Molecular Characterization and Induced Systemic Resistance of Trichoderma asperellum against Bacterial wilt of Tomato

Abstract

Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating disease of tomato in Bangladesh and no significant effective control measure is available here till date. In this research work, Trichoderma from tomato rhizosphere is being utilized formulated with farm yard manure (FYM) to combat this pathogen attack. Ten Ralstonia spp. were also isolated from the infected tomato fields and characterised where R. solancearum isolate RsBAU1 was found most virulent, resulted 288 bp amplicon size with the species specific primers. Among 10 Trichoderma isolates, TR3 isolates (OM 480709) showed highest inhibition in vitro against R. solancearum isolate RsBAU1 that was resulted about 633 bp amplicon size with ITS primers, showed 99-100% blast homology with the other T. asperellum in phylogenic tree. T. asperellum (OM 480709) was formulated with FYM which significantly reduced and delayed Ralstonia wilt incidence and increased tomato fruit yield including other agronomic characters under both net house and field conditions. This formulated Trichoderma (FT) decreased the Ralstonia wilt disease incidence by 51.5% and increased 49.73% tomato yield when compared with the pathogen-treated plot during 2022-2023. Again, FT treated plants significantly increased peroxidase (POX), phenylalanine ammonium lyase (PAL), polyphenol oxidase (PPO), β-1,3-glucanase and total phenol activities in compared to non-treated plants and these activities were increased up to 8^th days when challenged with R. solancearum (RsBAU1) and then declined.  This indicates T. asperellum (OM480709) might have collectively contributed to induced resistance in tomato plants against R. solanacearum (RsBAU1 isolate). Therefore, T. asperellum (OM480709) formulated in FYM can be a sustainable and eco-friendly management strategy for controlling Ralstonia wilt of Tomato in Bangladesh.