Botany Commons^™

Integration Of Medicinal Fungi Into The Heber W. Youngken Jr. Medicinal Garden, Anthony Makashov

Senior Honors Projects

The Heber W. Youngken Jr. Medicinal Garden is a one-of-a-kind resource that houses close to 300 medicinal plants and is filled to the brim with educational opportunities. For the College of Pharmacy, this garden has been the centerpiece of many classes taught here at the University of Rhode Island and has roots as a physical teaching space. While the garden contains a plethora of plant species, medicinal fungi have yet to have been included in the garden, despite their relevance as both sources of pharmaceutical drug discovery and as natural products with inherent physiological benefits themselves. The purpose of my …

Native And Non-Native Ant Impacts On Soil Microbes, Hannah A. Stewart

Biology Theses

Organisms produce chemical weapons for defense, but target organisms can develop resistance. In their introduced range, non-native species may bring “novel weapons” against which native organisms have not co-evolved resistance. The invasive European fire ant (Myrmica rubra) may have brought antimicrobial secretions to the Northeastern United States that are novel weapons against native fungal and bacterial soil organisms. I hypothesized that M. rubra would better inhibit seed pathogens resulting in greater emergence of native myrmecochorous Viola sororia seeds and, as a side effect, more strongly inhibit arbuscular mycorrhizal fungi than a native seed dispersing ant (Aphaenogaster picea …

Dicamba Tank Mixtures And Formulations And Their Effects On Sensitive Crops During Cleanout Procedures, Vinicius Velho

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

The introduction of dicamba-tolerant (DT) soybeans (Glycine max L. Merr) and cotton (Gossypium hirsutum L) in 2017 provided an additional tool for herbicide resistant weeds management. In the subsequent years, off-target movement of dicamba allegedly caused damage to sensitive crops and vegetation.

Possible causes of off-target movement include tank contamination, physical drift, and volatility. Additional products, such as herbicides to control grass, are often added to tank with dicamba, which is used to control broadleaf weeds, to increase the spectrum of control and application efficiency. Dicamba products registered for DT crops require the use of drift reducing …

Winter Cover Crop Impacts On Weed Dynamics In Eastern And Central Nebraska, Elizabeth Ann Oys

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

Reducing tillage in cropping systems causes weed management to be dependent on chemical and cultural methods for weed control. Over time, herbicide-resistant weeds have developed due to the continuous selection pressures from herbicides, particularly in the Midwest Corn Belt. Integrated weed management strategies, such as cover crops, can be used to mitigate some of these issues. Cover crops are primarily known for their soil health benefits, but there is evidence that cover crops can suppress weeds. However, less research has been done at the field-scale level to address cover crop impacts on the weed seedbank and aboveground weeds during the …

Regional Plant Community Differences In The Nebraska Sandhills, Travis Millikan

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

The Nebraska Sandhills is very valuable to the state of Nebraska, representing one of the most in-tact and largest grassland ecosystems in temperate regions in the world. Rangeland managers must understand plant community dynamics across the Sandhills to better inform management decisions. The first objective of this study was to evaluate plant community variability on upland Sands ecological sites across different precipitation zones in the Nebraska Sandhills. The second objective of our study was to utilize the Rangeland Analysis Platform (RAP) to examine spatial and temporal variability in biomass production and cover on pastures of ranches analyzed in the first …

Exploration Of Genes Controlling Grain Yield Heterosis In Hybrid Wheat (Triticum Aestivum L.) Utilizing 3ʹ Rna Sequencing, Nichole Lynn Miller

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

The implementation and future success of hybrid wheat (Triticum aestivum L.) is impacted by breeders’ inability to create consistent high yielding, high heterosis hybrids. This research addresses this problem by conducting an exploration of transcriptomes from hybrids and parent lines to determine what genes are active in heterotic or non-heterotic hybrids and how their level of expression can explain the phenotype of grain yield heterosis. Using hybrids that showed positive mid-parent heterosis (MPH), classified as heterotic in our study, and negative or no difference MPH hybrids, classified as non-heterotic, differentially expressed genes (DEGs) potentially related to heterosis and hybrid …

A Small Stem Assay For Chestnut Blight Resistance In Hybrid American Chestnut Trees, Evelyn Odle

Honors Theses

Cryphonectria parasitica (Murr.) Barr is the causal agent for the chestnut blight disease, which was brought to North America in the late 19th century on nursery stock from Japan (Anagnostakis 1987). A pandemic of chestnut blight lasted for the next half century, nearly wiping out all American chestnut trees (Castanea dentata Borkh.). Restoration works to restoring the American chestnut to its native range in North America’s canopy has been going on for the past century. The American Chestnut Foundation has strived to breed a resistant American chestnut by backcross breeding with Chinese species (C. mollissima Blume) since the 1980s. The …

Chromosome-Level Thlaspi Arvense Genome Provides New Tools For Translational Research And For A Newly Domesticated Cash Cover Crop Of The Cooler Climates, Adam Nunn, Isaac Rodríguez-Arévalo, Zenith Tandukar, Katherine Anna Frels, Adrián Contreras-Garrido, Pablo Carbonell-Bejerano, Panpan Zhang, Daniela Ramos Cruz, Katharina Jandrasits, Christa Lanz, Anthony Brusa, Marie Mirouze, Kevin Dorn, David W. Galbraith, Brice A. Jarvis, John C. Sedbrook, Donald L. Wyse, Christian Otto, David Langenberger, Peter F. Stadler, Detlef Weigel, M. David Marks, James A. Anderson, Claude Becker, Ratan Chopra

Department of Agronomy and Horticulture: Faculty Publications

Thlaspi arvense (field pennycress) is being domesticated as a winter annual oilseed crop capable of improving ecosystems and intensifying agricultural productivity without increasing land use. It is a selfing diploid with a short life cycle and is amenable to genetic manipulations, making it an accessible field-based model species for genetics and epigenetics. The availability of a high-quality reference genome is vital for understanding pennycress physiology and for clarifying its evolutionary history within the Brassicaceae. Here, we present a chromosome-level genome assembly of var. MN106-Ref with improved gene annotation and use it to investigate gene structure differences between two accessions (MN108 …

Temporal Dynamics And Seed Dispersal In Plant-Frugivore Communities Of The Dominican Republic, Spencer Christian Schubert

Biological Sciences Theses & Dissertations

Plant-animal mutualisms are a foundational component of biodiversity in terrestrial ecosystems. Most tropical forest plants have adapted to produce fleshy fruits to attract frugivorous animals to disperse seeds. Interaction patterns among plant taxa and their seed dispersers are driven by a complex suite of factors involving their evolutionary history and environmental context, and the structure of these mutualistic networks are theoretically tied to their ecological function. I carried out a series of field studies to investigate the temporal dynamics of mutualistic interactions of plant and avian frugivore communities in the central Dominican Republic and how their characteristics affect seed dispersal …

Agricultural Intensification Can Help Protect The Amazon Forest And Reduce Global Warming / Protecting The Amazon Forest And Reducing Global Warming Via Agricultural Intensification, Fabio R. Marin, Alencar J. Zanon, Juan P. Monzon, José F. Andrade, Evandro H.F.M. Silva, Gean L. Richter, Luis A.S. Antolin, Bruna S.M.R. Ribeiro, Giovanna G. Ribas, Rafael Battisti, Alexandre B. Heinemann, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

The Amazon basin includes 550 M ha covered with rainforests, with 60% of this area being in Brazil. Conversion of rainforest for soybean production raises concerns about the degree to which Brazil can reconcile production and environmental goals. Here we investigated the degree to which intensification could help Brazil produce more soybean without further encroachment of the Amazon Forest. Our analysis shows that continuation of current trends in soybean yield and area would lead to conversion of additional 5.7 M ha of forests and savannas during the next 15 years, with an associated 2550 Mt of CO2eq released into the …

Climate Change And Management Impacts On Soybean N Fixation, Soil N Mineralization, N2O Emissions, And Seed Yield, Elvis F. Elli, Ignacio A. Ciampitti, Michael J. Castellano, Larry C. Purcell, Seth Naeve, Patricio Grassini, Nicolas C. La Menza, Luiz Moro Rosso, André F. De Borja Reis, Péter Kovács, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Limited knowledge about how nitrogen (N) dynamics are affected by climate change, weather variability, and crop management is a major barrier to improving the productivity and environmental performance of soybean-based cropping systems. To fill this knowledge gap, we created a systems understanding of agroecosystem N dynamics and quantified the impact of controllable (management) and uncontrollable (weather, climate) factors on N fluxes and soybean yields. We performed a simulation experiment across 10 soybean production environments in the United States using the Agricultural Production Systems sIMulator (APSIM) model and future climate projections from five global circulation models. Climate change (2020–2080) increased N …

Hybrid Incompatibilities In Metrosideros, Jacyln Martinez

Undergraduate Research Symposium Podium Presentations

Prediction: Postzygotic reproductive isolating barriers, relating to hybrid incompatibilities are contributing to the speciation of Metrosideros

Two Fingerprinting Sets For Humulus Lupulus Based On Kasp And Microsatellite Markers, Mandie Driskill, Katie Pardee, Kim E. Hummer, Jason D. Zurni, Keenan L. Amundsen, Annette Wiles, Claudia Wiedowi, Josef Patza, John A. Henningi, Nahla V. Bassili

Department of Agronomy and Horticulture: Faculty Publications

Verification of clonal identity of hop (Humulus lupulus L.) cultivars within breeding programs and germplasm collections is vital to conserving genetic resources. Accurate and economic DNA-based tools are needed in dioecious hop to confirm identity and parentage, neither of which can be reliably determined from morphological observations. In this study, we developed two fingerprinting sets for hop: a 9-SSR fingerprinting set containing high-core repeats that can be run in a single PCR reaction and a kompetitive allele specific PCR (KASP) assay of 25 single nucleotide polymorphisms (SNPs). The SSR set contains a sex-linked primer pair, HI-AGA7, that was used …

Landscapes Are Cornerstones Of Sustainability Programs, Don Spence

Sustainability Conference

Typical American landscapes are not sustainable in an economic or biological framework. The essence of the idea of sustainable growth and development are centered on the idea that those activities are not degrading natural resources or that they are outstrip budgets. A significant piece of any sustainable management plan is tied to how we manage our landscapes, how we use plants; specifically, how much grass there is, and how many native plants there are. Sustainable landscapes should require less chemical and financial inputs, which in the end, saves money and increases the biological value of the land and creates a …

Oregon State Rank Assessment For Owyhee Clover (Trifolium Owyheense), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Owyhee clover (Trifoilum owyheense) using NatureServe methodology, 2022.

Variation In Bacterial Community Structure Under Long-Term Fertilization, Tillage, And Cover Cropping In Continuous Cotton Production, Ning Duan, Lidong Li, Xiaolong Liang, Aubrey Fine, Jie Zhuang, Mark Radosevich, Sean M. Schaeffer

Department of Agronomy and Horticulture: Faculty Publications

Agricultural practices alter the structure and functions of soil microbial community. However, few studies have documented the alterations of bacterial communities in soils under long-term conservation management practices for continuous crop production. In this study, we evaluated soil bacterial diversity using 16S rRNA gene sequencing and soil physical and chemical properties within 12 combinations of inorganic N fertilization, cover cropping, and tillage throughout a cotton production cycle. Soil was collected from field plots of the West Tennessee Agriculture Research and Education Center in Jackson, TN, United States. The site has been under continuous cotton production for 38 years. A total …

Molecular Evidence Of Cryptic Hybridization In The Japanese Nezasa Bamboos (Pleioblastus Section Nezasa), Ryan Long

Theses

The genus Pleioblastus is a complex group of Southeast Asian temperate bamboos with 7-21 species, depending on taxonomic authority. This study tests the hypothesis that taxonomic complexity in this group is due in part to hybridization and subsequent backcrossing in natural populations, resulting in a reticulate evolutionary history and a contemporary species assemblage that includes cryptic hybrids. This hypothesis is supported by recent research on the temperate bamboos that revealed intergeneric hybrids involving Pleioblastus and other genera of temperate bamboos (Triplett and Clark, 2021). The objective of the current study was to use data from Amplified Fragment Length Polymorphism (AFLP) …

Cryptic Hybridization In The Temperate Bamboos: Is Pleioblastus Simonii A Species Of Hybrid Origin?, Morgan Brown

Theses

Japanese river bamboo (Pleioblastus simonii, ‘medake,’‘kawadake’) is an ecologically important species of temperate bamboo native to Japan. This species is widely known and historically important in Japanese rural farm life. Based on morphological data, Japanese river bamboo is classified in Pleioblastus section Medakea (Poaceae: Bambusoideae) along with five other Japanese species, which are collectively considered to represent a phylogenetically distinct lineage. However, recent studies suggest that Japanese river bamboo may have arisen as a result of previously undetected hybridization (i.e., cryptic hybridization), while also calling into question the diversity of section Medakea. The role of hybridization in natural plant populations …

Evaluating Traits Influencing Hybrid Wheat Seed Production Using A Double Haploid Population Derived From Freeman × Camelot, Emre Karahan

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

Hybrid wheat (Triticum aestivum L.) cultivars are preferred for their advanced agronomic traits such as a yield improvement increase up to 20%. However, hybrid cultivars remain difficult to produce on a commercial scale due to inadequate pollen dispersal, the closed nature of the wheat floret and the high cost of inducing sterility or restoring fertility in cleistogamous wheat. Redesigning parent-specific traits and understanding their potential interactions with related agronomic traits are needed to breed improved male lines in hybrid seed production fields. To better understand the genetic control of anther extrusion (AE), 174 double haploid lines derived from Freeman …

Cattle Diet Selection During The Growing Season On Upland Sandhills Rangelands, Alejandro Orozco-Lopez

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

The Sandhills is a diverse and complex ecosystem comprised of different topographic positions (i.e. slopes and interdunes) that influence grazing distribution, plant species composition, and cattle diet selection. The first objective of this study was to evaluate how grazing intensity influences species composition on slopes and interdunes on native rangeland within the Hillside pasture (160 ha) at the UNL Gudmundsen Sandhill’s Laboratory (GSL). The second objective of this study was to evaluate forage quality of individual species from three plant functional groups (i.e. warm-season grasses, cool-season grasses, and forbs/shrubs) on native rangeland within the Hillside pasture (160 ha) at GSL. …