Molecular characterization of Sarocladium oryzae (Sawada) through RAPD technique: causal agent of sheath rot disease of Rice

Sarocladium oryzae isolates were characterized on various culture media, pathogenic virulence on susceptible variety and genetic variability by Random Amplified Polymorphic DNA (RAPD) technique. The radial growth of Sarocladium isolates was non-significantly differing on Potato Dextrose Agar (PDA) medium followed by Kirchhoffs medium. For the pathogenic virulence estimation, the maximum lesion length was recorded with isolates SR-8 (7.86cm). For genetic variability detection among the isolated Sarocladium isolates, it was recorded that in RAPD analysis, a total 23 bands appeared during gel electrophoresis and of those 17 bands were polymorphic and 6 bands were monomorphic pattern. The size of the amplicons was obtained and ranged from 100bp (minimum) to 2000bp (maximum). The phylogenetic tree/dendogram was prepared using NT-SYS software version 2.11W version. It separated Sarocladium isolates into two major clusters. Cluster I was comprised of 16 isolates except 2 isolates (SR-1 & SR-2). Average Polymorphic Information Content (PIC) value was calculated 0.161 and recorded that there is no much variation in isolated Sarocladium isolates. This research activity was done to find out genetic variability of the sheath rot causing fungus (Sarocladium oryzae) so that it may be used for rice improvement programme, economic and sustainable disease management strategies.