While we may not think about it, we all know how much barcodes at the supermarket save time by quickly identifying the item we’re buying.

Scientists too have long understood the importance of developing an efficient way to determine the species of an organism. Within the last few years, a barcode system of sorts has been developed and extensively applied to animals, in which a section of DNA – a “genetic marker” – is used that is present in all animals yet is different enough to describe the exact species tested.

However, use of the technique on plants has been delayed due to the complexity of the plant genome compared to that of animals. Scientists have proposed various markers, but no single marker has been agreed upon.

Researchers at the University of Toronto used a systematic approach to determine the best marker to use for the barcode system. By pooling DNA sequence data from over 500 different species of plants, researchers found seven possible locations that could be used for the barcode. Using criteria defined by the Consortium for the Barcode of Life (CBOL) such as ease of testing and species discrimination, researchers examined each of the seven DNA sequences for compatibility with the Barcode system. The results showed that no single DNA sequence met all the criteria, but a combination of the rbcL and matK DNA sequences, located in the plant’s chloroplast genome, could satisfactorily determine the species of a plant.

Researchers anticipate that such a system will be greatly beneficial to environmentalists working towards conservation of endangered plant species, since plant specialists are not always available to assist in matching. Applications in forensics are also possible, since only a small sample of plant tissue is required for a species match.

Discussion Question: How else might a barcode system be beneficial to scientists?

News Article: http://news.biocompare.com/News/NewsStory/283597/University-of-Toronto-Helps-to-’Barcode’-the-World’s-Plants.html

Journal Article: http://www.pnas.org/content/106/31/12794.abstract?sid=d8b27eeb-4c0c-45f8-9eb3-50451c5e03b8