缺锌胁迫对苹果叶片光合速率及叶绿素荧光特性的影响  

Effects of Zinc Deficiency on Photosynthetic Rate and Chlorophyll Fluorescence Characteristics of Apple Leaves

作　　者：付春霞[1] 张元珍[1] 王衍安[1] 范晓丹[1] 闫玉静[1] 张友朋[1] 

机构地区：[1]山东农业大学生命科学学院/作物生物学国家重点实验室,山东泰安271018

出　　处：《中国农业科学》2013年第18期3826-3833,共8页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31372015);现代苹果产业技术体系(MATS);公益性行业专项(201103003);国家科技支撑计划项目(2011BAD21B06)

摘　　要：【目的】研究不同程度的缺锌胁迫对大田苹果树叶片的叶绿素含量、光合速率、叶绿素荧光特性等的影响,进一步揭示缺锌对叶片光系统的伤害机理。【方法】以大田盛果期‘红富士/平邑甜茶’正常树和缺锌小叶病树为试材,对叶片锌含量、叶绿素含量、净光合速率、荧光参数等指标进行测定。【结果】缺锌胁迫下,苹果叶片叶绿素含量下降,单叶面积、比叶重显著减小;气孔导度降低,胞间CO2浓度升高,净光合速率和水分利用效率下降。随缺锌程度加重,叶片初始荧光Fo上升,PSⅡ潜在活性Fv/Fo、PSⅡ实际光化学效率ΦPSⅡ、光化学淬灭系数qP及PSⅡ天线转化效率Fv’/Fm’显著下降;J点相对可变荧光VJ和K点的相对变化Wk上升,电子传递的量子产额ETo/ABS和单位面积有活性的反应中心数量RC/CSo下降,光合性能指数PIABS显著降低。【结论】缺锌时非气孔限制是导致苹果叶片光合速率降低的原因之一;缺锌时首先引起放氧复合体(OEC)的破坏,进而使PSⅡ反应中心受损,PSⅡ供体侧、受体侧电子传递受抑制,影响叶片对光能的吸收、传递与利用。[Objective] The purpose of this study is to explore the effects of zinc deficiency on the chlorophyll content, photosynthetic rate and chlorophyll fluorescence characteristics of apple tree leaves, and to reveal the damage mechanism of Zn deficiency to the photosynthetic system of apple leaves. [Method] Normal trees without Zn deficiency symptoms and rosette trees with typical Zn deficiency symptoms （called ＂little leaf＇） in field of ＇Red Fuji＇ apple （rootstock Malus hupehensis Rehd） were used as materials, and the zinc content, chlorophyll content, net photosynthesis rate and fluorescence parameters of apple leaves under different Zn stress levels were measured. [Result] Under Zn deficiency, the chlorophyll content, single leaf area and specific leaf weight of apple leaves decreased significantly; the stomatal conductance decreased, intercellular CO2 concentration increased, net photosynthetic rate and water use efficiency also decreased. As the aggravation of Zn deficiency, the original fluorescence Fo rose while Fv/Fo, φpsⅡ, qP and Fv＇/Fm＇ decreased under Zn deficiency. The relative variable flurescence at J-step（Vj） and the ratio of variable fluorescence Fv to the amplitude Fj-Fo at the K-step（Wk） increased, the quantum yield for electron transport further than QA （ETo/ABS）, the density of active PS II reaction centers per cross section（RC/CSo） and the performance index on absorption （PI） basis decreased. [ Conclusion ] Non-stomatal limitation was one of the reasons for the reduction of photosynthesis rate under zinc deficiency. Zn deficiency first caused the damage of oxygen evolving complex （OEC） and then the reactive center of PS II, followed by the inhibited electron transfer of donor side and receptor side of the reaction center at the same time, which finally affected the absorption, transmission and utilization of light energy in apple leaves.

关 键 词：苹果 锌 叶片 光合速率 荧光特性 

分 类 号：S661.1[农业科学—果树学]