水分胁迫对冷蒿和差巴嘎蒿溶质累积的影响

冷蒿干物质累积高于差巴嘎蒿，水分胁迫出现时差值更显著；差巴嘎蒿可溶性蛋白质在土壤含水量为10%时即开始大量分解，冷蒿分解的时间稍后(在土壤含水量7%时)；正常土壤含水量条件下冷蒿硝态氮含量和硝酸还原酶活性高于差巴嘎蒿，极端干旱时两种牧草上述指标均降至很低且数值相近；冷蒿在土壤水分轻度胁迫时脯氨酸大量累积，累积量可达胁迫前的8.2倍，差巴嘎蒿只达原来的2.2倍；缺水使冷蒿可溶性糖大量累积，冷蒿达胁迫前的1.29倍，差巴嘎蒿只达胁迫前的0.37倍。

Accumulation of SolubleSubstances in Artemisia frigida and A. halodendron as Influenced by Water Stress

The higher accumulation of dry substances in the Artemisia frigida over A. halodendron is aggrandized by water stress. Considerable amount of soluble protein in the A. halodendron begins to be decomposed when the soil moisture is reduced to 10%, while that in the Artemisia frigida begins to be decomposed at lower soil moisture (7%). At the normal soil moisture conditions, the Artemisia frigida has more content of nitrate nitrogen and the activity of reductase of nitrate than A. halodendron. The content of nitrate nitrogen and activity of reductase of nitrate in both species are greatly reduced, to approximately the same level, at hyper-arid conditions. Artemisia frigida experiences large amount of proline accumulation at lighter soil water stress, which can reach as high as 8.2 times the protein accumulation without water stress, while A. halodendron can only increase by 2.2 times. Insufficiency of water leads to considerable accumulation of soluble sugar, it can increase by 1.29 times in the Artemisia frigida and 0.37 times in the A. halodendron compared with those without water stress.