Seed tocopherol assessment and geographical distribution of 1151 Chinese soybean accessions from diverse ecoregions

Abstract Soybean seeds are primary sources of natural tocopherols used by food and pharmaceutical industries owing to their beneficial impacts on human health. Here, we profiled the seed tocopherol compositions of 1151 Chinese soybean accessions that originated from different ecoregions, grown in three locations for two years in China. Thus, this study aimed to evaluate the effect of accessions, ecoregions of origin, accession types and geographical factors on tocopherol content of soybean as well as unveil the correlations among tocopherols and other important seed quality traits. The highest average contents of α- and γ-tocopherols (15.43 μg g-1 and 151.44 μg g-1, respectively) were observed in the Northern Region (NR) accessions of China. Also, α-, γ-, and total tocopherol contents were higher in cultivars than landraces. The correlation analysis showed that tocopherols were significantly associated with other seed quality traits. α- and γ-tocopherols had significant positive correlations with latitude and longitude, while δ-tocopherol showed a contrary trend. Taken together, we identified novel soybean accessions that can be utilized as raw materials for food industries and in breeding programs to improve the tocopherols contents of soybean seeds.