Flavonols play important roles in plant responses to various environmental stresses and in the regulation of seed coat development. In this study， a transparent seed coat mutant was obtained through ethyl methane sulfonate（EMS） mutagenesis screening， compared with wild-type Arabidopsis thaliana（Col-0）， the mature seed color of the mutant was yellow， and its phenotypic trait was controlled by a recessive single gene. Using map-based cloning and fine-mapping technology， the mutant gene TT4（At5G13930） was mapped to BAC of MAH20 on chromosome 5， and the 1 299th base C of the TT4 was mutated to T， resulting in the 324th amino acid glycine mutated to glutamic acid. TT4（transparent testa 4） encoded a structural gene for flavonoid synthesis， chalcone synthase（CHS）， and after mutation， the seed coat was transparent and the seed color was yellow， then the mutant was named tt4-1. The phenotype of brown seed coat was restored by functional complement mutants， which further demonstrated the important role of TT4 in regulating the development of seed coat color. The tissue expression analysis of TT4 was conducted by promoter coupling GUS assay， and it was found that TT4 gene was expressed in the roots， stems， leaves of plant seedlings and flowers respectively. Physiological phenotypic analysis showed that the mutant tt4-1 seeds germinated earlier， and the seedlings had shorter taproots， as well as more lateral roots and root hairs， larger stomatal opening and higher water loss rate in mature leaves compared with the wild type. This study would lay a theoretical basis for further elaborating the function of TT4 gene.
In order to reveal the mechanism of Ricinus communis response to heavy metal cadmium（Cd） stress， and screen out the resistance genes involved in Cd stress， by observing the seed germination and plant growth status， castor plants treated with water were used as controls to study their effects under three doses（300， 700 and 1 000 mg·L-1） of Cd stress. The response mechanism is expected to provide new ideas for revealing the defense and detoxification mechanism of castor plant under in Cd stress. Using differential proteomics to analyze the network regulation mechanism of castor under Cd stress， that is， with the increase of Cd stress concentration， the castor plant blocks the absorption of heavy metal Cd by roots， improves their own antioxidant capacity， and inhibits Cd2+ operation. As well as the induction of programmed cell death and other detoxification processes to resist Cd stress damage； according to the results of omics analysis， a significantly different gene RcBSK7 was screened. Through functional verification in Arabidopsis， it can be seen that this gene can improve tolerance of castor plants to Cd stress. This study enhances the understanding of the diversity and complexity of castor plants under three Cd stresses， and provides a valuable theoretical basis for the identification of Cd-tolerant genes and the restoration of heavy metal pollution in the soil.
To clarify the genetic diversity and genetic structure of a rare and the endangered small population of Ferula fukanensis， it is the basis and prerequisite to develop effective conservation and management strategies. The genetic diversity and structure of 87 endangered plants F. fukanensis from three populations based on 10 pairs of SSR primers with good polymorphism and stable amplification were analyzed respectively. The results showed that small population of F. fukanensis had relatively high genetic diversity， the Nei’s gene diversity index（hS） among the populations was 0.514， the total Nei’s gene diversity index（hT） was 0.516， the observed heterozygosity（Ho） was 0.881， the expected heterozygosity（He） was 0.512， the Shannon information index（I） was 0.836 and the percentage of polymorphic bands（PPB） was 100%， and the genetic differentiation degree of F. fukanensis was very low（Fst=0.007）， 95.9 % of the variation of F. fukanensis occurred within populations， and there was no significant correlation between genetic distance and geographical distance， 66.7% of the populations suffered from genetic bottlenecks. The results showed that F. fukanensis had abundant genetic variation and high evolutionary potential. Based on the current situation of this wild population， it is suggested to establish a protected area， and carry out in situ conservation and strengthen ex situ conservation measures such as introduction and artificial breeding to assist the conservation of F. fukanensis. This study can provide theoretical support for the conservation of plant resources of F. fukanensis and has important theoretical and practical significance.
Transcriptome analysis in Populus simonii × P. nigra overexpressing PsnCycD1；1 showed PsnHB3 and PsnHB15 are differential genes. Analysis of PsnHB13 and PsnHB15 conservative domains through InterPro tool. The STRING software was utilized to explore PsnHB13 and PsnHB15 proteins interaction network analysis. Yeast two hybrid was used to verify the interaction proteins，calculate the ratio of leaf length to width，the ratio of dry weight to fresh weight of leaves and stems of transgenic plants，and analyze the transcriptome of PsnHB13 overexpression plants. Conserved domain analysis showed that PsnHB13 and PsnHB15 genes belonged two subfamilies，showing that PsnHB13 mainly contains the HDZip I domain，and PsnHB15 mainly contains the HDZip Ⅲ domain. ，Each gene is screened to 10 interacting genes. Moreover，PsnHB15 has a higher probability of interaction with family proteins. Yeast two-hybrid assays demonstrated that PsnHB15 interacts with PsnHB13 and PsnHB13 interacts with PsnCycD1；1. The aspect ratio of leaves in transgenic lines overexpressing PsnHB13 and PsnHB15 increased in the early seedling stage.The ratio of dry weight to fresh weight in stems of PsnHB13 overexpression lines increased significantly（P<0.05）. The analysis of the transcriptome revealed that Gene Ontologies（GO） enrichment analysis identified 3 significantly enriched GO terms，including response to chemical，response to organic substance，regulation of RNA metabolic process. KEGG pathway enrichment analysis demonstrated that transcription factors，plant hormone signal transduction and Cytochrome P450 were significantly enriched. These differential genes，including MADS-box transcription factor，MYBP transcription factor，ERF1 transcription factor，GH3 auxin responsive genes，SAUR protein family. PsnHB13 and PsnHB15 play an important role in the growth and development of Populus simonii × P. nigra，and are key genes to explore the growth law of plants and reveal the relationship between cell cycle and growth regulation.
As an important auxin efflux carrier family in plants， PIN protein family shows extensive physiological effects in plant growth and development. In order to further understand the function of BpPIN3 and explore its response to different hormone signals and abiotic stresses during Betula platyphylla development，the BpPIN3 promoter sequence was analyzed by bioinformatics methods. Tissue expression patterns of roots， stems， leaves and apical buds of annual and biennial B. platyphylla clones were analyzed respectively. The seedlings were used as conduct hormone induction and light stress treatment with 100 μmol·L-1 auxin（IAA）， 100 μmol·L-1 gibberellin（GA3）， 200 μmol·L-1 abscisic acid（ABA） and long light conditions， respectively. RNA was extracted from leaves and roots of B. platyphylla at 0， 2， 4， 8， 16， 24 and 48 h after hormone treatment and at 0， 1， 3， 6， 12， 24， 48 and 72 h after light stress， and qRT-PCR was used to analyze the expression of BpPIN3. The results showed that the BpPIN3 promoter sequence contained different types of auxin response elements such as gibberellin， abscisic acid， and methyl jasmonate， as well as multiple stress-related cis-regulatory elements. BpPIN3 was expressed in many tissues of birch in different growth years， especially in leaves， and the expression of BpPIN3 in the second year was higher than that in the first year. The relative expression of BpPIN3 gene was different in different parts under different treatment conditions. IAA and GA3 could induce the up-regulation of BpPIN3 expression in leaf. Under ABA treatment， except for 16 and 48 h， the expression pattern of BpPIN3 gene was opposite to that under IAA treatment. IAA， GA3 and ABA could induce the expression of BpPIN3 in root， but shading stress induced the expression of BpPIN3 gene in leaf， the relative expression of BpPIN3 gene was significantly higher than that of the control（0 h） from 12 h in root， IAA， GA3 and ABA could induce the expression of BpPIN3 in root， shading stress induced the expression of BpPIN3 gene in leaf； the relative expression of BpPIN3 gene was significantly higher than that of the control （0 h）from 12 h in root. The results suggested that BpPIN3 gene played the important regulatory role in the growth and development of B. platyphylla，and the signal transduction pathways of IAA， GA3 and ABA and plant light response.
The complete chloroplast genome of Rhodiola himalensis was sequenced， assembled and annotated using high-throughput sequencing technology， and R. himalensis was used as material， an endemic medical species to the Qinghai-Tibet Plateau. The results showed that the complete chloroplast genome of R. himalensis was 151 074 bp in length with a GC content of 37.8%. It had a typical tetrad structure with a long single copy region， a short single copy region and a pair of inverted repeat regions， and the sequence length of them was 82 309， 17 017 and 25 875 bp， respectively. The complete chloroplast genome encoded 130 genes， including 86 protein coding genes， 37 tRNA genes and seven rRNA genes. Based on the chloroplast genome of R. himalensis， a total of 25 513 codons was detected， among which the largest proportion of codons was Leu. In the IRa and IRb regions of R. himalensis， the gene of rps19 and ycf1 was deletion， and the gene of trnH in LSC region was contraction. And R. himalensis and R. sacra had the closest genetic relationship were also found. Besides， the variation frequency of single nucleotide polymorphism（SNP） was the highest within the SSC region. The complete chloroplast genome of R. himalensis was reported， assembled， annotated and analyzed， which could provide the theoretical basis for the study of genetic diversity and rational development and utilization of R. himalensis in the future.
To clarify the function of SPL gene in growth and development of Betula platyphylla，the BpSPL9 gene was cloned， and the expression vector of BpSPL9 was constructed by CREST technology， and the genetic transformation was carried out by Agrobacterium mediated method， and the phenotype of the transgenic lines was observed， respectively. The results showed that the transgenic lines with BpSPL9 suppressed were successfully obtained. The height of transgenic lines was significantly lower than that of non-transgenic lines， with shorter node spacing and smaller leaf area. The contents of 6-BA and IAA in transgenic lines were lower than those of the non-transgenic lines. It is speculated that BpSPL9 gene participated in plant growth and development by affecting the synthesis of auxin and cell division.
Stems of Populus simonii×P. nigra ‘Baicheng’ in vitro plants were selected as explants and MS medium was used to establish tissue culture system by adjusting the hormone concentrations of 6-BA， NAA， TDZ and IBA. Based on the tissue culture system， the optimal concentration of kanamycin and infection time were confirmed to establish Agrobacterium tumefaciens-mediated genetic transformation system for P. simonii×P. nigra ‘Baicheng’. By using this system， the transgenic plants overexpressed a key tension wood formation regulator LBD39 （Lateral Organ Boundaries Domain） were created successfully. The results showed that the tissue culture system consisted of three stages， including adventitious bud differentiation induction （MS+ 0.5 mg·L-1 6-BA+0.1 mg·L-1 NAA+0.001 mg·L-1 TDZ， shoot differentiation rate=92.6%）， stem induction （MS+0.2 mg·L-1 6-BA+0.05 mg·L-1 NAA， multiplication coefficient=6.5） and rooting induction （1/2 MS+0.4 mg·L-1 IBA， rooting percentage=100%）. The optimal kanamycin concentration for genetic transformation was 30 mg·L-1 and the optimal infection time was 20 min， and the transgenic plants were obtained successfully after 30 d of adventitious bud differentiation induction， 15-30 d of stem induction and 25 d of rooting induction with 2% transformation efficiency respectively. By using this system， five overexpressed plants of LBD39 were obtained， and the transformation efficiency was 3.3%.
To screen out the tomato（Solanum） germplasm with waterlogging tolerance， 50 tomato germplasm were selected as the research object， and the survival rate and physiological indexes were compared after semi-submerged and submerged treatments respectively. The results showed that 12 waterlogging tolerant tomato germplasm with 100% survival rate after seven days submergence treatment were selected， and 12 waterlogging-tolerant germplasm were observed and distributed in S. lycopersicum，S. lycopersicum var. cerasiforme and S. pimpinellifolium respectively. Further analysis on waterlogging-tolerant tomato TK017 and waterlogging-sensitive tomato TK039 revealed that tomato TK017 could control the content of reactive oxygen species more effectively under submergence condition， and improved the waterlogging tolerance of tomato.
In order to investigate the molecular mechanisms of protein responses in Triadica sebifera to salt stress， two T. sebifera lines， including salt-sensitive P18（SS18） and salt-tolerant P21（ST21） were selected and treated with 0.4% NaCl solution. Isotope tags for relative and absolute quantitation（iTRAQ） were used to quantify leaf proteins abundance changes at different stress periods（0， 24， 72 h）. A total of 279 and 106 differentially expressed proteins（DEPs） were detected in SS18 and ST21， respectively. Four proteins， including catalase， extension factor 1-α， H+-ATPase c domain protein and thioredoxin， were significantly up-regulated in two clones under salt stress， suggesting that they may be important potential target proteins in the salt-tolerant response of T. sebifera’s. Pathway enrichment analysis showed that the DEPs of T. sebifera leaves under salt stress were primarily associated with photosynthesis， carbohydrate metabolism， amino acid metabolism， and fatty acid metabolism. The protein-protein interaction network showed that 5 core proteins（24 h） and 3 core proteins （72 h） involved in glucose decomposition and energy metabolism in SS18， while ST21 had 5 （24 h） and 4 （72 h） core proteins involved in carbon metabolism， photosynthesis， carbon fixation， photosynthesis and related to chlorophyll a-b binding. ST21 leaves improved metabolic pathways of sugars， amino acids and fatty acids， and accumulated a large number of small molecular soluble substances such as soluble sugars， amino acids and organic acids under salt stress， which might be an important aspect of salt stress response.
The effect of sampling time and plant growth regulators on the induction of callus， somatic embryo and adventitious bud were investigated with immature embryos of Iris lacteal var. chinensis as explants. The results showed that the most feasible sampling time for immature embryos was 35-45 d after pollination， the young embryos were fully developed， but the endosperm was not completely hardened， and the young embryo was easy to dissect. The optimum medium for callus induction was MS+1.0 mg·L-1 2，4-D+0.2 mg·L-1 6-BA with the induction rate of 83.33%. The appropriate medium for somatic cell induction was MS+0.25 mg·L-1 2，4-D+0.05 mg·L-1 6-BA with the induction rate of 71.67%. The most suitable medium for adventitious bud induction and proliferation was MS+0.2 mg·L-1 TDZ+0.05 mg·L-1 NAA with the induction rate of 78.33% and proliferation coefficient 3.65 in this experiment. The rooting rate was more than 95% after four weeks cultivation on MS medium supplemented with 0.1 mg·L-1 NAA. Then， the medium was washed off and explants were transplanted to sterilized vermiculite， and the survival rate was more than 95%. This study has established an efficient regeneration system of I. lacteal var. chinensis embryos， which can lay a foundation for genetic transformation and gene function analysis of I. lacteal var. chinensis.
To explore the fruiting characteristics and seed characteristics and their variation patterns of Abies species distributed in Northwest Yunnan， and to provide material support and theoretical basis for promoting the regeneration and restoration of Abies forest， the specimens and cones of seven Abies species distributed in Northwest Yunnan were collected and identified， and the seed morphological characteristics， seed viability， and fruiting characteristics were analyzed， and then the differences among species and regions were explored separately. The results showed that the length， width and thickness of seeds of seven Abies species in Northwest Yunnan were 6.04-10.22 mm， 2.03-3.32 mm and 1.26-2.24 mm， respectively， and the thousand-grain weight was 4.26-30.50 g. The thousand-grain weight was significantly correlated with seed length， width and thickness （r>0.8， P<0.01）. The average rates of plump， empty and insect-eaten seeds of seven Abies species in Northwest Yunnan were 27.51%， 4.92% and 67.58%， respectively. The rate of plump seed was low， and that of empty and insect-eaten seeds was high. Abies ernestii var. salouenensis was not further analyzed in this article due to field investigations revealing that most of them had no cone and only one tree’s cones were collected in this study. For the other six species， the rate of insect-eaten seeds did not differ significantly between species（P=0.750）， or between regions（P=0.204）. However， there were interspecies differences in the rate of plump seeds（P=0.005） and empty seeds（P=0.007）. There were interspecific（P=0.008） and interregional（P=0.036） differences in Abies seed viability. Therefore， seed viability of Abies was affected by both species characteristics and environmental factors.
In this study， the effects of NaCl， PEG（6000） and low temperature stresses on the levels of iATP （intracellular ATP） and eATP（extracellular ATP） of tobacco suspension cells BY-2（Nicotiana tabacum ‘Bright Yellow-2’） were studied respectively. The results showed that the tobacco suspension cells treated with 50-200 mmol·L-1 NaCl significantly increased membrane permeability（P<0.05）， the levels of iATP and eATP decreased significantly at 100 and 200 mmol·L-1 NaCl stresses（P<0.05）. With the increase of PEG mass concentration（50， 100 and 200 g·L-1）， the membrane permeability and eATP level increased. Under 200 g·L-1 PEG stress， eATP level increased significantly to 3.4-fold of the control（P<0.05）， iATP level decreased significantly to 0.5-fold of the control（P<0.05）. After the treatment with low temperature at 0-10 ℃， the membrane permeability and iATP level increased to different extents. iATP level increased to 1.9-fold of the control at 0 ℃， while eATP level decreased significantly to 0.8-fold the control at 10 ℃（P<0.05）. The above results indicate that iATP is the source of eATP in plant cells， iATP level is not the only factor that affects eATP level under abiotic stresses. The way in which plant cells transport ATP and other factors may affect eATP level under abiotic stresses.
A rapid and efficient regeneration system of liquid-solid alternate culture was developed for the tissue culture seedlings of Fraxinus mandshurica with lignificated stalk， aged leaves and dormant apical buds， and the axillary buds were germinated in a short time by liquid suspension culture， and the axillary buds were regenerated in vitro in solid culture to obtain the new tissue culture seedlings. On liquid and solid media supplemented of WPM with different plant growth regulators， axillary buds of F. mandshurica were induced to germinate and grow into seedlings. It was found that the axillary bud germination rate of F. mandshurica could reach 100% within 7-15 d after dark culture in WPM liquid medium supplemented with 0.6 mg·L-1 TDZ. After cutting the sprouted buds and inoculating them into WPM solid medium of 0.05 mg·L-1 TDZ and 0.6 mg·L-1 BA， axillary buds could grow into shoots after 1-2 subcultures with an average height of 2.64 cm and a multiplication coefficient of 4.04. After transplanting， the survival rate of rooting seedlings was 90% after 50 d. The establishment of the method could be conducive to the large-scale propagation of F. mandshurica， and the liquid-solid alternate circulation culture， simple， controllable， easy to operate， suitable for different production conditions and reduces the cost.
To assess the size and complexity of the genome of the endangered plant Tetraenamongolica， and reveal the hyper-arid mechanism of T.mongolica and further explore its characteristic genetic resources， and to better decipher the whole genome information of T.mongolica， the second-generation high-throughput sequencing technology of genome survey analysis was used as the method， and bioinformatics method was used to estimate the genome information such as heterozygosity， repeat sequence and GC content of T.mongolica respectively. The results showed that the genome size of T. mongolica was 1 079.25 Mb， the corrected genome size was 1 065.84 Mb， and the heterozygosity rate was 0.76%， the percentage of repetitive sequences was 75.25%， and the GC content was 33.57% respectively. After the initial assembly of T. mongolica genome 3 502 126 contigs were obtained， totaling 682 Mb， with an N50 of 187 bp. It was hypothesized that T. mongolica genome belonged to a homo-tetraploid complex genome， which was difficult to assemble by whole-genome sequencing. Due to the high heterozygosity of T. mongolica， the third-generation high-throughput sequencing technology（single-molecule sequencing） combined with chromatin region capture technology could be used subsequently， which was expected to finally obtain a high-quality whole-genome map of T. mongolica.
To improve materials for genetic breeding of Fraxinus mandshurica， the correlation among three hybrid combinations of Fraxinus mandshurica × F. rhynchophylla， F. mandshurica × F. sogdiana and F. mandshurica × F. velutina， and the genetic variation of lignin content and FmPAL nucleotide polymorphism in free-pollination offspring of female parent were analyzed respectively. One-year-old branches of Fraxinus mandshurica with 71 species of interspecies hybrid combinations in Maoer Mountain Forest Farm of Northeast Forestry University were used as materials， the genetic variation regularity of lignin was investigated， the differences in lignin content and variation parameters and mean values were analyzed， and joint analysis on the molecular level of lignin and its synthesis-related gene PAL were carried out. The result showed that the lignin content of the hybrid combinations of Fraxinus was extremely significant， and it was significantly different from the female parent free-pollinated offspring of F. mandshurica. The lignin content of most hybrid combinations of F. mandshurica was higher than that of the female parent F. mandshurica. The results showed that the haploid diversity value of the PAL gene of the F. mandshurica population reached 0.999 7， which was a high level. It confirmed that the FmPAL gene had a high variation. There were 3 SNP sites significantly related to the lignin content. There were significant differences in the lignin content of the cross combinations of F. mandshurica. The SNP sites in the FmPAL gene was significantly related to the lignin content.
The plant cyclic nucleotide-gated channels（CNGC） family has a variety of biological functions and plays an important role in the growth and development of plants and the response to stress. In this study， bioinformatics methods and qRT-PCR were used to analyze the basic physicochemical properties， structural characteristics， phylogeny， gene structure and conserved motif， cis-acting elements of the promoter and gene expression patterns of the PtrCNGC gene family members respectively. The results showed that a total of 19 PtrCNGC genes were identified in the whole genome of Populus trichocarpa. PtrCNGC gene family could be divided into four subgroups（Ⅰ， Ⅱ， Ⅲ and Ⅳ）， and subgroup Ⅳ could be divided into two subgroups（Ⅳa and Ⅳb）. The proteins encoded by the PtrCNGC genes were all basic proteins， and only one member of the PtrCNGC gene family was hydrophobic protein， while all the other members were hydrophilic proteins. A total of 19 PtrCNGCs were distributed unevenly on 11 chromosomes of P. trichocarpa， while the remaining 8 chromosomes had no members distributed. The PtrCNGC gene family contained seven pairs of homologous genes and the Ka/Ks value between them was far less than one. There was little difference in gene structure and protein conserved motif distribution among the family members. Predictive analysis of cis-acting elements in the promoter region of the PtrCNGC gene sequence showed that there were acting elements related to various hormones and stress. The qRT-PCR results showed that the expression of PtrCNGC gene family was specific in different tissues， with higher expression levels in stems and lower expression levels in roots and leaves. Under salt stress and drought stress， most members of the same branch of the PtrCNGC gene family showed similar expression patterns. The results of this study provid a reference for further study on the function of PtrCNGC family in abiotic stress.
In order to explore the reason why there is no fruit in autumn despite of thousands of flowers of ‘Kushui’ rose（Rosa sertate × R. rugosa Yu. et. Ku.） blossoming in garden， we conducted a genetic research on its cross fertility in this study. The results showed that the selfing of ‘Kushui’ rose did not bear fruit in nature or by artificial pollination. Meanwhile， there were no fruit obtained once pollen of ‘Kushui’ rose being pollinated on the stigmas of the other varieties in Rosa. In contrast to this， ‘Kushui’ rose could produce amount of seeds when pollinated with pollen from the same other materials. All evidences supported that the pollen of ‘Kushui’ rose rose was sterile. Further， several reproductive features， such as stamen petallization， P/O value， pollen heteromorphorsis， and pollen germination rate were studied， with the results showing the pollen of ‘Kushui’ rose deformed so seriously that the germination rate was nearly zero. Furthermore， microscopic observation of pollen mother cells at different phases of meiosis revealed there were so much abnormal behaviors of chromosome allocation as well as unequal cytokinesis that plenty of triads were yielded that coexisting with deformed tetrad in pollen sac. In conclusion， the study shows that the abnormal division of pollen mother cells of ‘Kushui’ rose is responsible for the pollen sterility and no fruit setting when used as paternal parent in hybridization. And that pollen abortion causing male sterile， rather than self-incompatibility commonly distributing in Rosaceae， is responsible for the intraspecific cross infertility of ‘Kushui’ rose， further implying it is feasible to improve its germplasm by acting as a maternal in cross-breeding.
A total of 106 clones of Picea crassifolia in Longqu P. crassifolia Clone Seed Orchard in Zhangye were used as materials， and the genomic DNA of P. crassifolia was extracted by improved CTAB method， the SLAF library was constructed and sequenced with high flux， and then the SLAF sequencing data were analyzed and SNP sites were screened， and the clustering of samples was obtained based on adjacency analysis respectively. The results showed that the efficiency of two terminal alignment was 95.33%， indicated that the SLAF database was successfully established. The Q30 of the sequence measured and the sequencing quality was high， but the error rate of base sequencing was low. A total of 4 058 883 SLAF tags were developed， and the average sequencing depth of the tags was 21.21×. A total of 12 275 765 P. crassifolia SNP markers were developed， and the number of SNPs in each P. crassifolia sample ranged from 1 890 934-4 487 841. Using the developed high quality SNP markers of P. crassifolia， 106 phylogenetic trees of P. crassifolia were constructed. It was found that P. crassifolia from different provenances were evenly distributed in each group， and P. crassifolia from different provenances mostly were clustered into one class. By SNP markers and principal component analysis， these clones were more likely to be derived from the same ancestor， indicated that the genetic relationship between clones was similar. It provids basic data for the analysis of genetic diversity and the construction of genetic map in the future， and also provids a basis for the elite seeds selection in P. crassifolia primary seed orchard， and lays a foundation for the construction of high generation seed orchard.
