海南草地贪夜蛾生物型鉴定与分析

Identification and analysis of biotype of fall armyworm in Hainan

海南是草地贪夜蛾北迁虫源的重要越冬基地。为监测分析其入侵海南的种群生物型,采用COⅠ和Tpi两种分子标记及碳稳定同位素测定方法,对2020—2022年三亚、海口、儋州高空测报灯诱集的草地贪夜蛾样品进行生物型分析。结果表明,基于COⅠ基因序列比对草地贪夜蛾水稻型占52.08%,玉米型占47.92%;基于Tpi基因第四外显子gTpi183Y位点鉴定均为玉米型,且gTpi192Y和gTpi198Y位点将玉米型分为了3个亚型:Tpi-Ca1(占比47.73%)、Tpi-Ca2(占比11.36%)、Tpi-Ca1/Ca2(占比40.91%);碳稳定同位素结果显示2020—2022年草地贪夜蛾取食C4(玉米)植物比例分别为42.86%、57.89%、58.34%,同时取食C3(水稻)、C4植物比例分别为57.14%、42.11%、33.33%,而取食C3植物只有2022年8.33%的样本。本研究有助于跟踪监测草地贪夜蛾在海南的生物型情况,为精准监测和早期预警提供参考。

Hainan serves as an important stop on the migration route of Spodoptera frugiperda in China.This study analyzed the biotype of S.frugiperda in Hainan by using two molecular markers,COⅠand Tpi,and carbon stable isotope determination methods.Samples were collected by vertical-pointing searchlight-trap in Sanya,Haikou,and Danzhou from 2020 to 2022.The results showed that 52.08%of the samples were rice-biotype and 47.92%were corn-biotype based on the COⅠgene sequence.All samples were identified as corn-biotype based on the gTpi183Y site of the fourth exon of the Tpi gene.Further analysis of the gTpi192Y and gTpi198Y sites revealed three subtypes of corn-biotype:Tpi-Ca1(accounting for 47.73%),Tpi-Ca2(accounting for 11.36%),and Tpi-Ca1/Ca2(accounting for 40.91%).The results of the carbon stable isotope indicated that from 2020 to 2022,the proportion of moths feeding on C4 plants(corn)was 42.86%,57.89%,and 58.33%,while the proportion of moths feeding on both C3(rice)and C4 plants was 57.14%,42.11%,and 33.33%,respectively.Additionally,only 8.33%of the moths sampled in 2022 fed on C3 plants.This study may aid in tracking and monitoring the biotype of S.frugiperda in Hainan and provide a reference for accurate monitoring and early warning.