Anastomosis grouping and genetic diversity of maize pathogen Rhizoctonia solani in Shandong
山东省玉米纹枯菌融合群类型及遗传多样性

One hundred and three isolates were obtained from the sheath blight samples of maize from 14 counties in Shandong Province. The cell nuclei were stained and observed under the fluorescent microscope. To identify the anastomosis group, the examined isolates were tested by pairing growth. The result showed that the isolates were assigned to the multinucleate groups AG-1-IA, AG-1-IB, AG-1-IC, AG-3, AG-4-HG-I, AG-5 and WAG-Z and binucleate group AG-Ba. Among the anastomosis groups, the type AG-1-IA was dominant in the population with a rate of 60.19%. Genetic diversity of the 103 isolates was investigated by the inter-simple sequence repeats (ISSR) analysis using 3 specific and stable primers. Forty-five sites were generated in total, among which 91.1% were polymorphic. The result indicated there was high genetic diversity among the populations. By UPGMA cluster analysis, the isolates were classified into six subgroups and the clustering had relationships in association with geographical origin and their anastomosis groups.