Heterosis and genetics parameters for yield and nutritional components in half-sibling maize progenies

The growing demand for maize creates a challenge to breeders, requiring the development of higher yielding and higher quality genotypes. The objective of this work was to estimate the most relevant heterosis, variance components and genetic parameters, and to use a multivariate approach to define narrow sense heritability profiles for yield and nutritional components in half-sib maize progenies. The experimental design used was random blocks, with a male parent (hybrid tester), five inbred lines (S5) as maternal parents and the progenies (hybrid Top Cross), totalizing 11 maize genotypes arranged in six replicates. Agronomic and nutritional characters were evaluated. Half-sibling progenies reveal greater additive genetic contribution to phenotypic expression through grain width and thickness, iron content, total flavonoids and carotenoids, soluble solids, and methionine. Narrow sense heritability values between and within progenies are higher for manganese content, glycine, proline and tryptophan. Regardless of the inbreeding line S5 used, heterosis gains are obtained for insertion of spike height, number of grain rows per spike, stem diameter, and zinc content, total carotenoids, soluble solids and pH. Specific heterosis’s evidenced for grain yield, glycine, serine, threonine, and phenylalanine. The multivariate approach used defines eight-character profiles regarding their genetic trends and indicates narrow sense heritability of the progeny mean as the major cause for this distinction.