Article
Heterosis and combining ability among maize narrow-base populations
Fecha
2010Autor
Parra, J.R.
Rivera, M.M.M.
Gonzalez, J.J.S.
De La Cruz Larios, L.
Marquez, M.R.
Diaz, J.L.R.
Institución
Resumen
Nine narrow genetic base maize (Zea mays L.) populations from Jalisco, Mexico representing different germplasm and selection criteria were considered in this study. The nine populations and 36 population crosses were evaluated at three locations in 2004 and 2005 that included four subtropical and two tropical environments. The objective in this study was to identify crosses as prospective non-conventional hybrids and/or as heterotic patterns to develop inbred lines for hybrids, in Jalisco, Mexico. GARCNER and EBERHART (1966) model II was used to test average, specific, and variety heterosis for grain yield and other agronomic traits. Analysis of principal components, generation of biplot graphs, and cluster analysis were also done for populations and population crosses for all traits. Average heterosis for grain yield was 55% and some population crosses had grain yields comparable to commercial testers. The first two principal components explained 54.9% of total variation among populations and population crosses, and grain yield was the most important trait to differentiate among populations and population crosses. Population and population crosses were separate from each other. There were greater distances among populations than their crosses, which could be an indication of genetic diversity among populations because of germplasm origin and selection criteria imposed by breeding programs. Mexican Dent (MEDT), introduced from USA Corn Belt, was the most distant population to others and to population crosses, but it had good crosses to adapted populations for grain yield and earliness.