小麦叶片光合速率对光温水的反应

RESPONSES OF LEAF NET PHOTOSYNTHETIC RATE OF WHEAT TO LIGHT,TEMPERATURE AND SOIL WATER CONTENT

对来自不同生态条件下１０个小麦品种的观测表明，各种条件下叶片光合速率品种间均有差异。叶片光合速率对光强、温度、土壤水分变化的反应明显不同。土壤含水量为５．２％时，叶片光合速率呈负值或接近零。短期土壤干旱后复水，叶片光合速率可恢复近原水平。随土壤干旱加剧，叶片暗呼吸速率增加。

The Photosynthetic characteristics of ten varieties of wheat collected from different ecological zones were studied.Leaf net photosynthetic rates had significant differences among the varieties under normal cultural conditions.Responses of leaf net photosynthetic rate of the ten varieties of wheat to light,temperature and change of soil water content were different,either.Leaf net photosynthetic rate decreaded greatly as the soil water stress incerased.The leaf net photosynthetic rates of all the varieties were near zero or became negative,when the soil water content was about 5.5%. Leaf net photosynthetic rate could recover to their normal values when water was irrigated after short periods of soil water stress.Leaf dark respiration rate increased with short periods of soil water stress,which also had differences among the ten varietis of wheat.