Analysis of Genetic Structure of the Endangered Plant Torreya jackii Population Based on SSR Markers

Abstract

Torreya jackii (Taxaceae) is a rare and endangered plant endemic to China. The study of the genetic structure of the population of T. jackii can provide a basis for its scientific management and the development of reasonable and effective protection strategies. Genetic structure of seven subpopulations of T. jackii in Baiyunyuan Forest Park of Tonglu County of Zhejiang Province was analyzed based on pre-developed SSR markers. The results showed that 41 alleles were found in the seven subpopulations using 8 pairs of SSR primers. The observed heterozygosity were 0.4688~0.6027 with the average of 0.5427. The expected heterozygosity ranged from 0.4453 to 0.5471 with the average of 0.5060. AMOVA analysis showed that the genetic variation was mainly found within subpopulation, the genetic differentiation among subpopulations was low (FST =0.064, RST = 0.089). STRUCTURE cluster analysis showed that there has a comparatively high mixing ratio among subpopulations. Mantel test showed that there was no significant relationship between genetic distance and geographic distance. BOTTLENECK analysis showed that recent bottleneck effects were found in the subpopulation of HongQi Forestry Centre. There is a significant distance isolation effect in the seed diffusion of T. jackii, while the dioecious and wind-borne pollen characteristics to a certain extent cause it to be able to maintain a more stable genetic diversity and genetic structure in relatively isolated plaques.