José Armando Carrillo-Fasio

Efecto de biocontrol e inhibición germinativa de Bacillus spp. sobre zoosporas de Phytophthora capsici

The oomycete Phytophthora capsici is a pathogen of economic importance in tomato ( Solanum lycopersicum L.) and chili ( Capsicum annuum L.) crops. The objective of this work was to evaluate the effect of germinative inhibition and biocontrol of two isolates of the genus Bacillus on zoospores of P. capsici . The isolates were identified as Bacillus amyloliquefaciens and B. thuringiensis . In the in vitro tests of the germination of zoospores of P. capsici , the percentages of inhibition with cell suspension of B. amyloliquefaciens and B. thuringiensis were significant with 88.15 and 97.05% respectively, while, the filtrates showed 24.30% of inhibition. In the in vivo study, tomato seedlings treated with cell suspension of B. amyloliquefaciens and B. thuringiensis , showed lower severity of the disease caused by P. capsici with 22.22 and 27.78% respectively, compared to that observed in chili seedlings where values of 61% were obtained. The tomato and chili seedlings treated with bacterial filtrates showed up to 94% severity. With cell suspension of B. amyloliquefaciens and B. thuringiensis the efficiency of biocontrol was 72 and 77% respectively, which show that these microorganisms can be used as biocontrol agents of P. capsici in tomato and chili plants.