干旱胁迫对小紫珠光合生理的影响  

Photosynthetic Characteristics of Callicarpa dichotoma under Drought Stress

作　　者：杨建伟 赵丹[1] 孙桂芳 刘嘉翔 安彤[1] 史宝胜[1] YANG Jianwei;ZHAO Dan;SUN Guifang;LIU Jiaxiang;AN Tong;SHI Baosheng(College of Landscape and Travel,Agricultural University of Hebei,Baoding,Hebei 071000,China)

机构地区：[1]河北农业大学园林与旅游学院,河北保定071000

出　　处：《西北植物学报》2018年第4期733-740,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：河北省林业科学研究院项目(17226320D);河北省林业厅项目(1704487)

摘　　要：以小紫珠(Callicarpa dichotoma)幼苗为试验材料,采用盆栽控水法设置4个水分梯度,分别为田间最大持水量的95%(对照)、75%(轻度干旱)、55%(中度干旱)和35%(重度干旱),研究土壤水分对小紫珠光合参数的影响。结果显示:(1)随着干旱胁迫的加剧,小紫珠的净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)和水分利用效率(WUE)逐渐下降,其胞间CO_2浓度(C_i)在轻度和中度干旱胁迫下逐渐下降,在重度干旱胁迫下显著升高。(2)随着干旱胁迫的加剧小紫珠的光饱和点(LSP)、最大净光合速率(Pnmax)、暗呼吸速率(Rd)和表观量子效率(AQY)显著减少,光补偿点(LCP)极显著增加(P<0.01)。(3)随着胁迫程度的增加,小紫珠的最大荧光(F_m)、最大光化学效率(F_v/F_m)和PSⅡ的量子效率(Fv/Fo)逐渐减少,初始荧光(Fo)显著升高(P<0.01);随着干旱胁迫的加剧小紫珠能量分配比率参数φPo、Ψo、φEo逐渐下降,φDo逐渐增加;代表单位反应中心活性的参数ABS/RC、TRo/RC、ETo/RC和DIo/RC逐渐升高。(4)随着胁迫程度的增加,小紫珠叶绿素a、叶绿素b、叶绿素总量和叶绿素a/b逐渐减少。研究表明,干旱胁迫下小紫珠光合速率的降低既有气孔因素也有非气孔因素,但轻度和中度干旱胁迫下以气孔限制为主,而在重度干旱胁迫下以非气孔限制为主。With Callicarpa dichotoma seedlings as test materials,using pot set four water moisture gradients,95% of water holding capacity of the largest field （control）,75% （mild drought）,55% （moderate drought）and 35% （severe drought）,we investgated the soil moisture affects C.dichotoma photosynthetic characteristics.The results show：（1）since the drought stress,the net photosyntheti crate（Pn）,transpi-ration rate（Tr）,stomatal conductance（Gs）and water use efficiency （WUE）of C.dichotoma were de-creased,while the intercellular CO2 concentration（Ci）in mild and moderate gradually decline,under se-vere drought stress significantly increased;（2）with the intensification of drought stress,the light satura-tion point（LSP）,maximum net photosynthetic rate （Pnmax）,dark respiration rate （Rd）and apparent quantum efficiency（AQY）of C.dichotoma significantly reduced,and light compensation point（LCP）in-creased significantly（P 〈0.01）;（3）with the increase of degree of stress,the maximum fluorescence （Fm）,maximum photochemical efficiency（Fv/Fm）and PSⅡquantum efficiency（Fv/Fo）of C.dichotoma were gradually reduced and the initial fluorescence（Fo）was significantly increased（P〈0.01）,since the drought stress energy distribution ratio parameters,φPo,Ψo,φEo and DIo/RC are gradually increasing;（4） with the increase of stress,chlorophyll a,chlorophyll b,chlorophyll and chlorophyll a/b of C.dichotoma gradually decreased.The study showed that the decrease of the combined rate of C.dichotoma in the drought stress has both the stomatal factor and the non-stomatal factor.The photosynthetic rate of C.di-chotoma under mild and moderate drought stress was dominated by stomatal restriction,while non-stoma-tal restriction was mainly due to severe drought stress.

关 键 词：小紫珠 干旱胁迫 光合生理 

分 类 号：Q945.79[生物学—植物学]