Antagonism ofTrichodermaorGliocladiumSpecies on Two Phytopathogenic Species ofFusarium

SUMMARY The antagonistic actions of Trichoderma and Gliocladium species against two phytopathogenic species of Fusarium (a serious disease in cotton production) were studied in vitro. The antagonist induced a substantial lysis of mycelium of the target fungi which became malformed and thickened. Bulging or swollen hyphal strands occurred and sometimes with clamydospores production. Antagonists produced chitinase and β-1,3-glucanase in liquid culture contained cell wall of Fusarium spp. as a sole carbon source. Crude enzyme preparations of the antagonists with lytic enzyme activities greatly reduced the germinated conidia of Fusarium spp. Moreover, aberrant morphology of conidia was observed with germ tube lysis. On the other hand, the resulted mycelia showed wilt mycelium, coagulated protoplasm, heavy vacuolization and swelling followed by the complete destruction of the hyphae.