兰州百合根及鳞茎水浸液自毒作用的研究

为探讨兰州百合自毒效应机制,明确百合根及鳞茎中主要自毒物质,设置水(CK)、百合根及鳞茎水浸液10、50、100、150 mg/mL,共计9个处理,用于自毒作用的生物学实验,采用分光光度法及滴定法测定百合幼苗中的生理生化指标,利用GC-MS技术分析兰州百合根及鳞茎中的主要自毒物质。结果显示,兰州百合根及鳞茎水浸液对自身幼苗生长的影响总体上表现为抑制作用,且存在浓度效应。随着水浸液浓度的增加,SOD、POD、CAT三种酶活性先上升后下降,MDA含量和相对电导率变化趋势则相反。浓度高于100 mg/mL时,脯氨酸及可溶性糖含量较对照显著增加(P<0.05)。根及鳞茎氯仿萃取液中分别鉴定出23种、14种化合物,主要包括:2,3-二氢茚、萘、2,4-二叔丁基苯酚、对乙烯基愈创木酚、香草醛、月桂酸、丁香醛、肉豆蔻酸、苯基异氰酸酯、对苯二甲酸二辛酯,其中多数被报道为化感自毒物质。兰州百合根及鳞茎水浸液对其幼苗的生长具有明显自毒效应。自毒作用是导致兰州百合连作障碍的重要原因之一。

Autotoxicity of water extracts of the root and bulb of Lilium davidii var.unicolor salisb

Autotoxicity is one of the main problems in the continuous cropping of Lanzhou lily.The aim of this study was to determine the mechanism of the autotoxic effect of Lanzhou lily and identify the organic compounds responsible for its autotoxicity.Water extracts of the root and bulb were applied to young lily plants at different concentrations (10,50,100,and 150 mg/mL) to test their effects on early development.Spectrophotometry and titration methods were used to measure various physiological indexes in the seedlings,and gas chromatography-mass spectrometry was used to identify compounds in the extracts.The extracts inhibited seedling growth in a concentration-dependent manner.As the concentrations of the extracts increased,the activities of superoxide dismutase,peroxidase,and catalase first increased and then decreased,and the malondialdehyde content and relative conductivity decreased.The contents of proline and soluble sugars increased significantly when the extracts were applied at concentrations greater than 100 mg/mL.Twenty-three and 14 compounds were identified in chloroform extracts of the root and bulb,respectively,including indane,naphthalene,2,4-bis(1,1-dimethylethyl)-phenol,2-methoxy-4-vinylphenol,vanillin,dodecanoic acid,4-hydroxy-3,5-dimethoxy-benzaldehyde,tetradecanoic acid,phenyl isocyanate,1,4-benzenedicarboxylic acid,and bis(2-eth-ylhexyl) ester.Most of the identified substances are known to be allelopathic.These results showed that water extracts of the root and bulb of Lanzhou lily showed autotoxic effects on lily seedling growth.