低氧胁迫下氮对樱桃氮代谢的影响.docVIP

摘要吉塞拉5号采用营养液水培方法，研究短期低氧条件对其生理特性的影响，以及氮和钙在樱桃低氧胁迫中的生理功能及其作用机理旨在探讨低氧胁迫对樱桃伤害，寻找克服或缓解低氧伤害的方法为樱桃栽培管理提供依据。低氧加氮处理减轻低氧伤害硝酸还原酶的代谢有密切的关系。低氧加氮使代谢原料充足，保证了各类酶的合成脯氨酸含量NR活性升高，能不断将硝酸盐还原，电子传递，活性氧水平和MDA含量SOD、POD、CAT）活性，缓解了对线粒体及各类膜系统的伤害，同时又生成各类中间产物为合成代谢提供了原料；GS、NADH－GDHNH4＋22.5mmol·L-1的处理效果好于15mmol·L-1的处理。低氧缺氮处理各指标与之变化相反。 关键词：樱桃砧木；低氧胁迫；氮；氮代谢 Abstract The method of controlling dissolved oxygen concentration in nutrient solution was used to study the effect of hypoxia stress on physiological characteristics of cherry seedlings ( Prunun cerasus×P.canescens). The effect mechanisms of calcium and nitrogen on cherry seedling physiology under hypoxia were studied as well. The main results were as the followings: Exogenous nitrogen application in nutrient solution could relieve hypoxia stress to cherry seedling, which maybe owing to the increase of NR activity. The materials for plant metabolizing were abundant and the synthesis of some enzymes was ensured; The content of chlorophyll, photosynthesis rate, soluble protein and proline content increased. The electron transfer was promoted, the ROS and MDA content decreased, and the activities of protective enzymes (SOD, POD, CAT) increased, as a result, the harm to mitochondria and membrane was relieved. The activities of NR and GS increased, which resulting in the decline of ammonium harm. Application 22.5 mmol·L-1 NO3－ in nutrient solution was better than at 15 mmol·L-1. However, the effect of nitrogen deficient treatment had the opposite result. Key words: Prunun. cerasus×P. canescens; Hypoxia stress; Nitrogen; Nitrogen Metabolism 低氧胁迫是指植物根际O2浓度降低，使植物根系暂时或长期处于低氧（hypoxia）或无氧（anoxia）状态，影响了植物正常生理代谢和生长发育，甚至导致死亡的逆境。研究表明在缺氧条件下，反硝化作用增强，土壤中的氮素损失严重低氧胁迫会降低植物对氮素的吸收利用效率（沈阿林等，1997；Zhou et al.，1997）。国内有关低氧胁迫对作物影响的研究近几年刚刚开始，研究对象多集中在部分蔬菜和农作物（汪天等，2005）。樱桃是经济效益较高的果树，但十分不耐，由于降雨不均、果园排水不良等原因十分严重的经济损失（韩文璞等，2004）。目前，有关果树低氧胁迫的研究。本文以樱桃组培苗采用营养液水培的方法，研究短期低氧对其的影响，以及氮在樱桃低氧胁迫中的生理功能及其作用机理，旨在探讨低氧胁迫对樱桃伤害机，寻找克服或缓解低氧伤害的方法为樱桃栽培管理提供理论依据。1.材料培养与处理 供试材料为樱桃‘吉塞拉5号’（Gisela 5）组培幼苗温室内，