COMBINING ABILITY FOR YIELD COMPONENTS IN GRAIN CORN LINES AT LA COMARCA LAGUNERA, MÉXICO

Abstract

The annual planted surface of corn (Zea mays L.) grown at the Comarca Lagunera, México, for forage and grain is 24 000 and 15 000 ha. This research was done to estimate the parent lines general combining ability (GCA) and the specific combining ability (SCA) of maize for grain of their respective crosses. In the 2004 spring season, 100 crosses were obtained from 10 lines used as male parents and 10 lines used as fermale parents, according to the North Caroline model II mating design. In the 2004 summer season the crosses were evaluated using a complete randomized blocks experimental design with two replications. The highest yields and GCA were showed by the M1 male and the H12 female lines. The highest SCA for yield components were showed by crosses: 3x20, 7x14, 5x17, 1x6 and 2x11. For the 1x16 cros yield depended on the number of grains per row and seed weight, traits contributed by male M1 and female H16, respectively. For the 5x17 cross yield depended on, ear length and number of grains per row, characteristicas which were inherited by the M5 and H17 parental lines, respectively. For the 6x12 cross grain yield relayedon the number of ear rows inherited from M6, and on the seed size inherited from H12.