HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

What's this?

This Article Full Text Full Text (PDF) Supplementary Data Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Stefanovic, S. Articles by Costea, M. Search for Related Content PubMed Articles by Stefanovic, S. Articles by Costea, M. Agricola Articles by Stefanovic, S. Articles by Costea, M. Social Bookmarking                            What's this?

Delimitation of major lineages within Cuscuta subgenus Grammica (Convolvulaceae) using plastid and nuclear DNA sequences¹

Saa Stefanovi⁴, Maria Kuzmina and Mihai Costea

²Department of Biology, University of Toronto at Mississauga, Mississauga, Ontario L5L 1C6, Canada; and ³Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada

ABSTRACT

Subgenus Grammica, the largest and most diverse group in the parasitic genus Cuscuta, includes 130 species distributed primarily throughout the New World, with Mexico as its center of diversity. To circumscribe the subgenus and assess the relationships among its major lineages, we conducted the first phylogenetic study of Grammica using plastid trnL-F and nrITS sequences from a wide taxonomic sampling covering its morphological, physiological, and geographical diversity. With the exception of one species belonging elsewhere, the subgenus was found to be monophyletic. The results further indicate the presence of 15 well-supported major clades within Grammica. Some of those lineages correspond partially to earlier taxonomic treatments, but the majority of groups are identified in this study for the first time. The backbone relationships among major clades, however, remain weakly supported or unresolved in some cases. The phylogenetic results indicate that the fruit dehiscence character is homoplastic, thus compromising its value as a major taxonomic and evolutionary feature. While several striking cases of long-distance dispersal are inferred, vicariance emerges as the most dominant biogeographical pattern for Cuscuta. Species placed within one of the clades with a predominantly South American distribution are hypothesized to have substantially altered plastid genomes.

Key Words: Convolvulaceae • Cuscuta • Grammica • molecular phylogeny • nuclear ribosomal ITS • parasitic plants • plastid trnL-F

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. Costea and S. Stefanovic Cuscuta jepsonii (Convolvulaceae): An invasive weed or an extinct endemic? Am. J. Botany, September 1, 2009; 96(9): 1744 - 1750. [Abstract] [Full Text] [PDF]