铝胁迫对常绿杨叶绿素荧光和叶绿体超微结构的影响

Chlorophyll Fluorescence and Chloroplast Ultrastructure of Evergreen Poplar under Aluminum Stress

选取常绿杨(Populus×euramericanacv.A-61/186)为试验材料,研究铝胁迫对带绿杨叶绿体荧光特性和超微结构的影响.结果表明铝胁迫对常绿杨叶片的超微结构产生明显伤害,会显著抑制叶片的光合性能,且随着胁迫浓度的加重和时间的延长而加重.0.370mmol/L铝胁迫60d后,光系统II最大光化学效率Fv/Fm降低,初始荧光F0和非光化学猝灭系数NPQ显著上升;叶绿体膜肿胀隆起,叶绿体内淀粉粒消失,叶绿体内基粒片层和基质片层间隙明显,片层弯曲呈蓬松排列.0.222mmol/L铝胁迫90d致使叶绿体内淀粉粒消失;Fv/Fm值显著低于对照、F0和NPQ值显著高于对照;铝胁迫浓度大于0.370mmol/L时,叶绿体肿胀体积增大,叶绿体膜明显隆起,叶绿体内基粒片层和基质片层明显分离,呈扭曲蓬松.铝胁迫下常绿杨叶绿体膜及其片层和淀粉粒的结构变化与光合效率的下降趋势相一致,可作为杨树铝毒鉴定的细胞学参考.

Evergreen poplar A-61/186(Populus×euramericanacv.A-61/186)was selected as the experimental object to reserach the aluminum stress on chloroplast fluorescence properties and leave ultrastructure.Results showed that aluminum stress on ultrastructure and photosynthetic capacity of leaves have obvious damage,which inhibit leaf photosynthetic performance with the increase of stress concentration and extension of stress time.After sixty days,the aluminum stress concentration of 0.370mmol/L,the maximum photochemical efficiency(Fv/Fm)decreased,the initial fluorescence(F0)and non-photochemical quenching coefficient(NPQ)rised significantly,The chloroplast membrane swelling bulge and starch granule disappeared,chloroplast grana slice layer and the substrate clearance,bending lamella were arranged fluffy.After ninety-days treatment with aluminum concentration of 0.222 mmol/L,the chloroplast starch grains disappeared,Fv/Fm was significantly lower than control,F0 and NPQ significantly higher than control.Aluminum concentration of 0.370mmol/L,the chloroplast swelling volume increased,membrane apparent apophysis,chloroplast grana slice layer and the substrate layer were clearly separated,distorted and fluffy.Therefore chloroplast membrane under aluminum stress and lamellar structure change of starch grains of evergreen poplar were consistent with the decline of photosynthetic efficiency,which can be taken as reference to poplar aluminum toxicity identification of cytology.