日光温室甜瓜冠层生态因子及光合作用日变化研究

Study on diurnal changes in ecological factors and photosynthesis in greenhouse-grown muskmelon

以伊丽莎白、银岭为试材,探讨了兰州地区春季日光温室条件下立体栽培甜瓜冠层的光合速率及环境因子日变化规律．结果表明:春季日光温室甜瓜冠层光合有效辐射明显低于相同生育期的露地正茬甜瓜冠层,湿度高于露地甜瓜．除上午通风前外,冠层CO_2高于露地环境．温室甜瓜冠层净光合速率和蒸腾速率日变化均呈单峰曲线型,没有明显的午休现象．但2个品种单叶光合作用日变化态势不同:伊丽莎白各叶层均表现为单峰型,而银岭部分叶片表现出光合午休现象．温室甜瓜光合生产效率的继续提高主要依赖于冠层光照条件的改善,可通过株行局配置和整枝技术的改良来实现．

Diurnal changes in main ecological factors and canopy photosynthesis were determined on two greenhouse-grown muskmelon cultivars, Yinling and Elizabeth. The results showed that the available photosynthetic radiation for muskmelon canopy in greenhouse was remarkably lower, air humidity was much higher, air temperature was slightly lower, while CO2 concentration was more changeable compared with those in the open field＂ at the fruiting stage. Net photosynthetic rate of greenhouse-grown muskmelon canopy showed no evidence of midday depression. Difference existed between the two cultivars in daily photosynthetic dynamics at individual leaf level. The improvement of muskmelon photosynthetic production in greenhouse depends mainly on light situation in the canopy, which can be modified through density regulation and plant pruning.