草业学报2011，Vol.20Issue(4)：108-115,8.
沿民勤绿洲荒漠过渡带分布的4种优势植物光合生理响应
Photosynthetic responses of four dominant species to environmental gradient along the oasis-desert ecotone of Minqin, China
摘要
Abstract
The vegetation of the oasis-desert ecotone plays an important role in the desertification control, therefore the evaluation of the dominant plant growth and health is very important. The photosynthetic characteristics of four dominant plant species (I. E. Nitraria tangutorum , Phragmites communis , Haloxylon ammo-dendron and Calligonum mongolicum) in four different distributing sites along the oasis-desert ecotone (I. E. Section 1, section 2, section 3, section 4 from the oasis to the desert) were investigated in this study. The water content, chlorophyll content of four species decreased gradually while the carotenoids content increased gradually along the oasis-desert ecotone, showed that four plant species suffered from the different extent of drought stress. The photosynthetic capacity of four plant species decreased gradually along the gradient of the ecotone, while the decreasing extent was different [the decrease of N. Tangutorum was the least, H. Ammo-dendron and P. Communis were biggist, while the photosynthetic capacity of C. Mongolicum was higher in the section 1 (the margin of oasis) and section 3]. The variational trend of stomatal conductance (Gs) in the four plant species was the same as the variational trend of photosynthetic capacity, but there were different with the trend of transpiration rate (E) and water use efficiency (WUE). The WUE of N. Tangutorum and P. Communis were highest in the section 2, C. Mongolicum was highest in the section 3, while the WUE of H. Ammo-dendron decreased gradually along the ecotone. In addition, the variational trend of chlorophyll fluorescence parameters (Fv/Fm and Fo) of four plant species indicated that the H. Ammodendron occurred the long-term pho-toinhibition and photodamage along the ecotone, while the N. Tangutorum was not influence, and that the C mongolicum and P. Communis only suffered from serious stress in the section 4 (I. E. The margin of desert). In conclusion, all our results suggested that the N. Tangutorum adapt to the drought conditions of oasis - desert ecotone more than C. Mongolicum and P. Communis, while the adaptive capacity of H. Ammodendron was the worst in the four plant species.关键词
过渡带/优势植物/光合作用/环境梯度/叶绿素荧光Key words
ecotone/ dominant species/ photosynthesis/ environmental gradient/ chlorophyll fluorescence分类
农业科技引用本文复制引用
田新民,赵长明,邓建明,张晓玮,陈拓,任贾文,王根轩..沿民勤绿洲荒漠过渡带分布的4种优势植物光合生理响应[J].草业学报,2011,20(4):108-115,8.基金项目
甘肃省自然科学基金(0710RJZA031),中国博士后科学基金(20080430795),王宽诚教育基金会和教育部新世纪优秀人才支持计划(NCET-08-0257)资助. （0710RJZA031）
