应用不同分子标记鉴别入侵广州草地贪夜蛾的寄主型

Host type identification of Spodoptera frugiperda invading in Guangzhou by different molecular markers

【目的】利用不同分子标记对入侵广州的草地贪夜蛾Spodoptera frugiperda进行寄主型鉴定,以便监测虫源扩散规律以及预测预警虫情。【方法】对采集自广州花都玉米植株的草地贪夜蛾,利用3个COI基因标记COI-A、COI-B和COI-C,以及Tpi基因标记进行鉴定,并对结果进行比较。【结果】序列比对和寄主型分析显示,COI-A、COI-B和COI-C标记鉴定到入侵广州的草地贪夜蛾为已报道的水稻型,且COI-A标记鉴定到草地贪夜蛾与黏虫Mythimna separate的杂合子。基于Tpi基因的标记鉴定到入侵广州的草地贪夜蛾为玉米型,且在第126和第127位碱基为GA/AT杂合。【结论】COI-A标记具有较强的物种鉴别能力,能够鉴定到草地贪夜蛾与其他近源种的杂交事件;Tpi标记可用于鉴定草地贪夜蛾寄主型。2个标记结合相互验证可以提高准确率。开发微卫星标记或者寄主取食功能性基因标记可以实现寄主型的精准鉴定。

【Objective】Different molecular markers were used to identify the host types of Spodoptera frugiperda which invaded Guangzhou,in order to monitor the diffusion of insect sources and to offer forecasting and early warning of insect conditions.【Method】The host types of S.frugiperda collected from maize plants in Guangzhou were identified using three COI gene markers(COI-A,COI-B and COI-C)and the Tpi gene marker.The identification results were compared.【Result】Based on sequence alignment and haplotype analysis,S.frugiperda samples invading Guangzhou were identified as the“rice strain”using COI-A,COI-B and COI-C markers.A sample was identified to be the hybrid of S.frugiperda and Mythimna separate using COI-A marker.S.frugiperda samples invading Guangzhou were identified as the“corn strain”using the Tpi gene marker,and the 126th and 127th bp were GA/AT heterozygous.【Conclusion】The COI-A marker has relatively strong ability of species identification as it can identify the hybridization events between S.frugiperda and other close related species.Tpi marker can be used to identify host types of S.frugiperda.Combining the two markers will improve the identification accuracy.The development of microsatellite markers or functional gene markers related to host feeding would enable precise identification of the host types.