The Study On Characteristics Of Drought Resistance Of Two Species Haloxylon Bunge Seedlings

Sacsaoul is a important plant distributed widely in the desert area of central Asian.The study use two species of sacsaoul (Haloxylon ammodendron and Haloxylon persicum)planted in pots,and treated with three leveal,which is soil relative water content of 60%,40% and 20% respectively.the drought resistance of them were discussed by measuring water potential,the biomass,the transpiration rate,the photosynthesis characteristic,the protection enzyme activity and the root Conductive tissue rigidity.Main results are as follows:1) Along with the increasing time and degree of water stress, water potential in assimilating shoots of Haloxylon ammodendron decreased,and Haloxylon ammodendron descended gradually.2)With the increasing time of water stress, the day transpiration rate in assimilating shoots of Haloxylon ammodendron first increased then decreased;the day transpiration rate of Haloxylon persicum declined rapidly.3)Along with the increasing time and degree of water stress,soluble protein content in assimilating shoots of sacsaoul all increased.Soluble sugar content was contrary to Starch content in assimilating shoots of them,and the extent of Haloxylon persicum was higher.4)With three water treatments,The change of the protection enzyme activity was different in assimilating shoots of two species Haloxylon Bunge.The changes in MDA were consistent with the membrane permeability,and were maintained at lower levels.5) The root Conductive tissue rigidity were different in them,and the change of total content of Cellulose,Hamicellulose and Lignin was small.However,compared two species Haloxylon Bunge with E. mooceroftii Wall.ex Schlecht which has the strong compatibility to the drought,the total content of sacsaoul were higher.