Using COI gene sequence to barcode two morphologically alike species: the cotton bollworm and the oriental tobacco budworm (Lepidoptera: Noctuidae)

Abstract

Due to limited morphological difference, the two closely related sister species, the cotton bollworm, Helicoverpa armigera (Hübner) and the oriental tobacco budworm, H. assulta (Guenée) (Lepidoptera: Noctuidae), are very difficult to distinguish, especially at the larvae stage. Recently, DNA sequence has been widely used as a bio-barcode for species identification. In this study, we attempted to distinguish H. armigera and H. assulta using the mitochondrial cytochrome C oxidase subunit I gene (COI) gene sequence as the barcode. We determined a 658 bp segment of the COI gene for 28 individuals of H. armigera, 8 individuals of H. assulta, and 10 individuals of Mamestra brassicae (as the outgroup) in Yunnan Province, southwest of P. R. China, together with one H. assulta and two H. armigera reported sequences from GenBank. Twenty-three haplotypes were identified in all 49 samples. As expected, network analysis of the haplotypes of the three species presented a clustering pattern consistent with the respective species status. Haplotypes of the same species differed from each other by no more than three nucleotide substitutions. However, each haplotype of H. armigera differed from that of H. assulta by at least 22 nucleotide substitutions. Both species differed from M. brassicae by more than 50 nucleotide substitutions. 17 unique diagnostic nucleotides were also used to discriminate the two species. The finding of large COI sequence differences between H. armigera and H. assulta suggested that it could be used to distinguish the two morphologically alike species and be employed for quick species identification during pest control.

Cross-species amplification and polymorphism of microsatellite loci in Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) in Brazilian cropping systems

“…Studies with mitochondrial and nuclear markers revealed high genetic diversity and low genetic structure (spatial, temporal, and host) (Endersby et al, 2007;Li et al, 2011;Perera and Blanco, 2011;Behere et al, 2007Behere et al, , 2013. Similar results have been observed in Brazil (Leite et al, 2014;Mastrangelo et al, 2014).…”

Genetic diversity and susceptibility to Vip3Aa20 protein in Brazilian populations of <i>Helicoverpa armigera</i> and <i>Helicoverpa zea</i> (Lepidoptera: Noctuidae)

“…However, we noted that the haplotype and nucleotide diversities found for H. armigera in Brazil are similar to or greater than those reported for natural H. armigera populations in the Old World LI et al, 2011). For example, one outer branch of the H. armigera haplotype network, formed by haplotypes H19, H18, H16, H12, H21, and H25, is noteworthy for having the greatest genetic distance from the central haplotypes (H1 and H3), and these haplotypes have yet to be identified in Old World populations LI et al, 2011). In addition, joint analysis of the haplotypes from Brazil and the Old World yielded an overall structure that was similar to the haplotype network obtained only from the Brazilian individuals.…”

“…Studies with mitochondrial and nuclear markers revealed high genetic diversity and low genetic structure (spatial, temporal, and host) ENDERSBY et al, 2007;LI et al, 2011;. Similar results have been observed in Brazil MASTRANGELO et al, 2014).…”

“…Ten microsatellites were used for Brazilian H. armigera, and eight were used for Brazilian and USA H. zea when intraspecific analyses were performed. Data analyses were performed with 17 populations of H. armigera, and 12 of H. zea collected in Brazil in 2012, 2013, and 2014 ;ENDERSBY et al, 2007;LI et al, 2011;). Where they co-occur, like in Brazil, there is no report of inter and intraspecific gene flow based on nuclear molecular markers.…”

“…Studies of population genetics of H. armigera and H. zea using mitochondrial and nuclear markers revealed high genetic diversity and low structure in different regions of the world ENDERSBY et al, 2007;LI et al, 2011;. For H. zea, 13 microsatellite loci were isolated and characterized (PERERA et al, 2007) and for H. armigera 20 loci were reported (TAN et al, 2001;JI et al, 2003;SCOTT et al, 2004;WU;ZHANG, 2005).…”