Targeted Acquisition of Fusarium oxysporum f. sp. niveum Toxin-Deficient Mutant and Its Effects on Watermelon Fusarium Wilt

摘要

Watermelon Fusarium wilt is a common soil-borne disease that has significantly affected its yield. In this study, fusaric acid-deficient mutant designated as Delta FUBT (mutated from Fusarium oxysporum f. sp. niveum, FON) was obtained. The Delta FUBT mutant showed significant decrease in fusaric acid production but maintained wild-type characteristics, such as in vitro colony morphology, size, and conidiation. A field pot experiment demonstrated that Delta FUBT could successfully colonize the rhizosphere and the roots of watermelon, leading to significant reduction in FON colonization in the watermelon plant. In addition, Delta FUBT inoculation significantly improved the rhizosphere microenvironment and effectively increased the resistance in watermelon. This study demonstrated that a nonpathogenic Fusarium mutant (Delta FUBT) could be developed as an effective microbial control agent to alleviate Fusarium wilt disease in watermelon and increase its yield.