摘 要 ：我们在原地测量了840米和2150米两地种植的冬小麦。“凤麦13”苗期、拔节期、抽穗期和灌浆初期的光合作用速率的日变化，光合作用速率对光量子通量密度的反应和 CO2 补偿点。结果表明生育前期（苗期和拔节期）和后期（抽穗期和灌浆初期）光合作用速率的一日内变化形式相反，而且低地种植的冬小麦其光合速率在前期高于高地种植的，后期高地种植的冬小麦有比低地高的光合速率。光饱和点基本相同。光补偿点在生育前期高地小麦比低地小麦低，而后期低地小麦的的光补偿点减低，并低于高地小麦的。高地小麦的光补偿点比较稳定。CO2补偿点高地小麦比低地的较低。并就两地气候条件讨论了上述差异。
Abstract:The authors have measured in situ daily changes in photosynthe-tic rate, its responses to quantum flux density, and CO2 compensation points of wheat plants (Triticum sativum L. c. v. "Fengmai 13" ) grown at both altitude localities of 840m (lowland) and 2150m (highland) during seedling, elongation, heading and early filling stages, respectiyely. The results showed that the feature of daily variation in photosynthetic rate during early growth (seedling and elongation) stages is contrary to that during later growth (head- ing and early filling) stages. During early stages, the photosynthetic rate of winter wheat grown at lowland is higher than at highland. During later stages, on the contrary, the photosynthetic rate of winter wheat grown at highland is higher than at lowland. At the same time, the light saturation point of both