胡杨披针形叶与宽卵形叶的超微结构与光合特性的差异  

Difference of Ultrastructure and Photosynthetic Characteristics between Lanceolate and Broad-ovate Leaves in Populus euphratica

作　　者：杨树德[1] 郑文菊[2] 陈国仓[3] 张承烈[3] 陈珈[1] 王学臣[1] 

机构地区：[1]中国农业大学生物学院植物生理学与生物化学国家重点实验室,北京100094 [2]中国科学院植物研究所光合作用与环境分子生理学重点实验室,北京100093 [3]兰州大学生命科学学院,兰州730000

出　　处：《西北植物学报》2005年第1期14-21,共8页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家基础研究发展规划项目资助 No.G19980101;G19990117

摘　　要：以胡杨的披针形叶和宽卵形叶作为实验材料,对其细胞超微结构、光合酶活性、稳定碳同位素组成进行了比较研究.结果表明,两种叶片都是等面叶,角质层厚,具皮下层和孔下室,含较多的粘液细胞,表现出明显的旱生结构特点;两种叶片均具有不整齐的维管束鞘细胞,Rubisco/PEPC值与小麦的接近,δ13C值分别为-27.9‰和-26.7‰,位于C3植物的δ13C值的范围内,表明两种叶片的碳同化途径均为C3途径;然而宽卵形叶较披针形叶的旱生结构更发达,叶肉细胞的线粒体数目及液泡中的泡状物质较多,Rubisco/PEPC值较低而δ13C值较高,表明宽卵形叶比披针形叶具有更强的抵抗逆境的能力.此外,还对两种叶片对胡杨适应其盐碱化生境的能力的贡献作了初步探讨.The two types of differently shaped leaves,lanceolate leaves and broad-ovate leaves in Populus euphatica,were surveyed for the ultrastructure,the activities of Rubisco,PEPC,Glycolate oxidase and the component of carbon stable isotope.Its was showed that the two type leaves exhibited obvious xeromorphic structure,such as well-developed epidermis with thickened cutin layer,hypodermis,stoma with substomatal chamber,mucilage cells.Both of the two type leaves did not have even vascular bundle sheath cells,the ratio of Rubisco/PEPC and the δ^(13)C value were close to that of typical C_3 plant as wheat.It showed that both type leaves possessed C_3 photosynthetic pathways.However,there are also obvious difference between the ultrastructure and the photosynthetic characteristic of the two type leaves due to the difference of microenvironmental factors between the top and the bottom of the P.euphrates crown such as irradiance,temperature,salt ion content:the broad-ovate leaves possessed more developed xeromorphic structure,contained more mitochondrions in mesophyll cells and more vesicle structures in the vacuole of mesophyll cells,had a lower photorespiration activity,a lower ratio of Rubisco/PEPC and a higher δ^(13)C value.Collectively,these result demonstrated that the broad-ovate leaves were more tolerant to drought,higher irradiance,higher temperature and salt stress.

关 键 词：胡杨 超微结构 光合特性 碳同位素组成 披针形叶 宽卵形叶 

分 类 号：Q944.56[生物学—植物学]