罗浮柿EST-SSR分子标记开发和种群遗传多样性评价

Development of EST-SSR Molecular Markers for Diospyros morrisiana and Assessment of Population Genetic Diversity

摘要:

该研究基于罗浮柿(Diospyros morrisiana)幼苗转录组数据，利用CandiSSR软件开发了1 620对具有多态性的EST-SSR分子标记，并基于随机筛选的15对EST-SSR分子标记对8个天然种源地的157株罗浮柿野生植株的遗传多样性进行评价。结果表明，转录组数据集包含100 285条Unigene序列，总长为98 738 602 bp；其中含有34 121个SSR位点，发生频率为34.02%，约每2.89 kb含1个SSR位点。从中随机选择的15对具有良好多态性的EST-SSR引物，多态性信息含量(PIC)为0.244~0.877，均值为0.623，其中12个位点具有高度多态性(PIC: 0.543~0.788)。基于15对EST-SSR引物的8个罗浮柿野生种群的观测杂合度为0.503~0.650，期望杂合度为0.574~0.610，Shannon多样性指数为1.072~1.245，表现出中等遗传多样性。罗浮柿野生种群的遗传变异绝大部分在种群内(83.29%)，种群间存在广泛的基因流，遗传关系较近。该研究为开展罗浮柿的种质资源评价、遗传多样性分析和分子标记辅助育种提供技术支持和科学依据。

Abstract:

Based on the transcriptome data of Diospyros morrisiana seedlings, 1620 pairs of polymorphic EST- SSR molecular markers were developed using CandiSSR software. The genetic diversity of 157 wild plants from 8 natural provenances was evaluated using 15 pairs of EST-SSR molecular markers randomly selected. The results showed that the transcriptome dataset contained 100 285 Unigene sequences with a total length of 98 738 602 bp; among them, 34 121 SSR loci were identified, with a frequency of 34.02%, approximately one SSR locus every 2.89 kb. The 15 pairs of EST-SSR primers with good polymorphism had a polymorphism information content (PIC) ranging from 0.244 to 0.877, with an average of 0.623, and 12 loci were highly polymorphic (PIC: 0.543-0.788). The observed heterozygosity of the 8 wild populations of D. morrisiana based on 15 pairs of EST-SSR primers ranged from 0.503 to 0.650, the expected heterozygosity ranged from 0.574 to 0.610, and the Shannon diversity index ranged from 1.072 to 1.245, indicating moderate genetic diversity. The majority of the genetic variation in the wild populations of D. morrisiana occurred within the populations (83.29%), and there was extensive gene flow among the populations, with a relatively close genetic relationship. These would provide technical support and scientific basis for the evaluation of germplasm resources, genetic diversity analysis, and molecular marker-assisted breeding of D. morrisiana.