Potential Plant Growth-Promoting Activity of Pseudomonas sp Isolated from Paddy Soil in Malaysia as Biocontrol Agent

Abstract

Pseudomonas fluorescens bacteria, a major constituent of Rhizobacteria, encourage the plant growth through their diverse mechanisms. In this investigation, 20 strains of Pseudomonads isolated from the rhizosphere soils of paddy areas in Malaysia and were screened for their plant growth promoting activity. All the 20 tested isolates of Pseudomonads were positive for the production of siderophores and HCN, while of the 20 antagonist bacteria strains, 15 strains (75%) showed positive for the production of plant growth-promoting hormone, IAA. Among the 20 isolates, 18 isolates (90%) produced phosphate solubilisation on NBRIP medium. All the twenty bacterial isolates (except DL21) inhibited the pathogen in the dual culture assay. Following API 20NE biochemical identification kit, of the 20 isolates, 15 strains were identified as Pseudomonas fluorescens, 3 isolates belong to the species of P.luteola, one isolates to the P.aeruginosa and a single isolate (TS14) showed a doubtful identification.