Cultural and morphological variability among the isolates of Macrophomina phaseolina (Tassi) Goid. Causing stem and root rot of sesame (Sesamum indicum L.)

Abstract

Cultural and morphological variability of different isolates of M. phaseolina collected from four locations of Gujarat viz., Anand, Junagadh, S. K. Nagar, Godhra and one from Raipur district of Chhattisgarh was studied on three different solid media viz., Potato dextrose agar, Oat meal agar and Host leaf extract agar revealed the considerable variation among the isolates of M. phaseolina indicated the existence of variability in the pathogen. Moreover, PDA was found as an excellent media to support the growth and sclerotial formation of isolates of M. phaseolina. Out of three media tested, Potato dextrose agar proved to be the best medium in respect of radial growth of pathogen for all the isolates. In case of isolates, Junagadh (Mp 2) and S. K. Nagar (Mp 3) isolates exhibited highest mean radial growth (90.00 mm). Among all the isolates of M. phaseolina, distinct differences in terms of type of margin, topography of colony, color of colony, size of sclerotia and shape of sclerotia were observed. The average sclerotial size of all isolates varied from 62.93-129.36 µm x 46.93-111.28 µm.