氮肥基追比对滴灌冬小麦旗叶光合特性的影响

(目的)为探索小麦滴灌条件下氮肥合适的基追比对冬小麦光合作用的影响,(方法)设置4种不同基追比滴灌处理研究小麦花后旗叶光合特性。(结果结论)研究表明,与对照相比基追比为4:6的处理能显著提高小麦旗叶的SPAD值和叶面积指数,同时提高了小麦的净光合速率(Pn),促进旗叶对胞间二氧化碳(Ci)的同化,增加了气孔导度(Gs),降低了胞间二氧化碳的浓度,提高了蒸腾速率(Tr),保持了相对较高的光合能力。

Effects of Nitrogen Fertilizer Basal-topdressing Ratio on Photosynthesis Characteristics of Winter Wheat Flag Leaf Under Drip Irrigation

To explore the effect of suitable basal-topdressing ratio of nitrogen fertilizer on photosynthesis of winter wheat under drip irrigation,‘Luyuan 502’was used as material, four different basal-topdressing ratio drip irrigation treatments were set up. Leaf area index (LAI), SPAD value, net photosynthetic rate (Pn), intercellular carbon dioxide concentration (Ci), stomatal conductance (Gs) and transpiration rate (Tr) were monitored dynamically. The results showed that, on the 35th days after anthesis, the LAI, SPAD, Pn, Gs and Tr of wheat flag leaves with basal-topdressing ratio of 4:6 was 1.52 times, 2.66 times, 2.57 times, 1.29 times and 1.43 times as much as the control, respectively, but Ci was only 90% of the control. They all were superior to the relative photosynthetic indexes of other treatments. It indicated that the basal-topdressing ratio of 4:6 could significantly improve the net photosynthetic rate, promote the assimilation of intercellular carbon dioxide by flag leaves, increase the stomatal conductance, decrease the concentration of intercellular carbon dioxide, increase the transpiration rate, and keep relatively high photosynthetic characteristics.