短期遮光对番茄叶片光合作用的影响

以2个耐弱光能力不同的番茄品种作为试材,研究了短期遮光(遮光率40.97%)对番茄叶片净光合速率及相关参数的影响。结果表明:遮光处理后两个番茄品种净光合速率、气孔导度、胞间CO2浓度下降,遮光处理7d时下降幅度最大,14d时略有上升,耐弱光品种下降幅度小于不耐弱光品种。遮光处理初期气孔限制值升高,遮光21d时与对照差异不显著,说明后期气孔限制不是导致净光合速率降低的主要因素。在遮光条件下,初期的蒸腾能力急剧下降可能与气孔限制有关,气孔的阻力降低了气孔的蒸腾速率。

Effect of Short-term Weak-light on the Photosynthesis of Tomato Leaves

By chosen two tomato breeds that differ in the ability of patience of weak-light as materials, the effect of short-term weak-light (40.97% shading) on net photosynthetic rate and related parameters of tomato leaves was studied. Compared with control group, net photosynthetic rate, stomata conductivity and intercellular CO2 density were decreased. During the shading treatment, the max decreasing extent was in 7day and increased slightly since 14day, the declining extent of weak-light tolerance breed was less than the other. At beginning, the stomata constraint value was raised; there was no obvious difference in 21day of treatment. Stomata constraint at the later stage was not the major factor for net photosynthetic rate decline. Under the shading condition, sharply decreased evaporation ability at the initial stage was possible related to the stomata constraint because of the resistance.