淹水对5种禾本科植物光合特性的影响

用氧电极和叶绿素荧光相结合测定的方法研究华南地区常用于水土保持的硬穗钝叶草、地毯草、宽叶和细叶百喜草、香根草等5种禾本科植物在不同淹水时间下的反应 5种植物生长于完全淹水的环境中,分别在第9、18、27、36、45、54d测定 淹水处理使地毯草总叶绿素含量随着淹水天数的延长而呈下降趋势,色素破坏明显;细叶百喜草和香根草则随着淹水反应时间的延长而上升,光合色素破坏不明显 淹水对植物的暗呼吸速率影响不同 原初光化学速率Fv/Fm在淹水影响下呈现不同程度的降低,与Fv/Fm下降相关的荧光参数Fm,Fv和Fo在3种植物中反应不同 叶绿素荧光测定的结果表明淹水反应中香根草、细叶百喜草的PSⅡ活性比地毯草具有较高的稳定性,qN增高,热耗散保护性作用增强 丙二醛(MDA)的相对含量,在18d淹水里钝叶草、宽叶百喜草和香根草呈现下降的趋势,后2者在淹水27d以后受刺激增高

The Effects of Submergence on the Photosynthetic Characteristics of Five Grasses

The effects of submergence on the photosynthetic pigments,malondialdehyde (MDA)and chlorophyll fluorescence parameters were investigated via different submergence time in five grasses, Vetiveria zizanioides,Paspalum notatum var.(broad-leaved type), P. notatum (narrow-leaved type), Axonopus compressu and Stenotaphrum secundatum. These five species were grown under the situation of complete submergence for over a month. As a result,the chlorophyll contents of A. compressu went down with submergence,but those of P. notatum and V. zizanioides went up. The photosynthetic pigments of V. zizanioides and P. notatum changed little during the submergence process. The maximum yield of primary photochemistry (Fv/Fm) decreased and Fm,Fv and Fo had different changes during the submergence. Non-photochemical quenching of variable chlorophyll fluorescent yields qN had the same reflection that rose up firstly,then went down in different species. ФPSⅡ were higher in V. zizaninoides and P. notatum than in A. compressu. During the 18-day submergence,the relative content of MDA of grasses decrease,but after 27-day submergence those of P. notatum var. and V. zizanioides went up.