【摘要】 植物释放的挥发性单萜在生态系统中起着重要的作用,这些单萜不仅能以空气为载体对其他植物显示直接的化感作用,而且也能以土壤为载体进行间接的化感作用。通过对三裂叶豚草挥发物对植物种子萌发和土壤微生物种群影响及其化学成分的鉴定研究,验证了以单萜类物质为主的三裂叶豚草挥发物可以经土壤载体对其他植物及土壤微生物显示化感效应。还对植物挥发物化学成分鉴定的GC(气相色谱)和GC-MS(气相色谱-质谱联用)方法存在的一些误区进行了澄清,这将有助于对生态系统中植物挥发物化感作用的研究和认识。更多还原

【Abstract】 Plant may release volatile monoterpenes into the environment under natural conditions.These volatile monoterpenes play an important role in ecosystems,including allelopathy and chemical interactions among the host plant,herbivore,and parasitoid or predator in tri-trophic systems.Allelopathy of volatile monoterpenes released from various plants species could be achieved by both air and soil media.In this study,chemical constituents of the volatiles released from Ambrosia trifida L.and their effects on the germination of crop seeds and microbial population in soil were investigated.As a result,the monoterpenes are major components(84.2%) of the volatiles from A.trifida.Furthermore,saturated aqueous solution of the volatile monoterpenes from A.trifida affected seed germination and microbial populations in soil,indicating that allelopathic potential of the monoterpenes can be mediated by soil.GC and GC/MS are the effective instruments to determine the chemical constituents of volatiles.However,some scientists who are not chemists often determine the volatiles components by means of GC/MS only,not both GC and GC/MS.And this resulted in incorrect identification of volatile chemical constituents.Actually, the combined analysis of GC retention indexes(Kováts indexes) and GC-MS data with the aid of the mass chromatograms of the characteristic fragment ions reported in the NIST and WILEY databases is essential for the reliable identification of volatile constituents.This study clarified some mistakes in experimental methods,especially in determination of chemical constituents of plant volatiles by means of GC and GC-MS.These methods and results of this study would be helpful to our further understanding of volatile allelochemicals released from plant species to the soils in ecosystems.更多还原