水稻育种进程中气孔密度的变化规律及其与光合作用的关系

High yield and high efficiency is the main target in rice production, and improvement in photosynthesis and photosynthetic nitrogen use efficiency (PNUE) is an effective way to further increase yield potential and nitrogen use efficiency in Rice. Recently, it was demonstrated that high density of small stomata could achieve high stomatal conductance, photosynthesis and PNUE. The objectives of this study are to disclose how stomatal density and the other leaf anatomical traits affect stomatal conductance and photosynthesis, and elucidate the influences of stomatal density on grain yield potential and nitrogen use efficiency. Rice varieties and combinations released in different decades since 1930s were used in this study. We will measure stomatal traits, leaf anatomy, leaf N content, leaf photosynthetic traits, grain yield and biomass accumulation. In this study, we will examine: (1) the effect of breeding history on stomatal density in Rice; (2) the relationship between stomatal density and the other leaf anatomical traits; (3) the effect of stomatal density on photosynthesis and PNUE; (4) the relationship between stomatal density and dry matter production and nitrogen use efficiency for biomass. Our study will provide theoretical foundation for high-yield and high-efficiency breeding and crop management in Rice.

高产高效是我国水稻生产的主要目标，提高叶片光合速率和光合氮素利用效率是提高水稻产量潜力和氮素利用效率的有效途径。近期一些研究表明高密度的小气孔可以增加植物叶片的最大气孔导度，并加快气孔的开闭速率，有利于提高叶片的光合速率和光合氮素利用效率。本研究以我国20世纪30年代以来的主推水稻品种为试验材料，通过测定叶片的气孔特征、叶片结构、叶片氮素含量、叶片光合参数以及成熟期产量和干物质积累量等指标来研究：（1）我国水稻育种进程对叶片气孔密度的影响；（2）气孔密度与其它叶片结构参数的关系；（3）气孔密度对光合速率及光合氮素利用效率的影响；（4）气孔密度与水稻干物质生产和氮素干物质生产效率的关系。本研究旨在揭示气孔密度与其它叶片结构参数如何协调影响气孔导度和光合速率；阐明气孔密度对提高水稻产量潜力和氮素利用效率的重要性。本研究将为水稻高产高效育种和栽培管理提供理论支持。