Botany Commons^™

Towards Cloning A Tyrosinase Gene From Pitayas, Kurt J. Chamberlain

Honors Program Theses

Betalains, such as those produced by pitayas, are water-soluble nitrogen-containing pigment molecules (Gandia-Herrero et al., 2005). In most families of the Caryophyllales, betalains replace anthocyanins, which are the pigment molecules found in all other families of flowering plants (Strack et al., 2001). Betalains accumulate in the flowers, fruits, and occasionally vegetative tissues of these plants (Strack et al., 2001). Depending on the structure of the molecule, betalains are classified as either betacyanins or betaxanthins. Betacyanins contribute to red-violet coloration, while betaxanthins contribute to the yellow-orange coloration found only in a limited number of plant species (Gandia-Herrero et al., 2005). The …

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 …

Ltr Retrotransposon Evolution In Wild Sunflowers, Kaitlin Marie Stimpson

Presidential Scholars Theses (1990 – 2006)

Transposable elements are DNA sequences that are able to move from place to place in the genome, and in some cases, make copies of themselves and reinsert back into the genome. Transposable elements are divided into three classes based on their method of transposition. Class I elements transpose by an RNA intermediate, and these include L TR (long terminal repeat) and non-L TR retrotransposons. Class II elements relocate in the genome without duplication. Interestingly, class III elements entirely lack genes and rely on products of other elements for transposition. Transposable elements are no longer considered unusual or unique components of …

Effect Of Light Duration On Pulvinar Motor Organ Movements In Phaseolus Vulgaris, Thomas William Rinehart

Presidential Scholars Theses (1990 – 2006)

With a well established model in place, the main objective of this study will be to determine if the pulvinar motor organs have a threshold radiation level to elicit paraheliotropic movements. Plants will be illuminated with full spectrum light at varying intensities and periods. Observation will take place minute-by-minute in an effort to denote certain lighting conditions which might trigger paraheliotropism.

The Use Of Aflp To Detect Genetic Differentiation Within And Among Populations Of Two Prairie Plant Species: Panicum Virgatum And Coreopsis Palmata, Christopher Andrew Hilker

Dissertations and Theses @ UNI

The degree of genetic diversity within any species is crucial to its survival with respect to environmental stresses and its ability to adapt. As native Iowa prairie plant populations continues to diminish, genetic diversity within the state becomes crucially important for restoration, reconstruction, and conservation efforts. This study seeks to determine the degree of genetic variation within native Iowa populations of Panicum virgatum (switchgrass) and Coreopsis palmata (prairie coreopsis, tickseed, prairie tickseed). Plants were obtained directly from the tallgrass prairie, from native seed plantings, and from greenhouse grown cultivated varieties (switchgrass). Amplified Fragment Length Polymorphisms (AFLP) provided genetic fingerprints of …

The Use Of Rapd To Detect Genetic Variation In Populations Of Liatris Aspera Michx., Duane Joseph Kitchen

Dissertations and Theses @ UNI

The tall grass prairie is one of the most degraded and fragmented ecosystems on earth. Interest in conserving, restoring, and reconstructing tallgrass prairie began early in the 1900s, and has increased dramatically since the 1960s. Early restoration and reconstruction efforts relied primarily on seed collected from prairie remnants near the planting site, but with the increase in prairie planting efforts came a greater demand for large quantities of affordable, viable seed of native prairie species. Following an increase in the use of cultivated varieties (cultivars) of seed, concerns over the loss of genetic integrity of local populations and low genetic …

Effects Of Sludge Application On Prairie Establishment, Brenda Joan Durbahn

Dissertations and Theses @ UNI

Native prairie in Iowa has all but disappeared since the development of agricultural land by European settlers over the past 165 years. Reconstructing prairie is one way to replace some of the acreage that was lost. A byproduct of settling an area is the generation of garbage and other wastes. Currently there is a surplus of sludge, the waste product of waste water treatment facilities. This material is usually disposed of in landfills, used on agricultural land or reclamation projects.

A small area of prairie was reconstructed on the top of a closed portion of the Black Hawk County Solid …

The Effects Of Herbicides On Microbial And Mycorrhizal Populations In Native Prairie, Corn, And Non-Native Prairie Vegetation, Using The Biolog Technique, Susann E. Ahrabi-Fard

Dissertations and Theses @ UNI

Soil bioremediation has primarily focused on the use of free living, actively growing microorganisms to degrade toxic organic substances. Recently, however, plants and rhizosphere activity, including mycorrhizal fungi have been increasingly studied to determine the role that consortial assemblages may play in bioremediation. While the enhanced absorbtion of nutrients, water, and minerals by mycorrhizal fungi has been well documented, less is known about their role in the degradation of soil contaminants. Using the Biolog plate technique, microbial communities were characterized in Native Prairie, Corn, and Non-Native Prairie vegetative strips prior to, and after two applications of Acetachlor, Alachlor, and Atrazine. …

Effect Of Light Intensity And Temperature On Light-Avoiding Leaf Movements In Two Phaseolus Species, Douglas Bielenberg

Presidential Scholars Theses (1990 – 2006)

It was the purpose of this experiment to determine the relationship between the factors of pulvinus temperature and light intensity in their role as factors that affect paraheliotropism. We also examined the differences in these relationships in two species adapted to different environments. The two species used were: Phaseolus vulgaris (common bean), a high yielding species which is grown in mesic climates, and P. acutifolius (tepary bean), an arid land bean which tolerates high temperatures and drought.

Multivariate Analysis Of The Carex Brevior Group In Iowa, Scott C. Zager

Dissertations and Theses @ UNI

In Iowa, the most troublesome sedges to identify are Carex brevior, C. festucacea, C. molesta, C. normalis, C. tenera, and C. tenera var. echinodes. These taxa form the C. brevior group--part of an even larger aggregate of species associated with C. straminea. Their morphological features are indistinct and intergrade into one another. Botanists have had difficulty classifying members of this aggregate for nearly 200 years. Some authors have viewed the taxa as separate species, others as polymorphic forms of a single species. Much of the contention has centered upon the variation of taxonomic characters used to delimit and distinguish species. …

Factors Related To The Occurrence Of Certain Prairie Graminoid Species In Black Hawk County, Iowa, Roadsides, Pauline Mary Drobney

Dissertations and Theses @ UNI

The native vegetation of Iowa was primarily tallgrass prairie and currently exists only in small isolated parcels, including some remnants occurring in roadsides. Roadside prairie remnants are important for historical, environmental, aesthetic, scientific, and economic reasons. Information about factors influencing the occurrance of roadside prairie vegetation could be useful to roadside vegetation managers in development of initial vegetation surveys and subsequent to restoration of roadside prairie vegetation.

This study was conducted to determine what factors most affected the percent coverage of prairie graminoids in roadsides; particularly soil moisture availability, drainage, soil disturbance, and availability of a prairie seed sources. Prairie …

A Survey Of The Vascular Flora Of Black Hawk County, Iowa, Karen E. Van Norman

Dissertations and Theses @ UNI

Black Hawk County, located in the east-central part of the state of Iowa, is a political subdivision of 570 square miles. The topography of the county is the result of glaciation, erosion and deposition, causing gently rolling plains. The Cedar and the Wapsipinicon rivers transect the county from the northeast to the southwest. With their tributaries, these rivers comprise a natural drainage network which has enhanced agricultural practices throughout the county.

The vascular flora of the county was surveyed in the field during the growing seasons of 1982 and 1983. Over 1500 voucher specimens were collected. Data were also compiled …

Plants Of Iowa: A Preliminary List Of The Native And Introduced Plants Of The State, Not Under Cultivation, Wesley Greene

Iowa Book Gallery

This preliminary list of more than 3,000 species includes only the native plants and those that have been introduced from other sections of this country, or other continents, and have escaped from cultivation, and become naturalized and are now a part of the flora of the state.