草地早熟禾（Poa pratensis L.）是我国北方应用最多的优良冷季型草坪草。水和氮素是制约其草坪质量的两个重要因素。水分缺乏造成植株氮素吸收和代谢能力下降，同时也易造成土壤氮素淋失。培育高肥效高水效品种是解决问题的重要途径。本研究采用形态、生理和分子生物学等综合技术，结合国有品种资源，探索水氮胁迫下草地早熟禾不同品种氮代谢变化规律及对氮素利用效率的调控机制。主要研究内容有：草地早熟禾形态结构、生长发育及生理代谢响应水氮胁迫对氮代谢及利用效率的影响；谷氨酰胺合成酶基因（GS）和水通道蛋白基因（PpTIP1）表达规律与氮代谢及利用效率的关系及二者在调节氮素合成和转运的功能及机制。综合比较分析筛选出提高草地早熟禾氮素利用效率和节水特性的有效指标。研究成果对丰富植物养分传输和代谢理论以及进一步通过转基因手段改良提高草地早熟禾氮素利用效率具有重要理论和现实意义。

Kentucky bluegrass (Poa pratensis L.) is the most commonly used cool season turfgrass in Northern China, where water and nitrogen(N) are two key factors influencing turf quality. Lack of water leads to reduce N absorption and metabolism and lose soil N. Therefore, cultivating species that has high water and N use efficiency is important to solve this problem. The objectives of this research are to investigate N metabolism and regulation mechanism of different species of Kentucky bluegrass (including native Kentucky bluegrass) under water and N stress, which will be conducted by morphological, physiological, and molecular biological techniques. The research will include water and N stress influence N use efficiency and morphological structure, growth, and physiological metabolism of Kentucky bluegrass response to this stress; the relationship between expression pattern of Glutamine synthetase (GS) gene and aquaporin (PpTIP1) gene and N use efficiency and the mechanism of two genes on N synthesis and transportation. Finally, effective indicators of improving N use efficiency and water saving of Kentucky bluegrass will be screened out after comprehensive comparison of above research. The results will be important to support the theory of plant nutrient transportation and metabolism, as well as to be significant in practice in improving N use efficiency of Kentucky bluegrass further by transgenic technigues.