外源硫对镉胁迫下苹果幼苗光合特性的影响  

Effects of Exogenous Sulfur on Photosynthetic Traits in Apple Seedlings Under Cadmium Stress

作　　者：梁魁景[1] 高小宽[1] 于占晶[1] 王芳芳[1] 刘辉[2] 侯晓杰[1] LIANG Kuijing;GAO Xiaokuan;YU Zhanjing;WANG Fangfang;LIU Hui;HOU Xiaojie(College of Life Science,Hengshui College,Hengshui,Hebei 053000;Institute of Guizhou Biotechnology,Guizhou Academy of Agricultural Sciences,Guiyang,Guizhou 550006)

机构地区：[1]衡水学院生命科学学院,河北衡水053000 [2]贵州省农业科学院生物技术研究所,贵州贵阳550006

出　　处：《北方园艺》2020年第12期17-24,共8页Northern Horticulture

基　　金：河北省科技计划资助项目(15226505);2018年度高层次人才科研启动基金资助项目(2018GC13)。

摘　　要：以"红富士"苹果幼苗为试材,采用盆栽法,研究(NH4)2SO4对CdCl2胁迫处理下苹果叶片光合色素、光合参数、叶绿素荧光参数和矿质营养元素等光合特性指标的影响,以期从光合特性层面揭示外源硫(S)介导的苹果解镉(Cd)毒机理。结果表明:10 mg·L^-1 CdCl2处理导致苹果叶片叶绿素a含量和叶绿素b含量显著下降;净光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度均显著降低,表明Cd处理影响苹果叶片光合作用的主要原因在于叶绿素合成受阻和气孔的关闭。Cd处理导致苹果叶片光反应系统II(PSⅡ)的紊乱,主要表现在PSⅡ实际光化学效率、电子传递效率、化学淬灭系数显著下降,而非化学淬灭系数显著上升;在Cd处理的基础上,添加100 mg·L^-1(NH4)2SO4对苹果叶片叶绿素a含量、叶绿素b含量和叶绿素a/b比值具有显著的提升作用,同时提升苹果叶片光合作用和PSⅡ原初光化学反应量子效率。对4种与光合作用具有关联作用的矿质元素含量进行分析,结果显示Cd处理对苹果叶片Fe含量无显著影响,但Mg、Mn、Cu含量显著降低。添加外源S可显著提升Mg、Mn、Cu含量,Fe含量亦有一定的提升。结果表明Cd处理下苹果光合作用受到影响与Mg、Mn、Cu元素的亏缺有关,而与Fe元素无关。添加外源S可通过提升苹果叶片对Mg、Fe、Cu和Mn元素的吸收,增强Cd处理下苹果叶片光合作用和叶绿素荧光参数。Malus pumila(apple) was taken as materials,a pot experiment was conducted to investigate the effects of exogenous(NH4)2SO4 on photosynthetic pigments,photosynthetic characteristics,chlorophyll fluorescence parameters,and mineral element contents in apple seedlings with the teatment of 10 mg·L^-1 CdCl2.In order to uncover the intrinsic mechanism of excess sulfur(S) in detoxification of cadmium(Cd) on the aspect of photosynthetic characteristics.The results indicated that Cd stress lead to the significant reduction in contents of chlorophyll a and b,as well as the decreasing in net photosynthesis rate(Pn),transpiration rate(Tr),stomatal conductance(Gs),and intercellular concentrations of carbon dioxide(Ci).Cd induced inhibition of apple leaf photosynthesis were mainly attributed to the blocking of chlorophyll biosynthesis and leaf stoma.Cd treatment also resulted in disfunction of photosystem II(PSⅡ) in apple seedlings by significantly decreasing actual photochemical efficiency,electron transfer efficiency,and chemical quenching coefficient,while increasing nonchemical quenching coefficient.However,after the addition of 100 mg·L^-1(NH4)2SO4 in Cd treatment,the contents of chlorophyll a and b,ratio of chlorophyll a/b were all significantly increased.And the photosynthesis and quantum yield of PSⅡ photochemistry were both significantly improved.Meanwhile,Cd treatment significantly decreased content of magnesium(Mg),manganese(Mn),and copper(Cu),while there was no significant variation on iron(Fe) content.Exogenous S resulted in the increasing contents of Mg,Mn,and Cu,as well as Fe.These results implied that the Cd incited photosynthesis inhibition and PSⅡ disfunction might be involved in the decreasing Mg,Mn and Cu content in apple seedling leaves,but not Fe.However,surplus S could improve the photosynthesis and chlorophyll fluorescence parameters in apple seedlings under Cd stress by increasing the absorption of Mg,Fe,Cu and Mn.

关 键 词：硫 镉胁迫 苹果 光合性状 矿质元素 

分 类 号：S661.1[农业科学—果树学]