Am. J. Bot. Join the BSA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (8)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Truyens, S.
Right arrow Articles by Shore, J. S.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Truyens, S.
Right arrow Articles by Shore, J. S.
Agricola
Right arrow Articles by Truyens, S.
Right arrow Articles by Shore, J. S.
(American Journal of Botany. 2005;92:1749-1758.)
© 2005 Botanical Society of America, Inc.

Systematics and Phytogeography

Phylogenetic relationships, chromosome and breeding system evolution in Turnera (Turneraceae): inferences from its sequence data1

Simon Truyens2, Maria M. Arbo3 and Joel S. Shore2,4

2Department of Biology, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3 Canada; 3Facultad de Ciencias Agrarias, Instituto de Botánica del Nordeste (UNNE-CONICET), C.C. 209, 3400 Corrientes, Argentina

ABSTRACT

Turnera provides a useful system for exploring two significant evolutionary phenomena—shifts in breeding system (distyly vs. homostyly) and the evolution of polyploids. To explore these, the first molecular phylogeny of Turnera was constructed using sequences of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA for 37 taxa. We attempted to resolve the origins of allopolyploid species using single-strand conformation polymorphism and sequencing of homeologous copies of ITS. Two allohexaploid species possessed putative ITS homeologues (T. velutina and T. orientalis). A phylogenetic analysis to identify progenitors contributing to the origins of these polyploids was unsuccessful, possibly as a result of concerted evolution of ITS. Breeding system evolution was mapped onto the phylogeny assuming distyly to be ancestral in Turnera. Self-compatible homostyly appears to have arisen independently at least three times in Turnera; however, we were not able to determine whether there have been independent origins of homostyly among hexaploid species in series Turnera. Our phylogenetic analyses suggest that series Turnera is monophyletic. Neither series Microphyllae nor Anomalae, however, appear to be monophyletic. Future taxonomic revisions may require new circumscriptions of these latter series.

Key Words: distyly • homostyly • ITS phylogeny • Piriqueta • polyploidy • Turnera • Turneraceae






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2005 by the Botanical Society of America, Inc.