| Abstract: | The soybean cultivar Yudou25 was sown at 5 locations of Henan Province on 13 different dates in 2001 and 2002. The data of isoflavone contents for the 109 samples of soybean seed and 33 eco-physiological factors including meteorological factors, soil nutrition and altitudes were received and used for statistical analysis. The step-wise regression was used to screen the correlated factors, which significantly effected isoflavone contents. Results showed that 9 eco-physiological factors were highly correlated with isoflavones. Low mean temperature, high diurnal temperature range at seed filling and maturity, more sunlight hours and low mean temperature at emergence were favorable to isoflavone accumulation. The rainfall at emergence showed a nonlinear relationship with isoflavone content and its optimum value was 75 mm for isoflavone formation. Low diurnal temperature range at branching, high organic matter and low sulfur content in soil were suitable for the formation of isoflavones. The isoflavone contents would not be affected by other eco-physiological factors in this study. |
