Insecticidal active ingredients and mechanism against Spodoptera frugiper-da in Mirabilis jalapa seeds
In order to study the insecticidal active components of Mirabilis jalapa seeds against Spodoptera frugiper-da,the petroleum ether extracts from Mirabilis jalapa seeds were separated by silica gel column chromatography and ana-lyzed by gas chromatography-mass spectrometry(GC-MS).The insecticidal activity of each fraction and chemical composi-tion against Spodoptera frugiperda was determined by insect immersion method.The results showed that the petroleum ether extract was separated by silica gel column chromatography,and a total of 20 fractions were obtained.Fraction 2 displayed the highest corrected mortality rate for the 3rd instar larvae of Spodoptera frugiperda,reaching 82.00%on the 7th day.Ac-cording to GC-MS analysis,the main chemical components of fraction 2 were tridecane(9.59%),ethyl linoleate(51.14%),and ethyl oleate(34.26%).On the 7th day,the LC50 values of the three chemical components against the 3rd instar larvae of Spodoptera frugiperda were 15.06 mg/ml,5.70 mg/ml,and 18.42 mg/ml,respectively.Ethyl linoleate had the best insecticidal activity.With the increase of ethyl linoleate concentration,the activity of acetylcholinesterase(AChE)showed a trend of first inhi-bition,then activation,and then inhibition,and the activity of carboxylesterase(CarE)revealed a trend of first inhibition and then activation,while the activity of Ca2+-Mg2+-ATPase indicated a trend of first activation and then inhibition.In sum-mary,ethyl linoleate was the compound with the best insecticidal activity in the petroleum ether extract of Mirabilis jalapa seeds,which could provide theoretical basis for the development and utilization of new plant insecticides.
万方数据
维普
