水氮处理对燕麦功能叶衰老及产量的影响

为给燕麦高产栽培中水氮管理提供依据,在防雨棚肥水控制条件下,研究了水氮处理对燕麦不同生育期叶片超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、可溶性蛋白含量等生理指标及产量的影响。结果表明,水氮及其互作对燕麦叶片各生育期生理指标影响显著(P<0.05)或极显著(P<0.01)。在水分胁迫条件下,适量施氮可使整个生育期保持较高的叶片SOD活性、可溶性蛋白含量、叶绿素含量及较低的MDA含量,延缓功能叶片衰老,增加燕麦产量;过量施氮会加剧燕麦的水分胁迫效应,导致叶片SOD活性、可溶性蛋白含量、叶绿素含量下降,提高MDA含量,加快叶片衰老,降低产量。在供水较充足的条件下,施氮明显提高叶片SOD活性、可溶性蛋白含量和叶绿素含量,降低MDA含量,使叶片衰老进程变缓,产量大幅增加,但当施氮量达到180kg.hm-2时,肥效下降。

Effects of Water and Nitrogen on Senescence Related Physiological Indexes of Functional Leaves and Yield of Oat

To understand the effects of water and nitrogen on physiological indexes and yield of oat,the leaf senescence related physiological indexes such as SOD activity,MDA content and soluble protein content of flag leaves at different stages,and yield of oat were examined in the controlled condition. The result showed that the interaction of water and nitrogen on leaf senescence related index of oat were restricted by soil moisture. In water stress conditions of W1 and W2,a moderate amount of nitrogen could keep higher SOD activity in the whole growth period,prevent the peroxidation of membrane lipid effectively,reduce the contents of MDA,soluble protein and chlorophyll,delay the aging of cell and improve the adaptability of oat to water stress . While increasing the amount of nitrogen,the effect of nitrogen fertilizer is negative,it could reduce SOD activity and the contents of soluble protein and chlorophyll,increase MDA content,as a result,speeding up the leaf senescence and reducing the yield. In the W3 conditions,nitrogen application could improve the SOD activity,and the contents of soluble protein and chlorophyll obviously,reduce the MDA content,finally delayed the leaf senescence and improved oat yield substantially. When nitrogen amount was up to 180 kg·hm^-2,the effects of nitrogen fertilizer reduced. The influence of water and nitrogen on senescence related physiological indexes at different growth periods and yield of oats were at significant or very significant levels,and the interactions between water and nitrogen were very significant.