Present address: Institute of Zoology, Zoological Society of London, Regent’s Park, London, NW1 4RY, UK.
DNA barcodes for Mexican Cactaceae, plants under pressure from wild collecting
Article first published online: 3 APR 2011
© 2011 Blackwell Publishing Ltd
Molecular Ecology Resources
Volume 11, Issue 5, pages 775–783, September 2011
How to Cite
YESSON, C., BÁRCENAS, R. T., HERNÁNDEZ, H. M., De La LUZ RUIZ-MAQUEDA, M., PRADO, A., RODRÍGUEZ, V. M. and HAWKINS, J. A. (2011), DNA barcodes for Mexican Cactaceae, plants under pressure from wild collecting. Molecular Ecology Resources, 11: 775–783. doi: 10.1111/j.1755-0998.2011.03009.x
- Issue published online: 15 AUG 2011
- Article first published online: 3 APR 2011
- Received 16 November 2010; revision received 3 February 2011; accepted 17 February 2011
- DNA barcodes;
- internal transcribed spacer;
- species identification
DNA barcodes could be a useful tool for plant conservation. Of particular importance is the ability to identify unknown plant material, such as from customs seizures of illegally collected specimens. Mexican cacti are an example of a threatened group, under pressure because of wild collection for the xeriscaping trade and private collectors. Mexican cacti also provide a taxonomically and geographically coherent group with which to test DNA barcodes. Here, we sample the matK barcode for 528 species of Cactaceae including approximately 75% of Mexican species and test the utility of the matK region for species-level identification. We find that the matK DNA barcode can be used to identify uniquely 77% of species sampled, and 79–87% of species of particular conservation importance. However, this is far below the desired rate of 95% and there are significant issues for PCR amplification because of the variability of primer sites. Additionally, we test the nuclear ITS regions for the cactus subfamily Opuntioideae and for the genus Ariocarpus (subfamily Cactoideae). We observed higher rates of variation for ITS (86% unique for Opuntioideae sampled) but a much lower PCR success, encountering significant intra-individual polymorphism in Ariocarpus precluding the use of this marker in this taxon. We conclude that the matK region should provide useful information as a DNA barcode for Cactaceae if the problems with primers can be addressed, but matK alone is not sufficiently variable to achieve species-level identification. Additional complementary regions should be investigated as ITS is shown to be unsuitable.