitable clones should be selected according to site when implementing clonal forestry. 30 elite clones with good growth performance are chosen by their genetic values of tree height which may be used in the promotion and application of P. abies asexual reproduction.
Response of Stem Radial Growth of Eucalyptus urophylla × E. grandis to Planting Density Based on Transcriptome Analysis
CHEN Mo, HE Sha-e, CHEN Shao-xiong, OUYANG Lin-nan, ZHANG Cheng, ZHANG Wei-yao
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.001
Objective To identify the key genes of secondary xylem development response to planting density for a well understanding of molecular mechanism of planting density affecting radial growth of eucalypts. Method By a combination of PacBio Iso-Seq and RNA-Seq analysis, the differentially expressed transcriptomes of xylem cells in Eucalyptus urophylla × E. grandis were identified under high and low planting densities. The tissues expression profiles of these key genes were analyzed via qRT-PCR. Result A total of 45 490 non-redundant full-length transcripts and 443 transcripts differentially expressed in xylem cells were obtained under high and low planting densities, and 60 transcripts encoding regulatory factors were obtained. Under low planting density, the diameters of trees increased significantly. The PXL2 and its interactional genes CUL1, T15D22.7 related to cell division, the MYB46, C3H14 with their downstream genes CesAs and LACs related to secondary wall regulation were preferentially expressed in the xylem cells. These genes might play key roles in the regulation of diameter growth under different densities. In addition, the NAC86 homologous genes involved in sieve element development and the inhibitor PTL homologous genes with dual functions in cambial cell proliferation and xylem differentiation were also up-regulated. They could promote the xylem development, which were different from the functions in herbaceous plants. The results of tissue expression analysis showed that PXL2, CUL1, T15D22.7, NAC86 and PTL were predominantly expressed in phloem and xylem, whereas MYB46, C3H14, CesA and LAC17 were predominantly expressed in xylem. Conclusion In this study, the candidate genes of xylem development related to planting density are identified and a model of molecular regulatory network that how the planting density affects radial growth of E. urophylla × E. grandis is proposed, which will benefit the intensive study of the molecular mechanism under different planting densities affecting radial growth for trees.
Expression of SPL-like Gene LaSPL2 and LaSPL3 in Japanese Larch (Larix leptolepis) During Somatic Embryogenesis
FAN Yan-ru, LAN Qian, HAN Su-ying, QI Li-wang, ZHANG Li-feng
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.009
Objective To reveal LaSPL2 and LaSPL3 function during somatic embryogenesis, based on their molecular characteristics and expression patterns. Method The full-length cDNA sequences of LaSPL2 and LaSPL3 were obtained by homologous cloning and RACE techniques. The amino acid sequences for known SPL family proteins were aligned using the ClustalX 2.1 software. The full-length protein sequence alignment was used to construct a phylogenetic tree according to the neighbor-joining method of the MEGAX program. Subcellular localization was performed by transient expression system of tobacco. The expression patterns of LaSPL2 and LaSPL3 during somatic embryogenesis were detected by qRT-PCR. Result In this study, two SPL homologous genes, LaSPL2 and LaSPL3, were isolated from Japanese larch, which encoded 532 amino acids and 191 amino acids respectively. Further analyses revealed that LaSPL2 and LaSPL3 mRNA were targeted by miR156. The deduced amino acid sequences of the LaSPL2 and LaSPL3 harbored a highly conserved SBP domain. A transient expression analysis of the LaSPLs-GFP fusion proteins in tobacco leaf epidermal cells revealed that the LaSPL2 and LaSPL3 proteins were localized in the nucleus. Moreover, the expression of LaSPL2 and LaSPL3 was down regulated by ABA during the early stage of somatic embryogenesis. With the further development of somatic embryos, the expression levels of LaSPL2 and LaSPL3 peaked at 10 and 14 days, respectively. Subsequently, with the maturation of somatic embryos, their transcription levels decreased gradually to the lowest level at 42 days. Conclusion The effects of ABA removal on the expression of LaSPL2 and LaSPL3 indicate that ABA might be the main factor in their down-regulation during the early stage of somatic embryogenesis. Furthermore, the expression of LaSPL2 and LaSPL3 will reach the peak at the early stage of somatic embryogenesis, implying it might encode an important regulator of early embryonic pattern formation. The sequence analysis and expression patterns of LaSPL2 and LaSPL3 indicated that they may be regulated by miR156 during somatic embryogenesis and play an important role in the maturation of somatic embryos.
Analysis of Codon Usage in the Chloroplast Genome of Cypripedium calceolus
DING Rui, HU Bing, ZONG Xiao-yan, HAN Chen-yang, ZHANG Li-jie, CHEN Xu-hui
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.021
Objective To analyze the codon usage bias of Cypripedium calceolus chloroplast genome, and identify the main factors influencing codon usage bias of this species in order to provide reference for the chloroplast genomics research of Orchidaceae species. Method Downloading the complete chloroplast genome sequence of C. calceolus and screening the protein coding sequences, the EMBOSS online program was used to calculate the GC content of each gene and codon, and the software CondonW was used to calculate the length of amino acid (LAA), effective number of codon (ENC), relative synonymous codon usage (RSCU), frequency of optimal codons (FOP) and the acid base content of the third nucleoside of each gene codon. The software SPSS was used to analyze the correlation among each index, and software Origin was used to plot. Result The third codon position of C. calceolus chloroplast genome sequence was rich in A and T, and the GC3 content was only 29%. The ENC values varied from 37.92 to 61.00, indicating a relatively weak codon usage bias. The correlation between the number of effective codons and GC3 showed an extremely significant level. There were 34 codons with relative synonymous codon usage greater than 1 and 29 codons ending with A and U. Analysis of neutral plot, ENC-plot and PR2-plot showed that the preference of C. calceolus chloroplast genome codons was mainly influenced by natural selection. Correspondence analysis showed a similar pattern of codon usage bias of the genes encoding photosynthetic system proteins, while other types of genes were quite different. Sixteen codons were finally determined as the optimal codons. Conclusion This study confirms that natural selection is the main factor affecting codon usage bias of C. calceolus chloroplast genome. The optimal codon of this species is screened. The results can provide a reference for the phylogeny and chloroplast genome codon evolution of Orchidaceae.
Identification of NLP Transcription Factors of Phyllostachys edulis and their Expression Patterns in Response to Nitrogen
YUAN Ting-ting, ZHU Cheng-lei, LI Zi-yang, SONG Xin-zhang, GAO Zhi-min
, Available online  , doi: 10.13275/j.cnki.lykxyj.2021.005.005
Objective To identify the NLP family members in moso bamboo (Phyllostachys edulis) and lay a foundation for further study on the molecular regulation mechanism of these NLPs. Method The molecular characteristics of the NLP members in moso bamboo were identified and analyzed comprehensively by bioinformatics methods, and the expression patterns of the NLPs in response to nitrogen were detected by quantitative real-time PCR (qPCR). Result Ten NLP members (PeNLP1~PeNLP10) were identified from moso bamboo. The length of PeNLPs ranged from 714 aa to 963 aa, with the molecular weight of 77.41~105.08 kDa, and the theoretical isoelectric point ranged from 5.36 to 6.25. The prediction of subcellular localization showed that all PeNLPs were located in the nucleus except PeNLP9 in the chloroplast. Phylogenetic analysis showed that PeNLPs could be divided into 3 groups with 4, 2 and 4 members, respectively. All PeNLPs contained 4 introns, and there were some differences in the size and position of introns among different members. There were 6 collinear gene pairs in PeNLPs and 9 collinear gene pairs between PeNLPs and OsNLPs, and their Ka/Ks were all less than 1.0, indicating that they had undergone purification selection in evolution. Tissue specific analysis showed that some PeNLPs expressed in tissue-specific manner, while some PeNLPs expressed constitutively. The expression of PeNLPs was induced by nitrogen starvation, and that of PeNLP1 was significantly up-regulated within 1 hour, while those of other 5 PeNLPs were significantly down-regulated (p < 0.01). After 72 hours of nitrogen starvation, the seedlings were resupplied with nitrogen, and the expression levels of all PeNLPs were significantly up-regulated (p < 0.05 or p < 0.01) within 24 hours. Conclusion There are 10 members of NLP family identified in moso bamboo. There are some differences in molecular characteristics and tissue expression specificity of each member. The expression of PeNLPs can respond to nitrogen starvation rapidly, and it is significantly up-regulated in the process of nitrogen resupply after nitrogen starvation.