Effects of 3-(p-chlorophenyl)-6-methoxy-s-triazine-2,4 (1H, 3H) dione triethanolamine (DPX-3778) treatment on the floral development of maize

Abstract

In a series of experiments to determine the physiological effects of a triazanone antidehiscence chemical, 3-(p-chlorophenyl)-6-methoxy-s-triazine-2,4 (1H, 3H) dione triethanolamine (DPX-3778), sex determination of the tassels of corn (Zea mays subsp. mays) was altered depending on the concentration and timing of application. Multiple applications of 0.005% (w/v) DPX-3778 to the leaf sheath of maize plants, or the addition of 1 ppm DPX-3778 to hydroponic growth medium, approximately 4 weeks before anthesis, caused reversion of staminate inflorescences to pistillate inflorescences. In addition to the normally developed gynoecium of the upper floret, DPX-3778 treatment resulted in the full development of the lower floret gynoecium in ear spikelets. These results could be duplicated in Northern Teosinte (Zea mays subsp. mexicana, race Nobogame). DPX-3778 could thus be useful for investigating the cellular and developmental physiology of stamens and gynoecia in corn and other monoecious grass species.