摘要: 为了研究氮素匮乏对小麦光合特性的影响，以中国春，和尚麦，丝籽麦为实验材料，在缺氮处理7，10，14天时，测定小麦幼苗的叶绿素含量，可溶性蛋白的含量，称根冠比以及小麦的光合特性相关指标。结果表明，缺氮处理后小麦叶绿素，可溶性蛋白，光合速率，蒸腾速率，气孔导度均比对照组低，根冠比和胞间CO2比对照高，表明氮素匮乏影响了小麦的叶绿素合成，导致小麦的光合速率降低，干物质积累变少，根冠比升高。氮素是小麦生长的必需元素，本实验为小麦的氮素利用以及生产上的应用提供一定的科学依据。

关键词 小麦； 氮素匮乏； 光合特性

Abstract : In order to research effect of nitrogen deficiency on the photosynthetic characteristics of wheat, this experiment with Chinese Spring wheat, Heshang wheat ,Sizi wheat as test materials.The effects of nitrogen deficiency on chlorophyll content, soluble protein content, root-shoot ratio, photosynthetic rate (Pn) , stomatal conductance(Gs),intercellularCO2(Ci) and transpiration rate(E) for 7d,10d,14d were measured in this paper.The results showed that chlorophyll content, soluble protein content , photosynthetic rate (Pn) , stomatal conductance(Gs),transpiration rate(E)was decreased significantly in wheats under nitrogen deficiency. However ,the root-shoot ratio and intercellularCO2(Ci) of wheat seedling were all improved.Therefore,based on the results, nitrogen deficiency have some effect on chlorophyll biosynthesis. And the net photosynthetic rate (Pn) of wheat decreased significantly,dry matter accumulation was decreased significantly, wheat root-shoot ratio were all improved..Nitrogen  is one of the necessary nutrients for wheats growth . This experiment would provide theoretic basis and technical approach for nitrogen use.

Key Word : Wheat; Nitrogen lack; Photosynthetic characteristics