CHARACTERIZATIONS OF Trichoderma sp. AND ITS EFFECT ON Ralstonia solanacearum OF TOBACCO SEEDLINGS

Abstract

This study aims to determine the molecular-based characteristics of Trichoderma sp. Tc-Jjr-02 and its effect as a biocontrol agent in protecting tobacco seedlings against bacterial wilt caused by R. solanacearum. The characterization of biocontrol agents was based on morphological and molecular data’s observation using microscope and the key of determination. The in vivo experiments was consist of five treatments: (1) inoculation of Trichoderma isolates at six hours before R. solanacearum inoculation, (2) inoculation of Trichoderma isolates at six hours after R. solanacearum inoculation (3) simultaneous inoculation of Trichoderma isolates and R. solanacearum, (4) inoculated only with R. solanacearum, and (5) without any inoculation. The experiment was repeated six times. Based on BLAST’s analysis, the Tc-Jjr-02 sequence is in accordance with T. asperellum with 100% Query Cover. Inoculation of T. asperellum Tc-Jjr-02 at six hours before and after and simultaneously with pathogens providing protection for young tobacco plants by slowing down the time for the onset of blight by 100–162%, reducing the symptom index by 56–63%, and increasing the dry weight of plant biomass by 39–53% compared to tobacco seeds which were only inoculated with R. solanacearum.