Phenotypic And Anatomical Diversity Of Leaf Of Davidia Involucrata Natural Populations In Sichuan Province

Davidia involucrata is one of the national first-class protective plants in China.In order to understand its variation and adaptation mechanism of leaf phenotypic traits,15Davidia involucrata natrual populations in Sichuan Provience were be focusd on.11 leaf phenotypic traits and 16 anatomical structures were be used to analysis the variation and adaptation mechanism by nested analysis of variance,correlation analysis,and cluster analysis.In addition,the uniformity of results between leaf phenotypic trait and anatomical structure was also be investigated,and preliminarily verified 15 Davidia involucrata population’s variation degree,regulation and adaptation mechanism.The results were as follows:（1）11 leaf phenotypic traits of 15 populations were investigated in Sichuan Province.The variation degrees of 11 leaf phenotypic traits were tested by nested analysis of variance,correlation analysis,and cluster analysis and so on.Significant and abundant variations of11 phenotypic traits were observed at inter-and intra-population levels.The mean phenotypic differentiation coefficient(V_st)among populations was 37.999%,which was less than that within populations（67.001%）,indicating that the variation within populations was the main source of the phenotypic variation of Davidia involucrata.The mean coefficient of variation（CV）of 11 phenotypic indices was 16.22%,ranging from4.32%to 29.10%.The mean dispersion coefficient（R′）of populations was 53.21%,ranging from 39.38%to 87.14%.The results of correlation analysis showed that there were significant correlations（P<0.01）among leaf length,leaf width,left leaf width,and petiole length,implying that some leaf phenotypic traits coordinate each other in the 15 Davidia involucrata populations.Leaf size,leaf thickness and petiole size were negatively correlated with latitude and altitude,with the leaves being gradually smaller and thinner with elevated latitude and altitude.The mean values of Shannon index for leaf phenotypic traits and for Davidia involucrata populations were 2.360 and 2.331 respectively,and were well-distributed as well.Results from the clustering analysis showed that the 15 Davidia involucrata populations in Sichuan Province could be classified into three groups,with a lack of continuous geographical variations.（2）Significant and abundant variations of 16 leaf anatomical atructure were also observed at inter-and intra-population levels.The mean anatomical atructuredifferentiation coefficient(V_st)among populations was 27.231%,which was less than that within populations（72.769%）,indicating that the variation within populations was the main source of the anatomical atructure variation of Davidia involucrata.The mean coefficient of variation（CV）of 11 phenotypic indices was 13.22%,ranging from 5.80%to 19.53%.The mean dispersion coefficient（R′）of populations was 46.82%,ranging from 41.48%to63.27%.The results of correlation analysis showed that there were significant correlations among Thickness of epidermis,palisade tissue,Snoopy tissue,Thickness of main vein,Thickness of vascular bundle in main vein,implying that some leaf anatomical atructures coordinate each other in the 15 Davidia involucrata populations.Thickness of leaf tissue,palisade tissue and Thickness of main vein were negatively correlated with latitude,with the leaves being gradually smaller and thinner with elevated latitude.The mean values of Shannon index for leaf anatomical atructure and for Davidia involucrata populations were2.890 and 3.093 respectively.Results from the clustering analysis showed that the 15Davidia involucrata populations in Sichuan Province could be classified into four groups,with a lack of continuous geographical variations as well.（3）The mean differentiation coefficient（Vst）of leave’s phenotypic traits and anatomical structures among populations were 36.999%and 27.231%respectively,which was less than that within populations（62.001%and 72.769%）,indicating that indicating that the variation within populations was the main source of the variation of Davidia involucrata.The mean values of Shannon index（H’）for leaf phenotypic traits and for anatomical structures were 2.360 and 2.881 respectively,and which among populations were 2.331 and 2.890,implying the diversity degree of leaf anatomical structures was higher than that of leaf phenotypic trait.Clustering analysis results of leaf phenotypic and anatomical structures showed a lack of continuous geographical variations,indicating the variation of leaf phenotypic traits was consistent with anatomical structures approximately among 15 Davidia involucrata populations in Sichuan Provience.Our results provided scientific basis for conservation and utilization of Davidia involucrata resources.