采用不同溶剂对芦苇[Phragmites australis (Cav.) Trin. ex Steud.]叶片水提物进行萃取,并以小麦(Triticum aestivum Linn.)和萝卜(Raphanus sativus Linn.)种子为实验材料对不同萃取物的化感效应进行检测;采用薄层层析和柱层析对抑制作用最强的正丁醇萃取物进行进一步分离,并采用GC-MS 法对生物活性较高的组分进行组成成分分析;在此基础上,选择相对含量高并具有代表性的潜在化感成分进行生物活性检测,以期筛选出芦苇叶中的潜在化感成分。结果显示:随质量浓度(20、100 和500 mg·L^-1 )提高,芦苇叶水提物的石油醚、二氯甲烷、乙酸乙酯、正丁醇和水萃取物对小麦和萝卜种子萌发的抑制作用均逐渐增强,其中正丁醇萃取物的抑制作用最强。在正丁醇萃取物的11 个组分中,Fr. 5、Fr. 6、Fr. 7、Fr. 9 和Fr. 10 组分均能显著抑制萝卜或小麦幼苗的生长,经质量浓度500mg·L^-1 各组分处理液处理后萝卜或小麦幼苗的株高、根长及单株鲜质量均显著低于对照(P<0. 05)。采用GC-MS法从Fr. 5、Fr. 6、Fr. 7、Fr. 9 和Fr. 10 组分中分别鉴定出11、15、15、12 和22 种成分,分别占各组分总相对含量的83. 02%、91. 31%、87. 36%、97. 92%和94. 34%,主要成分包括糖类、醇类、有机酸类、酮类、酰胺类和酯类。对14 种潜在化感成分生物活性的检测结果显示这些成分对小麦幼苗生长有明显的抑制作用,其中,经质量浓度20mg·L^-1  油酸酰胺、棕榈酸甲酯、亚油酸、2-苯乙胺、2-甲基烯丙醇和4-羟基-3-甲氧基苦杏仁酸处理后,小麦幼苗的株高、根长及单株鲜质量显著低于对照。综合分析结果显示:芦苇叶水提物具有较强的化感活性,其潜在的化感成分为油酸酰胺、棕榈酸甲酯、亚油酸、2-苯乙胺、2-甲基烯丙醇和4-羟基-3-甲氧基苦杏仁酸。

Water extracts from leaf of Phragmites australis (Cav.) Trin. ex Steud. were extracted by different solvents, and taking seeds of Triticum aestivum Linn. and Raphanus sativus Linn. as experimental materials, allelopathic effect of different partitioned extracts was determined. Partitioned extract of 1-butanol with the strongest inhibition effect was separated further by thin layer chromatography and column chromatography, and composition compounds in fractions with higher biological activity were analyzed by GC-MS method. On this basis, biological activity of potential allelopathic compound selected with high relative content and typicality were determined to screen potential allelopathic compound in leaf of P. australis. The results show that with enhancing of mass concentration (20, 100 and 500 mg·L^-1), inhibition effects of partitioned extracts of petroleum ether, dichloromethane, ethyl acetate,1-butanol and water in water extracts from leaf of P. australis on seed germination of T. aestivum and R. sativus increase gradually, in which that of 1-butanol partitioned extract is the strongest. Among eleven fractions from 1-butanol partitioned extract, Fr. 5, Fr. 6, Fr. 7, Fr. 9 and Fr. 10 fractions can significantly inhibit growth of R. sativus or T. aestivum seedling, and after treated by treating solution with mass concentration 500 mg·L^-1 of each fraction, height, root length and fresh weight per plant of R. sativus or T. aestivum seedling are significantly lower than those of the control (P<0. 05). 11, 15, 15, 12 and 22 compounds are identified from Fr. 5, Fr. 6, Fr. 7, Fr. 9 and Fr. 10 fractions by GC-MS method, accounting for 83. 02%, 91. 31%, 87. 36%, 97. 92% and 94. 34% of total relative content in above respective fractions, respectively. And main compounds include saccharides, alcohols, organic acids, ketones, amides and esters. The determination result of biological activity of fourteen potential allelopathic compounds shows that these compounds have an obvious inhibition effect on growth of T. aestivum seedling, in which,  after treated by oleamide, methylhexadecanoate, (Z,Z)-9,12-octadecadienoic acid, 2- phenethylamine,  2-methyl-2-propen-1-ol and DL-4-hydroxy-3-methoxymandelic acid with mass concentration 20 mg·L^-1 , height, root length and fresh weight per plant of T. aestivum seedling are significantly lower than those of the control. The comprehensive analysis result shows that water extracts from leaf of P. australis has strong allelopathic activity, and potential allelopathic compounds are oleamide, methyl hexadecanoate, (Z,Z)-9,12-octadecadienoic acid, 2-phenethylamine, 2-methyl-2-propen-1-ol and DL-4-hydroxy-3-methoxymandelic acid.