Morpho-cultural and pathogenic variability in Macrophomina phaseolina isolates from Soybean

Abstract

Fifteen isolates of M. phaseolina were characterized for cultural and morphological characteristics on PDA medium. Two fast growing isolates, seven medium growing isolates and six very slow growing isolates. The hyphal width of isolates was categorized in three groups. First group comprised of eight isolates with hyphal width ranging between 5-6 μm, second group 6-7 μm and third group more than 7 μm. Mycelial growth pattern observed in isolates were fluffy, partial submerged, submerged, and irregular, whereas the colony colour found to be dark black, greyish and light greyish in appearance. Pathogenic variability revealed that, all the isolates were found to be pathogenic and diverse. Aggressiveness study through in vitro blotter paper technique and cut stem inoculation technique exposed that variation exists within the isolates.