Identification of Erythroxylum taxa by AFLP DNA analysis.

Full Abstract

Erythroxylum coca, indigenous to the Andean region of South America, is grown historically as a source of homeopathic medicine. However, in the last century, cultivation of E. coca and several closely-related species for the production of illicit cocaine has become a major global problem. Two subspecies, E. coca var. coca and E. coca var. ipadu, are almost indistinguishable phenotypically; a related cocaine-bearing species also has two subspecies (E. novogranatense var. novogranatense and E. novogranatense var. truxillense) that are phenotypically similar, but morphologically distinguishable. The purpose of this research was to discover unique AFLP DNA patterns ("genetic fingerprinting") that characterize the four taxa and then, if successful, to evaluate this approach for positive identification of the various species of coca. Of seven different AFLP primer pairs tested, a combination of five proved optimal in differentiating the four taxa as well as a non-cocaine-bearing species, E. aerolatum. This method of DNA fragment separation was selective, and faster, for coca identification, compared with analyses based on flavonoid chemotaxonomy. Using the 5-primer AFLP approach, 132 known and unknown coca leaf accessions were evaluated. Of these, 38 were collected in 1997-2001 from illicit coca fields in Colombia, and all were genetically differentiated from coca originating in Peru and Bolivia. Based on the DNA profiling, we believe that the Colombian coca now represents a hybridization of E. coca var. ipadu. Geographical profiling within Colombia also seems feasible as new coca production areas are developed or new types of coca are introduced within traditional growing areas.

Author information

Author/s: Johnson, Emanuel L (EL); Saunders, James A (JA); Mischke, Sue (S); Helling, Charles S (CS); Emche, Stephen D (SD);

Affiliation: Alternate Crops and Systems Laboratory, Plant Sciences Institute, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Beltsville, MD 20705-2350, USA. johnsone(-atsign-)ba.ars.usda.gov

Journal and publication information

Publication Type: Journal Article

Journal: Phytochemistry (Phytochemistry), published in United States. (Language: eng)

Reference: 2003-Sep; vol 64 (issue 1) : pp 187-97

Dates: Created 2003/08/29; Completed 2004/01/06;

PMID: 12946417, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.