Biological Control of Fruit Rot and Die Back Disease of Capsicum annuum with Pseudomonas aeruginosa WS-1

摘要

Colletotrichum capsici is the causal agent of fruit rot and die back disease, the most important diseases of chilli worldwide. A rhizospheric isolate Pseudomonas aeruginosa WS-1 successftilly showed both in vitro (10^ cells/ml) and in vivo (3 x 10~8 cfu/ml) antagonistic activity against the pathogen C. capsici. On dual plate culture, the antagonist effectively suppressed the growth of the fungal pathogen. Light microscopy of mycelium from the interacting region showed hyphal shriveling, hyphal deformities, tip swelling, short branching and granulation of cytoplasm resulting in lysis of hyphae. The antifungal activity of this isolate is correlated with the production of siderophores and HCN. The strain also produces mycolytic enzyme-like proteases and chitinases, which are well known to lyse the cell walls of the fungal pathogen. The efficacy of P. aeruginosa WS-1 application under greenhouse conditions was comparable to that of fungicide (carbendazim) to manage the disease. This result suggests that P. aeruginosa WS-1 has the potential to be used as a biopesticide for effective management of fixiitrot and die back disease of chilli in India.