Environmental stability of contrasting seed tocopherol profiles in sunflower

Tocopherols (vitamin E) are the principal antioxidant compounds in oilseeds. Sunflower (Helianthus annuus L.) seeds mainly accumulate ¿-tocopherol although lines with alternative tocopherol profiles have been developed. The objective of this research was to assess the environmental stability of tocopherol profiles in a set of lines with modified tocopherols. Lines T589 (610 g kg¿1 ß-tocopherol), IAST-5 (800 g kg¿1 ß-tocopherol), T2100 and IAST-1 (>980 g kg¿1 ¿-tocopherol), TS-1 (390 g kg¿1 ¿-tocopherol and 580 g kg¿1 ¿-tocopherol), and IAST-4 (240 g kg¿1 ¿-tocopherol and 740 g kg¿1 ¿-tocopherol) were evaluated together with control line HA89 (990 g kg¿1 ¿-tocopherol) in 14 environments consisting of periodical sowing dates during 2 yr. Genotype effect was highly significant for all traits whereas environment main effect was only significant for the proportion of ¿- and ¿-tocopherol. Genotype × environment (G × E) interactions were observed for all traits although no consistent correlations between weather variables and tocopherol traits were identified The overall coefficients of variation in the 14 environments were 12.8 and 8.6% for ß-tocopherol in lines T589 and IAST-5, respectively, 0.4 and 0.6% for ¿-tocopherol in lines T2100 and IAST-1, respectively, and 19.5 and 12.5% for ¿-tocopherol in lines TS-1 and IAST-4, respectively. Despite the existence of environmental and G × E effects, the modified tocopherol traits were strongly expressed in all environments.Peer Reviewe