Am. J. Bot. SilverBiology ad
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 Google Scholar
Google Scholar
Right arrow Articles by Katinas, L.
Right arrow Articles by Sytsma, K. J.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Katinas, L.
Right arrow Articles by Sytsma, K. J.
Agricola
Right arrow Articles by Katinas, L.
Right arrow Articles by Sytsma, K. J.
(American Journal of Botany. 2008;95:229-240.)
© 2008 Botanical Society of America, Inc.

Systematics and Phytogeography

Evolution of secondary heads in Nassauviinae (Asteraceae, Mutisieae)1

Liliana Katinas2, Jorge V. Crisci2, Rachel Schmidt Jabaily3, Cody Williams3, Jay Walker3, Bryan Drew3, Jose M. Bonifacino4,5 and Kenneth J. Sytsma3,6

2 Museo de La Plata, Paseo del Bosque, 1900 La Plata, Buenos Aires, Argentina 3 Department of Botany, University of Wisconsin, Madison, Wisconsin 53706 USA 4 Laboratorio de Botánica, Facultad de Agronomía, Casilla de Correos 1238, Montevideo, Uruguay

ABSTRACT

The evolution of the inflorescence head in Asteraceae is important in the diversification of this largest angiosperm family. The aggregation of heads into higher-order capitulescences (secondary heads or syncephalia) is considered evolutionarily advanced. The genera Moscharia, Nassauvia, Polyachyrus, and Triptilion of the subtribe Nassauviinae (Mutisieae) have syncephalia with differing degrees of capitula condensation. ITS and plastid trnL-trnF regions were analyzed separately and together using maximum parsimony and maximum likelihood to examine the evolution of syncephalia in the Nassauviinae. The four genera displaying syncephalia do not form a clade minus taxa without syncephalia, indicating that secondary heads in Nassauviinae have either convergently evolved twice in the subtribe (or, very unlikely) once with multiple reversions. Strong support was obtained for a sister relationship between Leucheria (without syncephalium) and Polyachyrus, and both sister to Moscharia. Nassauvia and Triptilion form a distinct clade but are sister to other genera, Perezia and Panphalea, without syncephalium. Previous hypotheses postulated the evolution from simple to more complex secondary heads. We show that the ancestor of Moscharia, Polyachyrus, and Leucheria, in a more arid habitat, had a complex type of secondary head, and loss of complexity occurred in response to a shift from arid to mesic conditions.

Key Words: ITS • Leucheria • Moscharia • Mutisieae • Nassauviinae • Polyachyrus • syncephalia • trnL-trnF






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2008 by the Botanical Society of America, Inc.