氮和钾施用量对烟草光合特性的影响

以云烟202为试材,通过盆栽方法,研究了氮、钾肥施用量对烟草叶片光合特性的影响.结果表明:随着氮、钾肥施用量的增加,烟草叶片的表观量子效率(α)、最大净光合速率(Pmax)、表观暗呼吸速率(Rd)、光补偿点(LCP)及光饱和点(LSP)等光合特性参数均有所提高.在弱光条件下,高氮处理能有效提高烟草叶片的光合速率,低钾处理使烟草叶片更容易达到最大净光合速率.不同氮、钾肥施用量条件下,烟草叶片光合速率下降的主要原因是气孔因素限制;能提高光合速率的肥料处理均有利于提高烟草叶片的水分利用率(WUE).

Effects of different nitrogen and potassium on photosynthetic characteristics of tobacco

A variety,Yunyan 202,was used as plant material in this paper to study effects of different nitrogen and potash fertilizer treatments on tobacco leaves,photosynthetic characteristics and parameters by pot-planting. The results showed that:the apparent quantum efficiency(α),maximum net photosynthetic rate(Pmax), the apparent dark respiration rate(Rd),light compensation point(LCP) and light saturation point(LSP) was significantly different under different nitrogen and potassium fertilizer treatments. When nitrogen and potash fertilizer increased, all of these photosynthetic parameters were improved. In low intensity light, high nitrogen treatment could effectively improve the photosynthetic rate of tobacco leaves;on the conditions that other fertilizers of tobacco leaves were enough,tobacco leaves had the maximum Pmax. Under different nitrogen and potassium fertilizer treatments,photosynthetic rate of tobacco leaves decreased mainly because of limitation of stomatal factors;the different fertilizer treatments which improved the photosynthetic rate of tobacco leaves could also improve their water use efficiency(WUE).