营养胁迫对薄叶双盖蕨叶绿素荧光特征的影响

喀斯特区石灰土多具有高钙、低磷的特性,从而限制了植物在该环境中的生存。为探讨厌钙植物不能在石灰土中生存的原因,以厌钙植物薄叶双盖蕨作为研究对象,以专性钙生植物柳叶蕨为对比物种,以Ca2+浓度、H2PO4-浓度为控制因子,测定分析各个水平下叶片叶绿素荧光参数特征。结果显示,Ca2+浓度胁迫下薄叶双盖蕨叶绿素荧光参数变化特征与柳叶蕨有较明显的区别,而H2PO4-浓度胁迫下二者的差异性不大;Ca2+因子对薄叶双盖蕨叶绿素荧光参数的负效应显著大于H2PO4-浓度,且各胁迫水平的影响差异显著;培养液Ca2+浓度过高会使薄叶双盖蕨的Fo、Fv′/Fm′、Fv/Fm、ETR、qP、NPQ、P等叶绿素荧光参数显著降低。结论,石灰土环境中Ca2+浓度较高会影响和抑制薄叶双盖蕨捕获及转化光能用于光化学反应的相关能力,限制了薄叶双盖蕨在石灰土上的生存。

The Effects of Nutrient Stress on Chlorophyll Fluorescence Characteristics of Diplazium pinfaense

The calcareous soil in the karst area has such characteristics as high calcium concentrations and low phosphorus concentrations,which restricted the existence of some species.In order to study why calcifuges cannot exist in calcareous soil,a calcifuge,Diplazium pinfaense,was cultivated by nutrient solutions with different calcium concentrations and phosphorous concentrations.And their chlorophyll fluorescence characteristics were studied.Meanwhile,Cyrtogonellum fraxinellum,an exclusive calciphyte was used as a contrast.The results displayed that there were significant differences in chlorophyll fluorescence characteristics between Diplazium pinfaense and Cyrtogonellum fraxinellum,when under the control of Ca2+ concentrations,but there was no difference in low H2PO-4 concentration stress.The effects of Ca2+ concentrations were more negative than those of H2PO-4 concentrations,and the discrepancies of effects were up to activity level.The high Ca2+ concentrations could make the values of Diplazium pinfaense chlorophyll fluorescence parameters(Fo,Fv′/Fm′,Fv/Fm,ETR,qP,NPQ,P) decrease remarkably.It is proposed that the high Ca2+ concentrations in calcareous soil could restrain the abilities to catch and transform the light which will be used in photochemical reaction,thereby it could affect the existence of Diplazium pinfaense in calcareous soil.