Abstract:

Seven populations of Paeonia rockii in Qinling and Ziwuling Mountain areas of Shaanxi were selected to analyze the phenotypic diversity based on 20 phenotypic traits from leaves，flowers and fruits by nested ANOVA，correlation analysis and cluster analysis. The results showed：（1）There were highly significant differences in 20 phenotypic traits among populations. Plant height，Leaf length and seed diameter were highly significant differences within populations. The mean phenotypic differentiation coefficient（V_ST）of the 20 phenotypic traits was 71.07%，which indicated that the phenotypic variation mainly occurred among populations.（2）The average variation coefficient（CV） of phenotype traits ranged from 7.04% in seed average weigh to 21.66% in seed number in a fruit，which showed that there was low variation of phenotypic traits in Paeonia rockii populations. The average variation coefficient of traits on fruits was 14.45%，higher than that of leaves（13.19%）and flowers（11.40%）.（3）Correlation analysis showed that reproductive growth was slightly affected by vegetative growth.（4）The correlation analysis between geo-ecological factors and phenotypic traits showed that the latitude and longitude had significant effect on flowers traits，and the average annual rainfall had the maximum influence on fruits.（5）The cluster analysis on the phenotypic traits showed 7 populations were divided into 3 groups associated with environmental factors，which did not strictly classify according to the geography distance.

Key words: wild tree peony, phenotypic diversity, nature population, phenotypic differentiation coefficient