PLANT GROWTH PROMOTING AND ANTAGONISTIC TRAITS OF INDIGENOUS FLUORESCENT PSEUDOMONAS SPP. ISOLATED FROM WHEAT RHIZOSPHERE AND A. HALIMUS ENDOSPHERE

Abstract

Fluorescent Pseudomonas spp. are an important group of plant growth promoting rhizobacteria (PGPR). They increase the growth of their host plant directly or indirectly. In this study, 3 Fluorescent pseudomonads were isolated from the wheat rhizosphere and one from the endophyte of the halophyte Atriplex halimus. Based on biochemical, physiological reactions and 16S rRNA gene sequences, the isolates were identified as Pseudomonas putida AF2, P. aeruginosa RB5, P. fluorescens RB13 and P. aeruginosa EH4. These strains and P. fluorescens CHA0 were screened for their PGPR activities. All the strains solubilized phosphate with a maximum of 187.9 μg / ml. P. fluorescens CHA0 produced a significant amount (88.37μg/ml) of IAA. The siderophores production by all the strains was proved and the percent of production varied from 38 to 46. The strains produced HCN, protease and amylase. Mycelial growth of F. oxysporum and A. alternata was strongly reduced in the presence of antagonistic fluorescent Pseudomonas spp., with the inhibition rate varying between 25 to 38% and 17 to 27%, respectively. On the basis of excellent growth promoter, biocontrol activities, the fluorescent Pseudomonas spp. tested could be applied as inoculants of wheat for sustainable agriculture in salty soils.