为了解小麦和谷子叶片中C4光合途径关键酶磷酸烯醇式丙酮酸羧化酶(PEPC)、NADP-苹果酸酶(NADP-ME)、磷酸丙酮酸二激酶(PPDK)和苹果酸脱氢酶(MDH)的活性差异及其与光合速率和蒸腾速率的关系,以4个小麦品种(中国春、晋麦47、绵阳11、小偃6号)和4个谷子品种(豫谷1号、吨谷1号、冀谷19、冀谷20)为材料,在苗期、拔节期、抽穗期、开花期和灌浆期,分别测定了小麦和谷子叶片中四种光合酶的活性、净光合速率和蒸腾速率。结果表明,在小麦生育期,叶片中均可检测到这四种光合酶的活性,且酶活性与净光合速率变化趋势一致;谷子叶片中四种光合酶活性均远高于小麦;不同小麦和谷子品种间四种光合酶活性存在显著差异。小麦的PPDK和NADP-ME活性均与净光合速率呈显著正相关,与蒸腾速率相关不显著;谷子的MDH、PEPC和PPDK活性均与净光合速率呈显著正相关,仅豫谷1号的PEPC活性、冀谷20和吨谷1号的MDH活性与蒸腾速率呈显著正相关。 In order to understand the key enzymes phosphoenolpyruvate carboxylase (PEPC), NADP-malic enzyme (NADP-ME), phosphorylated pyruvate dikinase (PPDK) and malate dehydrogenase (China Spring, Jinmai 47, Mianyang 11 and Xiaoyan 6) and four millet varieties (Yugu 1, Tt Valley 1, Ji Gu 19, Ji Gu 20) were used as materials to measure the activities of four photosynthetic enzymes, net photosynthetic rate and transpiration in leaves of wheat and millet at seedling stage, jointing stage, heading stage, flowering stage and filling stage respectively. rate. The results showed that the activity of these four photosynthetic enzymes was detected in the leaves of wheat during the growth period, and the changes of enzyme activity and net photosynthetic rate were the same. The activities of all four photosynthetic enzymes in the leaves of millet were much higher than those of wheat. There were significant differences among the four photosynthetic enzyme activities in millet varieties. The activities of PPDK and NADP-ME in wheat were significantly and positively correlated with the net photosynthetic rate but not significantly with the transpiration rate. The activities of MDH, PEPC and PPDK in millet were significantly and positively correlated with net photosynthetic rate. Only PEPC activity in Yugu 1 There was a significant positive correlation between MDH activity and transpiration rate in Ji Gu 20 and Tang Gu 1.