RICE SCIENCE ›› 2008, Vol. 15 ›› Issue (2): 137-144 .

• Research Paper • Previous Articles     Next Articles

Genetic Diversity and Pathogenicity Variation in Rhizoctonia solani Isolates from Rice in Sichuan Province, China

XIAO Yong1; LIU Ming-wei4; LI Gang1; ZHOU Er-xun3; WANG Ling-xia1; TANG Jie1; TAN Fu-rong1;
ZHENG Ai-ping2; LI Ping1
  

  1. 1 Rice Research Institute, Sichuan Agricultural University, Wenjiang 611130, China; 2 Sichuan Province Center for Agri-Biotech Research, Wenjiang 611130, China; 3 College of Resources and Environment, South China Agricultural University, Guangzhou 510642, China; 4 Chongqing Medical University, Chongqing 400016, China
  • Received:2007-12-05 Online:2008-06-28 Published:2008-06-28
  • Contact: LI Ping and ZHENG Ai-ping
  • Supported by:

    the National High- tech Research and Development Program of China (Grant No. 2003AA212030), the Foundation for Doctorial Research in the Southwest University of Science and Technology (Grant No. 07ZX0101) and the Program for Changjiang Scholars and Innovative Research Team in University of China (PCSIRT)(Grant No. IRT0453).

Abstract: Fifty-five representative samples of Rhizoctonia solani isolates, which were collected and isolated from five different ecological regions in Sichuan Province, China, were purified and analyzed for the pathogenicity and molecular genetic variation. The hyphal fusion test revealed that almost all the isolates belonged to the AG-IIA group except the isolate D42. In addition, some of the isolates were ‘bridging isolates’, which could fuse with several groups simultaneously. The pathogenicity analysis on in vitro leaves confirmed a significant pathogenicity variation in the tested isolates. The 55 isolates were then classified into 8 groups by further RAPD (randomly amplified polymorphic DNA) cluster analysis at the similarity coefficient of 0.941. The results suggest that under the certain ecological conditions in Sichuan Province, China, most of the R. solani strains were genetically stable, but a few changed drastically.

Key words: Rhizoctonia solani, anastomosis group, randomly amplified polymorphic DNA, cluster analysis, pathogenicity, genetic diversity