中文摘要：

采用盆栽试验研究了土壤饱和含水量为100%、70%、60%及40%条件下,异株荨麻的光合作用—光响应特性。结果表明：非直角双曲线模型能很好地拟合异株荨麻的光合作用—光响应曲线;净光合速率在同等光合有效辐射时基本上表现为T2〉T3〉T1〉T4;异株荨麻叶片的表观量子效率、最大净光合速率、暗呼吸速率和光饱和点均在适度水分胁迫下达到最大,在重度干旱胁迫下最低,这说明适度水分胁迫有助于提高异株荨麻对光能的利用能力。

英文摘要：

The seedlings of Urtica dioica L.were grown in pots to study the effects of soil water stress on the response of photosynthetic parameters to light intensities.There were four soil water stress treatments： 100%,70%,60% and 40% of saturated soil water holding content.The results showed that light response curves of net photosynthetic rate（Pn） in P.euphratica and P.pruinosa were nonrectangular hyperbola function.At the same PAR,Pn of Urtica dioica L.rate was essentially in the order T2T3T1T4.Under the soil drought stress the values of Pnmax,AQY,LSP and Rday reached the maximum at moderate water stress and the minimum at severe water stress.It reflected that the moderate water stress can help improve the light use capacity of Urtica dioica L.