Biology Commons^™

Interspecific Gene Flow Potentiates Adaptive Evolution In A Hybrid Zone Formed Between Pinus Strobiformis And Pinus Flexilis, Mitra Menon

Theses and Dissertations

Species range margins are often characterised by high degrees of habitat fragmentation resulting in low genetic diversity and higher gene flow from populations at the core of the species range. Interspecific gene flow from a closely related species with abutting range margins can increase standing genetic diversity and generate novel allelic combinations thereby alleviating limits to adaptive evolution in range margin populations. Hybridization driven interspecific gene flow has played a key role in the demographic history of several conifer due to their life history characteristics such as weak crossability barriers and long generation times. Nevertheless, demonstrating whether introgression is adaptive …

Evaluation Of The Symbiotic Relation Between Endophyte And Poplar Trees Exposed To Landfill Leachate, Catalina Vega Hurtado

Masters Theses

“The contamination of soil and groundwater from leachate leakage from landfill has turned, nowadays, into a global public issue. One of the main concerns about this pollutant is the potential threat to human and ecosystem health. The current research studied endophyte bacteria in association with poplar trees (Populus sp.), as a method of bioremediation of landfill leachates. The objective of the project was to identify treatment strategies that may improve plant performance (survival rates, plant fitness, and degradation efficacy) with the purpose of being implemented in phytoremediation plots, aimed to intercept and treat landfill leachate, before the contamination of watershed. …

The Development Of Crassulacean Acid Metabolism (Cam) Photosynthesis In Cotyledons Of The C4 Species, Portulaca Grandiflora (Portulacaceae), Lonnie J. Guralnick, Kate E. Gilbert, Diana Denio, Nicholas Antico

Arts & Sciences Faculty Publications

Portulaca grandiflora simultaneously utilizes both the C₄ and Crassulacean acid metabolism (CAM) photosynthetic pathways. Our goal was to determine whether CAM developed and was functional simultaneously with the C₄ pathway in cotyledons of P. grandiflora. We studied during development whether CAM would be induced with water stress by monitoring the enzyme activity, leaf structure, JO₂ (rate of O₂ evolution calculated by fluorescence analysis), and the changes in titratable acidity of 10 and 25 days old cotyledons. In the 10 days old cotyledons, C₄ and CAM anatomy were evident within the leaf tissue. The cotyledons showed …

Plant Science Decadal Vision 2020–2030: Reimagining The Potential Of Plants For A Healthy And Sustainable Future, Natalie Henkhaus, Madelaine Bartlett, David Gang, Lonnie J. Guralnick, Et Al.

Arts & Sciences Faculty Publications

Plants, and the biological systems around them, are key to the future health of the planet and its inhabitants. The Plant Science Decadal Vision 2020–2030 frames our ability to perform vital and far‐reaching research in plant systems sciences, essential to how we value participants and apply emerging technologies. We outline a comprehensive vision for addressing some of our most pressing global problems through discovery, practical applications, and education. The Decadal Vision was developed by the participants at the Plant Summit 2019, a community event organized by the Plant Science Research Network. The Decadal Vision describes a holistic vision for the …

Comparing Water Quality For Aquaponics Systems With Different Solids Removal Methods And Biofilter Media, And Effluent Output To Grow Beds, John W. Cutt, Heather M. Joesting, Brigette A. Brinton

Honors College Theses

Aquaponics is a closed-loop, sustainable method of food production that combines fish and plant production. This method of agriculture has the potential to bring fresh, local food to food-insecure areas, but challenges remain due to high operating costs. In order to develop a strong aquaponics industry, the creation of the most efficient system designs will be critical in optimizing production. This study’s purpose was to compare water quality between two aquaponics system designs that differ in filtration and solid removal methods. System 1 used a sock filter for solid removal and Kaldnes media for biofiltration while System 2 used a …

Small-Scale Population Connectivity And Genetic Structure In Canada Thistle (Cirsium Arvense), Mahboubeh Hosseinalizadeh Nobarinezhad, Lavanya Challagundla, Lisa E. Wallace

Biological Sciences Faculty Publications

Premise of research. Population connectivity, the exchange of genes among geographically separated subpopulations, is thought to be a key process for the maintenance of genetic diversity and the survival of invasive species in newly colonized areas. Plant populations' degree of genetic connectivity, which occurs via pollen and seed dispersal, leads to different degrees of genetic admixture and genetic structure. Environmental barriers and differential selection pressures that are variable across time and space tend to alter genetic structure within and among populations via restriction or facilitation of gene flow. Canada thistle, an invasive species of the United States and Canada, is …

Phenotypic Variation Of Partridge Pea (Chamaecrista Fasciculata) From Mississippi Persists In A Common Garden, Lisa E. Wallace, Mahboubeh Hosseinalizadeh-Nobarinezhad, Robert Coltharp

Biological Sciences Faculty Publications

Intraspecific phenotypic variation occurs for many different reasons and understanding its basis has applications in taxonomy, ecology, and evolution. Chamaecrista fasciculata (partridge pea) is a widely distributed species with much phenotypic variation and varied interactions with other species in communities where it grows. Botanists have often noted that phenotypic variation in some traits of this species increases from north to south in the eastern United States. In this study, we grew seeds collected from five Mississippi populations in a common greenhouse environment to determine if the observed variation in leaf and stem traits is maintained in this environment. Interpopulation variation …

Morphological Diversity Of Wild Coffee (Coffea Kihansiensis) A Potential Coffee Species For Genetic Improvement, Paul M Kusolwa, Faraja Makwinja, Jackson Nashon, Mayomba Marianna, Amina Kibola

Tanzania Journal of Science

Coffee belongs to the genus Coffea in the Rubiaceae family, and is mostly grown in the tropical and subtropical regions. The Coffea genus comprises 103 species, of which Coffea arabica L. (Arabica coffee) and Coffea canephora P. (Robusta coffee) are the two most important commercial species. C. Arabica is a commercially important high quality coffee with low genetic diversity, while C. canephora is cultivated mostly in the northwestern region of Tanzania. Of recent, a discovered wild coffee (Coffea kihansiensis) in Tanzania may be a genetic resource for improvement of cultivated coffee.  Morphological descriptors from accessions evaluated in different sites at …

Characterization And Domestication Of Wild Edible Mushrooms From Selected Indigenous Forests In Burundi, Vincent Nteziryayo, Donatha D. Tibuhwa, Prosper Kiyuku, Tatien Masharabu

Tanzania Journal of Science

In Burundi, minimum work has been done to comprehensively identify and commercialize high yielding local mushrooms. The previous studies carried out on mushroom cultivation have focused on exotic strains. This is the first study undertaken on domestication of wild edible mushrooms from Burundi indigenous forests. Nine samples were collected from four protected areas and characterized using phenotypic and molecular markers. Germoplasm isolation through tissue culture techniques, spawn production and cultivation studies were also undertaken. Mushroom samples were identified as Pleurotus citrinopileatus, Lentinus squarrosulus, Hypholoma fasciculare, Laetiporus sulfureus, Macrolepiota dolichaula, Trametes polyzona, Amanita zambiana, Lactarius delicious and Amanita verna. Spawn production …

Antimicrobial Activities Of Endophytic Fungi Secondary Metabolites From Moringa Oleifera (Lam), Zuhura N. Mwanga, Esther F. Mvungi, Donatha D Tibuhwa

Tanzania Journal of Science

This study presents the antimicrobial activities of secondary metabolites of endophytic fungi isolated from a medicinal plant Moringa oleifera growing at the University of Dar es Salaam, Tanzania. Two endophytic fungi were identified, Nigrospora sp. from leaves, and Fusarium sp. from roots and seeds. The disc method was used in testing the antimicrobial activities of the crude extracts of endophytic fungi secondary metabolites against four human pathogens, namely, Bacillus substilis, Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that the crude extracts of endophytes secondary metabolites from leaves showed strong antimicrobial activities against two Gram positive bacteria and …

Climate Change Increasing Threats On Non-Conserved Mangroves Forests Of Micheweni, Zanzibar–Tanzania, Haji M. Hamad, Islam S.S. Mchenga, Mariam I. Hamisi

Tanzania Journal of Science

Overutilization of mangroves has been reported as the factor for mangrove declining across the globe. However, currently, the global climate change has been claimed to pose significant threats to the survival of mangroves. This study analysed the impacts of climatic variability (sea level rise, temperature and precipitation) to the mangroves of Micheweni (non reserve) and Ngezi-Vumawimbi (nature forest reserve). Multi-disciplinary approach was employed to collect information on community perceptions. Secondary time series data of up to 30 years for temperature, rainfall and sea level rise were collected and analysed. Inquiry results on how local communities perceived climate change showed that …

Seed‐To‐Seedling Transitions Exhibit Distance‐Dependent Mortality But No Strong Spacing Effects In A Neotropical Forest, Philippe Marchand, Liza S. Comita, S. Joseph Wright, Richard Condit, Stephen P. Hubbell, Noelle G. Beckman

Biology Faculty Publications

Patterns of seed dispersal and seed mortality influence the spatial structure of plant communities and the local coexistence of competing species. Most seeds are dispersed in proximity to the parent tree, where mortality is also expected to be the highest, because of competition with siblings or the attraction of natural enemies. Whereas distance‐dependent mortality in the seed‐to‐seedling transition was often observed in tropical forests, few studies have attempted to estimate the shape of the survival‐distance curves, which determines whether the peak of seedling establishment occurs away from the parent tree (Janzen–Connell pattern) or if the peak attenuates but remains at …

Landscape Scale: Inter- And Intraspecific Variation In Plant Interactions Along A Stress Gradient In The Sheep Range Of Nevada, Jordan Dowell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Impending threats to shrubland ecosystems, posed by climate change, necessitate niche modeling efforts to project vegetation range shifts. However, efforts often remain unguided by individual-scale interspecific plant interactions. The stress gradient hypothesis posits that facilitation should increase in areas of high abiotic stress, only if the individuals are able to ameliorate the surrounding area via functional traits. The Sheep Range of Nevada was used to assess the role of functional traits as predictors of plant association. Larrea tridentata, Coleogyne ramosissima, and Artemisia nova were selected as shrubs with variable life history strategies and ranges in order to identify general patterns …

Assessment Of Cytotoxic Activity Of Five Common Philippine Medicinal Plants Using Brine Shrimp Lethality Assay, Lloyd O. Balinado, Merab A. Chan

Biology Faculty Publications

A wide variety of plants in the Philippines are used to address several medical ailments; however, many of which have not yet undergone thorough pharmacological studies. The problem on the possible side effects caused by these medicinal preparations has, therefore, increased the interest in validating their safety for human use. The present study was conducted to determine the cytotoxicity of five common local medicinal plants. Annona muricata L., Cymbopogon citratus DC., Graptophyllum pictum (L.) Griff, Jatropha curcas L., and Piper betle L. were selected and subjected to crude aqueous leaf extraction. Extracts were then investigated for cytotoxicity potential using brine …

Soil Characteristics Drive Ficaria Verna Abundance And Reproductive Output, Justin P. Kermack, Emily Rauschert

Biological, Geological, and Environmental Faculty Publications

Lesser celandine (Ficaria verna Huds.), an invasive plant from Europe, is becoming widespread in river valleys throughout the northeastern United States and the Pacific Northwest. Its high rate of asexual bulbil and tuber production creates dense infestations threatening native spring ephemerals. Ficaria verna abundance and reproductive output (seeds, bulbils, and tubers) were examined in invaded transects spanning a disturbance gradient away from a river. Site characteristics (photosynthetically active radiation [PAR], soil pH, moisture, texture, and nutrients) were quantified to examine their roles in plant abundance and reproduction. A larger-scale study examined random transects not specifically chosen based on F. …

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

Evaluation Of Pheromone Mating Disruption For California Red Scale Control In Commercial California Citrus, Joel Timothy Leonard

Master's Theses

California red scale (CRS), Aonidella aurantii, is an increasingly injurious insect pest for the California citrus industry due to insecticide resistance, changing weather patterns, and shifting trade regulations. The presence of the insect on fruit, damages the rind of the fruit and high populations can cause dieback of branches as well as lower yields. Pheromone mating disruption of CRS has the potential to alleviate population control concerns and reduce insecticide use. The efficacy of the pheromone mating disruption technique for pest management of CRS was determined using the products CheckMate® CRS and Semios CRS Plus. CheckMate® CRS was evaluated …

Vines In The Neotropics: Phylogenomics, Biogeography And Systematics In Passion Flowers (Passiflora Subgenus Decaloba Section Decaloba), Serena Acha

Dissertations

With 600 species, Passiflora is a large, morphologically complex and broadly distributed genus in Passifloraceae that represents a major challenge to scientists interested in understanding the evolutionary history of tropical vines. Passiflora has been divided into subgenera, super sections and sections. One of the most enigmatic and species-rich (~120 spp.) groups in Passiflora is section Decaloba, which occurs in the Neotropics and is particularly diverse in Andean montane forests. In this study, we used phylogenomic and population genomic approaches to investigate the evolutionary history, biologeography, species boundaries, and taxonomy of Passiflora section Decaloba. We sampled herbarium specimens, extracted …

Stability Of Petal Color Polymorphism: The Significance Of Anthocyanin Accumulation In Photosynthetic Tissues, José Carlos Del Valle, Cristina Alcalde-Eon, Mª Teresa Escribano-Bailón, Mª Luisa Buide, Justen B. Whittall, Eduardo Narbona

Biology

Background: Anthocyanins are the primary source of colour in flowers and also accumulate in vegetative tissues, where they have multiple protective roles traditionally attributed to early compounds of the metabolic pathway (flavonols, flavones, etc.). Petal-specific loss of anthocyanins in petals allows plants to escape from the negative pleiotropic effects of flavonoid and anthocyanins loss in vegetative organs, where they perform a plethora of essential functions. Herein, we investigate the degree of pleiotropy at the biochemical scale in a pink-white flower colour polymorphism in the shore campion, Silene littorea. We report the frequencies of pink and white individuals across 21 populations …

Combination Of Curcumin And Luteolin Synergistically Inhibits Tnf-Α-Induced Vascular Inflammation In Human Vascular Cells And Mice, Lijuan Zhang, Xiaoyong Wang, Longyun Zhang, Carlos Virgous, Hongwei Si

Human Sciences Faculty Research

Emerging evidence shows that phytochemicals, the secondary plant metabolites present in a large variety of foods, have the potential ability in reducing the risk of cardiovascular diseases. However, the dosages of phytochemicals in the cellular and animal studies are too high to reach in humans by relevant foods or dietary supplement intake. The aims of this study were to investigate whether and how combined curcumin and luteolin synergistically inhibit tumor necrosis factor-alpha (TNF-α)-induced monocytes adhesion endothelium, a crucial step of the development of endothelial dysfunction, both in human vascular cells and mouse aortic endothelium. Our results show that combined curcumin …

Beyond The Binary (Part 1): Re-Envisioning The Complexity Of Life History Evolution In The Bromeliaceae With Comparative Data, Rachel Jabaily, Erin Bodine

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Plant Cell-Derived Growth Factors For Ex Vivo Mass Production Of Red Blood Cells, Xiaoting Wang

Student Theses and Dissertations

Generation of red blood cells from hematopoietic stem cells (HSCs) used for blood transfusion represents one of the focus in regenerative medicine. Erythropoietic growth factors (eGFs), including stem cell factor (SCF), erythropoietin (EPO) and interleukin 3 (IL-3) are vital for proliferation and differentiation of HSCs into mature red blood cells (RBCs) ex vivo. However, massive production of RBCs requires significant quantity and high quality of eGFs, making manufacturing at large scale cost prohibitive. Plant cell culture is proposed to be a promising bioproduction platform for growth factors based on the advantages of, fast growing, no risk of human pathogen, and …

Optimizing Hydroxyproline-O-Glycan Engineering In Tobacco Transient Protein Expression: Fish Il-22 And Enhanced Green Fluorescent Protein (Egfp), Cristofer Calvo

Student Theses and Dissertations

Despite the advantages of plant-produced recombinant proteins, the most important bottleneck that limits the commercialization is the low protein yields. Plants have a unique type of O-glycosylation that has potential to enhance the stability and solubility of recombinant proteins. Specifically, target gene sequences are fused with a sequence to code for hydroxyproline-O-glycosylated peptide (HypGP) tags. We targeted the expression of a very unstable rainbow trout interleukin 22 (rtIL-22) and a readily-monitored enhanced green fluorescent protein (EGFP). The HypGP-tagged rIL-22 accumulation in planta was significantly enhanced over the untagged protein and showed increase stability. Changes in gene expression of the marker …

Green Club After School Program Curriculum, Megan Willburn

Honors Program: Expanded Learning Clubs

Green Club is an after school program which encourages students to develop environmental empathy, passions for environmental sustainability, and knowledge about the workings of environmental systems.

Insect Population Dynamics, Varietal Preference And Performance Of Organic Bio-Pesticides, Anitha Chitturi, Jeanine Davis, Margaret Bloomquist, Franklin Quarcoo, Kokoasse Kpomblekou-A, Desmond Mortley

Professional Agricultural Workers Journal

Abstract

Organic farming prohibits use of synthetic agrochemicals and encourages use of Integrated Pest Management (IPM) methods. States in the Southeastern US generally lag behind the rest of the country in organic vegetable production partly because of high insect pressures that make it difficult to grow vegetables without pesticides. This study on summer squash (Cucurbita pepo), grown using organic management practices, was conducted at a research station located in Mills River, North Carolina. The objectives of the study were to assess insect population dynamics and to evaluate performance of three OMRI-approved bio-pesticides: Azadirachtin, Pyrethrin and Spinosad against major …

Identification Of Key Parameters Controlling Demographically Structured Vegetation Dynamics In A Land Surface Model: Clm4.5(Fates), Elias C. Massoud, Chonggang Xu, Rosie A. Fisher, Ryan G. Knox, Anthony P. Walker, Shawn P. Serbin, Bradley O. Christoffersen, Jennifer A. Holm, Lara M. Kueppers, Daniel M. Ricciuto

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Vegetation plays an important role in regulating global carbon cycles and is a key component of the Earth system models (ESMs) that aim to project Earth's future climate. In the last decade, the vegetation component within ESMs has witnessed great progress from simple “big-leaf” approaches to demographically structured approaches, which have a better representation of plant size, canopy structure, and disturbances. These demographically structured vegetation models typically have a large number of input parameters, and sensitivity analysis is needed to quantify the impact of each parameter on the model outputs for a better understanding of model behavior. In this study, …

Responses Of Bouteloua Eriopoda And Soil Stability To Precipitation Extremes In Chihuahuan Desert Grassland, Laura Kay Sadorf

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Shifts In Plant Functional Composition Following Long-Term Drought In Grasslands, Robert J. Griffin‐Nolan, Dana M. Blumenthal, Scott L. Collins, Timothy E. Farkas, Ava M. Hoffman, Kevin E. Mueller, Troy W. Ocheltree, Melinda D. Smith, Kenneth D. Whitney, Alan K. Knapp

Biological, Geological, and Environmental Faculty Publications

1. Plant traits can provide unique insights into plant performance at the community scale. Functional composition, defined by both functional diversity and community-weighted trait means (CWMs), can affect the stability of above-ground net primary production (ANPP) in response to climate extremes. Further complexity arises, however, when functional composition itself responds to environmental change. The duration of climate extremes, such as drought, is expected to increase with rising global temperatures; thus, understanding the impacts of long-term drought on functional composition and the corresponding effect that has on ecosystem function could improve predictions of ecosystem sensitivity to climate change.

2. We experimentally …

Systematics Of Carex Section Laxiflorae (Cyperaceae), Jenna Dorey

Dissertations, Theses, and Capstone Projects

Carex, with more than 2100 species, is the most species-rich genus of flowering plants in temperate regions of the world. Members of the family Cyperaceae are colloquially known as sedges, and members of the genus Carex are called “true sedges.” Carex occur on every continent except for Antarctica, they thrive in a panoply of habitats, and are ecologically important as a forage source for wildlife, carbon sequestration, prevention of soil erosion, and providing habitat for fresh water invertebrates. Despite their importance many sedges are still poorly known, such as the woodland sedges in Carex section Laxiflorae, which is …

Allopatric Speciation In Asia Contributed To The Diversity Anomaly Between Eastern Asia And Eastern North America: Evidence From Anchored Phylogenomics Of Stewartia (Theaceae), Jianhua Li, Peter Del Tredici, Alan R. Lemmon, Emily Moriarty Lemmon, Yunpeng Zhao, Chengxin Fu

Faculty Publications

Premise of research. The disjunct distribution of plant genera between eastern Asia (EA) and eastern North America (ENA) has long attracted the attention of biologists and biogeographers. For most genera that have been studied, there are more species in EA than in ENA, and the diversity anomaly may have resulted from the greater physiographical heterogeneity in EA than in ENA in conjunction with climate and sea level changes. However, few empirical studies have explicitly tested the association between species diversity and allopatric speciation events. The genus Stewartia (Theaceae) displays this diversity anomaly, with two species in ENA and 21 …