EVOLUTIONARY RELATIONSHIPS IN POLYGONEAE RCHB. (POLYGONACEAE) WITH AN EMPHASIS ON THE AMPHI-PACIFIC MUEHLENBECKIA MEISN.

Polygoneae is one of five tribes included in Polygonoideae that is in turn one of the three subfamilies recognized in the buckwheat family Polygonaceae. Representatives of the other two subfamilies, Eriogonoideae and the monotypic Symmerioideae, are included in this study as outgroups in addition to some species of the Plumbaginaceae. Taxon sampling was based on previous broad-scale studies in Polygonaceae and expanded for the eight genera thought to comprise Polygoneae. These include <em>Atraphaxis</em>, <em>Fallopia</em>, <em>Knorringia</em>, <em>Muehlenbeckia</em>, <em>Oxygonum</em>, <em>Polygonum</em>, <em>Polygonella</em> and <em>Reynoutria</em>. The following questions were addressed based on this taxon sampling: 1) What are the evolutionary relationships among the genera included in Polygoneae? 2) Is <em>Muehlenbeckia</em> a monophyletic group? 3) Is <em>Polygonella</em> included in <em>Polygonum</em> as morphological studies suggest? 4) Does the morphologically distinct <em>Oxygonum</em> that is restricted to Africa and for which there were no sequence data available prior to this study belong to Polygoneae? In addition, a species level study of <em>Muehlenbeckia</em> that sampled 22 of the 30 recognized species was done because <em>Muehlenbeckia</em> is unique in Polygonaceae based on its amphi-Pacific, Southern Hemisphere distribution in a predominantly North Temperate family. Therefore, the historical biogeography of <em>Muehlenbeckia</em> is of interest and in this study it is attempted to pinpoint geographic areas the most recent common ancestor of <em>Muehlenbeckia</em> occupied and to estimate divergence times within <em>Muehlenbeckia</em> using a fossil calibration point. Furthermore, because <em>Muehlenbeckia</em> shows great morphological variability and its members are not easily divided into discrete units, understanding evolutionary relationships in this group would benefit from a molecular phylogenetic approach.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2011

Author dc:creator

• Schuster, Tanja Magdalena

• botany

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/33492

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/33492