Invasion of the grasses

Native grass Austrostipa scabra. Credit: Janusz Molinski/Royal Botanic Gardens Melbourne
Native grass Austrostipa scabra. Credit: Janusz Molinski/Royal Botanic Gardens Melbourne

DNA barcodes could help farmers and conservationists identify wanted and unwanted grasses.

Identifying grasses is difficult especially when they’re not flowering. But identification is important. Australia’s agriculture and ecology are threatened by invading grasses, such as Chilean needle grass (Nassella neesiana) and serrated tussock (N. trichotoma). And efforts to re-introduce native grasses can be hampered if you can’t tell the grasses apart.

Heavy infestations of invasive and unpalatable species reduce productivity, cause injury to stock and reduce the value of wool and hides. Millions of hectares are infested with these weeds, and the cost to farmers runs into the tens of millions of dollars each year.

Scientists at the Royal Botanic Gardens Melbourne are developing DNA barcoding techniques to identify a grass from any part of a sample: leaves, roots, stems or seeds. It’s in collaboration with the Victorian Department of Primary Industries and is one of the first projects to DNA barcode Australia’s flora.

But DNA barcoding will only be reliable if there’s a good reference collection. Fortunately, the National Herbarium of Victoria has an extensive and well-verified collection of grass samples and access to further reference collections worldwide. The long term goal is to develop a library of DNA barcodes to offer a cheap, reliable and fast molecular identification service for grasses—helping to conserve native grasses, and to fight the war on invading grasses.

For more information: National Herbarium of Victoria, Royal Botanic Gardens Melbourne, Eleanor Bridger, Tel: +61 (3) 9252 2387, eleanor.bridger@rbg.vic.gov.au, www.rbg.vic.gov.au