ASSESSMENT OF PHYTOBENEFICIAL RHIZOSPHERIC BACTERIA ISOLATED FROM TWO NIGERIAN RICE CULTIVARS FOR PLANTGROWTH PROMOTING ABILITIE

Abstract

Rhizospheric plant bacteria present a sustainable way to encourage cheap and environmental-friendly alternatives to inorganic agrochemicals. Bacteria were isolated from the rhizosphere of two Nigerian rice varieties (OFADA and ITA 150). Assays including indole acetic acid (IAA) production, phosphate solubilization, seed germination, hydrogen cyanide (HCN) and ammonia production, and antifungal assay were conducted to identify the phytobeneficial isolates. One hundred and fifty three (153) strains were isolated while ITA 150 had higher bacterial counts (5.18 logCFU/g) as compared to OFADA (4.12 logCFU/g). Major bacteria genera observed were Bacillus, Enterobacter, Citrobacter, Klebsiella, Acinetobacter, Pseudomonas, Staphylococcus and Escherichia. Nine isolates out of 153 were positive for the assays in vitro. Seeds coated with nine isolates had germination rate that ranged from 81.48% to 100%, while vigour index ranged from 682 to 140. Thus, the nine isolates possessed multiple plant beneficial traits and could be considered as promising plant growth promoting bacteria.