| Abstract Detail
Recent Topics Posters Plume, Olofron [1]. Systematics of Calendula (Asteraceae): Toward a robust molecular phylogeny and a hypothesis of chemical diversification within the genus. The small Mediterranean genus Calendula includes 10-20 species, the best known of which is C. officinalis (pot marigold), cultivated for centuries for both medicinal and ornamental use. The genus is remarkable for the wide range of chromosome numbers across species (possibly resulting from the propensity of species with different chromosome numbers to hybridize and form new polyploid taxa) and for the biosynthesis of large quantities of secondary compounds used to treat a host of ailments, particularly inflammation of the skin. In order to elucidate relationships in the genus and to survey chemical variation across taxa, seeds of seven species of Calendula, including six regional variants of the highly polymorphic C. arvensis and three recognized subspecies each of both C. incana and C. suffruticosa, and one species of Dimorphotheca (a closely related genus in tribe Calenduleae) were obtained from USDA-GRIN and Horizon Herbs. The chosen taxa included both annual and perennial species, representatives of each of the known chromosome counts within the genus except two (species with 2n = 30 and ±85 were not available), and collections from much of the geographic range of the genus. Seeds germinated easily, and DNA was successfully extracted from leaf tissue of the mature plants. Chloroplast gene region ndhF-rpl32 was amplified and sequenced. Alignment of these sequences revealed informative variation even within subspecies, and parsimony analysis resolved the taxa into two major clades. Secondary compounds were extracted in methanol from fresh leaf tissue. HPLC analyses of these extracts showed considerable variation in presence and size of peaks among taxa, a promising result which could help answer questions both about phylogenetic relationships and about the evolution of chemical diversity in the genus.
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1 - Cornell University, L.H. Bailey Hortorium, Department of Plant Biology, 412 Mann Library, Ithaca, NY, 14853, USA
Keywords:
Calendula
molecular systematics
chemical diversity.
Presentation Type: Recent Topics Poster
Session: P
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM
Number: PRT004
Abstract ID:1110 |
