Mixed models and multivariate approach applied to maize breeding: A useful tool for biofortification

Biofortification and bioactive compounds enrichment of maize genotypes is a great alternative for mitigating micronutrients deficiency in human and animal diet, and also for improving the benefits of maize for human health. This work aimed to estimate variance components and genetic parameters of bioactive compounds and micronutrients to predict superior maize hybrids from different genetic bases, and to apply the RELM/BLUP methodology to multivariate techniques. The inbreed lines were crossed and the F1 hybrids were grown for evaluations in 2014/2015 and 2015/2016 growing seasons, respectively. Then, micronutrients and bioactive compounds related traits were evaluated. The variance components and genetic parameters were estimated by REML methodology. The BLUP methodology was employed to predict genetic values and to verify the percentages of genetic gain with selection. The predicted genetic values were applied to estimate genetic distances by the Mean Euclidean Distance. The relative contribution of each trait to genetic divergence was evaluated and the principal components analysis determined, proposing the genotypes that are potentially capable to increase a given trait. The presence of genetic variability was evidenced among genotypes, while some of them presented potential for increasing specific traits. The top cross hybrid L64XAS1590 showed the highest estimates for increasing antioxidant-responsible traits, and micronutrients contents such as manganese, cooper, iron and zinc. In general, there was the possibility of achieving genetic gains with selection under application of biofortified and bioactive compounds to enhance maize hybrids through conventional breeding. However, it does not applicable for iron content due to its low estimate of broad sense heritability.