Abstract:

This study explored the genetic diversity and structure of 261 wild Rosa roxburghii Tratt. samples from 29 populations across eight provinces in China, utilizing 10 pairs of polymorphic EST-SSR primers and capillary electrophoresis, providing a clear genetic background for the collection and breeding of R. roxburghii germplasm resources. Results identified 95 alleles among the 261 germplasm materials. The average polymorphism information content of the loci was 0.568. At the population level, the average number of alleles and effective number of alleles were 3.131 and 2.331, respectively, with observed heterozygosity and expected heterozygosity averaging 0.508 and 0.488. The average Shannon’s information index was 0.858, indicating substantial genetic diversity, likely due to the extensive range of sampling sites. Analysis of population genetic differentiation revealed an average genetic differentiation coefficient of 0.067 and gene flow of 4.511, suggesting considerable inter-population gene flow. Analysis of molecular variance (AMOVA) indicated that most genetic variation in R. roxburghii came from within populations (r=0.467, P<0.000 1). Nei’s standard genetic distance among populations ranged from 0.054 to 1.269, with an average of 0.657, and was significantly related to geographical distance. Clustering analysis grouped the 29 populations into three main clusters, which was related to geographical location. These results highlight southwestern China as a core distribution area for wild R. roxburghii resources, providing theoretical guidance for the formulation of R. roxburghii conservation strategies.

摘要：

基于10对EST-SSR引物，对中国8个省29个居群的261份野生刺梨（Rosa roxburghii Tratt.）进行毛细管电泳检测，探究其遗传多样性，并进行聚类分析。结果显示，共扩增出了95个等位基因，位点多态性信息含量（PIC）平均值为0.568；群体水平上，平均等位基因数（N_A）和有效等位基因数（N_E）分别为3.131和2.331，平均观测杂合度（H_O）和预期杂合度（H_E）分别为0.508和0.488，平均Shannon’s信息指数（I）为0.858，表明野生刺梨种质具有较高的遗传多样性水平。群体遗传分化分析结果显示，平均遗传分化系数（F_ST）为0.067，基因流（N_m）为4.511，说明刺梨群体间基因流动较频繁。分子方差分析（AMOVA）结果表明刺梨的遗传变异主要来源于居群内（93.64%）。各居群间的Nei氏标准遗传距离范围为0.054~1.269，平均值为0.657，与地理距离表现为显著相关（r=0.467，P<0.000 1）。聚类分析和PCA结果均将29个居群分为3个分支。研究结果说明中国野生刺梨资源核心分布区在我国西南地区。