50份黄瓜核心种质的SSR标记筛选与聚类分析

Screening of SSR Markers and Cluster Analysis in 50 Cucumber Core Germplasms

【目的】分析50份来自全国各地的黄瓜核心种质资源的遗传多样性,为黄瓜育种提供依据和参考。【方法】对50份黄瓜核心种质资源的重要外观农艺性状进行统计,并利用全基因组设计66对SSR引物对其进行分子标记筛选及遗传多样性聚类分析。【结果】供试50份黄瓜核心种质材料的瓜皮颜色、刺瘤、瓜皮斑纹具有多样性。66对引物中有32对引物能够在不同黄瓜种质间扩增出清晰而稳定的多态性标记,这32对SSR引物共扩增出280个等位基因片段,其中多态性片段216个、占片段总数的77.1%,表明本研究筛选出的32对SSR引物遗传多态性较高,适用于黄瓜种质材料的遗传多样性分析。聚类结果与所调查的种质资源性状表现结果较为一致。50份黄瓜核心种质遗传相似系数最低为0.62、最高达1.00。在遗传相似系数0.754处,50份黄瓜种质材料聚为7类,即9份华南型材料聚为6类:Ⅰ类、Ⅲ类、Ⅳ类、Ⅴ类、Ⅵ类、Ⅶ类,其中Ⅳ类包含1份中间材料与9号华南型材料;40份华北型黄瓜材料聚为1类:Ⅱ类。表明华北型黄瓜材料和华南型黄瓜材料间相似系数低、亲缘关系远;华北型黄瓜材料间相似系数高、亲缘关系近、遗传背景窄、遗传多样性差;而华南型黄瓜材料间相似系数较低、亲缘关系较远、遗传背景宽、遗传多样性丰富。【结论】筛选出32对SSR引物可有效对50份黄瓜核心种质材料进行聚类分析,遗传相似系数为0.754处50份黄瓜材料聚为7类,其结果与性状调查结果相吻合;华北型黄瓜遗传背景窄、遗传多样性差,华南型黄瓜遗传背景相对较宽,遗传多样性丰富。

【Objective】This study aims to analyse the genetic diversity of 50 cucumber core germplasm resources from all over the countryto provide a basis and reference for cucumber breeding.【Method】In this study,66 pairs of SSR primers were designed to screen 50 cucumber materials for molecular markers and cluster analyses of genetic diversity.【Result】50 cucumber core germplasms tested showed diversity in rind color,papilloma,and fruit stripe.The results showed that 32 of the 66 primer pairs were effective to amplify clear and stable polymorphic markers among different cucumber core germplasms, and the 32 pairs of SSR primers amplified a total of 280 allelic fragments, of which 216 were polymorphic, accounting for 77.1% of the total fragments. It indicated that 32 pairs of SSR primers screened have high genetic polymorphism and are suitable for genetic diversity analysis of cucumber germplasm materials. The clustering results were consistent with the results of the investigated germplasm resources. The lowest genetic similarity coefficient of 50 cucumber core germplasms was 0.62, and the highest was 1.00. At the genetic similarity coefficient of 0.754, 50 cucumber germplasm materials were clustered into 7 groups, that is, 9 South China type materials were clustered into 6 groups: I, III, IV, V, VI, VII, of which IV included one intermediate material and No.9 South China type material. 40 North China cucumber materials were clustered into one class: class II. This indicated that the similarity coefficient between North China type cucumber materials and South China type cucumber materials was low and the genetic relationship was far. The cucumber materials of North China type had high similarity coefficient, close genetic relationship, narrow genetic background and poor genetic diversity. The similarity coefficient between the South China cucumber materials is low, the genetic relationship is far, the genetic background is wide, and the genetic diversity is rich.【Conclusion】32 pairs of SSR primers were screened out, which could effectively cluster the 50 cucumber core germplasm materials. The 50 cucumber materials at the genetic similarity coefficient of 0.754 were clustered into 7 groups, and the results were consistent with the results of trait investigation. In addition, the genetic background of North China cucumber is narrow with poor genetic diversity. The genetic background of South China cucumber is relatively wide with rich genetic diversity .