Isolation and molecular identification of Bacterial antagonist against Paramyrothecium roridum causing brown leaf spot of mulberry. Molecular identification of Bacterial biocontrol agent against brown leaf spot of mulberry

Fifty bacterial isolates where isolated from the phylloplane of mulberry variety S1635. Out of these fifty isolates screened for antifungal activity against Paramyrothecium roridum (Tode) L. Lombard & Crous (syn. Myrothecium roridum Tode ex. Fr.), causing brown leaf spot, five were found to be antagonistic to P. roridum. On further evaluation all the five bacterial isolates significantly reduced the radial growth of the pathogen. Gram positive, rod shaped bacterial isolate MP-18-5 was found to be most effective against the pathogen showing 62.0% radial mycelial growth inhibition. MP-18-5 was identified by sequencing 16S rRNA region followed by the BLAST analysis, which revealed that the sequence of the bacterial antagonist had 97% nucleotide similarity with Bacillus zhangzhouensis, strain LA361a (KY622435). B. zhangzhouensis is already reported to be an effective bacterial biocontrol agent.