不同营养液浓度对温室黄瓜叶片光合特性的影响

为了探究不同电导率（electrical conductivity，EC）的营养液对温室黄瓜叶片光合特性的影响，该文于2009年10月至2010年7月在江苏大学Venlo型温室中进行试验，采用4种EC值的营养液浇灌黄瓜，对4种EC值条件下温室黄瓜叶片的光合速率、叶绿素荧光、叶绿素含量及产量进行了测定，并对EC对黄瓜叶片叶绿素仪读数、光合速率和最大电子传递速率的影响及其之间的关系进行了分析。研究结果表明，营养液的电导率值对温室黄瓜下部叶片的叶绿素仪读数值、最大光合速率、光能初始利用率和电子传递速率有较大的影响，中部叶、上部叶片的叶绿素仪读数值、最大光合速率、光能初始利用率、电子传递速率和产量在不同处理间无论是秋冬茬还是早春茬均表现为：营养液的电导率为2.5 dS/m和营养液的电导率为2.2 dS/m差异不显著，但显著大于营养液的电导率为1.5 dS/m和营养液的电导率为0.036 dS/m；构建了最大光合速率与叶片叶绿素仪读数值、光能初始利用率与叶片叶绿素仪读数值的关系模型；光合速率与电子传递速率之间呈幂指数函数关系。该研究为通过叶片光合速率进行营养液管理提供了理论依据。

Effect of different electrical conductivity on photosynthetic characteristics of cucumber leaves in greenhouse

In order to study the effect of different electrical conductivity (EC) on leaves photosynthetic characteristics, experiment was conducted in Venlo greenhouse at Jiangsu University from September 10th 2009 to June 30th 2011. In the experiment four kinds of nutrient solution with different EC were use to water cucumber and the EC value were 0.036 dS/m, 1.5, 2.2 and 2.5 dS/m, respectively. Moreover, photosynthesis rate, Chlorophyll fluorescence, Chlorophyll content and production with different EC were measured and relationship between among were analyzed. The result showed that electrical conductivity of nutrient solution had a great effect on value of SPAD, maximum photosynthesis rate, initial light use efficiency and electron transport rate of cucumber lower leaves in greenhouse. No significant difference was found between T3 treatment (EC=2.5 dS/m) and T2 treatment (EC=2.2 dS/m) about value of SPAD, maximum photosynthesis rate, initial light use efficiency, electron transport rate and production of Upper and Middle Leaves, but significantly bigger than T0 treatment (EC=0.036.5 dS/m) and T1 treatment (EC=1.5 dS/m). The experimental model among maximum photosynthesis rate and initial light use efficiency and soil plant analysis development of leaves were established. Relationship between photosynthesis rate and electron transport rate was described to power. This research can provide theoretic foundation to nutrient solution management based on leaves photosynthetic rate.