Growth promoting activities of antagonistic bacterial endophytes from Hevea brasiliensis (Willd. ex A.Juss.) Mull.Arg.

Abstract

Rubber plantations are known to udergo various biotic and abiotic stresses. However, the symbiotic bacterial endophytes that inhabit them provide protection. Here, we isolated bacterial endophytes from the rubber tree, Hevea brasiliensis (Willd. ex A.Juss.) Mull.Arg. and studied their antagonistic activity against major pathogens such as Phytophthora meadii, Corynespora cassiicola and Corticium salmonicolar. The antifungal metabolites such as HCN, siderophores and salicylic acid were produced by the antagonistic endophytes under in vitro conditions. Bioassay showed the growth promotion by a consortium of selected antagonistic endophytes in H. brasiliensis seedlings. The photosynthetic efficiency of seedlings increased after endophyte inoculation. Endophyte-treated plants showed accumulation of starch granules in root tissues. The selected antagonistic isolates belong to Bacillus sp. and Pseudomonas sp. The study revealed the biocontrol and growth promoting potential of bacterial endophytes from H. brasiliensis.