Genetic variability-, genotype x environment interactions- and combining ability-analyses of kernel tocopherols among maize genotypes possessing novel allele of γ-tocopherol methyl transferase (ZmVTE4)

Deficiency of vitamin-E or tocopherol causes neurological disorders in humans. alpha-tocopherol possessing the highest vitamin-E activity is present in low concentration in maize kernel. Nine lines and four testers possessing favourable allele of ZmVTE4 that significantly enhances vitamin-E activity were used to generate 36 hybrid combinations. Significant variation was observed for alpha- (5.95-39.03 mu g/g), gamma- (11.69-50.82 mu g/g), delta-(4.09-10.76 mu g/g) and total-tocopherol (33.18-90.53 pg/g). alpha-, gamma- and delta-tocopherol constituted 36%, 53% and 11% of the total tocopherol, respectively. Majority of the experimental hybrids possessed significantly higher atocopherol (mean: 21.37 mu g/g) than the check hybrids (mean: 11.16 mu g/g). AMMI analysis revealed that across tocopherols, genotype and interaction effect accounted 35-77% and 23-45% of variation, respectively. The environmental effects were of minor magnitude. Non-additive gene action was predominant for alpha-, gamma-, and total-tocopherol, while delta-tocopherol was conditioned predominantly by additive gene action. The information generated here assumes great significance in biofortification programme. This is the first report of variability, G x E interactions and combining ability for kernel tocopherol using maize hybrids possessing novel allele of ZmVTE4.