Molecular characterization and biocontrol-traits evaluation of Trichoderma virens TVH3 against Fusarium oxysporum, the causal agent of tomato wilt.

Document Type : Regular issue (Original Article)

Authors

Genetics Department, Faculty of Agriculture, Tanta University, Tanta, Egypt

Abstract

In atte mpt to screen for new biological control agents (BCA) with high activity against soil-borne fungal pathogens, an isolate of the BCA Trichoderma virens was obtained, identified using molecular techniques and named TVH3. The antagonistic activities of
this isolate were tested against Fusarium oxysporum, a major soil-borne fungal pathogen of diverse crops. Our results revealed that T. virens TVH3 displayed high antagonistic potential against F. oxysporum via different mechanisms to control its prey, such
mechanisms include competition for the available space and nutrients, mycoparasitism and
production of antimicrobial secondary metabolites including volatile organic compounds
(VOCs). The antifungal soluble metabolites in Trichoderma’s culture filtrate were found to
be thermal-stable and T. virens TVH3 was found to possess high natural immunity against
antimicrobial metabolites in F. oxysporum culture filtrate. In the biocontrol assay, isolate
T. virens TVH3 was applied as seed coat on tomato seeds before planting them in heavily
infested soil with pathogenic strain of F. oxysporum and the obtained results revealed that such seed treatment had significantly reduced wilt signs on plants and provided the seedlings with effective shield against pathogenic infection.

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