YIELD STABILITY OF DIALLELIC CROSSES AMONG MAIZE LINES OF HIGH AND LOW GENERAL COMBINING ABILITY

Abstract

In breeding programs focused on developing maize (Zea mays L.) hybrids, knowing the stability of grain yield of inbred lines in hybrid combinations is important. The objective of this study was to evaluate the stability of grain yield of single diallelic crosses from high and low general combining ability (GCA) maize lines. Eight lines of the Chalqueño race were used, four of high (H) and four of low (L) GCA, with different levels of inbreeding. The yield of ear per plant of 24 out of the 28 possible single crosses was evaluated in two locations of the State of Mexico, from 2011 to 2013; in the evaluations of 2012 and 2013 four commercial checks were included. The AMMI method was used and significant differences (P ≤ 0.01) were found between environments, genotypes, genotype × environment interaction and in the effects of the first principal component (PC1). The total variability due to interaction was explained by PC1 (86.62 %) and PC2 (13.38 %). The model retained 86.69 % of the total sum of squares. The crosses H × L expressed the highest yields and the crosses H × H the highest stability. The H3 × L3 cross was stable and with high yield (108.27 g per plant). The response of the crosses to a specific environment showed that in addition to the GCA of the lines, the adaptation and adaptability of the cross play a crucial role in the performance of grain yield. The best crosses equaled the best check in grain yield.