Genetic of resistance to ear rot causal agent (Fusarium moniliforme) in quality protein maize (QPM) using line×tester analysis

Abstract

Breeding for QPM ear rot resistant cultivars could offer a reliable environmental and economic control of mycotoxins especially for the resource-poor communities that require inexpensive protein diets. This research aims at evaluating a testcross of QPM inbreds with ear rot resistant cultivars to develop resistant topcrosses with high grain protein quality and yield. Seven QPM inbreds (lines) and two open pollinated ear rot resistant varieties (testers) were crossed in a line × tester method (2 × 7). The 14 F1 topcrosses, 9 parents and 2 commercial hybrids (checks) were evaluated at the Lower Niger River Basin Authority, Oke-Oyi, Nigeria in 2014 and 2015 cropping seasons. The ear rot disease ratings in all topcrosses were low (< 3.0), relative to the two controls of 3.4. K2GCA/ K2SCA values were higher than unity for grain yield, ear rot rating, husk cover, tryptophan and lysine characters, signifying that additive effects were controlling the inheritance of the traits. The three topcross hybrids (TZEQI 76× AMA TZBR YCF,TZEQI 74× AMA TZBR YCF,andTZEQI 81× TZEI 25) that possessed consistently low ear rot severity infection across years with TZEQI 76× AMA TZBR YCF,TZEQI 74× AMA TZBR YCF,andTZEQI 81× TZEI 25 outstanding for grain yield and quality protein are recommended for further evaluation in several years and locations before being released for commercial use.