Researchers Use DNA Barcodes to Investigate Fern Identify

Plant nurseries may unknowingly be selling plants that are not what they say they are. (Credit: Emilio Ereza/Alamy)

In the past, scientists used morphological clues to help identify and distinguish between different species. Now, with just a little bit of tissue, researchers can use a new tool called DNA barcoding to identify different species and determine the relationships between them.

Mystery Ferns

Recently, researchers in North Carolina used DNA barcoding to identify a species of fern plant being sold in a local plant nursery. The scientists were not convinced that the plant was labeled correctly. With the help of DNA barcoding, the scientists were able to determine that the ferns being marketed as Wrights Lip ferns (Cheilanthes wrightii), a species native to the southwestern United States and northern Mexico, were actually bristle cloak ferns (Cheilanthes distans), a species native to Australia and some islands in the South Pacific.

Ferns are particularly hard to identify due to a lack of fruits or flowers. Misidentifications can easily occur in a greenhouse setting, either intentionally or accidentally. Because most nurseries do not employ taxonomists, these mistakes often go by unnoticed. So whats the big deal? One problem lies in mistaking non-native plants for a native species. When this happens, there is a potential for introducing invasive species, or unknowingly selling endangered species.

DNA Barcoding

DNA barcoding is a relatively-new technique that was developed by scientists at the University of Guelph (located in Ontario, Canada) in 2003. According to the Consortium for the Barcode of Life, this technique uses a short DNA sequence from a standardized location in the genome as a way to identify a species using molecular data. Many liken this technique to the use of a barcode, or UPC label, on a product in a store. Though two items may look similar, each has a unique UPC code that is distinguished by a scanner that can read the code to identify the product. Similarly, a specific DNA sequence in a gene can be read to identify a species with the use of DNA barcoding.

Initially, the technique was applicable to animal species only. However, in 2008, scientists in the Department of Life Sciences at London’s Imperial College found that a DNA sequence in the gene called matK is nearly identical in plants of the same species, though it differs among plants of different species. Scientists can use this DNA sequence to identify plant species and determine relationships among them. This technique is especially helpful in either confirming or refuting relationships among species. For example, while identifying orchid species in Costa Rica using this technique, scientists determined that what was considered to be a single species of orchid was in fact two separate species.

Future Uses

According to one of the researchers involved in the North Carolina study, DNA barcoding could be used to prevent the sale of harmful, rare, or endangered plant species. It could also aid customs officers work in stopping the sale or trade of these species. The technique of DNA barcoding makes this scenario particularly possible because only a small amount of plant or animal material is necessary to identify a species, rather than the whole organism. In addition, several scientists imagine a scenario where researchers will be able to use a Star Trek-like transponder to easily identify one species from another. Though this molecular technique is still in its infancy, scientists are excited by the possibilities that DNA barcoding may have in the future.

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