Item Details

title

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

author

Schuster, Tanja Magdalena

abstract

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 Atraphaxis, Fallopia, Knorringia, Muehlenbeckia, Oxygonum, Polygonum, Polygonella and Reynoutria. The following questions were addressed based on this taxon sampling: 1) What are the evolutionary relationships among the genera included in Polygoneae? 2) Is Muehlenbeckia a monophyletic group? 3) Is Polygonella included in Polygonum as morphological studies suggest? 4) Does the morphologically distinct Oxygonum 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 Muehlenbeckia that sampled 22 of the 30 recognized species was done because Muehlenbeckia is unique in Polygonaceae based on its amphi-Pacific, Southern Hemisphere distribution in a predominantly North Temperate family. Therefore, the historical biogeography of Muehlenbeckia is of interest and in this study it is attempted to pinpoint geographic areas the most recent common ancestor of Muehlenbeckia occupied and to estimate divergence times within Muehlenbeckia using a fossil calibration point. Furthermore, because Muehlenbeckia 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.

subject

botany

fire ecology

Miocene

molecular systematics

plants

rhubarb family

contributor

Kron, Kathleen A. (committee chair)

Smith, Gerald L. (committee member)

Conner, William (committee member)

Johnson, A. Daniel (committee member)

Weigl, Peter D. (committee member)

Smith, William K. (committee member)

date

2011-07-14T20:36:21Z (accessioned)

2013-07-14T08:30:10Z (available)

2011 (issued)

degree

Biology (discipline)

embargo

2013-07-14 (terms)

identifier

http://hdl.handle.net/10339/33492 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation