通过高效液相色谱(HPLC)法测定不同试验地间18个苜蓿(Medicago sativa L.)品种植株及根际土壤中主要酚酸和香豆素物质的含量，分析其在不同品种苜蓿植株中的分布特征及不同试验地间差异。经过ASE 350型加速溶剂萃取仪萃取苜蓿植株及根际土壤中酚酸类和香豆素物质，萃取液存放于2oC冰箱，并用0.45 μm有机滤膜过滤后通过HPLC测定自毒物质含量。结果显示，18个苜蓿品种中香豆素、阿魏酸、绿原酸、咖啡酸的含量存在差异，其中香豆素、绿原酸含量显著高于阿魏酸、咖啡酸含量。各苜蓿品种间单一自毒物质含量差异显著(P<0.05)，香豆素、阿魏酸、绿原酸和咖啡酸的总含量差异明显。武威试验地酚酸和香豆素物质平均含量比会宁试验地低4.01%。研究表明：不同苜蓿品种间香豆素、阿魏酸、绿原酸、咖啡酸物质总含量差异显著；苜蓿植株中香豆素、阿魏酸、绿原酸、咖啡酸物质总含量与根际土壤中含量差异极显著。

To find out the distribution characteristics of major phenolic acids and coumarins in 18 alfalfa (Medicago sativa L.) varieties from different testing fields, the contents of these substances in plant and rhizosphere soil were determined by HPLC method. The coumarins and major phenolic acids in plant and rhizosphere soil were extracted using ASE 350 accelerated solvent extractor, and the extracts were stored at 2℃. After filtered through 0.45 μm organic filtration membrane, the autotoxins contents in the extracts were determined by HPLC. Results showed that the contents of coumarin, ferulic acid, chlorogenic acid and caffeic acid in 18 alfalfa varieties varied with plant varieties. Among these substances, the contents of coumarin and chlorogenic acid were dramatically higher than those of ferulic acid and caffeic acid. The differences of single autotoxin content among varieties were significant (P<0.05), and total contents of coumarin, ferulic acid, chlorogenic acid and caffeic acid varied with plant varieties as well. In addition, the average contents of phenolic acids and coumarins from Huining testing field were 4.01% higher than these from Wuwei testing field. In conclusion, the total contents of coumarin, ferulic acid, chlorogenic acid and caffeic acid were significantly different among various alfalfa varieties (P<0.05), and the total contents of these substances in alfalfa plant were remarkably different from those in rhizosphere soils.

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国家现代牧草产业技术体系建设专项(CARA-35)和全国牧草种质资源保种项目(NB2130135)资助。