灌水量及其分配方式对冬小麦水分利用效率、光合特性和产量的影响

Effects of Irrigation Quantity and Irrigation Ways on Water Use Efficiency,Photosynthetic Characters and Yield of Winter Wheat

为给冬小麦合理灌溉提供依据，以冬小麦临抗2号为材料，采用随机区组试验，设置5个等量不等次、等次不等量的灌水处理，研究了灌水量及其分配方式对不同生育时期冬小麦水分利用效率、光合特性和产量性状的影响。结果表明，灌溉对土壤含水量的影响主要在0～60cm土层内，对深层土壤含水量影响较小。灌溉通过影响千粒重来影响产量。抽穗后水分胁迫不利于增加千粒重，灌浆期适度水分胁迫不利于增加产量，但有利于提高水分利用效率，重度水分胁迫使水分利用效率和产量均降低，表明高产与高水分利用效率具有同步性，即在该地区节水600～1500m^3／ha条件下可不减产。各处理随生育进程的推进，光合速率（Pn）逐渐下降，蒸腾速率（Tr）和气孔导度（Gs）的变化因处理而异。抽穗后长期水分胁迫致使Pn明显下降，短期轻度水分胁迫对Pn影响不明显；抽穗后适度的水分胁迫不利于提高Gs和Tr，但水分胁迫后复水可以明显提高Gs和Tr。

In order to provide experimental basis for the dicision making of rational irrigation for different area and different winter wheat cultivars, a field experiment of random design including five differ ent irrigation teratments and different irrigation ways is conducted with wheat cultivars linkang 2; water use efficiency （WUE）, photosynthetic characteristics and yield characters of winter wheat are studied under different irrigation quantity and irrigation ways in this paper, The results showed that the soil moisture contents of the 0 - 60 cm soil layers were obviously affected by different irrigation ways, but the deep soil moisture contents were little affected. The yield is effected by irrigation through effects on 1000 grain weight; the water stress is disadvantage to increase 1000-grain weight after heading stage, the moderate water stress is disadvantage to increase yield but advantage to in crease WUE at grain filling stage, WUE and yield are reduced by heavy water stress at grain filling stage, so the high yield and high WUE was obtained synchronously,thus the yield could not reduce on saving water of 60041 500 m^3/hm^2 at Hexi areas of Gansu. Pn gradually declined with the growth period under different irrigation treatments, the changes of Tr and Gs varied at different irrigation treatments; Pn obviously decreasd following long-term water stress after heading stage, but Pn did not obviously declined after light and short-term water stress;Water stress isn＇t conducive to improving Gs and rr after heading stage, but supplement irrigation can improve Gs and Tr after water stress.