Abstract
Two lines of evidence are presented that support the theory of glucose oxidase involvement in the biocontrol of Verticillium wilt of eggplant by Talaromyces flavus isolate Tf‐1. Purified glucose oxidase from Tf‐1 significantly reduced the growth rate of Verticillium dahliae in the presence, but not in the absence, of eggplant roots. This suggested that glucose from the roots was metabolized by glucose oxidase to form hydrogen peroxide which is toxic to V. dahliae. Isolate Tf‐1‐np, a single‐spore variant of isolate Tf‐1 (which produced 2% of the level of glucose oxidase activity produced by Tf‐1), did not control Verticillium wilt of eggplant in a greenhouse experiment using non‐sterile field soil. In contrast, isolate Tf‐1 significantly reduced the incidence of wilt.