Drought Resistance Evaluation Of Several Desert Plants

Drought and soil salinization are the main factors in restricting the vegetation restoration in desertification areas in Inner Mongolia.This research with the physical and chemical characteristics of plants in arid regions is important and valuable to promote the vegetation restoration and improve the local soil conditions and climate.In this study,there are six kinds of sand species,they are Berberis amurensis,Salix gordejevii,Periploca sepium,Ampelopsis bodinieri,Salix cheilophila Schneid and Salix psammophila,Under the natural drought,there are three water gradients are formed:T1?soil moisture content in normal water conditions?,T2 and T3?soil moisture content in different degrees of water stress in the field?.Under different moisture gradients,fourteen drought-resistance-related indicators were determined for the tested tree species.Through multiple statistics and other methods,the drought resistance of each tested tree species was evaluated.The following results were obtained:?1?In the normal water content of the field,there were significant differences in the light saturation point of 7 photosynthetic indexes of 6 sand species.Among them,the net photosynthetic rate of light saturation point of Salix cheilophila Schneid is the highest(8.33?mol·m^-2s^-1),and the net photosynthetic rate of light saturation point of Salix gordejevii is the lowest(3.98?mol·m^-2s^-1).The transpiration rate of light saturation point of Periploca sepium is the highest(3.52?mol·m^-2s^-1),and the transpiration rate of light saturation point of Salix gordejevii is the lowest(1.05?mol·m^-2s^-1).The stomatal conductance of light saturation point of Periploca sepium is the highest(1.426?mol·m^-2s^-1),and the stomatal conductance of light saturation point of Salix gordejevii is the lowest(0.031?mol·m^-2s^-1).?2?Under different water gradients?T1,T2,T3?,there were significant differences in the rate of change of 7 photosynthetic indexes of 6 sand species.The net photosynthetic rate of light saturation point of each tree species was decreased with soil water stress,and the rate of change of the net photosynthetic rate of Salix psammophila is the highest?1.47?and the rate of change of the net photosynthetic rate of Periploca sepium is the lowest?0.50?.The transpiration rate of light saturation point was decreased with soil water stress,and the rate of change of Salix cheilophila Schneid is the highest?0.33?and the rate of change of Salix psammophila is the lowest?0.11?.The stomatal conductance of light saturation point was decreased with soil water stress,and the rate of change of Periploca sepium is the highest?0.3839?and the rate of change of Salix gordejevii is the lowest?0.0055?.?3?The malondialdehyde content of each tested tree species was increased with water stress.Among them,the rate of change of Berberis amurensis is the highest?0.0209?and the rate of change of Salix cheilophila Schneid is the lowest?0.0025?.The enzyme activity of POD was increased with water stress,of which Salix cheilophila Schneid is the highest?4.68?and Berberis amurensis is the lowest?0.35?.The enzyme activity of SOD was increased with water stress,of which Ampelopsis bodinieri is the highest?5.63?and Salix psammophila is the lowest?0.54?.Under water stress,each tested tree species can accumulate proline,soluble sugar and soluble protein to regulate osmotic potential.The rate of change of proline content of Salix psammophila is the highest?118.22?and the rate of change of Salix cheilophila Schneid is the lowest?2.99?.The content of soluble sugar of Salix psammophila is the highest?0.61?and Periploca sepium,is the lowest?0.08?.The rate of change of soluble protein content of Periploca sepium is the highest?4.41?and Salix gordejevii is the lowest?0.95?.The electric conductivity of Berberis amurensis is the highest?0.136?and Salix psammophila is the lowest?0.059?.?4?Evaluation of drought resistance of 6 Dendrobium species using fuzzy membership function method and multiple indicators.The results indicated that the drought resistance of Ampelopsis bodinieri is the highest?0.60?and Berberis amurensis is the lowest?0.31?under natural drought conditions,and the rank of drought resistance of 6 tree species was Ampelopsis bodinieri?0.60?>Salix cheilophila Schneid?0.59?>Periploca sepium?0.58?>Salix psammophila?0.57?>Salix gordejevii?0.48?>Berberis amurensis?0.31?...