Morphological and pathogenic variability of R. solani isolates associated with wet root rot of chickpea in India

Wet root rot caused by Rhizoctonia solani is one of the important diseases of chickpea (Cicer arietinum). Morphological and pathogenic variability of 50 isolates of R. solani, collected from 10 different states of India were studied. Majority of the isolates produced light brown mycelium with fluffy growth and were categorized into six groups on the basis of their growth rate. Sclerotia formed in different isolates were highly variable in number as well as size. The isolates were grouped into five and six categories based on the number of sclerotia and size, respectively. Most of the sclerotial were scattered followed by in circle at middle and peripheral in Petri plates. Irrespective of host of origin and anastomosis groupings (AGs), the isolates were proved to be pathogenic on chickpea, urdbean (Vigna mungo) and mungbean (Vigna radiata). The isolates were also variable in respect of their virulence and grouped into three categories such as high, moderate and less virulent isolates. This is the first study in which cultural and pathogenic variability of population of R. solani were determined in chickpea.