Genetics and Genomics Commons^™

Genome-Wide Association Studies In Maize And Sorghum, Preston Hurst

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Genome-wide association studies are used to identify genetic variants associated with a particular phenotype. GWAS has been used in a variety of taxa, from humans, to fish to plants . The present analysis is focused on two species important to the human species: maize and sorghum. A GWAS in maize was carried out on the modification of the Ga1-s allele. The Ga1 locus has long been studied as being involved in a unilateral crossing barrier . However, it has long been suspected that the locus is modified by background genetic factors . GWAS was used to observe candidates for this …

Surface Fire To Crown Fire: Fire History In The Taos Valley Watersheds, New Mexico, Usa, Lane B. Johnson, Ellis Q. Margolis

Aspen Bibliography

Tree-ring fire scars, tree ages, historical photographs, and historical surveys indicate that, for centuries, fire played different ecological roles across gradients of elevation, forest, and fire regimes in the Taos Valley Watersheds. Historical fire regimes collapsed across the three watersheds by 1899, leaving all sites without fire for at least 119 years. Historical photographs and quaking aspen (Populus tremuloides Michx.) ages indicate that a high-severity fire historically burned at multiple high-elevation subalpine plots in today’s Village of Taos Ski Valley, with large high-severity patches (>640 ha). Low-severity, frequent (9–29-year median interval) surface fires burned on the south aspects …

Using Publicly Available Genbank Data To Teach Plant Phylogeny In High School Classrooms, Madhav P. Nepal, Ethan J. Andersen

iLEARN Teaching Resources

In this teaching module, students will learn about NCBI GenBank, search for DNA/protein sequences from multiple plant species of a gene that encodes Rubisco enzyme, construct and interpret a phylogenetic tree, and discuss traits that allowed plants to adapt their life on land.

Climate Change, Woodpeckers, And Forests: Current Trends And Future Modeling Needs, Eric S. Walsh, Kerri T. Vierling, Eva Strand, Kristina Bartowitz, Tara W. Hudiburg

Aspen Bibliography

The structure and composition of forest ecosystems are expected to shift with climate‐induced changes in precipitation, temperature, fire, carbon mitigation strategies, and biological disturbance. These factors are likely to have biodiversity implications. However, climate‐driven forest ecosystem models used to predict changes to forest structure and composition are not coupled to models used to predict changes to biodiversity. We proposed integrating woodpecker response (biodiversity indicator) with forest ecosystem models. Woodpeckers are a good indicator species of forest ecosystem dynamics, because they are ecologically constrained by landscape‐scale forest components, such as composition, structure, disturbance regimes, and management activities. In addition, they are …

Predatory Hymenopteran Assemblages In Boreal Alaska: Associations With Forest Composition And Post-Fire Succession, Alexandria Wenninger, Teresa Hollingsworth, Diane Wagner

Aspen Bibliography

Changes to the fire regime in boreal Alaska are shifting the ratio of coniferous to deciduous dominance on the landscape. The increase in aspen and birch may have important effects on predatory hymenopteran assemblages by providing a source of extrafloral nectar and increasing prey availability. Furthermore, fire-induced changes in successional age alter habitat structure and microclimate in ways that may favor ants. This study is the first to characterize the influence of fire-related vegetation changes on boreal predatory hymenopteran assemblages. We compare the abundance, species richness, and composition of predatory hymenopteran assemblages among forests at different stages of succession and …

Application Of Short Tandem Target Mimic (Sttm) Technique For Functional Analysis Of Micro-Rna396 In Transgenic Poplar Trees, Surattana Boonsai

Dissertations, Master's Theses and Master's Reports

Short Tandem Target Mimic (STTM) is a commonly technique used for functional studies of a number of genes in several plant model systems. However, very little is known about application of STTM technique in tree species. In this study, STTM was applied to knock down microRNA396 (miR396) in transgenic poplar trees for the first time. STTM396 expression resulted in dramatic decrease in miR396 expression levels leading to taller plants with larger leaves and larger leaf cell size. Additionally, an expression analysis of growth regulating factor genes (GRFs) that are members of miR396 target gene family showed up-regulation of GRF07 gene …

The New Natural Distribution Area Of Aspen (Populus Tremula L.) Marginal Populations In Pasinler In The Erzurum Province, Turkey, And Its Stand Characteristics, Halil Bariş Özel, Sezgin Ayan, Serdar Erpay, Bojan Simovski

Aspen Bibliography

Background and Purpose: Genetic diversity is the basis for adaptation and survival of tree species under changing environmental conditions, representing the key issue of stability and productivity of forest ecosystems. This paper studies the marginal population characteristics and stand dynamics of aspen tree (Populus tremula L.) in natural, pure and mixed forest stands with Scots pine (Pinus sylvestris L.). These populations were observed on founding sites between Timarli Valley and Timan Plateau located in Pasinler in the Erzurum Province in Turkey.
Materials and Methods: Three replicated sample sites were established according to a randomised block design …

Dependence Of Aspen Stands On A Subsurface Water Subsidy: Implications For Climate Change Impacts, D. M. Love, M. D. Venturas, J. S. Sperry, P. D. Brooks, J. L. Pettit, Y. Wang, W. R. L. Anderegg, X. Tai, D. S. Mackay

Aspen Bibliography

The reliance of 10 Utah (USA) aspen forests on direct infiltration of growing season rain versus an additional subsurface water subsidy was determined from a trait- and process-based model of stomatal control. The model simulated the relationship between water supply to the root zone versus canopy transpiration and assimilation over a growing season. Canopy flux thresholds were identified that distinguished nonstressed, stressed, and dying stands. We found growing season rain and local soil moisture were insufficient for the survival of 5 of 10 stands. Six stands required a substantial subsidy (31–80% of potential seasonal transpiration) to avoid water stress and …

Phylogeographic Analyses Of A Widely Distributed Populus Davidiana: Further Evidence For The Existence Of Glacial Refugia Of Cool‐Temperate Deciduous Trees In Northern East Asia, Zhe Hou, Zhaoshan Wang, Zhanyang Ye, Shuhui Du, Shuya Liu, Jianguo Zhang

Aspen Bibliography

Despite several phylogeographic studies had provided evidence to support the existence of glacial refugia of cool‐temperate deciduous trees in northeast China, the species used in these studies were limited by the species ranges, which could not exclude the possibility that northern populations were the colonists from southern refugial populations during the last glacial maximum (LGM). Here, we estimated the nucleotide variation in Populus davidiana, a widespread species distributed in Eurasia. Three groups in northeast, central, and southwest China were constructed according to the simulation results from SAMOVA, composition of chloroplast haplotypes and structure results. We revealed that the northeast …

Generation And Evaluation Of Modified Opaque-2 (O2) Popcorn Suggests A Route To Quality Protein Popcorn (Qpp), Ying Ren

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

I have been working on a Quality Protein Popcorn breeding project where QPM conversion is carried out simultaneously for several elite popcorn germplasms. During my study in the graduate program, I led the following aspects of the Quality Protein Popcorn Breeding Project:

1. Identified suitable QPMs as opaque-2 allele donors.

2.Examined the feasibility of quick introgression of the opaque-2 allele into popcorn lines via marker-assisted selection.

3. Monitored modification by SDS-PAGE zein profiling and light box phenotypic selection to make sure multiple modifier loci for opaque-2 were incorporated each time generation advancement was carried out.

4. Carried out high throughput …

Phylogeny And Population Genetic Analyses Reveals Cryptic Speciation In The Bombus Fervidus Species Complex (Hymenoptera: Apidae), Jonathan B. Koch, Juanita Rodriguez, James P. Pitts, James P. Strange

Ecology Center Publications

Bumble bees (Bombus Latrielle) are significant pollinators of flowering plants due to their large body size, abundant setae, and generalist foraging strategies. However, shared setal coloration patterns among closely and distantly related bumble bee species makes identification notoriously difficult. The advent of molecular genetic techniques has increased our understanding of bumble bee evolution and taxonomy, and enables effective conservation policy and management. Individuals belonging to the North American Bombus fervidus species-complex (SC) are homogenous in body structure but exhibit significant body color phenotype variation across their geographic distribution. Given the uncertainty of the genealogical boundaries within the SC, some …

South American Leaf-Cutter Bees (Genus Megachile) Of The Subgenera Rhyssomegachile And Zonomegachile, With Two New Subgenera (Hymenoptera: Megachilidae), Víctor H. González, Terry Griswold, Michael S. Engel

All PIRU Publications

Leaf-cutter bees (genus Megachile Latreille) are among the most common and diverse group of bees. However, the identity and taxonomic placement of many species are problematic and species identification is often difficult. Some species are known only from a single specimen or from one of the sexes, and identification keys are not available for many groups. We address these taxonomic issues for the subgenera Rhyssomegachile Mitchell and Zonomegachile Mitchell, two poorly known South American lineages of leaf-cutter bees. We provide comparative diagnoses, redescriptions, illustrated identification keys, new geographical records, and designate needed neotypes for Megachile cara Mitchell, M. gigas Schrottky, …

Confirming World-Wide Distribution Of An Agriculturally Important Lacewing, Chrysoperla Zastrowi Sillemi, Using Songs, Morphology, Mitochondrial Gene Sequencing, And Phylogenetic Reconstruction, Zoe Mandese

Honors Scholar Theses

The Chrysoperla carnea-group of green lacewings is a cryptic species complex. Species within the group are morphologically similar, yet isolated from one another via reproductive mating song. Chrysoperla zastrowi, a species within the carnea-group, is currently described with a distribution ranging from South Africa to the Middle East and India. However, recent collections of carnea-group lacewings from Guatemala and California were preliminarily identified as Chrysoperla zastrowi based upon similarities in their vibrational courtship songs. This analysis aims to place six specimens, collected by collaborators in Guatemala, Armenia, Iran, and California, into a pre-existing phylogeny of the …

Aspen Recruitment In The Yellowstone Region Linked To Reduced Herbivory After Large Carnivore Restoration, Luke E. Painter, Robert L. Beschta, Eric J. Larsen, William J. Ripple

Aspen Bibliography

Quaking aspen (Populus tremuloides) recruitment during the 1980s–90s was suppressed by Rocky Mountain elk (Cervus canadensis) herbivory on winter ranges in the Yellowstone region, and saplings (young aspen taller than 2 m) were rare. Following the 1995–96 reintroduction of gray wolves (Canis lupus), browsing decreased and sapling recruitment increased in Yellowstone National Park. We compared aspen data from inside the park to data collected in three winter ranges outside the park. For most areas, the percentage of young aspen browsed annually was 80–100% in 1997–98, decreasing to 30–60% in 2011–15. Sapling recruitment was inversely …

Effects Of Stand Structure, Browsing, And Biophysical Conditions On Regeneration Following Mountain Pine Beetle In Mixed Lodgepole Pine And Aspen Forests Of The Southern Rockies, Kristen A. Pelz, Frederick W. Smith

Aspen Bibliography

Aspen (Populus tremuloides) and lodgepole pine (Pinus contorta var. latifolia) co-occur in the southern Rocky Mountains (USA), where mountain pine beetle (MPB, Dendroctonus ponderosae) has caused extensive lodgepole pine mortality since the late 1990s. Both species excel in post-disturbance high-light environments, but lodgepole pine has generally been thought to establish poorly on undisturbed seedbeds, and aspen suckering may be inhibited by intact aspen overstory. We ask whether lodgepole pine and aspen will regenerate in sufficient quantities to revegetate these forests. We visited a random sample of aspen and lodgepole pine stands across the affected landscape …

Grapevine Vein Clearing Virus: Epidemiological Patterns And Construction Of A Clone, Cory Von Keith

Graduate Theses/Dissertations

Grapevine vein clearing virus (GVCV) is a recently discovered virus belonging to the Badnavirus genus. Characteristic to its name, the virus is associated with a disease where symptoms manifest as pronounced vein-clearing, resulting in severe berry deformation and vine decline in susceptible grape varieties. Sustainable production of wine is dependent on healthy plants. The associated disease is mainly found in Midwest vineyards. Attempts were made in this thesis to provide evidence of causality of the virus to the associated disease and to infer the historical path and migration pattern of GVCV. Conclusions and discussions will provide grape producers with the …

The Identification Of Interspecific Hybrids Between Jaeger 70 X Vignoles Grapes Using Ssr Markers, Carl William Knuckles Iv

Graduate Theses/Dissertations

Jaeger 70 cultivar is an interspecific hybrid of Vitis linececumii x Vitis rupestris, with an interesting past. It was created by Hermann Jaeger of Neosho, MO, who is most notable for saving the French wine industry by developing phylloxera resistant rootstocks in the mid-1800s. Traditionally the Jaeger 70 variety has been grafted to French wine grape cultivars to impart disease resistance and cold hardiness while retaining desirable wine characteristics. One interesting characteristic of Jaeger 70 is that it is a female-only plant, allowing for many interesting areas of study. Vitis interspecific hybrid Vignoles, is a cold hardy cultivar of largely …

Fitness Consequences Of Interspecific Nesting Associations Among Cavity-Nesting Birds, James C. Mouton, Thomas E. Martin

Aspen Bibliography

Interspecific aggregations of prey may provide benefits by mitigating predation risk, but they can also create costs if they increase competition for resources or are more easily detectable by predators. Variation in predation risk and resource availability may influence the occurrence and fitness effects of aggregating in nature. Yet tests of such possibilities are lacking. Cavity-nesting birds provide an interesting test case. They compete aggressively for resources and experience low nest predation rates, which might predict dispersion, but across 19 years of study we found that they commonly aggregate by sharing nest trees. Tree sharing was more common when aspen …

Removal Of Invasive Plants From Pando Exclosure 2018, Marc Coles-Ritchie

Aspen Bibliography

On July 10-11, 2018 volunteers and staff from Great Old Broads for Wilderness and Grand Canyon Trust removed invasive plants from the Pando exclosure, a fenced portion of the Pando Clone aspen forest adjacent to Fish Lake, in Central Utah. This area has been fenced to restore a portion of the Pando Clone that has been lacking recruitment for decades, by protecting young aspen from browsing by deer and cattle. We have been removing invasive species for five years from this exclosure.

The 2018 trip included 10 women and one staffer of Great Old Broads for Wilderness, from the states …

Phytochemical Screening Of Quaking Aspen (Populus Tremuloides) Extracts By Uplc-Qtof-Ms And Evaluation Of Their Antimicrobial Activity, Annabelle St-Pierre, Dorian Blondeau, André Lajeunesse, Julien Bley, Nathalie Bourdeau, Isabel Desgagné-Penix

Aspen Bibliography

The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to …

Phosphorus Vs. Mycorrhiza: Mitigation Of Lead Uptake In Tomatoes, Helen Senerchia, Liz Miernicki, Andrew Margenot

PRECS 2018

This study seeks to understand how the mutualist relationship between arbuscular mycorrhizal fungi (AM) and Solanum lycopersicum (tomato) affects the uptake and distribution of iron (Pb) found in soil by tomatoes and how the effects of phosphorous (P) application may pose a trade-off between AM and P mitigation of bioavailability of Pb.

Polymorphisms Of Bovine Hsp90 And Their Implications In Beef Cattle Productivity, Glynn G. Smith

Animal Science Undergraduate Honors Theses

Production of beef cattle represents a $60 billion industry in the United States (USDA, 2015). The American beef cattle industry loses an estimated $370 million annually due to heat stress (St-Pierre, 2003). As of 2003, this was equal to nearly 99 million pounds of beef lost (USDA, 2015). The average American consumed roughly 65 pounds of beef in 2003; this means that the 99 million pounds of beef lost to heat stress would have been enough to feed approximately 1.5 million Americans for an entire year (Barclay, 2012).

Rapid Regeneration Offsets Losses From Warming-Induced Tree Mortality In An Aspen-Dominated Broad-Leaved Forest In Northern China, Pengwu Zhao, Chongyang Xu, Mei Zhou, Bo Zhang, Peng Ge, Nan Zeng, Hongyan Liu

Aspen Bibliography

Worldwide tree mortality as induced by climate change presents a challenge to forest managers. To successfully manage vulnerable forests requires the capacity of regeneration to compensate for losses from tree mortality. We observed rapid regeneration and the growth release of young trees after warming-induced mortality in a David aspen-dominated (Populus davidiana) broad-leaved forest in Inner Mongolia, China, as based on individual tree measurements taken in 2012 and 2015 from a 6-ha permanent plot. Warming and drought stress killed large trees 10–15 m tall with a total number of 2881 trees during 2011–2012, and also thinned the upper crowns. …

Breeding For Resistance In California Strawberry To Verticillium Dahliae, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This article focuses on breeding resistant strawberries to the fungus Verticillium dahliae, common name Verticillium wilt. This is a serious fungal disease that can result in a loss of 50% or more of a strawberry harvest when grown in infested soil. The main goal is to provide an example of how a cultivar can be made more resistant to a plant pathogen with the use of plant breeding methods.

Since 1930 the University of California, Davis, has been developing strawberry cultivars that are adapted to the agricultural industry and regional farms. Developing cultivars that require fewer inputs are of …

Genetic Diversity And Distinctness Of Wild Nebraska Hops And Hop Cultivars (Humulus Lupulus L.), Megan Franklin

Honors Program: Senior Projects (Public)

Background Commercial hop (Humulus lupulus) cultivars that are being grown in the Midwest are not performing as successfully as when they are grown in the Pacific Northwest, the region to which they are adapted. To increase adaptation to the Midwest environment, one strategy is to draw from the genetic pool of wild native Midwest hops, which have developed genes that allow them to grow successfully in this environment. Wild hop plants that are genetically distinct from commercial cultivars are likely to have more adaptations, such as pest/disease resistance and drought tolerance, which can be bred into commercial lines. The …

Developing Pennycress ( Thlaspi Arvense ) As A Biodiesel Feedstock Crop And Plant Model System, Michaela Mcginn

Theses and Dissertations

Thlapsi arvense L. (pennycress) is currently being developed as a profitable oilseed-producing winter annual cover crop with extreme cold tolerance and a rapid life cycle that can be grown on fallow farmland throughout the U.S. Midwest Corn Belt, controlling soil erosion and nutrient runoff while serving as an additional source of income for the American farmer without displacing food crops. The research comprising this dissertation demonstrates that pennycress can serve as a user-friendly model system highly similar to Arabidopsis thaliana, and is well-suited for both laboratory and field experimentation, being readily employable in existing growth facilities. After 10 generations of …

Genetic Assessment Of Inbred Chicken Lines Indicates Genomic Signatures Of Resistance To Marek's Disease, Lingyang Xu, Yanghua He, George E. Liu, Huanmin Zhang, Hans H. Cheng, Robert L. Taylor Jr, Jiuzhou Song

Faculty & Staff Scholarship

Background: Marek’s disease (MD) is a highly contagious pathogenic and oncogenic disease primarily affecting chickens. However, the mechanisms of genetic resistance for MD are complex and not fully understood. MD-resistant line 63 and MD-susceptible line 72 are two highly inbred progenitor lines of White Leghorn. Recombinant Congenic Strains (RCS) were developed from these two lines, which show varied susceptibility to MD.

Results: We investigated genetic structure and genomic signatures across the genome, including the line 63 and line 72, six RCSs, and two reciprocally crossed flocks between the lines 63 and 72 (F1 63 × 72 and F1 72 × …

Large Effect Quantitative Trait Loci For Salicinoid Phenolic Glycosides In Populus: Implications For Gene Discovery, Scott A. Woolbright, Brian J. Rehill, Richard L. Lindroth

Aspen Bibliography

Genomic studies have been used to identify genes underlying many important plant secondary metabolic pathways. However, genes for salicinoid phenolic glycosides (SPGs)—ecologically important compounds with significant commercial, cultural, and medicinal applications—remain largely undescribed. We used a linkage map derived from a full‐sib population of hybrid cottonwoods (Populus spp.) to search for quantitative trait loci (QTL) for the SPGs salicortin and HCH‐salicortin. SSR markers and primer sequences were used to anchor the map to the V3.0 P. trichocarpa genome. We discovered 21 QTL for the two traits, including a major QTL for HCH‐salicortin (R2 = .52) that colocated …

The Impact Of Reconstructed Soils Following Oil Sands Exploitation On Aspen And Its Associated Belowground Microbiome, Franck Stefani, Nathalie Isabel, Marie-Josee Morency

Aspen Bibliography

Oil sands surface mining in the Athabasca region of northern Alberta (Canada) is a significant anthropogenic disturbance that resets boreal forest development and succession to early stages. During surface mining, the vegetation is cleared, the topsoil is salvaged, and the overburden (the layer of sand and clay in between the topsoil and the oil sands) is piled (see Fig. 2 in Audet et al.1 for an explanation of the land-reclamation procedure). After mining is finished, the landforms (composed of overburden and tailings sand) are capped with organic matter-rich soil covers made of either upland-derived forest floor-mineral mix (FFMM) or a …

Hart Prairie Preserve Site Visit To Assess Aspen Health Nature Conservancy, Flagstaff, Az, Amanda Grady

Aspen Bibliography

On June 11, 2018, Amanda Grady, Entomologist, Arizona Zone, Forest Health Protection, performed a site visit to evaluate aspen health on the Nature Conservancy lands at Heart Prairie Preserve (HPP) near Flagstaff. Specifically, the evaluation was to determine whether or not the aspen within exclosures on Fern Mountain have symptoms or signs of Oystershell scale (OSS), an emergent forest pest contributing to aspen decline in northern Arizona.