Elucidating the diversity and plant growth promoting attributes of wheat (Triticum aestivum) associated acidotolerant bacteria from southern hills zone of India

Abstract

To elucidate the bio-diversity of plant growth promoting wheat associated acidotolerant bacteria from Southern hills zone of India. In this study, the diversity and phylogenetic relationships among plant growth-promoting (PGP) bacteria isolated from the wheat phyllosphere, rhizosphere and endophytic growing in acidic soils of Tamilnadu (pH 3.8-6.8) were investigated. Bacterial diversity was analysed through amplified ribosomal DNA restriction analysis (ARDRA) using three restriction enzymes Alu I, Hae III and Msp I which led to the grouping of 135 isolates into 33 clusters at >75% similarity index. 16S rRNA gene based phylogenetic analysis, revealed that isolates belonged to 4 phyla namely actinobacteria (4%), bacteroidetes (4%), firmicutes (52%) and proteobacteria (40%) with 33 distinct species of 13 genera. In vitro for plant growth promotion (PGP) traits were done at different pH which included solubilization of phosphorus, potassium and zinc, production of ammonia, hydrogen cyanide, indole-3-acetic acid and siderophore, nitrogen fixation, 1-aminocyclopropane-1-carboxylate deaminase activity and bio-control against Fusarium graminerum, Rhizoctonia solani and Macrophomina phaseoli. Acidotolerant isolates may have application as inoculants plant growth promoting and bio-control agents in crops growing under acidic condition.