Fusarium verticillioides induction of maize seed rot and its control.
Experimental evidence is lacking to demonstrate whether F. verticillioides (synonym=Fusarium moniliforme; teleomorph=Gibberella moniliformis, mating population A) functions as a causative agent or an opportunistic invader in seed (caryopsis) rot of maize (Zea mays). Previous researchers have isolated this fungus, along with many other microorganisms, from seed collected in the field long after rot commenced. The current investigations used an isolate of F. verticillioides transformed with a selectable marker and a reporter gene to inoculate previously disinfected maize seed. Seed rot developed, and F. verticillioides containing the introduced genes was isolated from inoculated, but not noninoculated, seed. The efficacy of Plantpro-45, an agent with an iodine-based active ingredient (a.i.), was analysed for controlling the growth of F. verticillioides from conidia and inoculated maize seed. A solution containing <10 µg a.i./ml inhibited the growth of conidia suspended for <30 s. Furthermore, seed rot was controlled without diminishing seedling survival at 10 mg a.i./kg maize seed. Thus, F. verticillioides can function as the causative agent of maize seed rot and can be suppressed and (or) controlled at the post-infection stage with Plantpro-45.