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Full-Text Articles in Life Sciences

Microsite Requirements For Successful Regeneration In Lowland Northern White-Cedar (Thuja Occidentalis) Forests, Jeanette Allogio Dec 2020

Microsite Requirements For Successful Regeneration In Lowland Northern White-Cedar (Thuja Occidentalis) Forests, Jeanette Allogio

Electronic Theses and Dissertations

Declines in stands of northern white-cedar (Thuja occidentalis L., hereafter cedar) have been observed as both shifts in species composition and reductions in cedar densities, particularly those stands in lowland sites (Curtis 1946, Boulfroy 2012). While several factors inhibiting cedar regeneration have been identified, a thorough understanding of the conditions that best promote regeneration is lacking. Our objectives for the first chapter were to characterize the site conditions associated with successful regeneration in lowland cedar stands and to describe how spatial patterns of various cedar size classes relate to site preference and to regeneration dynamics. These objectives were achieved …


Characterizing Patterns In Texas Gulf Coast Beach Dune Plant Species Composition, Cody Foster Dec 2020

Characterizing Patterns In Texas Gulf Coast Beach Dune Plant Species Composition, Cody Foster

Electronic Theses and Dissertations

Regional vegetation patterns of Texas beach plant communities were analyzed using cluster analysis, ANOSIM, SIMPER, NMDS, and ISA for fives zones representing the foredune complex of twenty Gulf Coast beaches. ANOVA revealed that zones differ in terms of percent bare sand, percent vegetative cover, and species richness. Cluster Analysis, ANOSIM, and SIMPER results indicate that Texas beaches can be divided into northern and southern regions based on differences in species composition of plant communities. Indicator Species Analysis (ISA) indicates that northern beaches are characterized by the presence of Rayjacksonia phyllocephala, Ambrosia Strophostyles, Ambrosia psilostachya, and Panicum amarum …


Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan Aug 2020

Evaluation Of Groundwater Sodium And Sodium Uptake In Taxodium And Its Hybrids On Galveston Island, Texas, Daniel Morgan

Electronic Theses and Dissertations

In September 2008, Hurricane Ike swept through the Gulf of Mexico striking the Gulf Coast, claiming hundreds of lives and causing billions of dollars in damage. The hurricane left behind elevated sea salt concentrations in the soil and groundwater, preventing the unaided return of live oaks and other species to the island. To determine effective ways to ameliorate the elevated Na+ concentrations in the soil, eight treatments were applied to the soil and combinations of three species of plants, live oak (Quercus virginiana), hybrid bald cypress (TaxodiumT406’), and yellow hibiscus (Hibiscus hamabo …


Effects Of Increased Atmospheric Carbon Dioxide Levels On Tobacco Mosaic Virus And Root-Knot Nematodes In Genetically Resistant And Susceptible Tomato Plants, Angie Nicholas May 2020

Effects Of Increased Atmospheric Carbon Dioxide Levels On Tobacco Mosaic Virus And Root-Knot Nematodes In Genetically Resistant And Susceptible Tomato Plants, Angie Nicholas

Electronic Theses and Dissertations

Rising atmospheric carbon dioxide (CO2) may affect plant/pathogen interactions. This study focused on the effects of elevated CO2 on Root-Knot Nematode (Meloidogyne arenaria) and Tobacco Mosaic Virus (TMV) infection in genetically resistant versus susceptible tomatoes (Solanum lycopersicum). Both resistant and susceptible tomatoes were grown in chambers with either ambient CO2 or CO2 elevated to 750 ppm and infected with M. arenaria or TMV. Measurements were taken at regular intervals to determine the effects of the pathogens on the plants. Resistant plants infected with M. arenaria maintained resistance while susceptible plants remained …


Role Of Plant Volatile Organic Compounds (Vocs) In Seed Priming And Plant-Herbivore Interactions., Abhinav Kumar Maurya May 2020

Role Of Plant Volatile Organic Compounds (Vocs) In Seed Priming And Plant-Herbivore Interactions., Abhinav Kumar Maurya

Electronic Theses and Dissertations

This dissertation explores and expands the existing knowledge on the role of plant volatiles in facilitating seed priming and providing direct defense against herbivore. Although the roles of plant volatiles in priming a plant’s defenses and providing direct defense against pests is well known, information regarding their effects on seed and the fitness of future plants and direct toxicity to herbivores is understudied. This dissertation does a thorough examination of these two understudied aspects of plant volatiles and provides novel insight into the role of plant volatiles in seed priming and direct defense (Chapter I). Seeds in the soil can …


Functional Analysis Of Squamosa-Promoter Binding Protein Like 13 In Controlling Flowering Time, Plant Architecture, Grain Size, And Grain Number In Wheat, Ajay Gupta Jan 2020

Functional Analysis Of Squamosa-Promoter Binding Protein Like 13 In Controlling Flowering Time, Plant Architecture, Grain Size, And Grain Number In Wheat, Ajay Gupta

Electronic Theses and Dissertations

Higher and stable yield is always a major objective of wheat genetic improvement programs. The SQUAMOSA-promoter binding protein-like (SPL) genes constitute a small family of plant-specific transcription factors with diverse functions in plant development and growth and have great potential in improving yield and other major agronomic traits. However, the functional characterization of the SPL gene family in wheat is far behind other cereal crops such as rice. Using phylogenetic analysis, we identified 56 wheat orthologues of rice SPL genes belonging to 19 homoeologous groups. Among these 19 orthologous TaSPL genes, nine harbor the micro RNA 156 recognition element (MRE) …


Characterization Of Bacterial Endophytes Isolated From Brassica Carinata And Their Potential Use To Decrease Nutrient Requirements In Crops, Alex Soupir Jan 2020

Characterization Of Bacterial Endophytes Isolated From Brassica Carinata And Their Potential Use To Decrease Nutrient Requirements In Crops, Alex Soupir

Electronic Theses and Dissertations

Bacterial endophytes have the capability to enhance plant growth by producing plant growth hormones, solubilizing phosphates, suppressing pathogenic fungi, and reducing plant stress hormones. These capabilities make them desirable limiting the amount of nutrients and pesticides that are applied to crops. Through these assays and isolations, it is possible to identify novel bacterial species. In-vitro testing had shown 9 of the 20 isolates possess the ability to produce indole-3-acetic acid (IAA) with Pantoea agglomerans BC09 producing a concentration of 30.2 ng/μl over 4 days. BC09, Bacillus subilis BC10, and Pantoea sp. BC12 were able to solubilize calcium phosphate, 7 endophytes …


Subalpine Forest Tree Seedling Response To Drought, Alex Goke Jan 2020

Subalpine Forest Tree Seedling Response To Drought, Alex Goke

Electronic Theses and Dissertations

Knowledge of tree species’ ability to tolerate drought is necessary to anticipate future forest dynamics with climate change, especially at the seedling stage given their role in shaping forest structure. We used precipitation reduction shelters to mimic drought for subalpine conifer seedlings (A. lasiocarpa and P. engelmannii) in the Rocky Mountains and compared survivorship and morphological and physiological responses to assess relative degrees of drought tolerance. We detected no significant investment in morphological tolerance traits (e.g. root biomass, leaf:stem area ratio) but substantial reductions in net photosynthesis. While shading partially ameliorated drought effects when precipitation reduction was moderate, …


Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil Jan 2020

Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil

Electronic Theses and Dissertations

Glyceollin is a secondary metabolite produced under stress conditions by soybean to act as a plant defender to pathogen attack. The antimicrobial nature of glyceollin makes it a promising natural alternative to antibiotics if incorporated into livestock feed. However, production of glyceollin is highly variable, dependent on soybean variety, and fungal elicitor used as inoculum. Our study compares two fungal spore elicitors, Trichoderma reesei and Aspergillus sojae on soybeans of diverse maturity level, and fungal susceptibility to determine highest glyceollin titer. Spore inoculation with T. reesei elicited highest glyceollin titers of 2.42±0.20 mg/g at 120 h, while A. sojae elicited …