适宜氮水平下冬油菜苗期不同叶位叶片光合氮分配特征  

Characteristics of Photosynthetic Nitrogen Allocation in Leaves of Different Positions in Winter Oilseed Rape at Seedling Stage Under Suitable Nitrogen Level

作　　者：刘涛[1] 鲁剑巍[1] 任涛[1] 汪威[1] 王振 王少华 

机构地区：[1]华中农业大学资源与环境学院/农业部长江中下游耕地保育重点实验室,武汉430070 [2]湖北省武穴市农业技术推广中心,湖北武穴435400

出　　处：《中国农业科学》2016年第18期3532-3541,共10页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31471941);国家油菜产业技术体系建设专项(CARS-13)

摘　　要：【目的】探讨适宜氮水平下冬油菜苗期不同叶位叶片的光合速率及其内部光合氮素利用特征,并分析氮素营养影响光合氮利用效率的限制因子,为合理施用氮肥提供理论依据。【方法】采用田间试验,设置4个施氮水平(0、45、180和360 kg·hm^(-2),分别用N_0、N_(45)、N_(180)和N_(360)表示),测定苗期干物质积累及成熟期产量。选取N_0(对照)和N_(180)(适宜氮水平)处理,将植株绿叶从上而下平均分为上部、中部和下部,测定不同叶位叶片最大净光合速率(P_n max)、氮含量(N_A)、叶绿素含量(Cc)以及可溶性蛋白氮含量(N_S)等相关生理、光合参数,并计算叶片氮素在光合组织系统(羧化系统、生物力能学组分和捕光系统)的分配比例,分析叶片氮素利用特征。【结果】施氮对冬油菜增产效果显著,N_(45)、N_(180)和N_(360)较N_0处理增产幅度分别达170.0%、505.6%和604.1%,其中,N_(180)与N_(360)处理产量差异不显著;苗期干物质积累与产量表现一致。与N_0处理相比,N_(180)处理冬油菜不同叶位叶片N_A、Cc和P_n max均显著升高,上部和中部叶片光合氮利用效率(P_NUE)有所下降。光合组织系统氮分配结果表明,N_(180)处理上部、中部叶片,氮素在光合组织系统中羧化系统(P_C)、生物力能学组分(P_B)及捕光系统(P_L)的分配比例均低于N_0处理,但各组分氮含量较N_0处理平均增加幅度分别达到20.6%、11.8%和28.8%。施氮与否对相同叶位叶片可溶性蛋白氮(N_S)与非可溶性蛋白氮(N_(non-S))的比例影响不大,但显著影响光合组织系统在N_S和N_(non-S)中的分配,其中N_0处理各部叶片的羧化系统氮含量(NC)占N_S的比例平均为83.4%,N_(180)处理比例为60.3%。基于边界线分析法定量各光合组织系统分配对P_NUE的影响结果表明,P_C和P_B对P_NUE的影响大小分别为26.8%和42.6%,显著高于P_L的影响。氮素营养对P_NUE的影响以P_C和P_B限制为主,平均所占比例达77.8%�[Objective] This study was carried out to investigate the effects of nitrogen allocation on the photosynthetic apparatus of leaves at different positions in winter oilseed rape under suitable nitrogen level at seedling stage and to analyze the limiting factors that affect the photosynthetic nitrogen use efficiency by nitrogen nutrition, and provide a theoretical basis for the reasonable application of nitrogen fertilizer. [ Method ] A field experiment was carried out with designed four nitrogen levels （0, 45, 180, 360 kg·hm^-2, marked as N0, N45, N180 and N360, respectively）. The dry matter at seedling stage and seed yield were determined. Then the No and N180 treatments were selected, the plant leaves were equally divided into 3 groups （upper, middle and lower） by leaf number from top to bottom. Some physiology and photosynthetic parameters （e.g., net photosynthetic rate （Pn max）, nitrogen content （NA）, chlorophyll content （Cc） and soluble protein nitrogen content （Ns）） tested on leaves at different positions were measured to calculate nitrogen allocation in the photosynthetic apparatus （carboxylation, bioenergetics and light-harvesting components）. [Result] Seed yield was increased significantly by nitrogen fertilization, compared with No treatment, N45, N180 and N360 were increased by 170%, 505.6% and 604.1%, respectively and the dry matter accumulation was consistent with the yield. Compared with No treatment, NA, Cc and Pn max were significantly increased in different leaf positions by nitrogen fertilization, but photosynthetic nitrogen use efficiency （PNUE） has significantly declined in the upper and middle leaves. For nitrogen allocation on the photosynthetic apparatus, the proportion of the carboxylation （Pc）, bioenergetics （PB） and light harvesting system （PL） in the upper and middle leaves of N180 treatment were lower than that of No treatment, but the nitrogen contents of those components were higher than that of No treatment and the increasing extent o

关 键 词：冬油菜 氮素营养 叶位 氮分配 光合氮利用效率 

分 类 号：S565.4[农业科学—作物学]