Genetic Variation in Populations of Picea schrenkiana Fisch. et C.A. Mey. Based on Simple Sequence Repeat Markers

Abstract

Picea schrenkiana is a tree species native to the Tian Shan Mountains of Central Asia in Western China, Kazakhstan, Kyrgyzstan. P. schrenkiana is one of the major forest species in the region with a gradually decreasing area due to anthropogenic factors and natural disasters. The goal of the present study was to assess the level of genetic diversity in five populations of P. schrenkiana collected in the Tian Shan mountains of Kazakhstan. Nineteen simple sequence repeat (SSR) markers were selected for the evaluation of the genetic diversity in populations of P. schrenkiana with typical upright and prostrate forms collected in the Tian Shan mountains in Kazakhstan. The analysis of P. schrenkiana samples allowed the identification of twelve polymorphic out of nineteen SSR markers, with six of them having Polymorphism Information Content (PIC) index values of 0.5 or higher. The average Nei’s genetic diversity index of the overall populations was 0.54 and comparable with results from studies of other Picea species. The total genetic variation in the species was partitioned as 86% within and 14% between populations. The Principal Coordinate Analysis plot suggested that twelve SSR markers effectively separated populations with typical upright and prostrate forms of P. schrenkiana. The estimated gene flow index (N_m) among populations based on all alleles was 3.05, confirming a high outbreeding rate within the species. Nevertheless, the application of SSR markers separated populations with typical upright and prostrate forms of P. schrenkiana. The results suggest that the maintenance of the genetic variation within P. schrenkiana can be successfully achieved through an in situ conservation strategy.