Abstract: 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.

Key words: Alfalfa, Dry-farming conditions, Index of resistance drought, Subordinate function value

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。

关键词: 紫花苜蓿, 旱作条件, 抗旱指标, 隶属函数