ESTIMATES OF MEANS COMPONENTS FOR MAIZE GRAIN-FILLING TRAITS

One of the strategies to increase maize yield is to select lines that present a higher matter accumulation rate in the grains. This work was carried out to identify the population with the most significant potential to obtain this line type. For this, nine commercial hybrids’ F1 and F2 generations were evaluated in four environments, involving two years and two seasons each year. The traits evaluated were the number of days to female flowering (NDF) and physiological maturity (NDPM), dry matter accumulation rate (RATE), and grain yield (YLD). For each trait, the contribution of the loci in homozygosity (m+a) and heterozygosis (d) was estimated. NDF, NDPM, and RATE predominated an additive effect with a higher m+a estimate. Regarding YLD, the estimate of d was much higher than m+a, indicating the greater importance of dominance. Hybrid 5 is the most promising for obtaining the segregating population because it associates a high m+a, and d estimate that, although it was not among the highest, represented 56.03% of the average. For this hybrid, considering the YLD, the mean of the lines in F∞ will be the highest and associated with sufficient variability in the population to enable successful selection.