摘要:为明确镁对小麦(Triticum astivum L.)花后高温胁迫的缓解机理,本研究采用盆栽试验和人工气候室模拟增温的方法,研究孕穗期施镁(0、20 kg•hm-2)对灌浆期不同时段(花后14-20天、花后21-27天,分别以T1、T2表示,昼/夜32/22℃)高温胁迫下小麦产量和碳氮代谢的影响。结果表明,相同温度的高温胁迫下,施镁处理较不施镁处理在旗叶净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)等方面得到了显著的提高,而胞间CO2浓度(Ci)降低;在氮、碳代谢方面,旗叶氮含量及硝酸还原酶(NR)和谷氨酰胺合成酶(GS)活性,可溶性糖含量、旗叶磷酸蔗糖合成酶(SPS)活性、籽粒蔗糖含量和蔗糖合成酶(SS)活性均显著提高;进而而提高籽粒的千粒重和产量。因此,施镁能够协调小麦源库的碳氮代谢平衡,显著减轻高温胁迫的伤害,增加小麦的抗逆性,从而有利于籽粒产量的形成。28127 毕业论文关键词:小麦;镁;高温胁迫;碳氮代谢;产量
Effects of magnesium on carbon and nitrogen metabolism and yield of wheat exposed to high temperature stress
Abstract: In order to clarify the remission mechanism of magnesium exposed to post-anthesis high temperature stress in wheat(Triticum astivum L.), pot experiment and artificial climate chamber were used to simulate temperature increasing. The effects of magnesium application (0,20 kg•hm-2)at booting stage on yield and carbon and nitrogen metabolism of wheat under different temperature stress during grain filling stage(14-20 days after flower, 21-27 days after flower, T1 and T2 respectively, day / night 32/22℃) were studied. The results show that under high temperature stress, magnesium fertilizer treatment than the same temperature without applying magnesium treatment significantly increased the net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr) decreased, intercellular CO2 concentration (Ci). The nitrogen content and nitrate reductase (NR) and glutamine synthetase (GS) activity, soluble sugar content and flag leaf sucrose phosphate synthase (SPS) activity were significantly increased in nitrogen and carbon metabolism. It was also found that the sucrose content and sucrose synthase (SS) activity were significantly increased, which affected the grain weight and the yield.Therefore, the application of magnesium can coordinate the balance of carbon and nitrogen metabolism of wheat source sink, significantly reduce the damage of high temperature stress, increase the stress resistance of wheat, which is conducive to the formation of grain yield.
Key words: wheat; magnesium; high temperature stress; carbon and nitrogen metabolism; yield
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