Genetic diversity and population structure of the endangered endemic species Paeonia decomposita from China and implications for its conservation

Paeonia decomposita, endemic to China, has important ornamental, medicinal and economic value and is regarded as a threatened endangered plant. The genetic diversity and structure have seldom been described. A conservation management plan is not currently available. In present study, 16 pairs of SSR primers were used to evaluate genetic diversity and population structure. A total of 122 alleles were obtained with a mean of 7.625 alleles per locus. The expected heterozygosity (He) varied from 0.043 to 0.901 (mean 0.492). Moderate genetic diversity (He=0.405) among populations were revealed, with Danba identified as the center of genetic diversity. Mantel tests revealed a significant positive correlation between geographic and genetic distance among populations (r=0.592, P=0.0001), demonstrating consistency with the isolation by distance model. Analysis of molecular variance (AMOVA) results indicated that the principal genetic variation existed within populations (73.48%) rather than among populations (26.52%). Bayesian structure analysis and principal coordinate analysis (PCoA) supported classification of the populations into three clusters. Based on the level of observed genetic diversity, three management unints were proposed as conservation measures. The results will be beneficial for the conservation and exploitation of the species, providing a theoretical basis for further research on its evolution and phylogeography. HightlightsO_LIGenetic diversity among populations was moderate in Paeonia decomposita C_LIO_LIThere is significant positive correlation between geographic and genetic distance among populations, consistent with the isolation by distance model C_LIO_LIPrincipal genetic variation existed within populations rather than among populations. C_LIO_LIThe populations divided into three clusters. C_LIO_LIThree management unints were proposed as conservation measures. C_LI