In-vitro Assessment of Native Plant Growth Promoting Rhizobacterial Isolates Against Diverse Fungal Phytopathogens

Although many Plant growth promoting rhizobacteria (PGPR) are used commercially, there is a need to explore more biocontrol agents to combat various pathogens and sustain the productivity of crops. PGPRs inhabit the rhizosphere region of plant and are effective in managing various pathogens. In this study, twenty-six PGPR isolates were screened in-vitro against various fungal phytopathogens in the Plant Bacteriological Laboratory, Department of Plant Pathology, Bidhan Chandra Krishi Vishwavidyalaya, Mohanpur, Nadia, West Bengal during 2021-22. All the thirteen native Bacillus isolates, showed antagonistic activity against Alternaria alternata, Colletotrichum gloeosporioides, Pestalotiopsis sp., Rhizoctonia solani and Sclerotium rolfsii. Among the thirteen fluorescent pseudomonads, all showed antagonistic activity against A. alternata, C. gloeosporioides and Pestalotiopsis sp., eight, CK2LPP, CK2LP8, CK2LP12, GP2, GP8, G11SP37, K11SP4 and S21SP14, against R. solani, two, GP2 and GP8, against S. rolfsii. BRB 42, BRB 56, PR 18, GP2 and GP8 had the highest antagonistic activity against the fungal pathogens under in-vitro condition based on average mycelium inhibition per cent. BRB 56, SM 9 and GP8, showed the maximum inhibition zone against all the phytopathogens.