Life Sciences Commons^™

Distribution And Genomic Diversity Of Pollen-Borne Viruses And Viroids At The Interface Of Peach And Wild Prunus Spp. In The Southeastern United States, Fabian Omar Rodriguez Bonilla

All Theses

Prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), and peach latent mosaic viroid (PLMVd) are important pollen-borne pathogens that affect peach orchards in the southeastern United States. My aim with this research is to identify potential sources of virus/viroid inoculum sources in the wild and determine pathogen movement and interactions between wild Prunus spp. and cultivars of peach (P. persica). In Chapter I, I review the literature on pollen borne viruses and viroids in peach. In Chapter II, I surveyed for these pathogens near peach production areas in South Carolina and Georgia, sampling from three endemic wild …

Reproductive Ecology And Phenology Of Thalassia Testudinum (Hydrocharitaceae) In Tampa Bay, Florida, Sheila Scolaro

USF Tampa Graduate Theses and Dissertations

Successful sexual reproduction and recolonization are critical in maintaining genetic diversity within seagrass meadows. Thalassia testudinum flower, fruit and seedling production were assessed visually at 10 sites within Tampa Bay, Florida approximately every 4 weeks from May to July 2017 to determine if there is spatial and temporal variation in sexual reproductive effort and if location within a meadow effects sexual reproductive effort. Results from this study reveal strong temporal variability throughout the reproductive season. The month of May was observed as peak Thalassia testudinum anthesis and June was peak fruiting in Tampa Bay during 2017. Flower and fruit density …

Method Development For Identifying Counterfeit Cigarettes Using Environmental Pollen Analysis, Tiffany Chan

Student Theses

Cigarette counterfeiting negatively impacts government revenue and undermines tobacco control policies. Tracking geographical origins and potential trade routes of counterfeit cigarettes is important for investigation illegal trade in tobacco products. Traditional pollen extraction techniques provide clear residues of pollen trapped on tobacco leaves and used for geographical identification; however, such methods are time-consuming and utilize concentrated chemicals. This study developed a simple, fast and environmentally friendly method for extraction of pollen grains used in differentiating genuine and counterfeit cigarettes. Experimental factors that may affect pollen recovery including number of cigarettes, extraction solution, and extraction temperature, were optimized. The optimum parameters …

Holocene Fire History Reconstruction Of A Mid-Evaluation Mixed-Conifer Forest In The Eastern Cascades, Washington, Zoe Rushton

All Master's Theses

Fire histories of mid-elevation mixed-conifer forests (MEMC) are uncommon, particularly in the eastern Cascades of Washington. As a result, fire regimes and the effects of 20th century fire suppression in these forests are not well understood. In the summer of 2014 a 7.80 meter-long sediment core was extracted from Long Lake, located approximately 45 km west of Yakima, WA, which exists in a grand fir-dominated mixed-conifer forest. Fire activity for the Long Lake watershed was reconstructed using macroscopic charcoal analysis and pollen analysis was used to reconstruct vegetation change through time. Charcoal results show low fire activity in the early …

Plants, Parasites, And Pollinators: The Effects Of Medicinal Pollens On A Common Gut Parasite In Bumble Bees, George Locascio

Masters Theses

Declines in several pollinator species are due to a variety of factors, including pathogens. Incorporating pollinator-friendly plant species into wild and agricultural habitats could reduce the stress of pathogens if food sources act medicinally against pathogens. Previous research demonstrated one domesticated sunflower cultivar (Helianthus annuus) can dramatically reduce a gut pathogen (Crithidia bombi) of the common eastern bumble bee, Bombus impatiens. To ascertain the breadth of this medicinal trait, we tested whether pollen from several H. annuus cultivars and four relatives could also reduce C. bombi infections in B. impatiens. We also investigated whether …

Flower Visitation In Relation To Pollen And Nectar Nutrition: Implications For Pollinator Habitat And Conservation, Megan E. Leach

Electronic Theses and Dissertations

Pollination of both wild and crop plants is at a crossroads; honey bee populations are experiencing losses at a higher rate than ever before, and some native bee species are declining in abundance to the point of being listed as endangered species. A few examples of these threats include pesticide exposure, habitat loss, and climate change. In response to bee population declines, conservation efforts have been initiated to increase habitat quality for bees by planting pollinator reservoirs or gardens. Plants provide nutrition to bees in the form of pollen and nectar. Several studies have shown links between higher nutritional quality …

The Effect Of Insects On Seed Set Of Ozark Chinquapin, Castanea Ozarkensis, Colton Zirkle

Graduate Theses and Dissertations

Ozark chinquapin (Castanea ozarkensis), once found throughout the Interior Highlands of the United States, has been decimated across much of its range due to accidental introduction of chestnut blight, Cryphonectria parasitica. Efforts have been made to conserve and restore C. ozarkensis, but success requires thorough knowledge of the reproductive biology of the species. Other Castanea species are reported to have characteristics of both wind and insect pollination, but pollination strategies of Ozark chinquapin are unknown. Experiments were conducted to determine the influence of insects on successful pollination of C. ozarkensis, as measured by production of burs and seeds. Exclosure treatments …

Foraging Behavior Of Spring Bees And Their Agricultural Implications, Michael D. Gregory

Biological Sciences Theses & Dissertations

Colony Collapse Disorder has greatly reduced honey bee populations in the last decade. Native bees have been largely neglected in research, and their floral preferences may have agricultural implications because native bees ameliorate the demand to rely solely on non-native bees. In this work, pollinator visitation to flowers with manipulated ultraviolet floral patterns was monitored. Populations of wild showy golden-eye in Colorado, plus cultivar populations of black-eyed Susan and lawn populations of buttercups in Virginia were monitored for pollinator landings to compare preference for unmanipulated ultraviolet-absorptive floral guide preferences. Another number, a proxy for pollen load, was manipulated on strawberry …

Pore Selectivity And Gating Of Arabidopsis Nodulin 26 Intrinsic Proteins And Roles In Boric Acid Transport In Reproductive Growth, Tian Li

Doctoral Dissertations

Plant nodulin-26 intrinsic proteins (NIPs) are members of the aquaporin superfamily that serve as multifunctional channels of uncharged metabolites and water. They share the same canonical hourglass fold as the aquaporin family. The aromatic arginine (ar/R) selectivity filter controls transport selectivity based on size, hydrophobicity, and hydrogen bonding with substrates. In Arabidopsis thaliana, NIP II subclass proteins contain a conserved ar/R “pore signature” that is composed of Alanine at the helix 2 position (H2), Valine/Isoleucine at the helix 5 position (H5), and an Alanine (LE1) and an invariant Arginine (LE2) at the two loop E positions. In this study, …

A Comparative Analysis Of The Relative Water Content Of The Pollen Of Early Diverging Angiosperms, Andrew Robert Moffatt

Chancellor’s Honors Program Projects

No abstract provided.

Developing Biocontainment Strategies To Suppress Transgene Escape Via Pollen Dispersal From Transgenic Plants, Hong Seok Moon

Doctoral Dissertations

Genetic engineering is important to enhance crop characteristics and certain traits. Genetically engineered crop cultivation brings environmental and ecological concerns with the potential of unwanted transgene escape and introgression. Transgene escape has been considered as a major environmental and regulatory concern. This concern could be alleviated by appropriate biocontainment strategies. Therefore, it is important to develop efficient and reliable biocontainment strategies.

Removing transgenes from pollen has been known to be the most environmentally friendly biocontainment strategy. A transgene excision vector containing a codon optimized serine resolvase CinH recombinase (CinH) and its recognition sites RS2 were constructed and transformed into tobacco …

Developmental Evolution Of The Progamic Phase In Nymphaeales, Mackenzie Lorraine Taylor

Doctoral Dissertations

The period between pollination and fertilization, or the progamic phase, is a critical life history stage in seed plants and innovations in this life history stage are hypothesized to have played an important role in the diversification of flowering plants. Over the course of this dissertation research, I investigated programic phase development in Nymphaeales (water lilies), an ancient angiosperm lineage that diverged from the basalmost or next most basal node of the angiosperm phylogenetic tree and that is represented in the oldest angiosperm fossil record. I used field experiments and microscopy to document pollination biology, breeding system, and reproductive developmental …

Ultraviolet-B Radiation: Effects On Pollen Of 34 Taxa, And Inheritance Patterns And Carryover Of Radiation Response In Arabidopsis, Javad Torabinejad

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Although considerable research has addressed effects of elevated ultraviolet-B (UV-8) radiation on vegetative plant structures and processes, the reproductive biology and patterns of inheritance of UV-B tolerance have received much less attention. I examined the effects of UV-B radiation on pollen of 34 taxa. I also addressed questions concerning the patterns of inheritance of UV-B tolerance in Arabidopsis thaliana and examined potential cumulative carryover effects of UV-B exposure through multiple generations of this species.

In the first study, a significant reduction in pollen germination occurred in only five species, but pollen tube growth in more than half of the species …

Limitation Studies Of Seed Set In The Onion Allium Cepa L. (Liliaceae), Nizar Shukri Shasha'a

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two field experiments were carried out. In the first experiment, 13 variables were studied for 3 inbred groups as influenced by genetic differences, source of pollen, soil moisture, fertilizers, and size of bulbs. Path-coefficient analysis was made of various insect pollinators influencing seed yield in different inbreds, and of components of seed production in all inbreds together. In the second experiment, 4 variables were studied for one male-sterile inbred and one male-fertile inbred as influenced by soil moisture and fertilizers.

Genetic differences among inbreds were the most important source of variation in seed yields. This points out that a major …

Linkage And Inheritance Studies Involving An Annual Pollen Restorer And Other Genetic Characters In Beta Vulgaris L., Theron E. Roundy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A pollen-restorer sugarbeet inbred, developed by four generations of selection of highly fertile plants from a CMS X table beet cross, was studied to determine if a change from sterile to fertile cytoplasm had occurred. Data showed that the fertility expressed by the restorer inbred was the result of genetic factors and not cytoplasmic reversion. Linkage tests with the R^f gene showed independence of the YRB group, m and vi₄. A yellow-leaf mutant was inherited as a simple recessive factor. A partial pollen-restorer character, found in the yellow-leaf material, was inherited as a single dominant gene. The …