三七重茬根际土壤中化感物质的测定及其对三七根腐菌的生长作用

目的 研究三七重茬根际土壤中化感物质的组成及其对病原微生物的化感作用。方法 采用乙酸乙酯提取三七重茬根际土壤中的化感物质，利用GC-MS对萃取液进行物质组成分析，并研究检测中出现的特征性化感物质对羟基苯甲酸、邻苯二甲酸二异丁酯对三七根腐病菌（F.oxysporum Schlecht）的化感作用。结果 采集的三七重茬土壤中共检测到29种化感物质，其中2种特征性化感物质对羟基苯甲酸、邻苯二甲酸二异丁酯对三七病原菌的生长呈现低促高抑的现象，且当对羟基苯甲酸浓度为5 mmol/L时能促进病菌小孢子的产生。结论 检测到的化感物质组分为苯甲酸及其衍生物类、酚类、酯类、饱和烃类等物质。这些物质在低浓度时有利于病原菌的生长，对病害的发生具有促进作用。

Detection and allelopathic effect of allelochemicals in the rhizosphere soil ofcontinuously cropped Panax notoginseng (BurK.) F.H. Chen

Abstract: Objective To study the components and allelopathic effect of allelochemicals in the rhizosphere soil of continuously cropped Panax notoginseng (BurK.) F.H. Chen. Methods The allelochemicals were extracted with ethyl acetate. The components of the extracts were analyzed using GC-MS, and the allelopathic effects of p-hydroxybenzoic acid and phthalic acid diisobutyl ester on F. oxysporum Schlecht were explored. Results 29 allelochemicals were detected from the rhizosphere soil of continuously cropped Panax notoginseng (BurK.) F.H. Chen, two among which, p-hydroxybenzoic acid and phthalic acid diisobutyl ester, had a promoting effect at low concentrations while inhibitory effect at high concentrations on the growth of the pathogen. And p-hydroxybenzoic acid at the concentration of 5 mmol/L promoted the generation of microspores. Conclusion 29 allelochemicals were detected from the rhizosphere soil of continuously cropped Panax notoginseng (BurK.) F.H. Chen, among which two allelochemicals, p-hydroxybenzoic acid and phthalic acid diisobutyl ester, have a promoting effect at concentrations while inhibitory effect at high concentrations on the growth of the pathogen.