水稻开花后叶片含氮量与光合作用的动态变化及其关系

The Dynamic Changes of Nitrogen Content and Photosynthesis and Their Correlations in Pot Rice Leaves after Anthesis

对9个日本栽培水稻品种盆栽植株开花后叶片含氮量与光合作用的动态变化及其关系的研究表明,水稻开花后叶片全氮含量（TNC）、净光合速率（P_n）和氮的光合效率（P_n/N,即P_n与 TNC的比值）呈持续性下降。增施氮肥的植株叶片TNC增加,并延缓P_n和P_n/N的下降。增施氮肥对早熟品种叶片TNC和P_n的促进作用大于中熟品种。水稻品种间叶片TNC的变化较小,P_n和P_n/N的变化较大。随着测定时期的推移,品种间 P_n和 P_n/N的变化增大。水稻开花后叶片P_n下降的百分率大于TNC下降的百分率。 水稻叶片TNC与P_n表现为显著正相关,开花期和乳熟期叶片TNC和P_n的相关程度较黄熟期密切。在同一含氮条件下,乳熟期叶片P_n高于黄熟期叶片。

The dynamic changes of nitrogen content and photosynthesis and their correlations were investigated in pot rice leaves after anthesis. The main results are as follows:Total nitrogen content (TNC), net photosynthetic rate (Pn) and photosynthesis based on nitrogen content (Pn / N) were persistently decreased in rice leaves of no nitrogen top-dressing. But, if nitrogen top-dressed, TNC was increased, and high Pn and Pn / N were maintained. Early varieties showed more increase in TNC and Pn than middle varieties after nitrogen top-dressing. The percentage of Pn decline were higher than that of TNC decline. Cultivar difference of Pn and Pn / N is larger than that of TNC. Cultivar difference of Pn and Pn / N were low at anthesis, and it were increased with the advance of leaf senescence.TNC was positively related with Pn in the leaves of rice after anthesis. The correlation of TNC and Pn at milking ripe stage was more close than that at yellow ripe stage.