Study On Physiological Response Of Relict Under Drought Stress In Western Ordos

In order to reveal the correlativity between habitat physical factor and the physiological response, show the physiological adjustment mechanism of the old Mediterranean relict under drought stress and make sure their protective policy, this paper has choose Potaninia mongolica, Tetraena mongolica and Ammopiptanthus mongolicus as experimental materials. These plants have different property on morphological adaptation. We adopt different concentrations of PEG to imitate drought stress environment. Then measure the physiological indexes changing situation such as protective enzyme, MDA, the activity and contents of endogenous hormone etc. At the same time, we also measure soil moisture content and nutritive element content of the plants habitat.The results of this research are as follows:1. Regression analysis shows that: IAA, POD, SOD and MDA of Tetraena mongolica play the leading role in response to drought stress, and MDA has best relativity with osmotic potential; SOD and IAA are balancing internal oxide of Potaninia mongolica, its MDA has best relativity with osmotic potential too; POD, IPA and SOD of Ammopiptanthus mongolicus play the leading role when stress to drought.2. The start of protective enzyme of Potaninia mongolica are related to Fe in the soil and the start of protective enzyme of Tetraena mongolica are related to Cu and Mo in the soil directly. Ammopiptanthus mongolicus can fix N in 30-40cm depth of soil.3. The order of defending physiological drought ability is Tetraena mongolica < Ammopiptanthus mongolicus