Peyote identification on the basis of differences in morphology, mescaline content, and trnL/trnF sequence between Lophophora williamsii and L. diffusa

The genus Lophophora includes two species: Lophophora williamsii (peyote) and L. diffusa. Contrary to earlier reports that L. williamsii contained mescaline and L. diffusa did not, some L. williamsii specimens lacked mescaline, showing that mescaline content alone cannot differentiate the species. The study examined morphology, mescaline content, and DNA sequences of the chloroplast trnL/trnF region. L. williamsii specimens fell into two groups: Group 1 had small epidermal protuberances, contained mescaline, and had an 881-base-pair (bp) DNA sequence (one exception at 877 bp); Group 2 had large protuberances, no mescaline, and a 893-bp sequence. L. diffusa had medium protuberances, no mescaline, and a 903-bp sequence. The PCR-RFLP method successfully distinguished the two species and differentiated the L. williamsii groups.

Study at a glance

Abstract

Genus Lophophora (Cactaceae) has two species: Lophophora williamsii Coulter, which is called peyote, and L. diffusa Bravo. Although it was reported that L. williamsii contained mescaline and L. diffusa did not, we found L. williamsii specimens that did not contain mescaline. This finding indicated that the two species could not be differentiated in terms of mescaline content. Moreover, the relationship between mescaline content and morphology of the two species is also unknown. In this study, we attempted to clarify the difference in morphology, mescaline content, and DNA alignment of the chloroplast trnL/trnF region between L. williamsii and L. diffusa. As a result, L. williamsii specimens were classified into two groups. Group 1 had small protuberances on the epidermis, contained mescaline, and the analyzed region on the trnL/trnF sequence was 881 base pairs (bp) long in all except one (877 bp). Group 2 had large protuberances on the epidermis, did not contain mescaline, and the analyzed region was 893 bp long. On the other hand, L. diffusa had medium-sized protuberances on the epidermis, did not contain mescaline, and the analyzed region was 903 bp long. Also investigated was the potential application of the PCR-restriction fragment length polymorphism (RFLP) method as a means of identification based on the trnL/trnF sequence. By applying the PCR-RFLP method, the two species could be distinguished and L. williamsii specimens could be differentiated into group 1 and group 2.