Abstract:

Vitamin E (VE) is an important nutrient factor for human beings, and soybean seed is one of major available VE recourses. To reveal the correlation between VE content in soybean seed and ecological factors, the present experiment was carried out using soybean cultivar Yudou 25 sown at 5 locations of Henan province on 13 different dates in 2001 and 2002. The data of VE contents for the 109 samples of soybean seed and 33 eco-physiological factors including meteorological factors, soil nutrition and altitudes were obtained and used for statistical analyses. Step-wise regression was used to screen the correlated factors, which showed significant effect on VE content. Results indicated that the VE contents was substantially affected by the environmental conditions and ranged from 500.99 μg g^-1 to 2353.68 μg g^-1 among all samples. Nine eco-physiological factors were highly correlated with VE content, including 6 meteorological factors, 2 soil nutrition factors and altitude. VE content was negatively correlated with rainfall at seedling (P<0.01), rainfall at branching (P<0.001), rainfall at blooming and podding (P<0.001), diurnal temperature range at blooming and podding (P<0.05), hours of sunlight at seed-filling and maturity (P<0.001), and hydrolysable N (P<0.001), but positively correlated with total P content in soil (P<0.001) and altitude (P<0.001). While the VE content was positively correlated with hours of sunlight at blooming and podding (P<0.001), and negatively correlated with the square of the factor (P<0.01). The result of this experiment is meaningful for the development of soybean cultivars with higher VE and for the production of soybeans with more VE.

Key words: Soybean [Glycine max (L.). Merrill], Vitamin E, Eco-physiological factors, Seeding dates