Genetic diversity and population structure of Rhododendron simsii Planch. (Ericaceae) populations based on microsatellite markers

8 February 2019

Wang, Shuzhen; Jin, Zhengqiang; Luo, Yanyan; Li, Zhiliang; Fang, Yuanping; Xiang, Jun; Jin, Weibin

Rhododendron simsii Planch., a valuable horticultural and medicinal plant species, belongs to the genus Rhododendron (Ericaceae). In this study, genetic diversity of eight wild R. simsii populations from Dabie Mountains (central China) was investigated with 29 microsatellite markers. Results showed that R. simsii harbored a high level of genetic diversity at species level (HE: 0.64-0.79; HO: 0.71-0.94; I = 1.917; h = 0.826), and 84.4% genetic variation was primarily maintained within populations, while variation among populations only accounted for 15.6%. Number of alleles ranged from 6 to 11, with an average of 9.069. Heterozygote excess was found, with the mean FIS and FIT values of -0.1739 and 0.0092, respectively. The average value of gene flow (Nm) was 1.3525. In particular, genetic diversity was highest in 'AHtianzhushan' population (I = 1.681), but lowest in 'YStaohuachongC' population (I = 1.131). Clustering map constructed using UPGMA model clustered the eight populations in two clades: 'LTjiuzihe' population was clustered alone, while the other seven populations were clustered together. In particular, genetic distance was in weak negative correlation with geographic distance, longitude difference, and elevation difference. This research will supply valuable advice for the conservation and sustainable utilization of wild R. simsii germplasm resources in central China.