利用InDel标记分析23份黄瓜种质的遗传多样性及核心种质资源筛选

Genetic diversity analysis of 23 cucumber germplasms and screening of core germplasm resources using InDel markers

为了研究不同来源黄瓜的亲缘关系,筛选适宜作杂交亲本的种质资源,基于黄瓜重测序开发的InDel标记,应用UPGMA进化树聚类、主成分分析和群体遗传结构分析3种方法分析了23份黄瓜种质的遗传多样性.结果表明:23份黄瓜种质的遗传相似性系数为0.23-0.95,平均值为0.56,相似性系数低于0.6的有137对组合,占全部组合的54%,说明这些材料的遗传多样性较好.3种分析方法均将23份黄瓜种质分为三大类群:P1来源于亚洲,都属于华南类型黄瓜;P2来源于欧洲和美国,包含欧洲类型长黄瓜、欧洲类型短黄瓜和2个美国加工型黄瓜;P3仅包含1个来源于广东的品种,从表型上看属于华南类型.P3亲缘关系更接近P1,P1和P2之间遗传差异明显.利用InDel标记分析的结果,对核心种质最佳样本量进行了预测,应用M策略将9份黄瓜种质确定为核心种质,包含了群体中几乎所有的黄瓜类型,外形上有白刺、褐刺以及光滑型,这9份核心种质能够很大范围地覆盖表型的变异.

In order to study the genetic relationship of cucumber from different sources and select suitable germplasm resources for hybrid parents, 23 cucumber germplasms were analyzed by UPGMA evolutionary tree clustering, principal component analysis and population genetic structure analysis based on InDel markers developed by re-sequencing. The results showed that the genetic similarity coefficients of 23 cucumber germplasms ranged from 0.23 to 0.95, with an average of 0.56.137 pairs of combinations with similarity coefficient below 0.6 accounted for 54% of all combinations, indicating that the genetic diversity of these materials was good. The 23 cucumber germplasms were divided into three groups by three analysis methods. P1 came from Asia and belonged to South China type cucumber;P2 came from Europe and the United States, including European long cucumber, European short cucumber and two American processed cucumber;P3 only contained one cucumber variety from Guangdong, and belonged to South China type cucumber from phenotype.The genetic relationship of P3 was closer to that of P1, and the genetic difference between P1 and P2 was obvious. Using the results of InDel markers analysis, the optimum sample size of core germplasm was predicted. Using M strategy, 9 cucumber germplasms were identified as core germplasms, including almost all types of cucumber in the population, with white thorn, brown thorn and smooth shape. These 9 core germplasms could cover phenotypic variations in a wide range.