基于五水转化装置的玉米光合特性分析

利用中国科学院地理科学与资源研究所“五水转化动力过程实验装置”，开展温室条件下玉米净光合速率及其关键影响因子的实验观测研究，探索玉米各生育阶段、植株各叶位叶片净光合速率的分布特征及其与叶片生理生态参数的关联性。结果表明：玉米全生育期内叶片净光合速率、叶绿素含量、气孔导度和氮含量均呈单峰曲线型变化趋势，但净光合速率峰值出现时间在乳熟期，比前人观测的大田峰值出现时间（抽雄吐丝期）晚一个生育期，且数值较低；净光合速率与叶绿素含量、气孔导度随叶位的变化大体呈现中间叶位高、基部与顶端叶位低的分布特征。各生育阶段玉米净光合速率与叶绿素含量间的相关系数最高（R=0.94，P＜0.05），其次为净光合速率与叶片N含量的相关性及其与气孔导度的相关性（R=0.77，P＜0.05）；各叶位净光合速率与气孔导度的变化特征一致。该装置更适合进行气候变化、水分变化、养分变化等控制实验研究。

Analysis on Photosynthetic Characteristics of Maize Growth in “Water Transformation Dynamical Processes Experimental Device”

The influencing factors of leaf net photosynthetic rate (Pn) in different growth stages and leaf position under greenhouse condition were studied by analyzing the dynamic characteristic of photosynthetic characteristic and the correlation between Pn and the eco-physiological factors based on the “Water Transformation Dynamical Processes Experimental Device” (WATDPED). The results showed that there was only one peak of the variations of Pn, chlorophyll content (chl), stomatal conductance (Gs), N content (N) during the growth period. However, the maximum value of Pn, appeared in milk stage, was lower and one growth stage later than the previous research results of fields (the tasseling and silking stage). The Pn, chl and Gs showed higher value in middle leaf positions than in other leaf positions. During the growth period, the correlation coefficient between Pn and chl was the highest (0.94, P<0.05), followed by the coefficient between Pn and N and that between Pn and Gs (0.77, P<0.05). The variation of Pn in different leaf position was similar to that of Gs. The device is more suitable to be used to conduct some control experiment studying the influence of climate change, water and nutrient stress on the crops or ecosystems.