Investigation of Mycoviral double-stranded (ds) RNA in Rhizoctonia solaniIsolates from Cotton in Aydin Province/Turkey

Abstract

Pathogenic forms of Rhizoctonia solani are known to attack many species of higher plants from different families. It is one of the causal agent of the damping-off and root rot of cotton. The current damping-off management practices are not satisfactory for preventing yield losses in cotton production. Hypovirulence, caused by particular mycoviruse species, is used in the management of certain plant diseases. The existence of mycoviral dsRNAs in the isolates of R. solani has been previously determined in various countries. This study aimed to investigate dsRNA content in the cotton isolates of R. solani collected from Aydin Province. In total, 64 R. solani isolates collected from cotton seedlings exhibiting light damping-off symptoms were subjected to dsRNA analysis. The dsRNA electrophoretic pattern with the size of 12-18 kb were detected in six R. solani isolates. The virulence of these six isolates were compared with a dsRNA-free isolate in apple assay. Two R. solani isolates having dsRNA content caused smaller lesions in the inoculation point on apple fruit, which may be the indication of hypovirulence.