Life Sciences Commons^™

A Genome Wide Association Study Of Heat Tolerance In Snap Bean (Phaseolus Vulgaris), Morgan Stone

All Theses

Bean production in the United States has decreased while the temperatures have been steadily increasing, reaching new highs each year. Heat stress is detrimental to common bean (also known as snap bean) production. Symptoms of heat stress include decrease in pollen viability, shriveling of pods, and pod abortion making them unmarketable. Pod production of 323 snap bean accessions from a large diversity panel was assessed in a randomized complete block design with field trials at two different times in the spring season. The results show a significant decrease in the number of pods produced per plant and weight of pods …

Physiological And Yield Responses Of Soybean Cultivars To Heat And Drought Stresses, Sadikshya Poudel

Theses and Dissertations

Soybean (Glycine max L.) is an important legume crop often exposed to heat and drought stresses during reproductive and early-seed setting stages, resulting in lower yields and seed quality. Ten soybean cultivars were phenotyped for individual (drought or heat) and combined stress tolerance. Under drought, reduced stomatal conductance and increased canopy temperature significantly reduced seed number (46%) and weight (35%). Heat stress alone reduced seed number (19%) and weight (23%) compared to control. Moreover, a degree increase in daytime temperature above 32 °C during the reproductive stage reduced seed weight by 4% and 7% under well-watered and drought conditions, respectively. …

Non-Destructive Imaging Of Phytosulfokine Trafficking In Plants Using Fiber-Optic Fluorescence Microscopy, Bernard Abakah

Electronic Theses and Dissertations

Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding these phenomena is key to improving plant health and productivity for food, fiber, and energy applications. Phytosulfokine (PSK), a sulfated peptide hormone, regulates plant cell division, growth, and stress tolerance via specific phytosulfokine receptors (PSKRs). This study uses fiber-optic fluorescence microscopy to elucidate trafficking of PSK in live plants. The microscope features two-color optics and an objective lens connected to a 1-m coherent imaging fiber mounted on either a conventional upright microscope body or 5-axis positioning system (X–Y–Z plus pitch and yaw). PSK and …

Targeted Mapping Of Oryza Sativa Chilling Tolerance Candidate Genes Using Multiple Stress-Relevant Quantitative Traits, Naoki Simon Shimoyama

Dissertations (1934 -)

Developing chilling tolerant accessions of domesticated Asian rice is a potential source of significant crop improvement to address the needs of a growing global population. The uniquely chilling sensitive nature of the tropically originating Oryza sativa make it the most important staple crop that could gain the maximum benefit from improved tolerance to low temperature stress. However, mechanisms underlying this complex trait are not fully understood. Oryza sativa has two major varietal groups with different levels of chilling tolerance, JAPONICA and INDICA, providing an ideal tool to investigate mechanistic differences in the chilling stress tolerance responses within this important crop …

Ecological Risk Assessment Of Transgenic Conditional Lethality Systems For Genetic Biocontrol Strategies, Fernan Rodrigo Perez-Galvez

Theses and Dissertations--Entomology

Genetic strategies of insect pest control are receiving increased interest due to recent advances in genetic engineering. By introducing alleles that make males functionally sterile, genetically modified (GM) insects can be used in area-wide pest management programs similar to the Sterile Insect Technique (SIT). Genetic control strategies carry several potential benefits, including improved efficacy and specificity, lower operation costs, and reduced dependence on chemical insecticides, but their use is still controversial despite extensive technical documentation indicating their innocuity to humans and the environment. This hesitation is likely due to the novel nature of the approach.

While the first field applications …