Anastomosis groups of Rhizoctonia solani causing tobacco sore shin and target spot in Guangxi

In order to investigate the anastomosis groups of the pathogens causing tobacco sore shin and target spot in Guangxi，two strains were isolated from diseased basal stems and three strains were isolated from diseased leaves. Based on morphological characteristics and nuclear staining，five strains were identified as Rhizoctonia solani and they all belonged to multinucleate. Through hyphal anastomosis reactions between tested strains and standard strains，the pathogens of tobacco sore shin and target spot in Guangxi were all divided into two anastomotic groups: AG-2 and AG-4. Moreover，ITS sequences analysis of the five strains indicated that the two anastomosis groups were AG-4 HG-I and AG-2-2 IIIB，and it was in accord with the result of hyphal anastomosis reaction. AG-2 and AG-4 were firstly found in tobacco leaf in China．