锌胁迫对“不知火”和“椪柑”的生理指标及锌分布的影响

采用砂基培养法，研究了0、0.05和0.5 mg·L^-1Zn²⁺（0.05 mg·L^-1为对照，0.5 mg·L^-1为锌过量，0 mg·L^-1为锌缺乏）处理下“不知火”和“椪柑”叶片的一些生理指标及不同部位锌含量的变化。结果表明：1）缺锌处理的“不知火”叶绿体色素含量和叶面积均显著低于其对照和锌过量处理；锌过量处理的“椪柑”叶绿体色素含量和叶面积均显著低于对照。2) 3个锌浓度处理间，“不知火”叶片POD、“椪柑”叶片CAT活性无显著性差异，“不知火”叶片CAT、SOD活性随着锌浓度的升高而升高，锌缺乏处理下“椪柑”叶片POD、CAT、SOD活性均显著地高于“不知火”，而锌过量时“不知火”叶片SOD活性显著高于“椪柑”；锌胁迫下“不知火”和“椪柑”叶片MDA含量均显著高于对照，锌过量时“椪柑”叶片MDA含量显著高于“不知火”。3）2品种柑橘不同部位的锌含量随着锌处理浓度的升高而升高，在相同浓度的锌处理下“椪柑”叶锌含量显著高于其他部位及“不知火”叶锌含量，“不知火”上部叶锌含量显著高于其下部叶。

Effects of zinc stress on the physiological indices and zinc distribution of citrus "Shiranuhi" and "Ponksn"

A sand culture experiment was conducted to study the effects of difierent concentration Zn on the leaf physiological indices and Zn contents of citrus"Shiranuhi"(Citrus reticulata×(C.reticulata×C.sinenesis))and"Ponkan"(Citrus reticulate).Three treatments were installed,i.e.,0 mg Zn·L~(-1)(Zn deficiency),0.05 mg Zn·L~(-1)(control),and 0.5 mg Zn·L~(-1)(Zn excess).Under Zn deficiency,the leaf chloroplast pigments content and leaf area of "Shiranuhi"were significandy lower;while under Zn excess,these two parameters of"Ponkan"decreased significantly.No significant differences in the leaf POD activity of"Shiranuhi"and leaf CAT activity of"Ponkan"were observed among the three treatments.The leaf CAT and SOD activities of"Shiranuhi"increased with increasing medium Zn concentration.Under Zn deficiency,the leaf POD,CAT and SOD activities of"Ponkan"were significantly higher than than those of"Shiranuhi";while under Zn excess,the leaf SOD activity of"Ponkan"was significantly lower than that of"Shiranuhi".The leaf MDA contents of"Shiranuhi"and"Ponkan"under Zn excess were significantly higher those under the control:and the leaf MDA content of"Ponkan"was significantly higher than that of"Shiranuhi".For both"Shiranuhi"and"Ponkan",their leaves at different positions were increased with increasing Zn concentration.In the same treatments."Ponkan" leaves had significantly higher Zn content than the other parts of"Ponkan"and the leaves of"Shiranuhi",and the Zn contents of"Shiranuhi"upper leaves were significantly higher than those of "Shiranuhi"basal leaves.