低钾胁迫下不同低钾耐性大豆光合特性及保护性酶的差异

田间试验选用耐低钾和低钾敏感的大豆品种各2个，研究低钾胁迫下不同品种光合特性及活性氧代谢的差异。结果表明，与施钾相比，低钾胁迫下，两类品种的相对叶绿素（SPAD）、光合速率（Pn）和气孔导度(Gs)均下降，但低钾耐性品种比低钾敏感品种下降的幅度小；而胞间CO2浓度（Ci）、蒸腾速率（Tr）和脯氨酸含量升高，且低钾敏感品种比低钾耐性品种升高幅度大。低钾耐性品种SOD活性在开花期低于低钾敏感品种，成熟始期又明显高于低钾敏感品种；CAT活性在开花期和结荚期低钾耐性品种都高于低钾敏感品种；成熟始期POD活性低钾耐性品种下降的幅度小于低钾敏感品种；MDA在生育中后期，低钾耐性品种明显低于低钾敏感品种。

Photosynthetic characteristics and protective enzyme activities of different low K-tolerance soybean varieties under low potassium stress

Potassium(K) is the most important cation in plants,which plays an important role in plant growth,metabolism and yield.K-deficient soils are common world-wide,and their widespread occurrence in the crop growing regions of northeastern China has been recognized in these years.Nowadays,the occurrence of K deficiency in soybean(Glycine max L.),the most important oil crop in northeastern China,has increased.This paper presents the responses of photosynthetic characteristics and active oxygen metabolism of four ...