中文摘要：

为了解紫花苜蓿（Medicago sativa L.）在南方干旱条件下的生理变化,对昆明地区春季旱作条件下的德钦野生紫花苜蓿、逸散紫花苜蓿AC-3及其6个杂交种株系的可溶性糖含量、脯氨酸含量、叶绿素含量和水分饱和亏缺4个指标进行了研究。结果表明：8个紫花苜蓿材料可溶性糖含量、脯氨酸含量和水分饱和亏缺随着旱作时间的延续明显增加,而叶绿素含量逐渐减少。通过隶属函数分析将8个紫花苜蓿材料可分为3类,高抗旱性：AC-3、杂交种4和杂交种6;中抗旱性：德钦紫花苜蓿、杂交种3和杂交种5;弱抗旱性：杂交种1和杂交种2。

英文摘要：

The soluble sugar content,proline content,chlorophyll content and water saturation deficit of wild alfalfa from Deqin county,Yisan alfalfa AC-3 and their six F1 hybrids that growing in Kunming were studied in order to investigate its physiological change under dry-farming conditions in spring.The results showed that the soluble sugar,proline content and water saturation deficit of alfalfas increased with duration of non-irrigation,but chlorophyll content gradually reduced.Drought resistance of different alfalfas was given based on subordinate function values analysis.Tested alfalfas could be classified into three drought resistant ranks.Hybrid 4,hybrid 6 and AC-3 were high drought resistance.Hybrid 3,hybrid 5 and wild alfalfa were middle drought resistance,and hybrid 1 and hybrid 2 were low drought resistance.