Abstract
The study was conducted in potted soil to screen out soybean (Glycine max L. Merrill) genotypes against the effects of a destructive pathogen Macrophomina phaseolina. Soybean genotypes (AJMERI, PSC-60, RAWAL-I, NARC-II and NARC-I) were artificially inoculated with the pathogen kept in a completely randomized designed in triplicate for 45 days. Based on the disease severity, genotypes were categorized into four groups i.e., resistant (AJMERI), moderately resistant (PSC-60 and RAWAL-I), susceptible (NARC-II) and highly susceptible (NARC-I). The infection of pathogen led to many morphological and biochemical changes including reduction in growth attributes, up regulation in total phenolics and activities of the antioxidant enzymes (peroxidase, polyphenol oxidase and catalase) in susceptible groups but not in resistant groups. Therefore, the growth inhibition index was significantly increased in susceptible genotypes. The results of study suggested that the currently investigated physiological and biochemical attributes in infected plants could be used to assist the screening of resistant plants in soybean.
