Genetic Variability of Alpha‐Tocopherol and Gamma‐Tocopherol in Corn Embyros1

Abstract

Vitamin E is an essential component of animal diets. Two predominant isomers were known to exist in different ratios, as well as concentration, in corn (Zea mays L.) grain. Furthermore, the biological value of the alpha isomer is substantially greater than gamma. The primary objective of this effort was to establish the magnitude of variation of the isomers and to estimate the rate of progress that might be expected through selection for the isomers individually or for total concentration. Alpha‐ and gamma‐tocopherol are the predominant vitamin E isomers in the embryos of corn. Tocopherol concentrations were determined in embryos of selfed seed of 100 S1 families derived from RSSSC, a corn synthetic, grown in two replications of a replicates within block design in 1980 and 1981. Tocopherols were extracted, separated by high‐performance liquid chromatography on a silica absorption column, and quantified by ultraviolet absorbence detection. Concentrations of alpha‐tocopherol ranged from 0.0 to 138.2 μg/g embryo while concentrations of gammatocopherol ranged from 0.0 to 409.3 μ/g embryo. Average concentrations were 61.4 and 194.4 μ/g embryo for alpha‐ and gamma‐tocopherol, respectively. Family heritability estimates of 0.62 ± 0.16 and 0.68 ± 0.15 for alpha‐ and gamma‐tocopherol indicate that selection would be effective for either of these isomers.