Although aspects of magnitude and significance are considered, the study of correlations between traits, alone, does not necessarily guarantee a cause and effect relationship between them. Therefore, the objective of this study was to use path analysis to allow the unfolding of correlations in direct and indirect effects, considering the carotenoids profile of maize genotypes. Data was obtained from the national assay of maize cultivars conducted by Embrapa Maize and Sorghum in the 2004/2005 growing season, with means of ten genotypes in five environments. The contents of total carotenoids (CT), alpha and β-carotene, lutein, zeaxanthin and β-criptoxantin were evaluated. Xanthophyll zeaxanthin provided the highest direct effect on β-carotene. The high correlations between β-carotene and total carotenoids and between β-carotene and β-criptoxanthin are due the indirect effect via zeaxanthin. The direct selection of genotypes with high levels of β-carotene appears as a more effective alternative, but if other fractions of carotenoids were also considered, methods of simultaneous selection of characters using selection indices are more efficient in obtaining genotypes with high levels of β-carotene than the correlated response.
Zea mays L.; carotenes; correlations; direct effects; indirect effects
