POTENTIAL AND PERFORMANCE OF NONPATHOGENIC ISOLATES OF Fusarium oxysporum IN THE BIOCONTROL OF FUSARIUM WILTING IN TOMATO
Fusarium oxysporum f. sp. lycopersici. Solanum lycopersicum. biological control.
Tomato plants (Solanum lycopersicum) are severely affected by Fusarium wilt, a disease caused by the fungus Fusarium oxysporum f. sp. lycopersici (FOL). Disease management is hampered by the limited efficacy of available chemical fungicides, which makes biological control a promising alternative. This study aims to evaluate the biocontrol potential of nonpathogenic Fusarium isolates in the management of Fusarium wilt in tomato plants. The research began with the screening of nonpathogenic isolates through inoculation tests in tomato cultivars susceptible to the three races of FOL. Then, the protective potential of these isolates was investigated in in vitro assays (blotter test) and in nursery, in addition to evaluating the interaction of nonpathogenic isolates with several plant species, including lettuce, eggplant, cucumber, arugula, beans and soybean. The results indicated that nonpathogenic isolates of Fusarium spp. were effective in protecting against vascular necrosis in tomato plants. However, the blotter test proved to be inadequate for evaluating the protective capacity of the isolates. In nursery tests, the isolates FUS 0806, FUS 1202 and FUS 2006 demonstrated protective effects, while FUS 0604 showed pathogenic behavior. Additional evaluations in different plant species showed variable responses, with FUS 0806 inducing necrosis in arugula and beans, while FUS 1202 did not show pathogenicity in any of the species analyzed. This study highlights the potential of nonpathogenic isolates as biological control agents, highlighting the need for further investigations on their avirulence mechanisms and efficacy in different crops, aiming at a more efficient integrated management.