GENETIC DIVERGENCE AMONG MAIZE GENOTyPES ON CAROTENOID CONTENTS IN GRAINS

Biofortification is an efficient alternative in helping to combat micronutrient deficiencies in the human population. In maize, breeding programs aim to obtain materials with high contents of Fe, Zn and pro-vitamin A (carotenoids) which require preliminary studies of genetic diversity among entries. The aim of this study was to estimate the genetic divergence among maize varieties for content and profile of carotenoids in grains. Data from the National Maize Variety Tests were used, from the 2004/2005 growing season. A total of ten genotypes were evaluated in two environments. Total carotenoids (TC), a and β-carotene, lutein, zeaxanthin, β-criptoxantina, the sum of carotenoids precursors of vitamin A (total of β-caroteno + ½ of a-caroteno + ½ of β-criptoxantina = Pro-VA) and grain yield were evaluated. Carotenoid levels were relatively low in the evaluated varieties, compared to those reported in the literature for elite-lines. Lutein and zeaxanthin were the most contributing characters to the genetic diversity among genotypes. The environmental effect on trait expression raises questions about the validity of diversity analysis in a single environment, emphasizing the need for studies to be conducted in multiple environmental conditions