Abstract:

In order to study the components of ‘ZhongMu No.1’ alfalfa root exudates in different planting years (1 year, 10 years, 20 years, 30 years), we leached its rhizosphere soil with two different polar solvents (ethyl acetate, dichloromethane). Finally, the chemical components of root exudates were analyzed by GC-MS. The results showed that:the root exudates of alfalfa mainly contained alkanes, esters, alcohols, acids, phenols, ketones and ethers, among which the proportion of alkanes was the largest, accounting for more than 75%. Most of the alkanes are linear, and a small number of them are branched alkanes and naphthenes. In the results of dichloromethane extraction, octadecane, hexadecane and tetradecane accounted for a larger proportion of planting 10 years, 20 years, 30 years of alfalfa root exudates. Diethyl phthalate, 1.54-dibromo pentadecane, eicosane, hexacosane and octadecane accounted for a larger proportion of the 1-year-planting alfalfa exudates. The results of ethyl acetate extraction showed that the relative content of octadecane was 8.82%, 11.5%, 17.85% and 25.69% respectively in the four kinds of cropping years. It extracted a relatively small amount of material compared with the results of methylene chloride.

Key words: Different planting years, Root exudates, GC-MS, Heneicosane

摘要：

为研究不同种植年限（1年、10年、20年、30年）紫花苜蓿‘中苜一号’根系分泌物的组分，分别以不同极性的浸提剂（乙酸乙酯、二氯甲烷）浸提其根际土壤，最终借助GC-MS气质联用技术分析其根系分泌物的化学组分。结果表明：苜蓿的根系分泌物主要含有烷烃类、酯类、醇类、酸类、酚类、酮类、醚类化合物，其中以烷烃类所占比重最大，占到75%以上，多数为直链烷烃，但也包括少数的支链烷烃和环烷烃。在二氯甲烷提取结果中种植10年、20年、30年的苜蓿根系分泌物以二十一烷、三十六烷、四十烷所占的比例较大，在种植1年的苜蓿分泌物中又以邻苯二甲酸二乙酯、1.54-二溴五十四烷、二十烷、三十六烷、二十一烷等所占比例较大。乙酸乙酯提取结果显示，在四种年限的提取结果中二十一烷的相对含量比例较大，分别占8.82%、11.5%、17.85%、25.69%，但相较于二氯甲烷结果，它提取到的物质种类相对较少。

关键词: 不同种植年限, 根系分泌物, GC-MS, 二十一烷