增铵营养对低温胁迫下棉花幼苗氮代谢的影响  

Effects of enhancing ammonium nutrition on the nitrogenous metabolisms of cotton seedlings grown hydroponically under low-temperature stress

作　　者：张淑英[1] 褚贵新[1] 梁永超[1,2] ZHANG Shu-ying CHU Gui-xin LIANG Yong-chao(College of Agronomy, Shihezi University, Shihezi, Xinjiang 832000, China College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China)

机构地区：[1]石河子大学农学院,新疆石河子832000 [2]浙江大学环境与资源学院,浙江杭州10058

出　　处：《植物营养与肥料学报》2017年第4期983-990,共8页Journal of Plant Nutrition and Fertilizers

基　　金：教育部重大项目培育基金(707057)资助

摘　　要：【目的】探明增铵营养提高棉花幼苗抗低温胁迫能力的机制。【方法】以棉花‘新陆早13号’为供试品种,在人工气候室内模拟不同温度处理(15℃和25℃),研究了不同铵硝态氮配比(NH_4^+-N/NO_3~–-N分别为0/100、25/75、50/50、75/25、100/0)对低温(15℃)胁迫下棉花苗期生长、氮素吸收量及氮代谢相关酶活性的影响。【结果】常温条件(25℃)下,较单一铵、硝营养,铵硝混合营养显著提高棉苗各器官的生物量,地上部和根系干物质量在NH_4^+-N/NO_3~–-N比为50/50处理时最大,单一铵营养处理时最小;对棉苗生物量的影响效果表现出铵硝混合营养处理优于单一铵、硝营养处理。低温胁迫(15℃)后棉苗各器官生物量减小,且差异显著。常温和低温条件下,随着营养液中NH_4^+-N比例增加,棉苗全氮含量逐渐递增,氮素吸收量先升后降;棉苗根系、茎秆及叶柄内硝态氮含量呈明显降低趋势;棉花幼苗叶片NR活性明显减小,相反,GS和GOGAT活性则极显著提高。常温处理下棉苗各器官的氮素累积量显著高于低温胁迫处理,低温抑制了棉苗对硝态氮的吸收,降低NR、GS和GOGAT活性。【结论】低温胁迫下,增铵营养可显著提高氮素养分含量,促进棉苗生长,同时通过提高GS、GOGAT等氮代谢相关酶活性,维持氮代谢平衡,增强棉花幼苗对低温的抗性。[ Objectives ] The aim of this Study was to investigate the effects of enhanced ammonium （NH4＋） on the growth and nitrogenous metabolisms of cotton grown hydroponically under low-temperature stress. [ Methods ] Using cotton （Gossypium hirsutum L. cv. Xinluzaol3） as the experimental material, we studied the influences of the different ammoniarn/nitrate ratios （NH4^-N/NO3--N of 0/100, 25/75, 50/50, 75/25, 100/0） on the growth, nitrogen uptake and accumulation, NO3 concentration, and the activities of nitrate reductase （NR）, glutamine synthetase （GS） and glutamine 2-oxyoglutarate aminotransferase （GOGAT） activity in cotton seedlings grown in a growth chamber under low-temperature stress （15 ~C）. [ Results ] The combined supply of ammoniam with nitrate significantly enhanced （P 〈 0.05） the biomass of different organs of cotton grown under the normal condition （25 ~2）. The dry matter yields of both shoots and roots were the biggest at the ammoniam/nitrate ratio of 50/50 and the smallest at the ammoniam/nitrate ratio of 100/0. The biomass of different organs of cotton was significantly decreased under low temperature （15 ~2）. Nitrogen concentrations and the activities of GS and GOGAT increased with increasing of NH4＋/NO3 ratios, but nitrogen accumulation increased firstly and then decreased in cotton seedlings grown under either normal or low temperature. The nitrate concentration in different organs of cotton seedlings, together with NR activity of cotton leaves decreased under either normal or low temperature. Nitrogen accumulation of cotton seedlings, nitrate concentration, and NR, GS and GOGAT activities decreased significantly under low-temperature stress. [ Conclusions ] The combined supply of ammoniam with nitrate could enhance the concentration of nitrogen and NO3--N, and the activities of GS and GOGAT of cotton seedlings, thus maintaining the balance of nitrogenous metabolism and enhancing the plant resistance to low- temperature stress, and the growth and biomass

关 键 词：棉花幼苗 铵硝态氮配比 低温胁迫 氮代谢 

分 类 号：S562[农业科学—作物学]