Molecular diagnostics of exotic pest aphids with emphasis on the population genetic structure of Rhopalosiphum padi (L.) in Victoria .

Ms Isabel Valenzuela, PhD Candidate

(Funded by Department of Primary Industries)

The project will develop a molecular diagnostic protocol to identify quarantine aphid species using molecular markers such as PCR-RLFP. This capability will provide a rapid and reliable identification procedure that can be used when more traditional methods such as morphological taxonomy are not possible (i.e. on nymphal stages). So far 30 aphid species have been collected across Victoria and identified using traditional taxonomy (morphological characters).These will be used to establish the molecular diagnostic protocol and create the reference collection that will be used to validate DNA profiles from other samples.Currently I have initiated laboratory work to develop the molecular diagnostic protocol.

In addition, samples of Rhopalosiphum padi have been taken from 29 sites across Victoria from Poaceae hosts so that I can determine the reproductive mode and population genetic structure of this pest species using microsatellite markers. I have commenced DNA extractions and will start screening these samples for microsatellite profiles over the next few months.