Preliminary Study On Drought Resistance On Five Species Of Landscape Ground Cover Plants

Establishing Urben greenland by the plant with drought resistance will relax the lack of water in city. Screening out the plant with enduring drought and expending water smaller is playing an important role in reducing maintain and overhead expenses, protecting entironment and saving water resource.This paper has chosen five kinds of cover plants which have market potential: Chrysa nthemum maximum, Beijing Summer Chrysanthemum , Beijing miniature chrysanthemum, Sedum .Spectablile Boreau and Sedum. Nicaeense All as experiment materials and under field controlling soil water environments, this paper mainly measure some water indexes and biochemical indexes of five kinds of cover plants in different soil water. We expected to discover difference of drought resistance mechanism and to comprehensive evalue the droughte resistance of five kinds of cover plants. The main results are follow:(1) Under the stress of drought , the soil moisture and the relative water content of five species was decreased. Of which'Chrysanthemum maximum'leaves show the greatest relative decline in water content, and'Sedum .Spectablile Boreau'which relative high water content show small decline in water content. But water saturation deficiencies of five species have a trend of increase with decrease of soil water content .(2) The leaf water losing rate of S.Speetablile Cav Carmen is maximum,and Chrysanthemum maximum is minimum under the drought stress. The trend of leaf water losing rate shows that Chrysanthemum maximum> Beijing miniature chrysanthemum> Beijing Summer Chrysanthemum> Sedum. Nicaeense All> Sedum .Spectablile Boreau. The confined water proportions and Va/Vs of five species are increasing with the decrease of soil water content. During the water stress the confined water proportions of Sedum. Nicaeense All and S.Speetablile Cav Carmen are heigher than other species.(3) Under the stress of drought , the study of the five species of the permeability of cell membranes, proline content, Water soluble carbohydrate content and malondialdehyde content show that with the deepening of water stress level, changes in trends in different plants are basically the same: Peroxide content of MDA, the permeability of cell membranes, proline content and Water soluble carbohydrate content are all gradually increase. The content of MDA with'Sedum .Spectablile Boreau'and'Sedum. Nicaeense All'increased firstly, reached the climax, then decreased. The content of MDA with'Beijing minichry santhemum','Dendranthema morifoliu ,'Beijing Summer Chrysanthemum''and'Chrysanthemum maximum'enhanced with the deeper of stressed.(4) Combination of physical observation. By principal components analysis and subordinate function analysis, results show that the drought resistance of the five kinds of cover plants from strongest to the weakest were as follow: Sedum .Spectablile Boreau, Sedum. Nicaeense All, Beijing miniature chrysanthemum, Beijing Summer Chrysanthemum, Chrysanth- emum maximum.