Tocopherols Concentration and Stability in Early Maturing Soybean Genotypes
Soybean [Glycine max (L.) Merr.] is an important source of tocopherols which have health-beneficial properties. A study was conducted to determine tocopherols concentration and stability in early maturing soybean genotypes and to determine their relationships to other important seed characteristics. Twenty soybean genotypes were grown in replicated trials in six environments of eastern Canada, and their total-, -, -, and -tocopherol concentrations were determined by high-performance liquid chromatography. Seed yield, 100-seed weight, and crude protein and oil concentrations were concurrently determined. Genotype and environment main effects and G x E interactions were observed for all tocopherols. Variations in the ranking of genotypes were, however, limited. Across environments and genotypes, relative proportions of -, -, and -tocopherol were 6, 34, and 60%, respectively. Variation in -tocopherol among genotypes was significant, with concentrations ranging between 8.7 and 33.2 µg g–1 across environments. Differences between environments were significant, albeit minimal, for all tocopherols; there was a 42% average variation in -tocopherol concentration across environments. Stability of genotypes for -tocopherol was not linked to mean concentration; however, some genotypes with high stability and mean concentration were identified, including the cultivar Heron. No correlations were observed between -tocopherol and any of the other seed characteristics investigated. However, negative correlations were observed between the other tocopherols and seed yield, 100-seed weight, and crude protein. Tocopherols were positively correlated with each other, except for a negative correlation between - and -tocopherol. The large variation observed among genotypes for -tocopherol, the relatively high stability of genotypes performance across environments, and the lack of negative correlation with other important seed characteristics suggest that selection for high -tocopherol could be possible.