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Novel Lipid Mediator 7s,14r-Docosahexaenoic Acid: Biogenesis And Harnessing Mesenchymal Stem Cells To Ameliorate Diabetic Mellitus And Retinal Pericyte Loss, Yan Lu, Haibin Tian, Hongying Peng, Quansheng Wang, Bruce A. Bunnell, Nicolas G. Bazan, Song Hong Mar 2024

Novel Lipid Mediator 7s,14r-Docosahexaenoic Acid: Biogenesis And Harnessing Mesenchymal Stem Cells To Ameliorate Diabetic Mellitus And Retinal Pericyte Loss, Yan Lu, Haibin Tian, Hongying Peng, Quansheng Wang, Bruce A. Bunnell, Nicolas G. Bazan, Song Hong

School of Medicine Faculty Publications

Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by …


6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew Mar 2024

6d Single-Fluorogen Orientation-Localization Microscopy For Elucidating The Architecture Of Beta-Sheet Assemblies And Biomolecular Condensates, Tingting Wu, Weiyan Zhou, Jai S. Rudra, Rohit V. Pappu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

We develop six-dimensional single-molecule orientation-localization microscopy (SMOLM) to measure the 3D positions and 3D orientations simultaneously of single fluorophores. We show how careful optimization of phase and polarization modulation components can encode phase, polarization, and angular spectrum information from each fluorescence photon into a microscope’s dipole-spread function. We used the transient binding and blinking of Nile red (NR) to characterize the helical structure of fibrils formed by designed amphipathic peptides, KFE8L and KFE8D, and the pathological amyloid-beta peptide Aβ42. We also deployed merocyanine 540 to uncover the interfacial architectures of biomolecular condensates.


Spectralomics – Towards A Holistic Adaptation Of Label Free Spectroscopy, Hugh Byrne Mar 2024

Spectralomics – Towards A Holistic Adaptation Of Label Free Spectroscopy, Hugh Byrne

Articles

Vibrational spectroscopy, largely based on infrared absorption and Raman scattering techniques, is much vaunted as a label free approach, delivering a high content, holistic characterisation of a sample, with demonstrable applications in a broad range of fields, from process analytical technologies and preclinical drug screening, to disease diagnostics, therapeutics, prognostics and personalised medicine. However, in the analysis of such complex systems, a trend has emerged in which spectral analysis is reduced to the identification of individual peaks, based on reference tables of assignments derived from literature, which are then interpreted as biomarkers. More sophisticated analysis attempts to unmix the spectrum …


Investigating The Structural Ensemble And Dynamic Interactions Of Protein Interacting With C-Kinase 1 (Pick1) Using Computational Tools, Amy E. Stevens Mar 2024

Investigating The Structural Ensemble And Dynamic Interactions Of Protein Interacting With C-Kinase 1 (Pick1) Using Computational Tools, Amy E. Stevens

Chemistry and Chemical Biology ETDs

Protein Interacting with C Kinase-1 (PICK1) is a scaffolding protein that offers a promising solution to support individuals suffering from substance use disorders. While many efforts have been put towards identifying small-molecule drugs with the potential to target PICK1 and ultimately support individuals suffering from the effects of substance use disorders, all efforts have so far fallen short. The purpose of this work is to use computational tools to assist the design of a small-molecule inhibitor of PICK1 while also advancing the knowledge of its biological functions. This work provides information that is currently missing the field by (1) revealing …


Comparing Task Graph Scheduling Algorithms: An Adversarial Approach, Jared Coleman, Bhaskar Krishnamachari Mar 2024

Comparing Task Graph Scheduling Algorithms: An Adversarial Approach, Jared Coleman, Bhaskar Krishnamachari

Computer Science Faculty Works

Scheduling a task graph representing an application over a heterogeneous network of computers is a fundamental problem in distributed computing. It is known to be not only NP-hard but also not polynomial-time approximable within a constant factor. As a result, many heuristic algorithms have been proposed over the past few decades. Yet it remains largely unclear how these algorithms compare to each other in terms of the quality of schedules they produce. We identify gaps in the traditional benchmarking approach to comparing task scheduling algorithms and propose a simulated annealing-based adversarial analysis approach called PISA to help address them. We …


Dissolved Nickel Speciation At The Bermuda Atlantic Time-Series Study (Bats) Site, Caitlyn E. Parente Mar 2024

Dissolved Nickel Speciation At The Bermuda Atlantic Time-Series Study (Bats) Site, Caitlyn E. Parente

USF Tampa Graduate Theses and Dissertations

Here I present the first depth profiles of dissolved nickel (DNi) speciation over an annual cycle at the Bermuda Atlantic Time-series Study (BATS) site in the North Atlantic. Seawater samples were collected in March, May, August, and November 2019 and analyzed for labile DNi using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). Labile DNi was measured by CLE-AdCSV as the fraction of DNi that exchanges with an added competitive ligand in an overnight equilibration. Results revealed two distinct fractions of DNi present throughout the water column: a labile fraction, and a strongly organically complexed (i.e., non-labile) fraction. More than 50% …


Drought Legacy Interacts With Wildfire To Alter Soil Microbial Communities In A Mediterranean Climate-Type Forest, Anna J. M. Hopkins, Aaron J. Brace, Jess L. Bruce, J. Hyde, J. B. Fontaine, L. Walden, W. Veber, K. X. Ruthrof Mar 2024

Drought Legacy Interacts With Wildfire To Alter Soil Microbial Communities In A Mediterranean Climate-Type Forest, Anna J. M. Hopkins, Aaron J. Brace, Jess L. Bruce, J. Hyde, J. B. Fontaine, L. Walden, W. Veber, K. X. Ruthrof

Research outputs 2022 to 2026

Mediterranean forest ecosystems will be increasingly affected by hotter drought and more frequent and severe wildfire events in the future. However, little is known about the longer-term responses of these forests to multiple disturbances and the forests' capacity to maintain ecosystem function. This is particularly so for below-ground organisms, which have received less attention than those above-ground, despite their essential contributions to forest function. We investigated rhizosphere microbial communities in a resprouting Eucalyptus marginata forest, southwestern Australia, that had experienced a severe wildfire four years previously, and a hotter drought eight years previously. Our aim was to understand how microbial …


On The Reconstruction Of An Integro-Differential Dirac Operator With Parameter-Dependent Nonlocal Integral Boundary Conditions From The Nodal Data, Baki Keskin, Yu Ping Wang Mar 2024

On The Reconstruction Of An Integro-Differential Dirac Operator With Parameter-Dependent Nonlocal Integral Boundary Conditions From The Nodal Data, Baki Keskin, Yu Ping Wang

Turkish Journal of Mathematics

We consider the integro-differential Dirac operator with parameter-dependent nonlocal integral boundary conditions. We derive the asymptotic expressions for the eigenvalues and the zeros of eigenfunctions (nodal points or nodes) and develop a constructive procedure for solving the inverse nodal problem for this operator.


Tractor Beams And Disease: Probing Repeat Rna Structure Through Single Molecule Force Spectroscopy, Joshua Webster-Ford Mar 2024

Tractor Beams And Disease: Probing Repeat Rna Structure Through Single Molecule Force Spectroscopy, Joshua Webster-Ford

Undergraduate Honors Theses

Huntington’s Disease is characterized by an extended (CAG)n repeat found in the huntingtin (Htt) gene. While the typical human contains 6-20 CAG repeats, people with over 36 repeats manifest symptoms of the disease. The extended CAG repeats allow the Htt pre-mRNA transcript to form a hairpin loop structure which can sequester certain vital proteins such as Muscleblind like protein 1 (MBNL1), hindering their functional role. Further understanding the structure of the MBNL1-RNA complex is possible through force spectroscopy, or “optical tweezers”, applied on the single molecule level. Force spectroscopy generates force versus distance plots for individual RNA molecules, revealing the …


Traveling Wave Fronts Of Reaction Diffusion Differential Equations With Diffusive Delay In Biological And Chemical Models, William Barker Mar 2024

Traveling Wave Fronts Of Reaction Diffusion Differential Equations With Diffusive Delay In Biological And Chemical Models, William Barker

Theses and Dissertations

Functional differential equations (FDE) incorporate past states and or rates in the modeling of physical phenomena. Unlike ordinary and even some partial differential equations there is no method to find solutions of general FDE explicitly. Therefore, in order to study solutions of FDE, iterative techniques are often employed. Reaction diffusion equations are a specific type of partial differential equations that model diffusive spread, the rate of spread of due to a reaction term of some quantity. These equations arise naturally in fields such as biology, ecology and chemistry. In terms of studying dynamics of populations, previous states and even rates …


Highly Efficient Dopamine Sensing With A Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure, Harish Singh, Jiandong Wu, Kurt A.L. Lagemann, Manashi Nath Mar 2024

Highly Efficient Dopamine Sensing With A Carbon Nanotube-Encapsulated Metal Chalcogenide Nanostructure, Harish Singh, Jiandong Wu, Kurt A.L. Lagemann, Manashi Nath

Chemical and Biochemical Engineering Faculty Research & Creative Works

Carbon nanotube-encapsulated nickel selenide composite nanostructures were used as nonenzymatic electrochemical sensors for dopamine detection. These composite nanostructures were synthesized through a simple, one-step, and environmentally friendly chemical vapor deposition method, wherein the CNTs were formed in situ from pyrolysis of a carbon-rich metallo-organic precursor. The composition and morphology of these hybrid NiSe2-filled carbon nanostructures were confirmed by powder X-ray diffraction, Raman, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy images. Electrochemical tests demonstrated that the as-synthesized hybrid nanostructures exhibited outstanding electrocatalytic performance toward dopamine oxidation, with a high sensitivity of 19.62 μA μM-1 cm-2, low detection limit, broad linear …


Accuracy Of Nitrate Hysteresis And Flushing For Agricultural Watersheds In The Midwest, Noah Rudko, Sara K. W. Mcmillian, Jane Frankenberger, François Birgand Mar 2024

Accuracy Of Nitrate Hysteresis And Flushing For Agricultural Watersheds In The Midwest, Noah Rudko, Sara K. W. Mcmillian, Jane Frankenberger, François Birgand

Graduate Industrial Research Symposium

Storm event-based metrics, such as hysteresis (HI) and flushing (FI), are used to differentiate nitrate pathways and sources, which is essential for watershed management. Estimations of these event-based metrics typically use high frequency (15-minute – hourly) measurements, but daily data are also used due to their greater availability. To date, there has been no study assessing how using lower frequency samples affect the accuracy of HI and FI, which could skew interpretation of potential nutrient pathways and sources. We used continuous measurements of nitrate collected at 9 watersheds throughout the Midwest spanning 448 storms. HI and FI were estimated from …


Characterization Of Biological Particles Using An Integrated Hyperspectral Imaging And Machine Learning, Kaeul Lim, Arezoo Ardekani Mar 2024

Characterization Of Biological Particles Using An Integrated Hyperspectral Imaging And Machine Learning, Kaeul Lim, Arezoo Ardekani

Graduate Industrial Research Symposium

Hyperspectral imaging (HSI) is a promising modality in medicine with many potential applications. This study focuses on developing a label-free lipid nanoparticle characterization method using a convolutional neural network (CNN) analysis of HSI images. The HSI data, hypercube, consists of a series of images acquired at different wavelengths for the same field of view, providing continuous spectra information for each pixel. Three distinct liposome samples were collected for analysis. Advanced image preprocessing and classification methods for HSI data were developed to differentiate liposomes based on their material compositions. Our machine learning-based classification method was able to distinguish different liposome types …


A Machine Learning Model Of Perturb-Seq Data For Use In Space Flight Gene Expression Profile Analysis, Liam F. Johnson, James Casaletto, Lauren Sanders, Sylvain Costes Mar 2024

A Machine Learning Model Of Perturb-Seq Data For Use In Space Flight Gene Expression Profile Analysis, Liam F. Johnson, James Casaletto, Lauren Sanders, Sylvain Costes

Graduate Industrial Research Symposium

The genetic perturbations caused by spaceflight on biological systems tend to have a system-wide effect which is often difficult to deconvolute it into individual signals with specific points of origin. Single cell multi-omic data can provide a profile of the perturbational effects, but does not necessarily indicate the initial point of interference within the network. The objective of this project is to take advantage of large scale and genome-wide perturbational datasets by using them to train a tuned machine learning model that is capable of predicting the effects of unseen perturbations in new data. Perturb-Seq datasets are large libraries of …


Student Perspectives On Assignment Deadline Policies In Computer Science Courses, J. Kim, Christian Murphy Mar 2024

Student Perspectives On Assignment Deadline Policies In Computer Science Courses, J. Kim, Christian Murphy

Computer Science Faculty Works

While the COVID-19 pandemic encouraged higher education to be more flexible, there is now growing uncertainty regarding the usefulness of flexibility as students return to in-person classes, particularly in fast-paced, rigorous fields such as Computer Science (CS). A big part of providing flexibility in education is through assignment deadlines. On one hand, flexible deadline policies may reduce student stress, help students face unexpected circumstances, and improve student learning; on the other, too much flexibility may lead to procrastination and poor time management. In order to help CS instructors make informed decisions when choosing an assignment deadline policy, we compared student …


Development Of Bifunctional Peptides As Scaffolds For Bifunctional Catalysis And A Novel Method Of Peptide Stapling Using Squaric Esters, Adam X. Wayment Mar 2024

Development Of Bifunctional Peptides As Scaffolds For Bifunctional Catalysis And A Novel Method Of Peptide Stapling Using Squaric Esters, Adam X. Wayment

Theses and Dissertations

Enzymes are some of nature's most powerful tools in chemical processes. However, their molecular complexity makes them difficult to synthesize and complicates their application in traditional organic synthesis. Peptides, a building block of enzymes, can be rapidly synthesized and have been used as a possible alternative in achieving enzyme-like catalysis. However, most peptide-based catalysts are limited in reaction-scope and are unable to incorporate traditional organic catalysts. We have designed a helical peptide scaffold capable of being functionalized with a wide variety of organocatalysts as well as transition-metal based catalysts. In order to understand how the peptide structure effects reactivity and …


Metatranscriptomic Insights Into The Interaction Between Microcystis Blooms And Hydrogen Peroxide, Taylor L. Hancock Mar 2024

Metatranscriptomic Insights Into The Interaction Between Microcystis Blooms And Hydrogen Peroxide, Taylor L. Hancock

USF Tampa Graduate Theses and Dissertations

For this dissertation I studied the interactions of hydrogen peroxide and cyanobacterial harmful algal blooms (cHABs) dominated by Microcystis in the Caloosahatchee River, FL. Specifically, I examined how taxonomic and functional succession relates to both natural hydrogen peroxide dynamics and hydrogen peroxide added to the environment as a cHAB treatment. Chapter 2 investigated how taxonomic succession and gene expression patterns relate to blooms and associated elevated hydrogen peroxide concentrations. The results showed that gene expressions related to cyanobacterial growth were positively correlated with hydrogen peroxide. The genes identified included enzymes capable of hydrogen peroxide generation which were expressed by blooming …


Enriched Regions Of 228Ra Along The U.S. Geotraces Pacific Meridional Transect (Gp15), Willard S. Moore, Matt Charette, Paul Henderson, Doug Hammond, Nathaniel Kemnitz, Emilie Leroy, Eun Young Kwon, Mikael Hult Mar 2024

Enriched Regions Of 228Ra Along The U.S. Geotraces Pacific Meridional Transect (Gp15), Willard S. Moore, Matt Charette, Paul Henderson, Doug Hammond, Nathaniel Kemnitz, Emilie Leroy, Eun Young Kwon, Mikael Hult

Faculty Publications

The half‐life of 228Ra (5.7 years) aligns well with near‐surface and near‐bottom ocean mixing timescales. Because 228Ra is sourced from sediments, regions of enhanced activity represent water that has recently interacted with sediments on the continental margin or seabed. The GP15 meridional transect from Alaska to Tahiti along152°W encountered several regions in the upper ocean where 228Ra was enriched. These enrichments follow surface and subsurface ocean current patterns and pair with earlier measurements of 228Ra and transient radionuclides to reveal the origins of these enriched regions. An enriched region at Alaska margin stations 1–3 was sourced locally but did not …


Spatial Distribution And Movement Of Atlantic Tarpon (Megalops Atlanticus) In The Northern Gulf Of Mexico, Shane A. Stephens, Michael A. Dance, Michelle Zapp Sluis, Richard J. Kline, Matthew K. Streich, Gregory R. Stunz, Aaron J. Adams, R. J. David Wells, Jay R. Rooker Mar 2024

Spatial Distribution And Movement Of Atlantic Tarpon (Megalops Atlanticus) In The Northern Gulf Of Mexico, Shane A. Stephens, Michael A. Dance, Michelle Zapp Sluis, Richard J. Kline, Matthew K. Streich, Gregory R. Stunz, Aaron J. Adams, R. J. David Wells, Jay R. Rooker

School of Earth, Environmental, & Marine Sciences Faculty Publications

Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades. Generalized additive models (GAMs) indicated that salinity and water temperature played a significant role in tarpon presence, with tarpon occurrences peaking in the fall and increasing …


Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan Mar 2024

Induction Of Neuroinflammation And Brain Oxidative Stress By Brain-Derived Extracellular Vesicles From Hypertensive Rats, Xinqian Chen, Xin Yan, Leah Gingerich, Qing Hui Chen, Lanrong Bi, Zhiying Shan

Michigan Tech Publications

Neuroinflammation and brain oxidative stress are recognized as significant contributors to hypertension including salt sensitive hypertension. Extracellular vesicles (EVs) play an essential role in intercellular communication in various situations, including physiological and pathological ones. Based on this evidence, we hypothesized that EVs derived from the brains of hypertensive rats with salt sensitivity could trigger neuroinflammation and oxidative stress during hypertension development. To test this hypothesis, we compared the impact of EVs isolated from the brains of hypertensive Dahl Salt-Sensitive rats (DSS) and normotensive Sprague Dawley (SD) rats on inflammatory factors and mitochondrial reactive oxygen species (mtROS) production in primary neuronal …


Identification Of Alfalfa Chromosomes Using Giemas Banding And Image Analysis Techniques, G R. Bauchan, M A. Hossain Mar 2024

Identification Of Alfalfa Chromosomes Using Giemas Banding And Image Analysis Techniques, G R. Bauchan, M A. Hossain

IGC Proceedings (1977-2023)

Chromosomes of two diploid (2n=2x=16) subspecies of Medicago sativa, ssp. caerulea and ssp. falcata, their hybrid and tetraploid (2n=4x=32) cultivated alfalfa (M. sativa, ssp. sativa) were studied. Feulgen’s staining, C- and N-banding techniques and an image analysis system were used. The chromosomes of ssp. falcata have only centromeric bands, however, a multitude of bands were observed in both the C- and N-banding pattern of ssp. caerulea and ssp. sativa enabling the precise identification of each of the eight sets of chromosomes and development of a karyotype. The differences in banding patterns between the diploid subspecies makes it possible …


Advances In Breeding Apomictic Brachiaria In Tropical America, J W. Miles, C B. Do Valle Mar 2024

Advances In Breeding Apomictic Brachiaria In Tropical America, J W. Miles, C B. Do Valle

IGC Proceedings (1977-2023)

Prior to 1988 Brachiaria improvement was based exclusively on the collection, introduction, and evaluation of natural germplasm from Africa. Breeding programs in Brachiaria have been possible only in the past 10 years with the creation of a sexual, tetraploid B. ruziziensis cross-compatible with B. decumbens and B. brizantha. Applied Brachiaria breeding projects are underway both in Colombia (International Center for Tropical Agriculture, CIAT) and Brazil (National Centre for Beef Cattle Research - Brazilian Corporation for Agricultural Research, CNPGC/EMBRAPA). These seek to combine the broad edaphic adaptation and other desirable agronomic attributes of B. decumbens cv. Basilisk with spittlebug resistance. An …


Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass, K F.M. Reed, S G. Clark, W M. Feely Mar 2024

Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass, K F.M. Reed, S G. Clark, W M. Feely

IGC Proceedings (1977-2023)

Over four years, sowing perennial ryegrass (Lolium perenne) with a range of subterranean clover (“sub clover”, Trifolium subterraneum) cultivars was found to reduce the yield of clover per se by 31% and increase pasture yield by 11%. For one high-producing experimental variety, the presence of grass did not reduce clover yield (P<0.001). Clover yield in monoculture plots was poorly correlated with that measured in mixed swards (r = 0.44), but clover yield (± grass) was correlated with total herbage yield (r = 0.94). Clover seed yield was not reduced by the presence of grass. However, in year 2 - but not in the establishment year - grass reduced seed weight. Irrespective of grass treatment, the new late maturing cultivar, Leura outyielded the other commercial cultivars (P<0.05). Enfield and Enfield x Daliak crosses set the most seed and regenerated with a greater density than other cultivars (P<0.05) - apart from Leura. It was concluded that the winter-active, late maturing cultivar, Leura, will compete most successfully with perennial ryegrass.


Gene Flow In Medicago Through Somatic Hybridization, S Arcioni, F Crea, O Calderini, F Damiani, P D. Cluster, F Pupilli Mar 2024

Gene Flow In Medicago Through Somatic Hybridization, S Arcioni, F Crea, O Calderini, F Damiani, P D. Cluster, F Pupilli

IGC Proceedings (1977-2023)

The objective of this research was the characterization at both molecular and phenotypic level of three somatic hybrid plants obtained by electrofusion of protoplasts of Medicago sativa with those of M.coerulea, M.falcata and M.arborea, three Medicago species in a different relation with alfalfa. Different kinds of rearrangements including the amplification of new spacer-length variants were detected at rDNA loci in the somatic hybrids. Analysis of field performances confirmed the suitability of these plants for breeding purposes.


Ssr- And Rapd Analysis Of A New Agropyron Repens Genotype, G Gyulai, H Ohm, I Dweikat, E Kiss, H Sharma, J Janovszky, L Heszky Mar 2024

Ssr- And Rapd Analysis Of A New Agropyron Repens Genotype, G Gyulai, H Ohm, I Dweikat, E Kiss, H Sharma, J Janovszky, L Heszky

IGC Proceedings (1977-2023)

SSR-(single sequence repeat), and RAPD (randomly amplified polymorphic DNA) primer generated DNA fingerprints were used to distinguish a new genotype of quackgrass from its original type of Agropyron repenes L. Beauv. (= Elytrigia repens). Products of polymerase chain reactions (PCR) were separated by agarose (AGE) and denaturing gradient gel electrophoresis (DGGE). Although, both kinds of primers were found to be polymorphic, the microsatellite primer with sequence of 5í-AC(GACA)4-3í generated distinguishing fingerprints in the two types of quackgrasses. This result gives genetic evidence for the new genotype of quackgrass.


Screening Ryegrass Cultivars For Aluminium Sensitivity In Nutrient Soluations, F O. Gallardo, S Benavides, R Demanet, F Borie Mar 2024

Screening Ryegrass Cultivars For Aluminium Sensitivity In Nutrient Soluations, F O. Gallardo, S Benavides, R Demanet, F Borie

IGC Proceedings (1977-2023)

The objective of this study was to evaluate Al and H+ tolerance of nine ryegrass (Lolium perenne and L. multiflorum) cultivars by growing plants in a mineral solution (pH 4.8 and 6.0 and 0-200 (M Al). Results showed that Yatsyn-1, with a relative root length of 91 was the cultivar least affected by acidity (H+), and Concord ( RRLpH = 58) was the cultivar with the highest H+ sensitivity. In connection with Al-tolerance, Yatsyn-1 and Concord, were the most tolerant cultivars with 88 and 87 RRLAl, respectively whereas Nui and Marathon, were the most sensitive ones, reaching only …


Breeding For Persistence In Lotus Corniculatus, M Rebuffo, N Altier Mar 2024

Breeding For Persistence In Lotus Corniculatus, M Rebuffo, N Altier

IGC Proceedings (1977-2023)

The objectives of this study were to develop a more persistent germplasm of birdsfoot trefoil (Lotus corniculatus L.) and to evaluate its potential use in Uruguay. Two cycles of phenotypic recurrent selection were done under field conditions. Eight hundred and 1600 spaced plants were established for the first and second cycle of selection. Both nurseries were visually assessed for crown rot, relative growth, plant habit and foliar diseases. The final selection of the breeding population LE 65-56 includes thirty six plants selected from sixteen elite families. This selection was more persistent and productive than the check varieties in plot …


Apomixis And The Reproductive Dynamics Of Eastern Gamagrass Tripsacum Dactyloides L., B Kindiger, C L. Dewald Mar 2024

Apomixis And The Reproductive Dynamics Of Eastern Gamagrass Tripsacum Dactyloides L., B Kindiger, C L. Dewald

IGC Proceedings (1977-2023)

Studies were conducted to determine the reproductive characteristics of Tripsacum, a perennial, native pasture species and to identify methods for breeding agronomically superior cultivars. Reproductive methods and types of individuals generated were evaluated with triploid and hexaploids possessing a novel method for transferring sexual germplasm into apomictic tetraploids and tetraploid germplasm into sexual diploids. Triploids and hexaploids are demonstrated to be useful materials for introgressing and transferring desirable alleles across ploidy levels and reproductive barriers.


Cytogenetical Studies In Range Grasses Of Iran, M Sheidai, A Tavasoli, P Derakhshandeh Mar 2024

Cytogenetical Studies In Range Grasses Of Iran, M Sheidai, A Tavasoli, P Derakhshandeh

IGC Proceedings (1977-2023)

Cytogenetical and breeding studies of range grasses are in hand. Present article describes preliminary cytogenetical analysis of wheatgrass (Agropyron) and bromegrass (Bromus) taxa (Agropyron trichophorum n = 21, A. pectinoforome n = 21), two different populations of A. repens (n = 28) and Bromus stenostachyus (n = 14). The species varied with regard to chiasma number and distribution. The highest value occurred in A. repens (Mako population). Heterogenity test for the paired samples showed lack of heterogenity for chiasmata indicating homogenity of Agropyron taxa. However a test for ring and rod bivalents showed significant differences …


Direct Selection Response For Stem Rust Resistance In Tall Fescue, R E. Barker, R E. Welty Mar 2024

Direct Selection Response For Stem Rust Resistance In Tall Fescue, R E. Barker, R E. Welty

IGC Proceedings (1977-2023)

Resistance to stem rust (caused by Puccinia graminis Pers.: Pers. subsp. graminicola Z. Urban.) would be beneficial in tall fescue (Festuca arundinacea Schreb.). Two cycles of polycross (PX) selection on progenies from thirty-four parent plants (14 forage-types and 20 turf-types) were compared to one cycle of open pollination (OP) followed by one cycle of PX selection using a 2-stage greenhouse screening process. Response from selection was determined from composite half-sib progenies from each cycle. Number of plants with resistant reaction based on pustule type increased from 5 to 54% in the PX forage-type population and from 6 to 50% …