Resurrecting deadly carrots: towards a revision of Thapsia (Apiaceae) based on phylogenetic analysis of nrITS sequences and chemical profiles. (13th March 2014)

• Record Type: Journal Article
• Authors: Weitzel, Corinna; Rønsted, Nina; Spalik, Krysztof; Simonsen, Henrik Toft
• Is Part Of: Botanical journal of the Linnean Society. Volume 174:Number 4(2014:Apr.)
• Page Start: 620
• Page End: 636
• Publication Date: 2014-03-13
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/boj.12144
• Languages: English
• ISSNs: 0024-4074

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <italic>Thapsia</italic> is a small genus of herbaceous perennials in Apiaceae. <italic>Thapsia</italic> occurs around the Mediterranean, extending from the Atlantic coasts of Portugal and Morocco to Crete and other Greek Islands. <italic>Thapsia</italic> is commonly known as deadly carrot because of its poisonous effects. The resin from <italic>Thapsia</italic> spp. has been used in traditional medicine and included in European pharmacopoeias, and several species contain biologically important sesquiterpene lactones, such as thapsigargin. Accordingly, <italic>Thapsia</italic> has for decades been subject to chemical investigations searching for new specialized metabolites with potential as drug leads. However, no generally accepted taxonomic concept of > 40 species and synonyms exists. To address the phylogenetics and circumscription of <italic>Thapsia</italic>, we present the first molecular phylogenetic hypothesis of <italic>Thapsia</italic> based on sequences of the nuclear ribosomal internal transcribed spacer (nrITS) region from 50 accessions of <italic>Thapsia</italic> and representatives of all currently recognized genera in subtribe Daucinae. Phylogenetic analysis using maximum parsimony and Bayesian inference resulted in a well‐resolved topology with strong support for inclusion of all the species studied here from <italic>Ammodaucus</italic>, <italic>Distichoselinum</italic>, <italic>Elaeoselinum</italic>, <italic>Guillonea</italic> and <italic>Margotia</italic> in <italic>Thapsia</italic>, in correspondence with previous phylogenetic studies of Apiaceae. <italic>Elaeoselinum</italic> is not monophyletic. Clades in <italic>Thapsia</italic> correlate well with previous observations of groupings based on the occurrence of biologically important sesquiterpene lactones, such as thapsigargin and thapsane and derivatives thereof. The result of the phylogenetic analysis necessitates nomenclatural adjustments. Thus, we propose a broader generic concept for <italic>Thapsia</italic>. Here <italic>T. asclepium</italic>, <italic>T. gummifera</italic> and <italic>T. tenuifolia</italic> are reinstated, new name combinations are made for <italic>T. leucotricha</italic>, <italic>T. scabra</italic> and <italic>T. thapsioides</italic>, and one new species, <italic>T. smittii</italic>, is established from <italic>T. maxima</italic> type II. © 2014 The Linnean Society of London, <italic>Botanical Journal of the Linnean Society</italic>, 2014, <bold>174</bold>, 620–636.</p> </abstract>