Toronto, Ontario, Canada
July 28, 2009
An international team of
scientists, including botanists from the
University of Toronto, have
identified a pair of genes which can be used to catalogue the
world's plants using a technique known as DNA barcoding — a
rapid and automated classification method that uses a short
genetic marker in an organism's DNA to identify it as belonging
to a particular species.
"Barcoding provides an efficient means by which we can discover
the many undescribed species that exist on earth," says Spencer
Barrett, a professor of ecology and evolutionary biology at the
University of Toronto and the head of the Canadian plant
barcoding working group. "This discovery is important because
understanding biodiversity is crucial to long-term human
existence on the planet."
DNA barcoding has been widely used to identify animal species
since its invention five years ago. But its use for plants was
delayed because of the complex nature of plant genetics and
disagreements over the appropriate DNA regions to use.
"We compared the performance of the seven leading candidate gene
regions against three criteria: ease of obtaining DNA sequences;
quality of the DNA sequences; and ability to tell species apart
based on a sample of 550 species of land plants", says Barrett.
"Based on this global analysis we recommended that matK and rbcL
— two chloroplast genes — are adopted as the DNA barcode for
land plants."
The primary application of the methodology will be the
identification of the many species in the world’s biodiversity
hotspots where a shortage of specialists hinders conservation
efforts. Other applications include identifying illegal trade in
endangered species, identifying invasive organisms, poisonous
species and fragmentary material in forensic investigations. The
technique will work on minute amounts of tissue and can be used
on fragments of plant material, small seedlings, and in some
cases digested or processed samples.
The methodology will also be used immediately in global projects
such as Tree-BOL which aims to build the DNA barcode database
for all the species of trees of the world — many of which are of
economic and conservation importance.
The report appears this week in Proceedings of the National
Academy of Sciences under the group authorship of the Consortium
for the Barcode of Life (CBOL) Plant Working Group.
The scientific team involves 52 researchers working in 10
countries representing the following institutions: Royal Botanic
Garden Edinburgh; National Center for Biotechnology Information;
University of Guelph, Guelph; University of Johannesburg; Royal
Botanic Gardens Kew; Smithsonian Institution; UBC Botanical
Garden & Centre for Plant Research and University of British
Columbia; Natural History Museum, London; Korea University;
University of Toronto; Universidade Estadual de Feira de
Santana; Universidad de Costa Rica; Columbus State University;
University of Wisconsin; Universidad de los Andes; South African
National Biodiversity Institute; Aberystwyth University;
University of Cape Town; Hallym University; Seoul National
University; Natural History Museum of Denmark and University of
Copenhagen; Universidad Nacional Autónoma de México; Imperial
College London; New York Botanical Garden.
The Canadian portion of the project was funded by Genome Canada. |
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