Genetics and Genomics Commons^™

Conservation, Comparative Genomics And Species Delimitation Of The Reindeer Lichens (Cladonia), Jordan R. Hoffman

Dissertations, Theses, and Capstone Projects

The genus Cladonia represents one of the most speciose genera of lichenized fungi, with more than 500 known species encompassing a diverse array of morphologies and habits. These lichens form keystone species in many habitats, serving a variety of ecological roles. However, despite being among of the more well studied lichens, there is much still unknown or under-studied about them. As is the case with most lichen study systems, phylogenetic study has been limited to a small number of partial loci, while adoption of next-generation sequence methods has been slow. As a consequence, there are still knowledge gaps in Cladonia …

Dna Barcoding Of The High-Altitude Artemisia And Nepeta Species, Vyacheslav Dushenkov, Csanad Gurdon, Shukhratdzhon Satorov

Publications and Research

DNA barcoding was performed for four medicinal plant species from the mountain region of Tajikistan. The nucleotide sequences for Artemisia sieberi, Artemisia scoparia, Artemisia vulgaris, and Nepeta glutinosa were deposited into the GenBank at the National Center for Biotechnology Information.

Evolution And Development Of The Seed Coat In Gymnosperms, Cecilia Zumajo

Dissertations, Theses, and Capstone Projects

Gymnosperms and angiosperms are the most abundant plant lineages on earth and constitute a turning point in the evolution of plants because they are at the origin of the seed, a key morphological and developmental novelty in the evolution of land plant. Although the morphological variation of the seed, across seed plants, may on its own, explain the complexity of this structure, the origin, and evolution are even more, the understanding of these topics is still under discussion. Evidence shows that previous studies have often lacked the component of gene expression, particularly in species that are not model species. The …

Distribution And Population Structure Of The Invasive Nitellopsis Obtusa (Desv. In Loisel.) J. Groves And Native Species Of Characeae In The Northeast U.S.A., Robin Sleith

Dissertations, Theses, and Capstone Projects

Freshwater ecosystems are some of the most biologically diverse environments on Earth. Billions of humans rely on functioning freshwater ecosystems for drinking water and many other services. These ecosystems are increasingly threatened by human impacts including nutrient pollution, invasive species, and climate change. Here I contribute four research chapters that investigate freshwater diversity and ecosystem threats using the Characeae, a family of freshwater green macroalgae, as a study system. Characeae are a diverse and ancient group with more than 500 extant species and a fossil history spanning at least 250 million years. These algae are macrophytes in freshwater ecosystems, and …

A Contribution Toward A Global Monograph Of Gyroporus: Taxonomy, Phylogeny, Biogeography, Naveed Davoodian

Dissertations, Theses, and Capstone Projects

Gyroporus (Sclerodermatineae, Boletales, Agaricomycetes, Basidiomycota, Fungi) is a genus of ectomycorrhizal mushroom-forming fungi distributed throughout the world in suitable habitats. Previous attempts to untangle the diversity of this genus proved difficult due to the presence of semi-cryptic species and equivocal results from phylogenetic analysis of ribosomal RNA markers. To overcome these obstacles, a combined taxonomic and phylogenetic (emphasizing protein-coding genes) approach is used here to delimit species and elucidate geographic and evolutionary patterns of Gyroporus. Careful study of relevant literature and herbarium specimens was augmented by field work in North America, Australia, and East Asia for observation and collection …

A First Linkage Map And Downy Mildew Resistance Qtl Discovery For Sweet Basil (Ocimum Basilicum) Facilitated By Double Digestion Restriction Site Associated Dna Sequencing (Ddradseq), Robert M. Pyne, Josh Honig, Jennifer Vaiciunas, Adolfina R. Koroch, Christian Wyenandt, Stacy Bonos, James Simon

Publications and Research

Limited understanding of sweet basil (Ocimum basilicum L.) genetics and genome structure has reduced efficiency of breeding strategies. This is evidenced by the rapid, worldwide dissemination of basil downy mildew (Peronospora belbahrii) in the absence of resistant cultivars. In an effort to improve available genetic resources, expressed sequence tag simple sequence repeat (EST-SSR) and single nucleotide polymorphism (SNP) markers were developed and used to genotype the MRI x SB22 F2 mapping population, which segregates for response to downy mildew. SNP markers were generated from genomic sequences derived from double digestion restriction site associated DNA sequencing (ddRADseq). Disomic segregation was observed …

Lichen Conservation In Eastern North America: Population Genomics, Climate Change, And Translocations, Jessica Allen

Dissertations, Theses, and Capstone Projects

Conservation biology is a scientific discipline that draws on methods from diverse fields to address specific conservation concerns and inform conservation actions. This field is overwhelmingly focused on charismatic animals and vascular plants, often ignoring other diverse and ecologically important groups. This trend is slowly changing in some ways; for example, increasing number of fungal species are being added to the IUCN Red-List. However, a strong taxonomic bias still exists. Here I contribute four research chapters to further the conservation of lichens, one group of frequently overlooked organisms. I address specific conservation concerns in eastern North America using modern methods. …

Metabolic Profiling And Polymer Formation Of Gene Silenced Potato Periderms, Qing Cai

Dissertations, Theses, and Capstone Projects

Suberin is a biopolyester constituent of specialized plant periderm tissues formed within the phellem cell walls. Suberin and waxes of the periderm layer act to prevent water diffusion, mechanical breakdown and pathogenic invasion in plants. Ferulic esters, ω-hydroxyacids and α,ω-fatty diacids are considered to be the most important linkage between aliphatic and aromatic suberin domains and also linked with cell-wall polysaccharides. The potato gene FHT (fatty ω- hydroxyacid/fatty alcohol hydroxycinnamoyl transferase) esterifies ferulic acid to suberin. Diminished levels of feruloyl transferase activity have been associated with lowered amounts of feruloyl esters of fatty acids in both suberin-associated waxes and suberin …

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …