Maize as the main staple food, development of maize cultivars with enhanced levels of two essential amino acids such as lysine and tryptophan are a must. Most of the improved maize varieties released so far for commercial production are poor sources of quality protein since normal maize protein is deficient in two essential amino acids which are lysine and tryptophan. Developing quality protein maize (QPM) hybrids is therefore important to improve the human health. Determining the standard heterosis of QPM hybrids is an essential step to facilitate the development of QPM hybrids and their commercialization. This study was conducted to estimate standard heterosis of fifteen single-cross QPM hybrids. The crosses were made in a 6x6 half diallel mating design which produced fifteen F1 single crosses. These single crosses along with three standard checks were evaluated for their grain yield and other traits, using alpha lattice design with three replications. L3xL4 gave the highest standard heterosis for grain yield over the best check BH546 (13.08%) and mean of the three checks, BH546, BH547 and BHQ548 (35.26%). L3xL6 and L4xL6 had also higher magnitude of standard heterosis over the checks. Thus, these hybrids can potentially be proposed for commercialization, and the breeding values of their parents can be exploited for QPM breeding.
grain yield, half-diallel, normal maize, quality protein maize, standard heterosis
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