Bioefficacy of Indigenous Isolates of Biocontrol Fungi and Bacteria against Macrophomina Phaseolina Causing Root Rot Disease in Green Gram

Abstract

Green grams are the most valuable pulse crops in terms of plant-based protein, dietary fiber, and various phytochemicals. Although green gram is found susceptible to the soil-borne fungus Macrophomina phaseolina (Tassi) Goid, it leads to severe root-rot disease and causes a significant reduction in crop yield. Thus, the study aims to determine the bioefficacy of indigenous isolates of biocontrol fungi and bacteria viz., T. asperelloides AMUTASPD-51, T. asperellum AMUTASPM-51, T. asperellum AMUTASPM-52, T. asperellum AMUTASPM-53, T. atroviride AMUTATROV-31, T. harzianum AMUTHZ-71, T. harzianum AMUTHZ-72, T. harzianum AMUTHZ-73, T. harzianum AMUTHZ-74, T. hamatum AMUTHM-31, T. viride AMUTVR-61, T. viride AMUTVR-62, T. virens AMUTVNS-41, T. longibrachiatum AMUTLONB-41, Pochonia chlamydosporia AMUPC-31, Purpureocillium lilacinum AMUPL-31, Aspergillus niger AMUAN-41, Bacillus subtilis AMUBS-80 and Pseudomonas fluorescens AMUPF-80 against Macrophomina phaseolina AMUMP-2 by using dual inoculation technique for seven days incubation at a temperature under in-vitro condition. All species of Trichoderma fungus showed high biocontrol potential to suppress the radial growth of M. phaseolina AMUMP-2 over control. Among the biocontrol fungi and bacteria, T. viride AMUTVR-61 resulted in the highest radial inhibition of M. phaseolina AMUMP-2 by 95.0% over control. The T. harzianum AMUTHZ-72 was second most effective in decreasing the radial growth by 94.2% of the pathogens, followed by T. harzianum AMUTHZ-71 (92.8%), T. asperellum AMUTASPM-53 (86.1%), and T. harzianum AMUTHZ-74 (83.7%) over control. However, B. subtilis AMUBS-80 was found to be the least effective, suppressing radial inhibition of M. phaseolina AMUMP-2 by 21.7% over control. The present study indicates that T. viride AMUTVR-61 and T. harzianum AMUTHZ-72 were the most significant indigenous biocontrol fungi against M. phaseolina AMUMP-2. Furthermore, its application led to a substantial decrease in the soil-borne pathogen population that affects plant health, especially green gram, and adverse environmental and human effects.