PHENOTYPIC STABILITY OF SINGLE CROSSES AND COMMERCIAL HYBRIDS OF MAIZE (Zea mays L.)

Abstract

Given the diversity of environmental conditions under which maize (Zea mays L.) is sowed and the need to produce improved genotypes for consistent expression over locations, this research evaluated the phenotypic stability of grain yield, days to male flowering and plant height of ten simple crosses of maize outstanding by their grain yield. These crosses were obtained from a diallel crossing scheme with ten S₆-S₈ inbred lines, and ten hybrids: some of them commercially distributed by local and transnational companies and some others were local experimental hybrids. The stability analysis was performed by the additive main effects and multiplicative interactions (AMMI) model; this analysis was justified by the resulting statistical significance of the genotype - location interaction from the combined analysis of variance. The traits under evaluation were differentially modified by the environments (locations), being days to male flowering and plant height the most affected ones; the stability of the genotypes was also different between traits. Single crosses were more stable than commercial hybrids, except for plant height; hybrids displayed positive interaction with locations with better production conditions, but there was no interaction with locations with restrictive conditions. Aside from higher grain yield compared to some commercial hybrids, crosses had shorter phenological cycles and plant height similar to current commercial archetypes. Results showed that the single crosses evaluated might represent an option for maize grain production.