Trichoderma atrobrunneum: In vitro analysis of exoenzyme activity and antagonistic potential against plant pathogen from agricultural fields in the Patna region, India

Abstract

Background: Fungi and oomycetes continue to be the primary source of plant diseases, which cause major crop loss factors in agriculture. Trichoderma is a genus of ascomycete fungus that lives in soil and is known for its ecological significance as a bio-fungicide. Aim: The current study aimed to assess and contrast the antagonism and exoenzyme activity of Trichoderma isolates against Pythium sp., which causes damping-off and root rot diseases on tomato plants. Trichoderma spp. was isolated from rhizospheric soil of healthy plants in the agricultural fields of Patna, Bihar district, India. Methodology: The Trichoderma isolates were evaluated for their suitability as antagonists by in vitro dual culture and non-volatile assay. Results: The results showed that the isolated Trichoderma species were effectively reduced the growth of Pythium sp. in the dual culture assay and non-volatile metabolites (12.5%, 25% and 50% v/v concentration) assay. Trichoderma atrobrunneum effectively inhibited the mycelial growth of Pythium sp. both in the dual culture (81.48%) and non-volatile metabolite assay (71.37%). Followed by Trichoderma harzianum (79.01% and 58.82%), and Trichoderma asperellum (65.43% and 50.58%) respectively. Exoenzyme activities of the Trichoderma isolates were also investigated. The antagonistic Trichoderma atrobrunneum exhibited maximum activities of β-1,3-glucanase (41.39 U/ml) and chitinase (33.06 U/ml) in comparison to T. harzianum and T. asperellum. The capacity of antagonism is enhanced by the production of the enzyme. Based on the above results, it can be said that the non-volatile metabolites and the exoenzyme of the antagonist T. species act synergistically in inhibiting Pythium growth. Conclusion: The secretion of enzymes by Trichoderma species shows that they can be used in plant disease control as novel biocontrol agents as well as to produce enzymes in biotechnological processes.