Relationship between RAPD Genotype and Pathotype of Rice Sheathe Blight Fungi (Rhizoctonia solani AG-1 IA) in Guangdong Province

It is firstly analyzed the relationship between randomly amplified polymorphic DNA (RAPD) genotype and pathotype of rice sheathe blight fungi (Rhizoctonia solani AG-1 IA ) from Guangdong province in China. The results show that pathotype diversity (H=3.485) and genetic diversity are abundant in rice sheathe blight fungi population from Guangdong. A total of 39 pathotype based on 9 rice hosts were recorded in fifty-five isolates,and ninety-one RAPD bands t were amplified with eleven arbitrary decamer primers,among which 94.51% were polymorphic. Each isolate of R. solani AG-1 IA has unique RAPD molecular fingerprint pattern based on twenty-two RAPD putative loci. The fifty-five isolates were classified into different cluster groups,according to the virulence data,RAPD 0/1 data,the combined virulence and RAPD data,by using UPGMA analyses,and the first cluster consisted of a majority of isolates. The separate virulence and RAPD molecular Jacarrd similarity matrix were compared for level of relation using MXCOMP program. The correlation coefficient was very low (r=0.0137),which suggested the DNA molecular haplotype,was largely independent of virulence,and no association between RAPD genotype and pathotype