Isolation, Identification and in vitro Screening of Rhizospheric Fungi for Biological Control of Macrophomina phaseolina

The present study was aimed to identify charcoal rot pathogen of groundnut (Arachis hypogaea L.) in Anantapur district, Andhra Pradesh and assess the interactions among the fungal isolates from rhizosphere. During field survey, a potential charcoal rot pathogen Macrophomina phaseolina was isolated and identified. About 10 different rhizosphere soils of healthy groundnut plants were selected for isolation of fungi. Among 25 isolates assayed for antagonism, ten different fungi significantly inhibited colony growth of M. phaseolina in dual culture plates and morphological identification was done at (400X). Antagonistic fungi inflicted 25.6-41% mycelial growth inhibition in M. phaseolina. Colony growth and sclerotia production of M. phaseolina ceased effectively by Emericella nidulans and E. rugulosus, respectively. Mutual inhibition between Alternaria alteranata, Aspergillus flavus, A. terreus, Penicillium chrysogenum and M. phaseolina was observed. Penicillium oxalicum, Gliocladium roseum and Aspergillus versicolor significantly reduces growth with <1 mm demarcation lineat 7 and 14 Days after Inoculation (DAI) on PDA medium. These antagonistic interactions influence the growth of the pathogen.