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作 者 ：刘小平 王晨

期 刊 ：西北植物学报 1992年 2期

关键词：CAM；光合型；叶龄；长药景天；

Keywords:Sedum spectabile, CAM (Crassulacean Acid Metabolism), photosynthetic type, phosphoenolpyruvate (PEP) carboxylase, acid content, water stress.,

摘 要 ：用CO_2分析。含酸量和PEP羧化酶活性测定的方法对长药景天(Sedum spectabile)光合型进行研究,其成熟叶浇水时表现为C_3型,干旱条件下转变成CAM型,但极度的干旱又使其CAM活性降低。浇水植株的幼叶PEP羧化酶活性和含酸量低,成熟叶较高。但在干旱过程中,幼叶酶活性和含酸量的增加比成熟叶更为显著,表明幼叶对水分胁迫更敏感。水分胁迫中,叶最大PEP羧化酶活性和最大含酸量在植株由下而上各叶位转移。

Abstract:With methods of CO_2 exchange analyse, acid content and phosphoenolpyruvate carboxylase activity determination, the photosynthetic type was studied in Sedum spectabile, a widely distributed plant in China. The mature leaves in well watered plants were of

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