应用ISSR-PCR分析福建水稻纹枯菌的遗传多样性

Genetic diversity analysis of Rhizoctonia solani populations from Fujian using Inter-Simple Sequence Repeats (ISSR) technique

本研究应用简单序列重复区间(inter-simple sequence repeats,ISSR)标记技术对福建省10个县市100个水稻纹枯病菌菌株的遗传多样性进行了分析。从16个随机引物中筛选出3个重复性好、特异性高的引物对菌株进行ISSR-PCR扩增,共产生41个ISSR分子标记,其中90.2%的片段具有多态性。PopGene分析结果表明,种群的平均多态位点百分率为55.14%,Shannon表型多样性指数I平均为0.2953,具有较高的遗传多样性;种群间存在着明显的遗传分化(Nei′s信息多样性指数h平均值为0.1991,Gst平均值为0.6423),聚类分析可将它们分成5个遗传聚类群。同时还进行了菌株生长速率和致病力的测定。ISSR遗传聚类组群的划分与菌株的地理来源有明显的相关性,但与菌株的致病力和生长速率都没有明显的相关性。以上结果为进一步开展水稻纹枯病菌群体遗传分析和纹枯病防治提供了一定的理论依据。

Genetic diversity of one hundred rice sheath blight isolates of Rhizoctonia solani from ten counties, Fujian Province, was investigated by the inter-simple sequence repeat （ISSR） technique, with three specific and stable primers selected from 16 primers. A total of 41 sites were generated, among which 90.2% were polymorphic. The data were analyzed by PopGene. The average percentage of polymorphic loci of populations is 55.14% and demonstrated high genetic diversity （the average value of Shannon index I is 0. 295 3 ）. The genetic variation was significant among populations （average Nei＇s index h is 0. 199 1, and average Gst, is 0. 642 3）. The tested isolates could be classified into 5 ISSR groups. At the same time, the growth rate and pathogenicity of the isolates were surveyed. The ISSR clustering groups had obvious correlation with geographical origin of the isolates, but had no significant correlation with growth rate and pathogenicity variation. The results will contribute to further study on the population of R. solani and control of the disease.