摘要：氮素能显著影响水稻的抗倒伏能力，水稻抗倒伏能力与其茎秆的机械强度有密切联系，茎秆机械强度则与茎秆内部的结构性碳水化合物含量相关，其中木质素是有着基础性作用的主要物质之一。本文以两个粳稻品种武运粳23号和W3668为试验材料，设置两个水平0 kg ha-1（低氮）、180kg ha-1（高氮）的氮素穗肥处理，研究氮素对水稻茎秆木质素的影响以及调控水稻茎秆木质素形成的生理机制。通过对不同氮素处理下水稻茎秆力学特性、形态学指标和生理学指标的差异分析发现，过量施氮会抑制茎秆中木质素的合成；其机理是施氮使植株氮代谢旺盛，叶片中光合产物被大量消耗来合成蛋白质，从而导致转运到茎秆中的碳降低，依托大量碳水化合物合成的木质素含量也相应地减少，茎秆机械强度降低。26612
毕业论文关键词：氮素；水稻；茎秆；木质素；生理机制
The Physiological Mechanism of Nitrogen Fertilizer  of Lignin Biosynthesis in Rice stems
Abstract：Nitrogen could significantly affect the lodging resistance of rice, and rice lodging resistance is closely related with mechanical strength of its stem. Mechanical strength of stem is related to the structural carbohydrate content in it, and the lignin is one of the main materials that have fundamental influences.        The experiments were conducted by using two varieties of japonica rice Wuyunjing23 and W3668. It set 0 kg ha-1 (low nitrogen), 180 kg ha-1 (high nitrogen ) of panicle nitrogen fertilizer treatment to study the effect of nitrogen on rice stem lignin and the physiological mechanism of regulating the rice stem lignin formation. According to analyse the differences of mechanical properties, morphological indices and  physiology indicators under different nitrogen treatments, the experiment results show that excessive nitrogen can inhibit the synthesis of lignin in stem. Its mechanism is that nitrogen makes nitrogen metabolism of rice vigorous, then a large number of photosynthate in leaves is consumed to  synthesize proteins, and it reduce the carbon which transports to stems. The content of lignin in stems also decreased because lignin is compounded with carbohydrate, and it reduces the lodging resistance of stems.
Key words: nitrogen；rice；stem；lignin；physiological mechanism
目  录
摘要1
关键词1
Abstract1
Key words1
引言1
1材料与方法2
1.1试验材料与设计2
1.2 测定项目 2
1.2.1氮素差异调控水稻茎秆木质素形成试验2
1.2.2氮素处理下碳水化合物从叶片到茎秆的转运研究2
1.3测定方法2
1.3.1抗倒伏力学指标测定2
1.3.2非结构性碳水化合物2
1.3.3木质素含量测定3
1.3.4蔗糖含量测定3
1.3.5氮含量测定3
1.3.6扫描电镜观察3
1.3.7木质素染色切片3
1.3.8基因表达3
1.4统计分析方法3
2结果与分析3
2.1氮素对抽穗后20天水稻植株表型的影响3
2.2氮素对水稻茎秆机械强度的影响 4
2.2.1氮素对水稻茎秆力学指标的影响4
2.2.2氮素对水稻茎秆次生壁积累的影响 5
2.3氮素对水稻茎秆木质素的影响 6
2.3.1不同氮素处理下茎秆木质素染色切片的观察6
2.3.2氮素对水稻茎秆木质素含量的影响6
2.3.3氮素对木质素合成基因表达的影响 7
2.4氮素对水稻光合作用的影响 7
2.5氮素对水稻植株中物质组成的影响 8
2.5.1氮素对叶片和茎秆中非结构性碳水化合物含量的影响 8
2.5.2氮素对叶片和茎秆中氮含量的影响 9
2.5.3氮素对叶片和茎秆中蔗糖含量的影响 10
2.5.4氮素对叶片和茎秆中蔗糖转运基因的影响 11
3讨论12
3.1木质素对水稻茎秆机械强度起关键作用 12   3.2氮素调控茎秆木质素形成的生理机制12 氮素调控水稻茎秆木质素形成的生理机制:http://www.751com.cn/shengwu/lunwen_20845.html