【作者】 郭改玲；

【导师】 刘克礼； 高聚林；

【作者基本信息】 内蒙古农业大学 ， 作物栽培与耕作学， 2006， 硕士

【摘要】 2003-2005年在内蒙古农业大学教学农场,采用15-1106、新春6号、宁春4号、巴优1号四个小麦品种,研究了小麦衰老进程以及不同氮肥处理对小麦衰老进程的影响,结果如下:小麦开花后旗叶光合速率、叶绿素含量和可溶性蛋白质含量,叶片过氧化氢酶(CAT)活性先缓慢下降,至衰老后期转为快速下降,其变化趋势均可用函数Y=A+BX+CX2(Y为上述各指标,X为开花后天数)进行描述。旗叶丙二醛(MDA)为膜脂过氧化产物,其含量高低反应了细胞膜脂过氧化水平,小麦MDA含量和质膜透性开花后先缓慢升高,衰老后期转为快速升高,变化趋势可用函数Y=AeBX(Y为代谢指标值,X为开花后天数)进行描述。小麦的生长具有同步特性,其叶片衰老的同时籽粒进行灌浆,根据籽粒生长进程的Logistic曲线方程,把籽粒生长进程分成三个阶段:籽粒建成阶段、籽粒线形增重阶段和籽粒缓慢增重阶段。高产条件下,适当加大小麦生育中后期追氮比例,进行氮素调控,可明显提高小麦籽粒形成期叶面积指数和叶面积持续期,有效抑制叶绿素的降解,并使植株体内叶片保护酶(POD、SOD、CAT)保持较高活性,降低生育后期细胞膜脂过氧化水平,从而延缓了功能叶片的衰老,有利于延长籽粒灌浆期与光合产物的形成和积累,提高籽粒产量。更多还原

【Abstract】 The change of senescence process and the effect of different nitrogen application on senescence process in wheat plants were studied with four spring wheat (cv. 15-1106、Xinchun 6、Ningchun 4、Bayou 1) from 2003 to 2005 in the experimental farm of Inner Mongolia Agricultural University. The results were as follows.After anthesis, it was all declined slowly in initial phase and fast in last phase of senescence for photosynthetic rate along with contents of chlorophyll and soluble protein in the flag leaf, and catalase (CAT) activity in leaves. A function of Y=A+BX+CX2, where Y refers to the values of above parameters and X to the days after anthesis. Content of malondialdehyde (MDA) and permeability of plasma membrane in the flag leaf phase changed from slow ascent after anthesis into fast ascent in late phase of senescence, which could be described by a function of Y=A+BX+CX2, where Y refers to the values of metabolic substances and X to the days after anthesis.Grain growth process well fitted to Logistic curve, which could be divided into three phases, i.e. the grain establishment, linear grain in weight and slow grain in weight.Under high-yielding conditions, putting off the stage of nitrogen application and adding later nitrogen application appropriately could increase LAI and LAD during grain filling obviously, suppress chlorophyll degrading, keep the activity of POD,SOD and CAT at high level, and decrease the membrane lipid peroxidation level in later growing stage and this practice could delay the functional leaf senescence, and promote the forming and accumulation of photosynthetic product during grain filling and increase the grain yield.更多还原