裸燕麦不同生育时期对干旱胁迫后复水的响应

为给裸燕麦(Avena nuda L.)高效节水生产提供理论和技术支持,在温室盆栽条件下,研究了裸燕麦持续性干旱胁迫后不同生育时期复水的生理响应。结果表明,拔节-抽穗期内复水较正常供水处理显著(P<0.05)提高株高6.57%～7.67%,其他时期复水株高与正常供水处理差异不显著(P>0.05);拔节-孕穗期和抽穗-灌浆期内复水,裸燕麦功能叶片净光合速率(Pn)、气孔导度(Ci)、胞间CO2浓度(Gs)和蒸腾速率(Tr)等光合参数均表现出补偿或超补偿效应,灌浆期后复水无法恢复叶片正常光合能力;拔节期、孕穗期、抽穗期和灌浆期复水,较持续干旱胁迫处理显著提高裸燕麦籽粒产量,产量增幅分别为14.29%、152.38%、66.67%和32.80%;孕穗-灌浆期复水有利于提高灌溉水利用效率。说明裸燕麦持续干旱胁迫后孕穗期和抽穗期复水对植株生长、功能叶片光合能力和产量的补偿效应明显,有利于灌溉水高效利用。

Response to Water Stress and Re watering of Oat at Different Growth Stages

Pot experiment was carried out on naked oat(Avena nuda L) cv Baiyan 2,a major cultivated variety in the semiarid areas of northeast China,to study the response of oat in photosynthetic characteristics and other physiological parameters to water stress and re-watering.The results showed that the height of oat plant was significantly(P<0.05) higher with rewatering at the stages of jointing and booting than that under the well-watered treatment by 6.57% to 7.67%,respectively,while,there were no significant differences in re-watering at other stages.Photosynthetic parameters of net photosynthesis rate(Pn),stomatal conductance(Ci),intercellular CO2 concentration(Gs) and transpiration rate(Tr) showed good physiological compensation effects with re-watering at jointing stage and heading stage after serious water stress,whereas photosynthetic parameters scarcely recovered by re-watering after grain filling stage.The kernel yield was enhanced than the water stress treatment by 14.29%,152.38%,66.67% and 32.80% for re-watering at the stages of jointing,booting,heading and filling,respectively.It was an advantage for improving irrigated water use efficiency by re-water between booting and heading stages.These results suggested that oat under the continuous water stress gain the better physiological compensation effects on growth,photosynthesis and yield by re-watering at booting and heading stages.