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

This Article Full Text Full Text (PDF) 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 ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Markwith, S. H. Articles by Scanlon, M. J. Search for Related Content PubMed Articles by Markwith, S. H. Articles by Scanlon, M. J. Agricola Articles by Markwith, S. H. Articles by Scanlon, M. J.

Multiscale analysis of Hymenocallis coronaria (Amaryllidaceae) genetic diversity, genetic structure, and gene movement under the influence of unidirectional stream flow¹

²Department of Geography, University of Georgia, Athens, Georgia 30602 USA; ³Plant Biology Department, University of Georgia, Athens, Georgia 30602 USA

ABSTRACT

Understanding gene movement patterns in unidirectional flow environments and their effect on patterns of genetic diversity and genetic structure is necessary to manage these systems. Hypotheses and models to explain genetic patterns in streams are rare, and the results of macrophyte studies are inconsistent. This study addresses Ritland's (Canadian Journal of Botany 67: 2017–2024) unidirectional diversity hypothesis, the one-dimensional stepping stone model, and the metapopulation model within and among populations. Hymenocallis coronaria, an aquatic macrophyte of rocky river shoals of the SE USA, was sampled in four river basins. Within populations and among populations <16.2 km apart had significant isolation by distance. However, the rate of gene flow decay was not consistent with a one-dimensional stepping stone model, nor was evidence strong or consistent for Ritland's hypothesis. Some evidence indicates that localized metapopulation processes may be affecting genetic diversity and structure; however, gene flow patterns inconsistent with the assumptions of the linear and unidirectional models are also a possible influence. We discuss three variants on the one-dimensional stepping stone model. Future research in linear environments should examine the expectations of these models. This study is also one of the first efforts to calculate population genetic parameters using a new program, TETRASAT.

Key Words: Amaryllidaceae • aquatic plant • Cahaba-lily • gene flow • genetic differentiation • shoals spider-lily • southeastern United States

This article has been cited by other articles:

				M. Medrano and C. M. Herrera Geographical Structuring of Genetic Diversity Across the Whole Distribution Range of Narcissus longispathus, a Habitat-specialist, Mediterranean Narrow Endemic Ann. Bot., August 1, 2008; 102(2): 183 - 194. [Abstract] [Full Text] [PDF]