钾肥对灌浆期冬小麦群体内叶片光合特性的影响

通过在连续6年施钾与不施钾处理的试验区内,对冬小麦(Triticum aestivum)灌浆期群体内旗叶叶片光合特性的研究表明,施用钾肥时,最大净光合速率(Pmax)增加,光饱和点(LSP)和光补偿点(LCP)提高,表观量子效率(α)降低,表观暗呼吸速率(Rd)略有上升;施钾与不施钾处理的净光合速率(Pn)日变化,晴天和阴天均呈单峰曲线,晴天午前与午后及阴天各时刻的瞬间净光合速率(Pn)下降的主要原因是“气孔因素”,而晴天中午前后则更主要是由于“非气孔因素”作用.

Effect of potassium fertilization on the photosynthetic characteristics of the leaf of winter wheat population during its grain filling stage

Six years field trials with or without potassium application showed that under potassium application,the maximum photosynthetic rate (Pmax),light saturation point (LSP) and light compensation point (LCP) of the flag leaf of winter wheat during its grain filling stage increased, the apparent photon utilization efficiency(α) decreased, and the dark respiration rate (Rd) increased slightly. For the daily variation of net photosynthetic rate(Pn) of winter wheat with and without potassium application, it appears a single peak curve, whether the weather condition was sunny or cloudy. "Stomatal factor" was the main cause of the decrease of net photosynthetic rate (Pn) in the beforenoon and afternoon of sunny days and in the whole day of cloudy days, while "non stomatal factor" was the main cause for the decrease of Pn around midday in sunny days.