ISOLATION OF CURVULARIA AFFINIS CAUSING RICE LEAF SPOT FROM WEST BENGAL RICE FIELD AND OPTIMIZATION OF CULTURE CONDITIONS

Abstract: Typical Curvularia leaf spot disease of rice was observed in a rice field of Barasat area in West Bengal and the pathogen isolate was identified as Curvularia affinis Boedjin, 1933 (PP /2883) by ITCC. It is one of the six main pathogenic fungi that infect rice and cause yield loss. This is the first report of C. affinis infection from West Bengal. In this study we isolated, identified and optimized the vegetative growth media and sporulating media for C. affinis. The hyphal branching pattern on different media was also observed at specific time intervals. Here it has been found that potato dextrose agar (PDA) media was best suited for vegetative growth compared to oat meal agar (OMA), malt extract agar (MEA) and plain agar media whereas for conidia and conidiophore development OMA was found to be superior over the other three media. This basic information has relevance towards culture of C. affinis in the laboratory for further studies of the host pathogen interaction and disease development in rice.

Keywords: Curvularia affinis, rice disease, media, radial growth, hyphal branching.