Isolation and Characterization of Rhizosphere Bacteria for the Biocontrol of the Asochyta Rabiei in Iran

Abstract

Chickpea (Cicer arietinum), a cool season grain legume grown on a surface of 11million ha with worldwide production of about 9 million tons, is cultivated in more than 45 countries throughout the world including Iran where it is grown mostly in rainfed areas and on marginal lands in the province of West Azarbayjan. Ascochyta blight is perhaps the most frequent and damaging disease of chickpea worldwide. It is caused by Ascochyta Rabiei; a fungus that selectively attacks chickpea. Ten isolated bacteria from chickpea plants rhizosphere soil, were evaluated in vitro as a potential antagonist of fungal pathogen. Sequencing of 16S rDNA and comparison with Gen Bank database of sequences revealed that antagonistic strains belong to the species Pseudomonas fluorescens (three strains), P. putida (three strains), Bulkholderia multivorans (three strains) and Mezorhizobium ciceri (one strain). All the strains significantly inhibited A. rabiei, and resulted in >30% inhibition on PDA.