茄子Pn日变化及光合“午休”的生理生态子分析

以两个品种圆茄（二苠茄和快圆茄）为试材，系统研究了其光合速率（Pn）日变化及影响光合“午休”生理生态因子。结果表明，茄子晴天Pn日变化无论品种是否相同（二苠茄和快圆茄）、生育期是否相同（苗期、初花期和盛果期）、叶位是否相同（上部叶片、中部叶片和底部叶片），无一例外地表现为“双峰”曲线，即有光合“午休”现象存在，只是“午休”的时间和程度上有差异；光合“午休”时气孔导度（Gs）、蒸腾速率（Tr）、细胞间隙CO2浓度（Ci）、大气CO2浓度（Ca）均下降，而光合有效辐射（PAR）和叶片温度（TL）此时几乎处于最大值，茄子光合“午休”是由气孔因素引起的。

The Diurnal Change of Net Photosynthetic Rate and Physiological-ecological Factors of Photosynthetic "Midday Depression" in Eggplant (Solanum melongena L.)

The diurnal change of net photosynthetic rate (Pn) and physiological-ecological factors of photosynthetic "midday depression" in eggplant (Solanum melongena L.) were studied. The results showed that, the diurnal changes of Pn of leaves in eggplant showed a double peak curve (there was a significant "midday depression" at noon), whether of Erming or Kuaiyuan; seedling stage, flowering stage, or fruits growing stage; top leaves, middle part leaves or bottom leaves. But the extent and the time of midday depression were different. The stomatal conductance (Gs), transpiratory rate (Tr), intercellular CO2 concentration (Ci), and air CO2 concentration (Ca) of eggplant leave were decreased when midday depression was happened, but photosynthetic active radiation (PAR) and leaf temperature (TL) were maximum. The reasons of midday depression of eggplant leaves were stomatal factors.