DNA barcodes for biosecurity: invasive species identification

Abstract

Biosecurity encompasses protecting against any risk through 'biological harm', not least being the economic impact from the spread of pest insects. Molecular diagnostic tools provide valuable support for the rapid and accurate identification of morphologically indistinct alien species. However, these tools currently lack standardization. They are not conducive to adaptation by multiple sectors or countries, or to coping with changing pest priorities. The data presented here identifies DNA barcodes as a very promising opportunity to address this. DNA of tussock moth and fruit fly specimens intercepted at the New Zealand border over the last decade were reanalysed using the cox1 sequence barcode approach. Species identifications were compared with the historical dataset obtained by PCR-RFLP of nuclear rDNA. There was 90 and 96% agreement between the methods for these species, respectively. Improvements included previous tussock moth 'unknowns' being placed to family, genera or species and further resolution within fruit fly species complexes. The analyses highlight several advantages of DNA barcodes, especially their adaptability and predictive value. This approach is a realistic platform on which to build a much more flexible system, with the potential to be adopted globally for the rapid and accurate identification of invasive alien species.

Potential use of DNA barcoding for the identification of Salvia based on cpDNA and nrDNA sequences

“…Tree-based methods were used to test the applicability of the seven loci and three combinations for species identification. The methods based on the clustering of individuals on phylogenetic trees have been suggested because statistical support can be measured through bootstrap and the resulting tree provides a visual representation of the affinities of the query sequence (Armstrong and Ball, 2005). The neighbor-joining (NJ) tree based on different barcodes was constructed using MEGA 4.0 (Tamura et al, 2007).…”

Identification of exotic North American crayfish in Europe by DNA barcoding

“…DNA barcoding has repeatedly been shown to be highly useful for the identification of invasive species (e.g., Armstrong and Ball, 2005;Saunders, 2009;Van de Wiel et al, 2009;Floyd et al, 2010). The method may also be used to distinguish closely related species or cryptic species complexes (e.g., Bickford et al, 2007;Dillman et al, 2010).…”

“…Missing data on relevant taxa may prevent identification, while the presence of a closely related congener but absence of a conspecific in the reference data set may lead to misidentification of the invader (Armstrong and Ball, 2005). Before reaching conclusions on the taxonomic status of seemingly divergent lineages, more data on genetic variation within the concerned taxon should be obtained from the original distribution range.…”

Screening mitochondrial DNA sequence variation as an alternative method for tracking established and outbreak populations of Queensland fruit fly at the species southern range limit

“…An alternative molecular marker, mitochondrial DNA (mtDNA), that is inherited independently from nuclear (microsatellite) markers has previously been employed for species identification of B. tryoni (Armstrong & Ball, 2005; Blacket, Semeraro, & Malipatil, 2012; Cameron et al., 2010). MtDNA DNA sequences are ideal for cumulative studies, as they can be unambiguously scored and can be built up into a spatial and temporal “library” as samples become available.…”