Morpho-pathogenic and molecular diversity among Rhizoctonia bataticola isolates causing dry root rot of chickpea in Madhya Pradesh, India

Abstract

Aim: The present study was conducted to identify the morphological, pathological and molecular variations in isolates of Rhizoctonia bataticola, causing dry root rot of chickpea collected from different parts of Madhya Pradesh, India. Methodology: The isolation, purification and identification of Rhizoctonia bataticola isolates was done from dry root rot infected chickpea plants, collected from 23 districts of Madhya Pradesh, India. Total 32 isolates of pathogen were obtained and further used for morphological, cultural, pathological and molecular characterization. The acquired data were subjected to DARwin5 software analysis for variability studies. The DNA isolates of the pathogen were also obtained and analysed to study molecular variability by RAPD analysis and the bands produced were subjected to PAST software for cluster analysis. Results: Thirty two isolates of R. bataticola with diverse origin showed a large variation in shape, size and initiation time of sclerotia. These isolates were pathogenic and grouped into three categories; highly virulent (59%), moderately virulent (25%) and less virulent (16%), under artificially inoculated conditions in sick soil method. The study of pathogenic variability revealed that ICC12441, ICC11332 and Pusa 212 were susceptible to all the isolates evaluated, whereas ICC12450, Pusa362, Pusa1103 showed moderate resistance against maximum isolates. Based on molecular characterization, the isolates were grouped into four clusters indicating that no two or more isolates were similar. Interpretation: The isolates of R. bataticola of chickpea from different agro-climatic zones of Madhya Pradesh, possess variability in their morphological and cultural characteristics, which not limited to geographical boundaries. The present study would be extremely useful for dry root rot management, as well as, in identifying donors for resistance breeding programmes. Key words: Chickpea, Diversity, Dry root rot, Pathogenicity, Rhizoctonia bataticola