español Antagonism of Trichoderma sp. on Ralstonia solanacearum from banana clone “Gran Enano”

Abstract

Banana (Musa paradisiaca) plants are susceptible to different microbial agents that cause diseases. One of these diseases is Bacterial Moko (BM) caused by Ralstonia solanacearum. The objective of this work was to determine the antagonistic capacity of Trichoderma spp. on the development of R. solanacearum. Seven strains of the bacterium were isolated from banana plants with BM symptoms, three strains were morphologically, biochemically and molecularly identified as R. solanacearum. Two native strains of Trichoderma sp. were used for antagonism tests. Molecular analysis of the fungal strains identified them as T. asperellum and T. atroviride, and were marked as Jc 01 and Ban 1, respectively. The initial confrontation of the fermented and cell-free culture medium showed a greater antagonistic capacity of T. asperellum Jc 01. T. asperellum Jc01 was grown in liquid medium for 5, 10 and 14 days, finding the highest antagonistic capacity (37 %) of the fermented and cell-free culture media at 5 days. Regardless of the fermentation time, the unfiltered supernatant totally inhibited the growth of R. solanacearum. The antibacterial activity of T. asperellum Jc01 is emphasized and speculated on the inhibitory mechanism.