青花菜种质资源遗传多样性的SSR分析

摘要

采用SSR分子标记技术,从50对引物中筛选出14对条带清晰、稳定性好的多态性引物分析了28份青花菜种质资源的遗传多样性.结果表明,14对引物在28份材料中共扩增出94条条带,多肽信息量为0.20~0.91.供试的28份材料的遗传相似系数为0.585 1~0.904 3,平均遗传相似系数为0.728 9.其中TN12和TN14亲缘关系最近(相似系数为0.904 3),TN503和TN597亲缘关系最远(相似系数为0.585 1).聚类分析表明,在遗传相似系数0.688处,28份青花菜材料可分为2大类.第一大类(Ⅰ)包括TN501、TN526等26份材料,第二类(Ⅱ)由TN539和TN597两个材料组成.同时,从主成分分析二维图结果来看, 28份材料分成4个组,第一组由TN539和TN597构成,第二组由TN55、TN591等6个材料组成,第三组由TN671等6个材料组成,第四组由14份材料组成.两种分类方法都得出TN539和TN597与其他26份材料亲缘关系较远的结果.结果表明,这28份青花菜种质资源总体遗传多样性较低,但部分材料存在较大遗传差异,为供试材料的利用和杂交亲本选配提供了参考.%Simple sequence repeat (SSR) markers were used to analyze genetic diversity among 28 broccoli (Brassica oleracea L.var.italica) materials.Fourteen pairs of SSR marker primers selected from 50 pairs of SSR primers generated 94 polymorphic bands among these 28 materials.The polymorphism information content (PIC) ranged from 0.20 to 0.91.The overall genetic similarity values ranged from 0.585 1 to 0.904 3 with an average value of 0.728 9.Among them, TN12 and TN14 were the most similar while TN503 and TN597 were the most distant ones with genetic similarity values of 0.904 3 and 0.585 1, respectively.The cluster analysis divided the 28 broccoli materials into two clades (Ⅰand Ⅱ).Clade Ⅰ was constituted of 26 broccoli inbred lines and clade Ⅱ were formed by TN539 and TN597.While the result of principal coordinates analysis showed that all 28 materials were grouped into 4 clades, which consist of 2, 6, 6, 14 broccoli germplasm materials, respectively.Both of the two methods showed that TN539 and TN597 had a low genetic similarity with other 26 germplasm materials.These results revealed that 28 broccoli materials had a narrow genetic base while part of them had wide variations, which provide information for their use and the hybrid parents choice.