<i>Fusarium</i> <i>verticillioides</i> induction of maize seed rot and its control

Abstract

Experimental evidence is lacking to demonstrate whether Fusarium verticillioides (synonym = Fusarium moniliforme J. Sheld.; teleomorph = Gibberella fujikuroi (Sawada) Ito in Ito &amp; K. Kimura, mating population A) functions as a causative agent or an opportunistic invader in seed (caryopsis) rot of maize (Zea mays L.). 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. Efficacy of Plantpro-45, an agent with an iodine-based active ingredient (a.i.), was analyzed for controlling growth of F. verticillioides from conidia and inoculated maize seed. A solution containing &lt;10 µg a.i./mL inhibited growth of conidia suspended for &lt;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 postinfection stage with Plantpro-45.Key words: mycotoxin, reporter gene, germination, iodine.