Photosynthetic Diurnal Variation of Soybean Cultivars with High Photosynthetic Efficiency

<正> The photosynthetic characters were investigated among soybean cultivars with high photosyn-thetic efficiency and high yield. The results indicated that: 1) There were significant differences in photosynthetic rate (Pn) and dark respiration rate (DR) under saturation light intensity and appropriate temperature. 2) There were a little difference in light compensation point among them. Photo flux density (PFD) were about 360 μmol/m2-s when Pn tended to zero. 3) When PFD>1 900 μmol/m2·s, photoinhibition occuried a-