氮肥调控对川麦39灌浆期旗叶光合特性的影响

为明确氮肥调控对小麦光合作用的影响。采用盆栽试验研究了氮肥调控对川麦39灌浆期旗叶光合特性日变化及其相互关系的影响。结果表明，不同氮肥水平及不同追氮时期和比例处理下川麦39光合特性日变化曲线不同。随着施氮量的增加和氮肥后移，川麦39旗叶净光合速率的平均值和峰值呈先升高后降低的趋势，川麦39旗叶净光合速率的平均值和峰值均以施氮180kg／hm。最高，且各个氮肥处理的上午净光合速率平均值均显著高于下午的。通径分析表明，中、低氮水平和氮肥后移影响净光合速率主要是由于蒸腾失水严重．高氨水平和氮肥前移影响净光合速率主要是由于相对湿度过大、叶片肥厚使得蒸腾作用减弱。

Effect of N on Flag Leaf Photosynthetic Characteristics during Grain Filling in Chuanmai 39

The effects of different N amount, N applicution stages, and proportion on the diurnal variation of leaf photosynthetic characteristics and their interaction were studied in a pot experiment. The diurnal variation curves of photosynthetic characteristics were different in Chuanmai 39 with different N amounts and application stages. Photosynthetic rate and peak value in Chuanmai 39 increased an then decreased with the increase of N amounts and postponing at the 180 kg/hmz of N amounts. Photosynthetic rates always were higher in the morning than in afternoon for all N amounts and application stages. Path analysis showed that the transpiration is higher at low, middle amounts of N application stages; and postponing of N application stages; and transpiration is lower at high amounts of N and advancing of N application stages.