Aspergillus and Fusarium control in the early stages of Arachis hypogaea (groundnut crop) by plant growth-promoting rhizobacteria (PGPR) consortium

In this study, we have attempted to develop a plant growth promoting rhizobacteria (PGPR) consortia against early-stage diseases in Arachis hypogaea (Groundnut crop) plantation of Andhra Pradesh, India. The dominant PGPRs were selected by considering the various plant growth and protection qualities, followed by characterisation and grouping based on compatibility to form a consortium of PGPRs [Group-1 includes EX-1 (Acinetobacter baumannii stain HAMBI 1846); EX-3 (Pseudomonas aeruginosa strain A1K319); EX-5 (Bacillus subterraneus strain CF1.9); KNL-1 (Bacillus subtilis strain JMP-B); CTR-4 (Enterobacter cloacae strain VITKJ1); ANT-4 (Bacillus subtilis strain SBMP4) and Group-2 includes EX-4 (Pseudomonas otitidis strain SLC8); KDP-4 (Pseudomonas aeruginosa strain Kasamber 11); NLR-4 (Bacillus species ADMK68); ANT-6 (Bacillus subtilis subsp. inaquosorum strain KCTC 13429)]. In addition to resistance to early stage pathogens, in both in vitro and pot experiments the PGPR consortium showed significantly higher germination rate and root induction (Aspergillus niger; A. flavus; Fusarium oxysporum) when compared to control and fertilizer treated groups. In addition, Group 2 was more successful in stimulating and protecting plant growth among the two groups of PGPRs developed. The PGPR consortia developed showed multiple plant growth characteristics, including phosphate solubilization, production of HCN and Indole acetic acid along with broad antagonism against the tested phytopathogens.

Keywords: Arachis hypogaea; Consortium; Early stage fungal pathogens; PGPRs.