Biochemical responses of soil-borne necrotroph Macrophomina phaseolina during the pathogenesis on chickpea

Charcoal rot caused by Macrophomina phaseolina is a potential threat to chickpea yield. This disease cause severe damage to plant on almost all growth stage. In our study we have selected two genotype of chickpea i.e one is resistant genotype (JG315) and another susceptible genotype (K850) and two isolates of M. phaseolina i.e., highly aggressive (Dark MP4J) and least aggressive (CP3). Both isolates were inoculated on both genotypes and observation of enzymatic activity was done. Catalase activity was highest in case of resistant genotype inoculated with highly aggressive isolate at 24 hai but it decrease at 72 hai. There was depletion in catalase and superoxide dismutase activity but enhancement in activity of peroxidase and ascorbate peroxidase whether it was inoculated with highly or least aggressive isolate. The enhanced biochemical activities during plant pathogen interaction triggers the defense related enzymes such as wall-bound phenolics, flavonoids and induction of hypersensitive reaction (HR) etc., which resulted in cell strengthening and enhances resistance to pathogen. The depletion of catalase and superoxide dismutase during host-parasite interaction might be due to induction of antioxidant enzyme in plant which leads to oxidative stress and multiplication of pathogen.