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Full-Text Articles in Botany

Evidence Of Ecological Speciation In Phacelia., Pamela Michele Glass Dec 2007

Evidence Of Ecological Speciation In Phacelia., Pamela Michele Glass

Electronic Theses and Dissertations

Phacelia purshii Buckley and P. fimbriata Micheaux are two species that are nearly morphologically indistinguishable. Seed germination experiments showed that the high elevation endemic, P. fimbriata requires lower temperatures to trigger germination. Following interspecific crosses, pollen tubes enter ovules and maternal tissue of the gynoecium matures but hybrid diploid and triploid organs fail to develop. DNA sequences from the ribosomal DNA internal transcribed region showed that P. fimbriata and P. purshii comprise a monophyletic clade but that P. fimbriata is more differentiated from related species. In contrast, P. purshii supported significantly higher levels of intraspecific polymorphism. Phacelia fimbriata and P. …


A Systematic Study Of Trillium Subgenus Delostylis, Susan B. Farmer Aug 2007

A Systematic Study Of Trillium Subgenus Delostylis, Susan B. Farmer

Doctoral Dissertations

This study focused on the systematics of Trillium subg. Delostylis, an enigmatic group endemic to the southeastern United States. Phylogenetic analysis of DNA sequence data was used to examine the circumscription and phylogenetic placement of Delostylis. The results of the phylogenetic analysis of data from the ITS, matK, and psbA-trnH sequence data suggested that the circumscription of Delostylis be narrowed to consist of T. persistens, T. catesbaei, and T. pusillum sensu lato. A revised Delostylis was characterized by the presence of a style with three slender stigmatic branches in those plants whose flowers are either white-fading-to-pink …


Molecular Evolution Of Mads-Box Genes In Cotton (Gossypium L.), Wusheng Liu May 2007

Molecular Evolution Of Mads-Box Genes In Cotton (Gossypium L.), Wusheng Liu

Doctoral Dissertations

The purpose of this study was to examine the molecular evolution of floral developmental MADS-box genes in diploid and allotetraploid cotton (Gossypium, Malvaceae). We isolated and characterized both cDNA and genomic DNA sequences of four MADS-box genes, B-sister, APETALA3 (AP3), PISTILLATA (PI, two copies) and AGAMOUS (AG), in seven Gossypium species (2 A-genome species, 2 D-genome species, 1 C-genome species and 2 AD-genome species) as well as an outgroup species, Gossypioides kirkii. We then studied the expression patterns of each gene by reverse-transcriptase PCR (RT-PCR) in each flower part for different flower stages of G. …


Systematics Of The Lobulomycetales, A New Order Within The Chytridiomycota, David Rabern Simmons May 2007

Systematics Of The Lobulomycetales, A New Order Within The Chytridiomycota, David Rabern Simmons

Electronic Theses and Dissertations

Based on molecular phylogenetic analyses, the polyphyletic order Chytridiales, one of the four orders in the Chytridiomycota, contains several well-supported clades. One species, Chytriomyces angularis, however, does not group within the robust clades of the Chytridiales or any other chytrid order. The light-level morphology and zoospore ultrastructure of this aquatic species also differ from those of the type species of the genus Chytriomyces. I amassed nine additional pure culture isolates of soil-inhabiting chytrids with morphologies or rDNA sequences similar to C. angularis, including two isolates of C. poculatus, and studied the molecular phylogeny of these ten …


Myriophyllum Heterophyllum Michx. (Haloragaceae): Control And Vegetative Reproduction In Southwestern Maine, Jacolyn E. Bailey May 2007

Myriophyllum Heterophyllum Michx. (Haloragaceae): Control And Vegetative Reproduction In Southwestern Maine, Jacolyn E. Bailey

Electronic Theses and Dissertations

Native to the southeastern United States, variable-leaf watermilfoil (Myriophyllum heterophyllum) is an invasive species in the Northeast and has been documented in Maine lakes for twenty years. Variable-leaf watermilfoil is targeted by the Maine Department of Environmental Protection as a species of grave concern as it has aggressively colonized twenty-six water bodies in Maine. This aquatic invasive plant grows in dense mats and outcompetes native vegetation. It is causing both ecological and economic disruption to Maine's lakes and ponds. The plants clog boat motors and deter people from swimming and other water related activities. Allofragmentation and autofragmentation occur …


The Development Of A Gc/Ms Protocol For The Analysis Of Polysaccharides In Echinacea Purpurea, Michaela Knapp Apr 2007

The Development Of A Gc/Ms Protocol For The Analysis Of Polysaccharides In Echinacea Purpurea, Michaela Knapp

Undergraduate Theses and Capstone Projects

Echinacea purpurea is an herbal supplement used to reduce symptoms of common colds and flu-like illnesses. As of right now, it is not well understood what chemical components in the plant are immunologically active. The four main potentially immunologically active chemical components in E. purpurea are caffeic acid derivatives, alkamides, polyacetylenes, and polysaccharides. In this investigation, a protocol was developed in an attempt to identify polysaccharides present in Puritan’s Pride E. purpurea (aerial) “non-irradiated” herbal supplement First, an estimate of the crude total polysaccharide content in Puritan’s Pride and in a ChromaDex certified botanical standard (E. purpurea -powdered root) was …


Succession Of An Iowa Sand Prairie Into An Adjoining Old-Field, Susan Jill Kirt Jan 2007

Succession Of An Iowa Sand Prairie Into An Adjoining Old-Field, Susan Jill Kirt

Dissertations and Theses @ UNI

Native plant succession studies were conducted in 2000 and 2001 at the Cedar Hills Sand Prairie northwest of Cedar Falls, IA. The study site consisted of a remnant sand prairie with an adjoining old-field that had been undergoing secondary succession since the mid-1970s. Vegetation was sampled over a 100 m transect of the remnant prairie and a 200 m transect of the old-field. The transect was sub-divided into 50 m subsites to examine progression of native species into the old-field. To analyze changes in vegetation, the similarity of the sub-sites were compared for percent canopy cover and number of species …


Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan Jan 2007

Plant Assemblage Structure On Barrier Island ‘Pimple’ Dunes At The Virginia Coast Reserve Long-Term Ecological Research Site, Brett A. Mcmillan

Biological Sciences Theses & Dissertations

The habitats at the VCR LTER that were the focus of the current study are the Hog Island and Parramore Island 'pimples', small, rounded dunes forming along main dune ridges of the barrier islands. There are distinct plant assemblage zones found on pimples, although most of these dunes are 10–20 m in diameter. Hypotheses of the study were that fresh water availability was a main determinant of differences between assemblages and that pimple size and location would influence diversity and assemblage structure. Research goals were (1) to describe the plant assemblages on pimples, (2) to relate edaphic and geomorphological factors …