Heterosis y aptitud combinatoria en siete progenitores de maíz (con 4 tablas)

This research was carried out to learn the performance of seven maize lines and their F 1 progenies. Germplasms were assessed in two trials during spring-summer 1997B to ear rot (ER), caused by Fusarium moniliforme and grain yield (GY). To estimate heterosis and its components, the Gardner & Eberhart (8) model II and Griffing (13) design 2 model 1 were applied. The estimated values of heterosis and its components, and those of GCA and SCA, show that in this work, Gardner & Eberhart (8) model was better in all estimations; with Griffing (13) design 2, the effects, principally SCA, were over estimated. The crosses 1x6 (AC8223-4-2-1-2 x 88-2-3-1-1) and 3x6 (AC7929-38-3-2-1 x 88-2-3-1-1), showed low ear rot percentage (18,01% and 14,09%). According to Jeffers's et al. (16) classification these crosses could be regarded resistant, and with acceptable grain yield (7,79 and 7,71 t ha - 1 ), superior to the general mean of the experiment (5,18 t ha - 1 ), but 0,62 t ha - 1 lower than the cross 5x6 (AC8149-5-1-2-1 x 88-2-3-1-1) that produced 8,33 t ha - 1 . With the best crosses, it is possible to begin a breeding program for pedigree, to generate germplasm with resistance to ear rot and high grain yield.