微咸水灌溉下3种耐盐植物光合特性及水分利用效率比较研究

以微咸水灌溉下耐盐植物胡杨、柽柳和四翅滨藜为研究对象,采用Li-6400便携式光合测定系统对其主要光合参数及水分利用效率等进行了观测及比较分析。结果表明:(1)光强在0～2 000μmol.m-2.s-1范围内,净光合速率(Pn)和气孔导度(Gs)随光强变化均表现为柽柳始终处于较高水平,胡杨次之,四翅滨藜较小;(2)光强为400～2 000μmol.m-2.s-1时,3种耐盐植物的蒸腾速率(Tr)、胞间CO2浓度(Ci)大小顺序为柽柳>胡杨>四翅滨藜,而水分利用效率(WUE)却表现为四翅滨藜>柽柳>胡杨;(3)光强在0～400μmol.m-2.s-1时,蒸腾速率(Tr)和水分利用效(WUE)表现为胡杨较高,柽柳次之,四翅滨藜较小,但是四翅滨藜的胞间CO2浓度(Ci)高于胡杨和柽柳。综合比较3种耐盐植物中,四翅滨藜的水分利用效率较高,蒸腾耗水较少,属于节水型树种;而胡杨和柽柳的水分利用效率较低,蒸腾耗水较高,属于相对耗水型树种。此外,四翅滨藜、胡杨和柽柳能适应高温、光照强烈和干旱的环境,在一定程度上表明其具有较强的逆境适应性。

Photosynthetic Characteristics and Water Use Efficiency of Three Species of Desalination Plant Irrigated by Saline Water

With saline water irrigation,we comparatively analyzed main photosynthetic parameters and water efficiency of three desalination plants,Populus euphratica,Tanmrix spp.and Atriplex canescens by using Li-6400 portable photosynthesis system.The results were as follows.(1)In the light intensity 0-2 000 μmol·m-2·s-1,the net photosynthetic rate(Pn) and stomata conductance(Gs)of Tanmrix spp.were always in the highest level among 3 species,the next was P.euphratica.(2)When light intensity was in 400-2 000 μmol·m-2·s-1,the quantity order of transpiration rate(Tr) and intercellular CO2 concentration(Ci)was Tanmrix spp.> P.euphratica > A.canescens.But the quantity order of water use efficiency(WUE) was A.canescens > Tanmrix spp.> P.euphratica;(3)When light intensity was in 0-400 μmol·m-2·s-1,P.euphratica had the largest Tr and WUE,the next was Tanmrix spp.On the contrary,Ci of A.canescens was significantly higher than that of Tanmrix spp.and P.euphratica respectively.In summary,Atriplex canescens had higher water use efficiency and lower transpiration rate among 3 species of desalination plants,so it was water-saving and anti-drough plant relatively;P.euphratica and Tanmrix spp.had lower water use efficiency and higher transpiration rate,thus they were water consumption plants.Three tested plants all could adapt the environments with higher temperature,higher illumination and drought,indicating to some extent,the 3 species were adaptable to the stressed environment.