Morphological and physiological variation among isolates of Rhizoctonia solani inciting wet root rot of chickpea

Wet root rot chickpea (Cicer arietinum L.) caused by Rhizoctonia solani Kuhn is an economically important disease in india and elsewhere. Eight isolates of R. solani, obtained from Rajasthan (Bikaner, Hanumangarh, Nagaur and Sriganganagar), Haryana (Gurgaon, Hisar and Karnal) and Indian Agricultural Research Institute, New Delhi were studied for their discernible characters. The isolates tested for their pathogenic nature using susceptible C-235 variety of chickpea were found virulent in sterilized as well as in unsterilized soil. The isolate Bikaner was highly virulent. There was practically no direct correlation between the cultural characters and virulence of any of the isolates. The mycelial growth of eight isolates of Rhizoctonia solani varied on czapek'sdox agar basal medium with different carbon, nitrogen sources and also at different levels of temperature and pH.