入侵物种三裂叶蟛蜞菊挥发物质的鉴定及其抗菌活性

Identification and fungitoxicity of volatiles of invasive plant Wedelia trilobata L.

采用水蒸气蒸馏法提取入侵杂草三裂叶蟛蜞菊地上部的挥发油,并用生长速率法测定挥发油对水稻稻瘟病菌、水稻纹枯病菌和玉米纹枯病菌生长的影响,采用气相色谱-质谱法(GC-MS)对挥发油的成分进行了分离鉴定。结果表明:三裂叶蟛蜞菊挥发油对3种植物病原菌有显著抑制作用,最高抑制率分别为54.8%、32.9%和56.3%。从挥发油中检测出34种成分,用质谱图检索鉴定出其中29个化合物。已鉴定化合物占挥发油总量90.88%,主要化合物为2,6,6-三甲基-二环[3.1.1]-2-庚烯(25.16%)、2,7,7-三甲基-二环[2.2.1]-2-庚烯(22.90%)和γ-松油烯(8.98%)。本研究表明:入侵植物三裂叶蟛蜞菊挥发物具有较强抑菌作用,可防止本地病菌入侵,这可能是该外来入侵植物大面积扩散的一个重要原因。

Volatile oil from the shoot of Wedelia trilobata L. , an invasive alien weed in South China, was extracted by steam distillation and its fungitoxicity to Magnaporthe grisea Barr. , Rhizoctonia solani （ Oryza sativa L. ） and Rhizoctonia solani （ Zea mays L. ） investigated. The chemical constituents of the volatiles were identified by GC-MS analysis. The volatiles inhibit mycelial growth of the above 3 pathogens at the maximum of 54.8% , 32.9% and 56.3% respectively. 34 constituents are found in the volatile oil, of which 29 identified by mass spectrum constitute 90.88% volatile oil. The main constituents of the volatile oil are 2,6,6-Trimethyl-Bicyclo [ 3.1.1 ]-2-heptene （25.16%）, 2,7,7-Trimethyl-Bicyclo [ 2.2.1 ]-2-heptene （22.90%） and γ-terpinene （8.98%）. The results indicate that volatiles of W. trilobata have strong antibiotic effect on native pathogens. This may be an important mechanism for the successful invasion of the exotic plant.