Abstract
The antagonistic potentials of endophytic bacteria isolated from chilli plants were determined in vitro against four pathogens, viz., Sclerotium rolfsii, Fusarium oxysporum, Colletotrichum capsici and Pythium sp. The effect of endophytic bacteria towards these fungi revealed that most of the isolates showed antagonistic activity against Pythium sp. (37.8%), followed by 35.1% isolates against F. oxysporum and C. capsici, and 21.6% to S. rolfsii. The identification of potential bacterial isolates through Microbial Identification System (Biolog) and 16S rDNA sequencing of the isolates revealed the presence of 8 genera. Among them Bacillus species were the dominant antagonists. Characterized by BOX-PCR fingerprints, the 23 antagonistic endophytic bacterial (AEB) isolates represented 19 different cluster types. To explore the antagonistic mechanisms, the agar diffusion method was used to detect cell-wall degrading enzyme activity and siderophore secretion. The isolates BECS7, BECS4 and BECL5 showed clearly the growth promoting activity, reduction of disease incidence and high yield under field conditions. Hence, these isolates are promising plant growth promoting isolates showing multiple attributes that can significantly influence the chilli growth. The results of present study provide a strong basis for further development of these strain as bio-inoculants to attain the desired plant growth promoting activity in chilli growing fields.