Two species into one: bottleneck history of Helicoverpa zea from Helicoverpa armigera revealed by DNA barcoding
Behere, Gajanan T., Russell, Derek A., Batterham, Philip and Tay, Wee Tek (2006) Two species into one: bottleneck history of Helicoverpa zea from Helicoverpa armigera revealed by DNA barcoding. In: 7th International Workshop on the Molecular Biology and Genetics of the Lepidoptera, 20-26 August 2006, Orthodox Academy of Crete, Kolympari, Crete, Greece. (Unpublished)Full text not available from this repository.
The use of mitochondrial DNA Cytochrome Oxidase I (mtDNA COI) gene in species identification has gained popularity in recent years, with its effectiveness in identifying cryptic and new species demonstrated in birds and Lepidoptera. The noctuid moths of the genus Helicoverpa include two of the most devastating agricultural pest species: H. armigera of the old world, and H. zea found exclusively in the north and south American continents. Both of these species are polyphagous targeting >150 crop species. Phylogenies of H. armigera and H. zea have to-date been constructed based on coding nuclear DNA sequences and morphological characters, but a mtDNA phylogeny of H. zea and H. armigera has been lacking. Differentiating H. zea and H. armigera based on morphological characters relies almost exclusively on characters of the male genitalia, although accurate identification has remained problematic due to over-lapping ranges in character measurements. H. zea and H. armigera are presently recognised as two separate species despite successful bi-directional, ‘inter-specific’, mating experiments that gave rise to viable offspring, and the trapping of H. zea males when using H. armigera sex pheromones in the North American continent. Using a 511 base pair sequence of a partial mtDNA COI gene, we analysed the phylogenetic relationships amongst 228 H. armigera individuals sampled from China, Australia, Africa, India and Pakistan, plus 14 H. zea from North America, H. punctigera from Australia and H. assulta from India, using Heliothis virescens as an outgroup. Our mtDNA COI phylogeny of Helicoverpa species indicates that H. punctigera is ancestral to H. assulta which is in turn ancestral to H. armigera and H. zea. Furthermore, the long branch-length of H. zea from the H. armigera clade suggests a recent bottleneck event in H. zea’s separation from H. armigera. H. zea and H. armigera show an intermediate level of nucleotide diversity, lying between expected values for intra-specific and inter-specific sequence comparisons, possibly suggesting rapid nucleotide divergence in H. zea due to selection pressures imposed on movement by agricultural practices.
|Item Type:||Conference or Workshop Item (Paper)|
|Additional Information:||Abstract of oral presentation. List of the abstracts from the workshop are available in the Journal of Insect Science: Vol. 7 Article 29 ISSN: 1536-2442 (www.insectscience.org/7.29).|
|Uncontrolled Keywords:||lepidoptera,Helicoverpa zea, Helicoverpa armigera, DNA barcoding|
|Subjects:||Q Science > QH Natural history > QH301 Biology|
|School / Department / Research Groups:||Natural Resources Institute|
Natural Resources Institute > Agriculture, Health & Environment
|Last Modified:||11 Nov 2011 12:06|
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