【作者】 张洋；

【导师】 翟丙年；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2010， 硕士

【摘要】 水分不足和养分亏缺是限制我国旱地农业发展的关键因素,然而有限的水肥资源也未得到充分利用。因此,提高旱地作物水肥利用效率便成为研究和追求的目标。在诸多的方法和途径中,充分利用作物自身的遗传特性,挖掘自身利用养分和水分的潜力,选育水分和养分高效利用的基因型品种,扩大其种植面积,是缓解水资源短缺、养分不足和提高作物产量的有效途径。目前,关于基因型筛选的报道已有很多,但关于基因型差异的生理机制尚不十分清楚。本文在前期研究工作的基础上,选择冬小麦不同水氮效率基因型小偃22号和小偃6号,通过水培和田间小区试验,从生理代谢、干物质积累和碳、氮分配规律等多方面探讨其差异的内在机制,进一步分析水氮高效的形成机制,为充分利用遗传特性提高作物水氮利用效率及培育水氮高效利用基因型品种提供理论依据。得出以下主要结论:1、施氮可以显著提高冬小麦的有效穗数,穗粒数和千粒重,且施氮对小偃22的增产效果更加明显。就产量构成要素而言,有效穗数对小偃6号的籽粒产量影响较大,千粒重和穗粒数对小偃22的籽粒产量贡献较大。2、施氮可以显著提高两种冬小麦的水分利用效率和氮素吸收利用效率,且在150 kg/hm2施氮处理下保持在较高水平;就两个基因型品种而言,小偃22的水氮利用效率显著高于小偃6号。3、介质供氮显著提高了冠层干重、叶片相对含水量、根系活力、叶片叶绿素含量及地上部、地下部的含氮量;不施氮处理下,硝酸还原酶活性、叶水势、叶绿素含量明显降低,而施氮后可以明显提高;叶水势、叶绿素含量在150 kg/hm2施氮处理下保持在较高水平;就选用的两个基因型品种来说,小偃22比小偃6号的生理代谢更加旺盛,施氮增强了这种作用。4、在开花期,不同干物质转运量在不同器官中的分配为“茎>叶>穗”;冬小麦不同器官转移的干物质对子粒的贡献叶片最大,其次是茎,穗部最小;在籽粒灌浆过程中,就选用的两个基因型品种来说,茎、叶、颖壳中可溶性糖含量小偃22高于小偃6号;灌浆前期小偃22的籽粒可溶性糖含量高于小偃6号,灌浆后期则相反;小偃22的全氮含量在灌浆期均高于小偃6号。更多还原

【Abstract】 Water shortage and nutrient deficiency are key factors that restricted crop production in Arid and semiarid areas, limited water and nutrient can’t fully use. Therefore improve the utilization efficiency of water and nutrient have become researching and pursuiting of the goal. Among these ways and approaches, it is an important one in remission the shortage of water and nitrogen resources, and increasing plant yield that exploiting plant descendible characteristics and potential of water and nutrients use, by cultivating or utilizing genotype with high water and nutrition use efficiency. Lots of studies on the screening of genotypes with higher NUE (nitrogen use efficiency) and WUE (water use efficiency) have been reported, but little have been done to understand the physiological mechanism in which winter wheat genotypes can use water and nitrogen efficiently. The experiment were carried out to discuss the difference of the physiological mechanism of different genotypes from metabolism, accumulation of dry matter, carbon and nitrogen transfer et al with two genotypes after having been studying for past several years. The genotype Xiaoyan 22 with high effect high response and the genotype Xiaoyan 6 with low effect low response were screened from local dominating winter wheat varieties. The main results are as follows:1. Canopy dry weight, RWC, root activity,leaf chlorophyll content were significantly increased under nitrogen application; root dry weight increased under nitrogen stress; water stress causing RWC and root activity increased under nitrogen stress;RWC of Xiaoyan 22 was higher than Xiaoyan 6. Xiaoyan 22 with high water and nitrogen use efficiency was more adaptable to water and nitrogen stress than Xiaoyan 6 with low water and nitrogen use efficiency, and physiological metabolism was more vigorous than Xiaoyan 6.2. Ear number, grain number and 1000-grain weight were increased significantly under nitrogen application, yield-increasing effect on Xiaoyan 22 were more apparent under nitrogen application. The results of yield components showed that the yield of Xiaoyan6 mainly dependent on effective spikes, otherwise 1000-grain weight and the number of spikes contribute to that of Xiaoyan 22.3. The net photosynthetic rate of Xiaoyan 22 are higher than that of Xiaoyan6 under nitrogen application. With nitrogen application increasing, leaf water use efficiency of Xiaoyan 6 decreased and Xiaoyan 22 decreased after increased at N150 treatment. The two genotypes winter wheat group water use efficiency increased under nitrogen treatment, and Xiaoyan 22 are higher than Xiaoyan6.4. The yield, nitrate reductase enzyme activity, leaf water potential and chlorophyll content were reduced significantly under no nitrogen application. But under the condition of nitrogen application, they were significantly increased. Leaf water potential and chlorophyll content of winter wheat leaf could be kept at the high level at 150 kg/hm2 nitrogen application. As far as two kinds of genotypes, the physiological activity of Xiaoyan 22 was more exuberant than Xiaoyan 6, nitrogen application strengthened this function.5. In the process of grain filling, stem, glume and grain soluble sugar content have the trend of slow- fast- slow; leaf soluble sugar content in nitrogen treatment have the trend of reduce-elevate, and in none-nitrogen treatment have the tread of reduce- elevate-reduce. Total nitrogen content of stem, leaf, grain have the trend of reduce- elevate, and glume total nitrogen content have the trend of reduce- elevate-reduce. Total nitrogen content of different winter wheat organ maintain in high level under 150 kg/hm2 nitrogen application. As two kind of different varieties, stem, leaf, glume soluble sugar content of Xiaoyan 22 are higher than Xiaoyan 6; Xiaoyan 22 grain soluble sugar content are higher than Xiaoyan 6 at earlier filling stage, Xiaoyan 22 grain soluble sugar content are lower than Xiaoyan 6 at late filling stage; total nitrogen content of Xiaoyan 22 are higher than Xiaoyan 6 in filling stage.更多还原