西瓜枯萎病菌致病型的遗传多样性分析

从我国7个西瓜产区(山东、湖北、安徽、江苏、湖南、河南及河北)的西瓜枯萎病病株和病土样中分离获得31株西瓜枯萎病菌株,采用幼苗共培养法测定各菌株的致病力。利用12个寡聚核苷酸随机引物对受试菌株的全基因组DNA进行PCR-RAPD分析。结果表明:31个受试西瓜枯萎病菌株可被划分为非致病型、弱致病型和强致病型3种致病型;其中非致病型菌株5株,致病型菌株26株。利用UPGMA软件对受试菌株间的遗传距离进行聚类分析,也发现来自不同地区的西瓜枯萎病菌存在明显的致病型分化;不同致病型的西瓜枯萎病菌具有丰富的遗传多样性,并划分为两个大的基因型,但与菌株的致病型没有显著的关系。

Genetic Diversity of Pathogenesis in Watermelon Fusarium oxysporum Isolates

Thirty-one isolates of Fusarium oxysporum were achieved from the samples of watermelon(Citrullus lanatus) roots and soils collected in Shandong,Hubei,Anhui,Jiangshu,Hunan,Henan and Hebei.Their pathogenicity was identified by means of the co-culture methos.And the genetic diversity of 31 F.oxysporum isolates was analysed by PCR-RAPD using 12 primers selected from 100 random primers.The results showed that the 31 isolates could be classified into three types: nonpathotype,weak pathotype and strong pathotype,of which 5 were non-pathogenic to watermelon and 26 pathogenic.The genetic distance and the genetic relationships of the strains were reconstructed by UPGMA(unweigthted pair-group method with anthmetic average) cluster analysis.It was found that there existed obvious differentiation of pathotypes and genetic diversity within the 31 isolates of F.oxysporum,but there was no direct relationship between pathotype and genotype.