Investigation of the antagonistic effects of tomato rhizosphere fungi against Fusarium oxysporum f.sp. lycopersici, causal agent of tomato wilt disease

In the research on biological control of tomato wilt disease caused Fusarium oxysporum f.sp. lycopersici (FOL), totally 29 candidate fungal antagonists were isolated from tomato rhizospheres. The highest population consisted of Aspergillus species (52.0%) following Mortierella (14.3%) and Penicillium species respectively. All the Penicillum and Aspergillus species inhibited in vitro mycelial growth of FOL with different grades. While all these fungi produced inhibition zones on PDA medium, some of them preceded with their volatile, non-volatile or mycelial competition. Although Trichoderma species were isolated with low frequency, they exhibited suppressive effect on mycelial growing rate of FOL by both volatile and non-volatile antibiotic production in in vitro. Aspergillus flavus, Penicillium griseofulvum and Trichoderma aggressivum inoculation inhibited disease incidence on plants by 26.3%, 31.6% and 21.1% respectively. T. brevicompactum was the most effective fungus inhibiting disease incidence by 78.9% effect.