YIELD COMBINING ABILITY AND HETEROSIS OF CORN LINES AT THE COMARCA LAGUNERA, MÉXICO

Abstract

This work was carried out at two locations (San Pedro and Torreón, Coahuila) of the Comarca Lagunera, in 1999. The main objective was to determine the general combining ability (GCA) and the especific combining ability (SCA) of six corn inbred lines, which were: L-AN-123R, L-AN-447, L-AN360PV, L-AN-130, L-AN-123 and L-AN-388R. To estimate the effects of GCA and SCA the method II of the Griffing diallels (1956) was used. The experimental desing used was a complete randomized block desing with two replications, at each location. The combined analysis showed significant differences among locations and genotypes. The best yielding genotypes were: LAN-130xL-AN-388R, L-AN-360PVx L-AN-123 y L-AN-360PV x LAN-130. The líneas L-AN-123 , L-AN-130 y L-AN-123R showed the highest GCA, and the crosses L-AN-447xL-AN-123, L-AN-447xL-AN360PV y L-AN-360PVxL-AN-130 showed the highest SCA effects. All the crosses showed mid-parent and high parent positive heterosis. The main gene action was the dominance (overdominance) and the broadwise heritability on mean basis was 94.73 %. The results showed that the crosses of this research might be used to develop commercial hybrids.