Genetic diversity analysis of Rhizoctonia solani populations from Fujian using inter-simple sequence repeats (ISSR) technique.

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.