地黄对芝麻的化感作用及其化感物质的分离鉴定

通过分离地黄(Rehmannia glutinosa)组织中抑制芝麻(Sesamum indicum)生长发育的化感物质, 以弄清地黄茬种植芝麻造成芝麻严重减产的原因。以芝麻为受体的生物测定为检测跟踪手段, 通过浸提、萃取、硅胶柱层析分离方法及气相色谱-质谱(GC-MS)鉴定方法, 分离鉴定了地黄组织影响芝麻的化感物质。对地黄不同组织的浸提液进行的生物测定结果表明: 影响芝麻生长发育的化感物质在地黄叶中含量高。地黄叶浸提液的不同有机相萃取组分的生物测定结果表明: 乙酸乙酯相化感活性最强, 乙酯乙酯相通过硅胶柱层析分离获得的洗脱组分Fr7化感活性最强。通过GC-MS及验证试验证明: 地黄抑制芝麻生长的化感物质是月桂酸和2,6-二叔丁基苯酚。研究表明地黄他感作用与自毒作用的化感物质是不同的。

ISOLATION AND IDENTIFICATION OF ALLELOCHEMICALS FROM REH-MANNIA GLUTINOSA THAT AFFECT SESAMUM INDICUM

Aims Our objective was to explore why Sesamum indicum yield declined severely when planted after Rehmannia glutinosa in crop rotation.Methods We used extraction, silica gel column chromatography, gas chromatography mass spec-trometry and bioassay to isolate and identify allelochemicals from R. glutinosa that affect S. indicum. Bioassays were conducted with extractions from different parts of glutinosa.Important findings Leaf parts had high allelochemical content. Ethyl acetate phase extraction contained most allelochemicals. Active elution Fr7 was obtained by silica gel column chromatography. Allelochemicals lauric acid and 2,6-Ditertbutyl phenol were isolated and identified by use of gas chromatography mass spectrometry. R. glutinosa and S. indicum both have serious continuous cropping obstacles. Allelochemicals affecting 5. indicum are different from toxic materials of R. glutinosa. Additional research is needed to further explore interactions of allelochemicals with soil and effects on S. indicum and on the possibility of reducing the effect of R. glutinosa on S. indicum.