干旱胁迫下不同施氮水平对烤烟幼苗光合系统PSⅡ功能的影响  

Effects of different nitrogen rate on the functions of flue-cured tobacco seedlings photosystemⅡ under drought stress

作　　者：金微微[1] 王炎[1] 张会慧[1] 孙广玉[1] 

机构地区：[1]东北林业大学生命科学学院,黑龙江哈尔滨150040

出　　处：《南京农业大学学报》2012年第4期21-26,共6页Journal of Nanjing Agricultural University

基　　金：国家自然科学基金项目(30771746;31070307);黑龙江省烟草专卖局项目(2007;2009)

摘　　要：以烤烟品种‘龙江911’为材料,利用快速叶绿素荧光诱导动力学曲线分析技术(OJIP),探讨干旱胁迫下不同施氮水平(土壤中施纯氮量为0、0.36和0.72 g.kg-1)对移栽后‘龙江911’幼苗叶片光合系统Ⅱ(PSⅡ)功能的影响。结果表明:在不同程度干旱胁迫下,烤烟幼苗叶片PSⅡ最大光化学效率(Fv/Fm)、潜在活性(Fv/F0)、表观电子传递速率(ETR)等均下降,用于光化学反应的能量比例也有所降低,导致烤烟幼苗受到光抑制,PSⅡ反应中心也受到伤害。而施用适量的氮肥(土壤中纯氮施用量为0.36 g.kg-1)可通过减少PSⅡ反应中心与光能吸收和电子传递相关蛋白的降解,增强剩余活性反应中心的开放程度,并保证电子传递链的相对稳定。此外,施用适量的氮肥,还增加了幼苗捕获的光能比例(φPo)、吸收到的光能用于QA-以后的电子传递的能量(φEo),以及用于电子传递的能量(ETo/RC)等,可通过及时提高热耗散减轻干旱胁迫带来的伤害,有效地提高‘龙江911’幼苗的抗旱能力。Taking the polyphasic rise of the chlorophyll a fluorescence transients（OJIP）as probe,this study was conducted to determine the effects of different nitrogen rate（0,0.36,0.72 g·kg-1）on photosystemⅡ（PSⅡ）functions in leaves of flue-cured tobacco seedlings during the transplantation stage under drought stress.A flue-cured tobacco variety＇Longjiang 911＇was used as experimental material.The results showed that the maximum photochemical efficiency（Fv/Fm）,potential activities of PSⅡ（Fv/F0）and the apparent electron transport rate（ETR）in leaves of flue-cured tobacco seedlings decreased under drought stress,the proportion of energy which was used for photochemical reaction also reduced,and the photoinhibition of photosynthesis occurred evidently under drought conditions,and the PSⅡ reaction centre was hurt.The appropriate amount of nitrogen fertilizer application（0.36 g·kg-1,pure nitrogen in soil）could increase the opening degree in surplus activity center and maintain the stability of electron-transport chain,and it also could improve the amount of light energy by capturing（φPo）,the quantum yield for electron transport（φEo）and the electron transport efficiency of per reaction center（ETo/RC）by reducing the degradation of protein that was related to light energy capturing and electron transport in leaves of flue-cured tobacco seedlings.At the same time,the appropriate amount of nitrogen fertilizer application protected the flue-cured tobacco from injury during drought stress by increasing the heat dissipation,and observably improved the drought resistance of flue-cured tobacco seedlings.But the over-fertilization of nitrogen always caused the reduction of the drought resistance of flue-cured tobacco seedlings.

关 键 词：烤烟 干旱胁迫 氮素水平 叶绿素荧光 

分 类 号：S572[农业科学—烟草工业] S311[农业科学—作物学]