摘要
以天目琼花(Viburnum sargentii Koehne)幼苗为实验材料,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%(轻度胁迫)、55%(中度胁迫)和35%(重度胁迫),研究土壤水分对天目琼花光合参数的影响.结果表明:天目琼花的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)随着土壤水分递减而减少,胞间CO2摩尔分数(xCO2)在轻度和中度干旱胁迫时下降,在严重干旱时显著升高.随着胁迫程度的加剧,天目琼花的光饱和点(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)显著增加(P<0.01).天目琼花的最大荧光(Fm)、最大光化学效率(Fv/Fm)和光系统Ⅱ(PSⅡ)的量子效率(Fv/Fo)随着土壤水分递减而减少,初始荧光(Fo)显著升高(P<0.01);随着土壤含水量的下降能量分配比率参数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.研究表明,在轻度和中度干旱胁迫下天目琼花光合作用能力的降低主要是由气孔限制因素引起的,重度干旱主要是非气孔限制因素引起的.
Using Viburnum sargentii Koehne seedlings as test materials,using pot-set four water moisture gradients,correspondins to 95%of water holding capacity the largest field(control),75%(mild drought),55%(moderate drought)and 35%(severe drought),the effect of soil moisture on V.sargentii photosynthetic parameters was studied.The results show that:the net photosynthetic rate(Pn),stomatal conductance(Gs)and transpiration rate(Tr)of V.sargentii reduced with soil water decreasing and intercellular mole fraction of CO2(xCO2)in mild and moderate drought stress decreased significantly,but increased under severe drought stress.When the drought stress V.sargentii light saturation point(LSP),maximum net photosynthetic rate(Pnmax),dark respiration rate(Rd)and apparent quantum efficiency(AQY)significantly reduced,light compensation point(LCP)increased significantly(P<0.01).The maximum fluorescence(Fm),maximum photochemical efficiency(Fv/Fm)and PSⅡquantum efficiency(Fv/Fo)decreased with the soil water decreasing,and the initial fluorescence(Fo)(P<0.01)was significantly increased.When the drought stress energy distribution ratio parameters,φPo、Ψo、φEo gradually decline,heass ipation ratio of quantumφDo increase gradually.As the drought stress intensifies,the parameters of plant unit reaction center activity ABS/RC,TRo/RC,Eto/RC and DIo/RC increase gradually.Studies have shown that:the decrease of the photosynthesis was mainly caused by stomatal factors,and the net photosynthetic rate was caused by the non-stomatal factors in severe drought stress.
作者
杨建伟
赵丹
孙桂芳
刘嘉翔
赵艺璇
史宝胜
YANG Jianwei;ZHAO Dan;SUN Guifang;LIU Jiaxiang;ZHAO Yixuan;SHI Baosheng(College of Landscape Architecture and Tourism,Hebei AgriculturalUniversity,Baoding 071000,China;Forestry and Grassland Bureau of Xinglong County,Xinglong 067300,China;County Housing and Urban-Rural Development Bureau of Xinglong,Xinglong 067300,China)
出处
《河北大学学报（自然科学版）》
CAS
北大核心
2019年第5期529-535,共7页
Journal of Hebei University(Natural Science Edition)
基金
河北省林业厅资助项目(1704487)
河北省林业科学研究院资助项目(17226320D)
关键词
天目琼花
干旱胁迫
光合特征
Viburnum sargentii Koehne
drought stress
photosynthetic characteristics
