IMPROVED STRAINS OF TRICHODERMA AS BIOCONTROL AGENTS, METHODS OF OBTAINING SAME AND USE THEREOF FOR CONTROLLING DISEASES CAUSED BY PHYTOPATHOGENIC FUNGI

摘要

The invention relates to a method of obtaining strains of Trichoderma that overproduce various lytic enzymes for use as antagonists of phytopathogenic fungi owing to the increased mycoparasitic activity thereof. According to the invention, a gene ofTrichoderma virens that codes for a mitogen-activated kinase protein (MAP kinase) was cloned, said gene being related to the mycoparasitic response, conidiation and observed biocontrol of Trichoderma. Strains of Trichoderma with suppressed expression of the isolated MAP kinase gene demonstrated a clear increase in the expression level of mycoparasitism-related genes (MRGs) under simulated mycoparasitism conditions during direct confrontation with the plant pathogen Rhizoctonia solani.Biocontrol assays consistently demonstrate that the inventive strains are considerably more effective at controlling diseases than the wild strain or a chemical fungicide. In addition, the inventive strains sporulate abundantly in submerged cultures, which does not normally lead to sporulation in the wild strain.