Genetic diversity in the endangered Camellia nitidissima assessed using transcriptome-based SSR markers

Abstract

Camellia nitidissima is an endangered species whose flowers are bright yellow. In the past 50 years, habitat changes caused by climate and human activity have greatly reduced the extent and size of natural populations of C. nitidissima. Here, to provide a fundamental basis for this plant’s protection and utilization, the genetic diversity and genetic structure of C. nitidissima natural populations were studied using simple sequence repeats (SSR) markers. Based on a comparative analysis of multiple transcriptomes from different Camellia species, a group of consensus transcript sequences were obtained for marker development. We screened 237 predicted transcript loci, and identified 21 highly polymorphic SSR markers for population analysis. In total, 82 alleles were obtained to assess the genetic diversity of four natural populations in Guangxi Zhuang autonomous region, China. The results revealed that the mean observed heterozygosity (Ho) and expected heterozygosity (He) of the populations were 0.624 and 0.546, respectively, and the genetic diversity was mostly among populations. Further, we uncovered a significant positive correlation between the genetic distance and geographic distance of C. nitidissima populations. The high genetic diversity found in this study holds promise for the future conservation and restoration of C. nitidissima populations based on efforts from in situ and ex situ strategies implemented in a carefully monitored way.