棉花黄萎病菌遗传多样性的ISSR分析

Genetic diversity of Verticillum dahliaeof cotton with ISSR markers

【目的】利用ISSR分子标记技术,对不同地理来源的棉花黄萎病菌株进行分子指纹分析,以了解其遗传关系。【方法】选用25条引物,对来自于我国11个省(市、自治区)的28个棉花黄萎病菌株进行分子指纹分析,研究各菌株间的遗传相似性。【结果】从25条ISSR随机引物中筛选出9条多态性好、条带稳定的引物,用其对28个棉花黄萎病菌株进行扩增,共获得1 989条谱带,其中1 908条为多态性条带,多态性比率为95.9%,表明ISSR标记对棉花黄萎病菌具有较高的多态性;通过对棉花黄萎病菌ISSR遗传相似系数的统计与分析,得到其相关系数r=0.88,该r值介于0.8和0.9之间,表明进化树符合较好,故将ISSR标记应用于棉花黄萎病菌的遗传多样性分析,具有较高的一致性和可信度。ISSR多态性与棉花黄萎病菌的落叶型有一定的相关性,而与菌落形态类型、地理来源未表现出相关性。【结论】供试的不同地理来源的棉花黄萎病菌株遗传相似性较高,基因多样性较低,且ISSR多态性与地理来源未表现出相关性。

【Objective】 ISSR markers were used to study the strains of Verticillium dahliae of cotton collected from different areas to understand their genetic relationship.【Method】 Twenty five primes were chosen to determine 28 strains of V.dahliae of cotton collected from 11 different provincial areas in China to study their genetic similarity.【Result】 Nine primers having informative and consistent amplification in the analysis of 25 primers were selected to amplify DNA of 28 strains of V.dahliae.There were 1 989 fragments obtained by amplification of ISSR with those 9 primers.Among them,1 908 were polymorphic.It indicated that ISSR molecular analysis had comparatively high polymorphism in V.dahliae of cotton and the polymorphic rate reached 95.9%.A correlation coefficient（r=0.88） was obtained by calculation of ISSR markers of V.dahliae of cotton and r value between 0.8-0.9 showed that the phylogenetic tree coincided well,so ISSR molecular marker technique had the high consistency and confidence to detect the genetic diversity of V.dahliae of cotton.By using cluster analysis,it was found that ISSR polymorphism was related to defoliating type of V.dahliae of cotton,but there was no relation to colony morphology and geographical distribution.【Conclusion】 There were higher and lower genetic diversity between the strains of V.dahliae of cotton collected from different areas,and ISSR polymorphism was not related to geographical distribution.