关键词: 科尔沁沙地, 建群植物, 抗旱性机理

Abstract: Measured results of several drought-resistant indexes of Artemisia frigida and Artemisia Halodendron under the conditions of field moisture capacity and water stress showed that:1. Under two soil water conditions A. Frigida has a lower water potential than A. haoldendron and exhibits a relative water deficit, bound water content, ratio of bound water content to free water content and comprehensive drought-resistant index are significantly higher than those of A. halodendron, furthermore the change range of above-mentioned indexes of A. frigida is larger than that of A. halodendron before and after water stress. 2. Under the condition of field water capacity A. frigida has a higher accumulation rate of dry matter and nitrate nitrogen and a hehger nitrate reductase activity than A. halodendron but its soluble protein and chlorophyll contents are lower than those of A. halodendron. Under water stress condition, the protein degradation range of A. frigida is hihger than that of A. halodendron; the proline accumulation content of A. frigida could be 8.2 times what it is before water stress happens, while that of A. halodendron is only 2.2 times as large as its original value;soluble saccharide content of A. frigida could be 1.29 times what it is before water stress happens and that of A. halodendron only increase 0.37 times. Under water stress condition the chlorophyll content of A. frigida is hihger than that of A. halodendron. 3. In the harsh desert environment the transpiration rate of A. frigida in different time of a day is wower than that of A. halodendron and shows a gentle daytime change.

Key words: horqin sandy land, edificator, drought-resistant mechanism