Preliminary investigation of the effect of ethyl 4'fluorooxanilate as a male gametocide of sweet stem sorghum

Abstract

ABSTRACTAn effective male sterility system enables targeted crosses between parent plants with desired and complementary characteristics. The use of chemical hybridising agents (CHAs) to induce male sterility is quicker and more efficient than manual emasculation. This study investigated the concentration, stage of application and frequency of application of ethyl 4'fluorooxanilate (E4FO) for inducing male sterility of sweet stem sorghum without affecting female fertility. In Trial 1, the dose rate of E4FO was determined to optimise male sterility. In this experiment three genotypes were tested at E4FO dose rates. In Trial 2 the frequency of application of E4FO was determined using three sweet stem sorghum genotypes, three E4FO doses, and six frequencies of application. Data on sterility was inferred based on seed set and seed count from the treated plants. Male sterility was achieved when E4FO was applied during heading stage using the following rates: 1 g l−1, 1.5 g l−1 and 2 g l−1, with more than one application. Applying E4FO twice during the heading stage at a rate of 2 g l−1 would induce male sterility in the tested sweet stem sorghum genotypes, a result that could be useful in hybrid breeding programmes.