DNA barcoding of tussock grasses (Poaceae: Poeae)

Project summary

In Australia, the tribe Poeae of the grass family Poaceae includes 17 genera and approximately 94 species. These include economically and environmentally important native genera, such as Poa (tussock grasses) and Festuca (fescues), as well as introduced genera such as Lolium (rye grasses). The largest Australian genus, Poa, contains around 46 species, including dominant species of coastal, tableland and alpine grasslands.

Accurate identification of Poa species is essential for vegetation and habitat monitoring of grasslands, and for ecological restoration projects using nativePoa species. We will generate and apply molecular and morphological data to determine the taxonomic boundaries of several cryptic species, including the most common species, Poa labillardieri and Poa sieberiana. Incorporation of molecular data (DNA barcodes) is necessary as grasses are difficult to identify when flowers or fruit are absent, and morphological characters used to identify species can vary within a single individual or across different habitats.

Identification using DNA sequence data is often referred to as 'DNA barcoding'. DNA barcoding can facilitate rapid identification of plant material. To ensure accuracy of grass DNA barcodes, an extensive molecular reference library of Australian tribe Poeae species is being generated, based on authoritatively identified, vouchered reference material held at the National Herbarium of Victoria (MEL). This will allow rapid identification of both native and invasive Poeae species, such as Festuca gauteri, to prevent their introduction and spread in Australia.

The project will determine the phylogenetic relationships of taxa in tribe Poeae in Australia, revise species concepts and establish a molecular reference library that supports identification of taxa using DNA barcoding techniques. The primary focus will be on the largest genus, Poa, which is thought to comprise a number of undescribed taxa. Evolutionary relationships of many Australian Poaspecies are yet to be determined and these relationships will be explored and used to investigate divergence dating of the Poa radiation in Australia.

Project team

Support

  • ABRS Bushblitz research grant

Publications

Birch, J.L., Cantrill, D.J., Walsh, N.G. and Murphy, D.J. (2014). Phylogenetic investigation and divergence dating of Poa (Poaceae tribe Poeae) in the Australasian Region. Botanical Journal of the Linnean Society 175, 523–552. DOI: 10.1111/boj.12185.