白天短期不同温、光、CO_2对甜瓜幼苗叶片光合作用的影响

通过光照培养箱准确控制光温环境,对不同温度、光照强度和CO2浓度环境因子组合条件下的甜瓜苗期叶片净光合速率的连续测定,并通过单因素相关性分析温度、光照强度和CO2浓度对叶片光合作用的综合作用。结果表明:在光照强度600μmol·s-1·m-2一定的条件下,温度在12～30℃范围内,叶片净光合速率与温度呈正相关,且在30℃时达到最大值;温度在30～36℃范围内,净光合速率与温度呈负相关;固定CO2浓度为1000μL·L-1,光照强度在70～600μmol·s-1·m-2之间,净光合速率与光照强度呈正相关;在温度一定的条件下,CO2浓度在400～1600μL·L-1范围内,净光合速率与CO2浓度具有很好的正相关性。

Effects of Different Environmental Factors(Temperature, Light Intensity and Carbon Dioxide Concentration)Combination on Melon Leaf Photosynthesis at Seedling Stage

To get the most suitable environmental conditions for melon（Cucumis melo L.）photosynthesis at seedling stage, net photosynthetic rate（Pn）was measured under different environmental factor（temperatures, light intensity and CO2 concentration）combination. Variations of net photosynthetic rate under different environmental factors were analyzed by fixing one environment variable. Effects of temperature, light intensity and CO2 concentration on leaf photosynthesis were discussed by single-factor correlation calculations. The results show that: when the light intensity was fixed at 600 μmol·s^-1·m^-2, the temperature in the range of 12～30 ℃, leaf net photosynthetic rate was positively correlated with temperature, and reached maximum at 30 ℃; while in the temperature range of 30～36℃, the net photosynthetic rate turned into negative correlation; in a fixed CO2 concentration of 1 000 μL·L^-1, light intensity in the range of 70～600 μmol·s^-1·m^-2, leaf net photosynthetic rate was positively correlated with light intensity; under certain conditions of temperature, CO2 concentration in the 400～1 600 μL·L^-1 range, the net photosynthetic rate and CO2 concentration has a very good positive correlation.