磷营养对水稻不同耐冷品种光合特性的影响

以不同磷水平的营养液培养水稻幼苗，比较研究了低温处理后耐冷性不同品种光合特性的变化。低温下2个品种的水稻叶片的叶绿素含量、光合速率、F_v/F_m和qp均降低，冷敏感品种比耐冷品种的降低幅度更大。与缺磷和正常磷水平培养的材料相比，高磷培养的材料在低温下具有较高的叶绿素含量、光合速率、F_v/F_m和qp；缺磷培养的材料在低温下叶绿素含量、光合速率、F_v/F_m和qp下降加剧，耐冷品种的NPQ升高，但冷敏感品种的NPQ变化不大。磷营养水平对冷敏感品种光合作用的影响比对耐冷品种更明显，通过体外施磷，可以提高水稻的耐冷性。

Effects of Phosphorus Nutrient on Photosynthetic Characteristics in Rice Cultivars with Different Cold-Sensitivity

The experiment was conducted under low temperature using two rice cultivars with different cold sensitivities grown in cultured solution with different phosphorus concentrations. The result showed that chlorophyll content, photosynthetic rate, Fv/Fm and qp were decreased in the two rice cultivars under chilling stress, and they were decreased more in chilling sensitive cultivar than in chilling tolerant cultivar. The seedlings cultured in higher level of phosphorus nutrient had higher levels of chlorophyll, photosynthetic rate, Fv/Fm and qp. Phosphorus deficiency reduced the chlorophyll content, photosynthetic rate, Fv/Fm and qp. NPQ under chilling stress and phosphorus deficiency was increased in chilling tolerant cultivar, but not changed much in the chilling sensitive cultivar. The results indicated that photosynthesis and the chilling resistance of rice can be improved by exogenous application of phosphorus. Phosphorus nutrition status had a more significant effect on the photosynthesis in chilling-sensitive cultivar than in chilling-tolerant cultivar.