Isolation and molecular identification of potential bacterial antagonist for the management of brown leaf spot of mulberry

Abstract

Fifty bacterial isolates were obtained in axenic form from the phylloplane of mulberry variety S1635, of which five were found to be antagonistic to Paramyrothecium roridum (Syn: Myrothecium roridum Tode ex. Fr.) causing brown leaf spot of mulberry. Further evaluation revealed that all the five bacterial isolates significantly reduced the radial growth of brown leaf spot pathogen. Gram positive, rod shaped bacterial isolate MP-18-5 was found to be most effective against the pathogen exhibiting 62.0% radial mycelial growth inhibition. Based on 16S rRNA gene sequence analysis, strain MP-18-5 was identified as belonging to the genus Bacillus with Bacillus zhangzhouensis DW5-4T (sequence similarity value of 97.79%) as its closest phylogenetic neighbour.