祝麗香桔梗自毒作用初步研究.docVIP

桔梗自毒作用初步研究 祝丽香 摘要：目的：研究桔梗是否存在自毒作用。方法：采用室内生物测定方法研究桔梗全株不同溶剂提取液对自身种子萌发的影响，桔梗全株、不同部位水浸液对桔梗幼苗生长发育的影响。结果：结果表明, 桔梗用不同溶剂提取物显著抑制其种子萌发和幼苗生长。桔梗全株的抑制作用依提取溶剂不同而有差异，表现为甲醇水乙酸乙酯石油醚氯仿，且抑制强度呈浓度效应型，甲醇提取液抑制强度为氯仿的3倍。桔梗各部位均含有抑制物质且具有器官差异性，根抑制作用最强。结论：研究结果证明了桔梗存在明显的自毒作用，这是导致桔梗连作障碍的原因之一。 关键词：桔梗；自毒作用 Autotoxicity of Platycodon grandiflorum Zhu Li-xiang1, Bi Sheng2, Liu Yan1 (1 College of Agronomy, Shandong Agricultural University, Tai’an, 271018; 2 Medicinal Technician College of Shandong,Tai’an 271000 ) Abstract: To explore whether plantycodon grandiflorum exists autotoxicity. Bioassay were conducted to study effects of extracts from the whole plant of P. grandiflorum with different solvents on seed germination and the effects of water-extract from different parts of P. grandiflorum on seedling growth. Results showed that extracts from P.grandiflorum significantly inhibited itself seed germination and seedling growth, the inhibition varied depending on the extracting solvents with decreasing order of methyl, water, ethyl acetate, petroleum ether and chloroform. The inhibitory strength of ethyl extract was three times higher than that of chloroform. The inhibitory effect generally increased with the increasing concentration of extract and presented significantly organic difference，the highest value was root. It proved that P. grandiflorum have significantly autotoxicity, which is one of the causes of problems associated with the continuous cropping obstacle of P. grandiflorum. Key words: Platycodon grandiflorum; autotoxicity 近年来，由于中药材需求不断增加，实行连作或复种连作的面积越来越大，连作障碍成为制约我国中药栽培的主要问题。桔梗（platycodon grandiflorum）属于不耐连作的植物。从产地调查发现，连作地块桔梗长势弱、病虫害严重，连作6年基本绝产。随着桔梗栽培面积的逐渐扩大，连作障碍日益严重。长期以来，桔梗生产主要致力于提高栽培技术和防治病虫害等方法来缓解连作障碍[1,2]，效果并不理想，其中的重要原因是对其连作障碍的机制尚未清楚。因此，明确桔梗连作障碍形成原因对克服桔梗连作障碍非常重要。目前还没有关于桔梗连作障碍方面的报道。研究人员对在当归[3]、地黄[4]、伊贝母[5]等药用植物研究发现，自毒作用是导致药用植物产生连作障碍的主要原因之一。桔梗是否存在自毒作用，即前茬桔梗 是否通过根系分泌、地上部淋湿、残茬腐解等途径产生有害物质而直接影响下茬桔梗生长目 前还不清楚。以往研究表明，种子萌发特性影响田间出苗率，幼苗生长则直接影响到植株的