Genetic variability for kernel tocopherols and haplotype analysis of γ-tocopherol methyl transferase (vte4) gene among exotic- and indigenous- maize inbreds

ABSTRACT Vitamin-E deficiency is a serious health problem worldwide. In maize, α-tocopherol possessing the highest vitamin-E activity is regulated by vte4 gene. Here, 54 maize inbreds possessing three favourable (0/0, 7/0 and 0/118) and one unfavourable (7/118) haplotypes of vte4 were evaluated at three locations. Significant variation was observed for α-, γ-, δ- and total-tocopherol. Variation in β-tocopherol was narrow. The mean α-tocopherol of 0/0, 7/0 and 0/118 haplotypes was much higher than the unfavourable (7/118) haplotype. Further, 0/0, 0/118 and 7/0 haplotypes possessed higher proportion of α-tocopherol/ total tocopherol than 7/118 haplotype. α-, γ- and δ- tocopherols were positively correlated (r = 0.56, 0.88 and 0.45, respectively) with total tocopherol. Across tocopherols, genotypes explained 34.7-90.4%, while environment represented 0.3-21.7% of total variation. β- and δ-tocopherols were minute in concentration, and α- and γ- tocopherols were the predominant fractions. This is the first report on genetic analysis of tocopherols among maize inbreds possessing four haplotypes of vte4 for use in biofortification programs in India.