Digital Commons Network^™

Foliar Micronutrient Application For High-Yield Maize, Zachary P. Stewart, Ellen T. Paparozzi, Charles S. Wortmann, Prakash Kumar Jha, Charles A. Shapiro

Department of Agronomy and Horticulture: Faculty Publications

Nebraska soils are generally micronutrient sufficient. However, critical levels for current yields have not been validated. From 2013 to 2015, 26 on-farm paired comparison strip-trials were conducted across Nebraska to test the effect of foliar-applied micronutrients on maize (Zea mays L.) yield and foliar nutrient concentrations. Treatments were applied from V6 to V14 at sites with 10.9 to 16.4 Mg ha−1 yield. Soils ranged from silty clays to fine sands. Soil micronutrient availability and tissue concentrations were all above critical levels for deficiency. Significant grain yield increases were few. Micronutrient concentrations for leaf growth that occurred after foliar applications were …

Estimating Economic Minimums Of Mowing, Fertilizing, And Irrigating Turfgrass, Douglas J. Soldat, James T. Brosnan, Ambika Chandra, Roch E. Gaussoin, Alec Kowalewski, Bernd Leinauer, Frank S. Rossi, John C. Stier, J. Bryan Unruh

Department of Agronomy and Horticulture: Faculty Publications

The public health crisis and economic recession caused by the COVID-19 pandemic have forced turfgrass industry professionals to re-evaluate standard practices. Minimum costs required to fertilize, irrigate, and mow turfgrasses can be roughly estimated using climate data, turfgrass physiology information, and resource costs. Although the actual minimum costs vary situationally and regionally, mowing golf putting greens optimally requires about US$34 per acre per month, whereas other turfgrass areas cost less than US$11 per acre per growing month. Fertilizer applications to turfgrass cost US$22 or less per acre per growing month. Irrigation costs (water and electricity for pumping) vary widely, with …

Continuous Cropping Alters Multiple Biotic And Abiotic Indicators Of Soil Health, Pervaiz Ahmad, Javed Iqbal, Qingming Zhang, Dima Chen, Hui Wei, Muhammad Saleem

Department of Agronomy and Horticulture: Faculty Publications

The continuous cropping (CC) of major agricultural, horticultural, and industrial crops is an established practice worldwide, though it has significant soil health-related concerns. However, a combined review of the effects of CC on soil health indicators, in particular omics ones, remains missing. The CC may negatively impact multiple biotic and abiotic indicators of soil health, fertility, and crop yield. It could potentially alter the soil biotic indicators, which include but are not limited to the composition, abundance, diversity, and functioning of soil micro- and macro-organisms, microbial networks, enzyme activities, and soil food web interactions. Moreover, it could also alter various …

Use Of Family Structure Information In Interaction With Environments For Leveraging Genomic Prediction Models, Reyna Persa, Hiroyoshi Iwata, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

The characterization of genomes with great detail offered by the modern genotyping platforms have opened a venue for accurately predicting the genotype-by-environment interaction (GE) effects of untested genotypes in different environmental conditions. Already developed statistical models have shown the advantages of including the GE interaction component in the prediction context using molecular markers, pedigree, or both. In order to leverage the family information of highly structured populations when pedigree data is not available, we developed a model that uses the family membership instead. The proposed model extends the reaction norm model by including the interaction between families and environments (FE). …

Coal Char Affects Soil Ph To Reduce Ammonia Volatilization From Sandy Loam Soil, Dinesh Panday, Maysoon M. Mikha, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Ammonia (NH3) volatilization loss adversely affects N availability in soil-plant systems, reduces crop yield, and negatively impacts environment. Char (coal combus- tion residue), which contains up to 293 g kg−1 total C by weight, has been shown to reduce NH3 volatilization due to its considerably high surface area and cation exchange capacity. The NH3 loss can be greatly affected by a shift in soil pH or urea hydrolysis. A 21-d laboratory study was conducted to evaluate the effects of char on soil pH, N transformations, and subsequent NH3 volatilization in sandy loam soil. Two char rates (0 and 13.4 Mg …

Isoseq Transcriptome Assembly Of C3 Panicoid Grasses Provides Tools To Study Evolutionary Change In The Panicoideae, Daniel S. Carvalho, Aime Nishimwe, James Schnable

Department of Agronomy and Horticulture: Faculty Publications

The number of plant species with genomic and transcriptomic data has been increasing rapidly. The grasses—Poaceae—have been well represented among species with published reference genomes. However, as a result the genomes of wild grasses are less frequently targeted by sequencing efforts. Sequence data from wild relatives of crop species in the grasses can aid the study of domestication, gene discovery for breeding and crop improvement, and improve our understanding of the evolution of C₄ photosynthesis. Here, we used long-read sequencing technology to characterize the transcriptomes of three C₃ panicoid grass species: Dichanthelium oligosanthes, Chasmanthium laxum, and …

The Lateral Root Density Gene Regulates Root Growth During Water Stress In Wheat, Dante F. Placido, Jaspreet Sandhu, Shirley Sato, Natalya Nersesian, Truyen Quach, Thomas Clemente, Paul Staswick, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Drought stress is the major limiting factor in agriculture. Wheat, which is the most widely grown crop in the world, is predominantly cultivated in drought-prone rainfed environments. Since roots play a critical role in water uptake, root response to water limitations is an important component for enhancing wheat adaptation. In an effort to discover novel genetic sources for improving wheat adaptation, we characterized a wheat translocation line with a chromosomal segment from Agropyron elongatum, a wild relative of wheat, which unlike common wheat maintains root growth under limited-water conditions. By exploring the root transcriptome data, we found that reduced …

Adjusting Corn Nitrogen Management By Including A Mineralizable-Nitrogen Test With The Preplant And Presidedress Nitrate Tests, Jason Clark, Fabián G. Fernández, Kristen S. Veum, James J. Camberato, Paul R. Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, C. A.M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

The anaerobic potentially mineralizable N (PMN) test combined with the preplant (PPNT) and presidedress (PSNT) nitrate tests may improve corn (Zea mays L.) N fertilization predictions. Forty-nine corn N response experiments (mostly corn following soybean [Glycine max (L.) Merr.]) were conducted in the U.S. Midwest from 2014–2016 to evaluate the ability of the PPNT and PSNT to predict corn relative yield (RY) and N fertilizer over- and under-application rates when adjusted by PMN. Before planting and N fertilization, PPNT (0–30, 30–60, and 60–90 cm) and PMN (0–30 cm) samples were obtained. In-season soil samples were obtained at the …

Relating Four-Day Soil Respiration To Corn Nitrogen Fertilizer Needs Across 49 U.S. Midwest Fields, G. M. Bean, Newell R. Kitchen, Kristen S. Veum, James J. Camberato, Richard Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A.M. Laboski, Emerson Nafziger, John E. Sawyer, Matt Yost

Department of Agronomy and Horticulture: Faculty Publications

Soil microbes drive biological functions thatmediate chemical and physical processes necessary for plants to sustain growth. Laboratory soil respiration has been proposed as one universal soil health indicator representing these functions, potentially informing crop and soil management decisions. Research is needed to test the premise that soil respiration is helpful for profitable in-season nitrogen (N) rate management decisions in corn (Zea mays L.). The objective of this research was two-fold: (i) determine if the amount of N applied at the time of planting effected soil respiration, and (ii) evaluate the relationship of soil respiration to corn yield response to …

Adding A Late Fall Application Of Proxy (Ethephon) Before Two Traditional Spring Applications Improves Seedhead Control Of Annual Bluegrass, Zachary Reicher, Matthew Sousek, Aaron J. Patton, Adam Van Dyke, William C. Kreuser, John C. Inguagiato, Kevin M. Miele, John Brewer, Shawn D. Askew, Aaron Hathaway, Thomas A. Nikolai, Alec Kowalewski, Brian Mcdonald

Department of Agronomy and Horticulture: Faculty Publications

Annual bluegrass (ABG) (Poa annua L.) is a prolific seed producer in the spring on golf courses that in turn decreases aesthetic quality and trueness of ball roll on coolseason putting greens. Proxy (ethephon) applied twice in the spring after green-up is the current industry standard after the loss of Embark (mefluidide) from the turf and ornamental market. However, plant growth regulators including Proxy have been used for years to help suppressABGseedheads with inconsistent success. The primary objective of this study was to determine if ABG seedhead suppression is improved by adding a late fall application of Proxy to …

Multiple True-False Questions Reveal More Thoroughly The Complexity Of Student Thinking Than Multiple-Choice Questions: A Bayesian Item Response Model Comparison, Chad Brassil, Brian A. Couch

School of Biological Sciences: Faculty Publications

Background: Within undergraduate science courses, instructors often assess student thinking using closed-ended question formats, such as multiple-choice (MC) and multiple-true-false (MTF), where students provide answers with respect to predetermined response options. While MC and MTF questions both consist of a question stem followed by a series of options, MC questions require students to select just one answer, whereas MTF questions enable students to evaluate each option as either true or false. We employed an experimental design in which identical questions were posed to students in either format and used Bayesian item response modeling to understand how responses in each …

Temperature Alters The Shape Of Predator–Prey Cycles Through Effects On Underlying Mechanisms, John P. Delong, Shelby Lyon

School of Biological Sciences: Faculty Publications

Background: Predicting the effects of climate warming on the dynamics of ecological systems requires understanding how temperature influences birth rates, death rates and the strength of species interactions. The temperature dependance of these processes—which are the underlying mechanisms of ecological dynamics—is often thought to be exponential or unimodal, generally supported by short-term experiments. However, ecological dynamics unfold over many generations. Our goal was to empirically document shifts in predator–prey cycles over the full range of temperatures that can possibly support a predator–prey system and then to uncover the effect of temperature on the underlying mechanisms driving those changes.

Methods: We …

Identification And Characterization Of Differentially Expressed Genes In Caenorhabditis Elegans In Response To Pathogenic And Nonpathogenic Stenotrophomonas Maltophilia, Leah J. Radeke, Michael A. Herman

School of Biological Sciences: Faculty Publications

Background: Stenotrophomonas maltophilia is an emerging nosocomial pathogen that causes infection in immunocompromised patients. S. maltophilia isolates are genetically diverse, contain diverse virulence factors, and are variably pathogenic within several host species. Members of the Stenotrophomonas genus are part of the native microbiome of C. elegans, being found in greater relative abundance within the worm than its environment, suggesting that these bacteria accumulate within C. elegans. Thus, study of the C. elegans-Stenotrophomonas interaction is of both medical and ecological significance. To identify host defense mechanisms, we analyzed the C. elegans transcriptomic response to S. maltophilia strains of varying pathogenicity: K279a, …

Mammal Community Structure Through The Paleocene-Eocene Thermal Maximum, Danielle Fraser, S. Kathleen Lyons

School of Biological Sciences: Faculty Publications

Human-mediated species invasion and climate change are leading to global extinctions and are predicted to result in the loss of important axes of phylogenetic and functional diversity. However, the long-term robustness of modern communities to invasion is unknown, given the limited timescales over which they can be studied. Using the fossil record of the Paleocene- Eocene Thermal Maximum (PETM; ~ 56 Ma) in North America, we evaluate mammalian community-level response to a rapid global warming event (5° to 8°C) and invasion by three Eurasian mammalian orders and by species undergoing northward range shifts. We assembled a database of 144 species …

Ectomycorrhizal Fungi Drive Positive Phylogenetic Plant–Soil Feedbacks In A Regionally Dominant Tropical Plant Family, R. Max Segnitz, Sabrina E. Russo, Stuart J. Davies, Kabir G. Peay

School of Biological Sciences: Faculty Publications

While work in temperate forests suggests that there are consistent differences in plant–soil feedback (PSF) between plants with arbuscular and ectomycorrhizal associations, it is unclear whether these differences exist in tropical rainforests. We tested the effects of mycorrhizal type, phylogenetic relationships to overstory species, and soil fertility on the growth of tree seedlings in a tropical Bornean rainforest with a high diversity of both ectomycorrhizal and arbuscular mycorrhizal trees. We found that ectomycorrhizal tree seedlings had higher growth in soils conditioned by close relatives and that this was associated with higher mycorrhizal colonization. By contrast, arbuscular mycorrhizal tree seedlings generally …

Lithological Constraints On Resource Economies Shape The Mycorrhizal Composition Of A Bornean Rain Forest, Monique Weemstra, Kabir G. Peay, Stuart J. Davies, Mohizah Mohamad, Akira Itoh, Sylvester Tan, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

• Arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) produce contrasting plant–soil feedbacks, but how these feedbacks are constrained by lithology is poorly understood.

• We investigated the hypothesis that lithological drivers of soil fertility filter plant resource economic strategies in ways that influence the relative fitness of trees with AMF or EMF symbioses in a Bornean rain forest containing species with both mycorrhizal strategies.

• Using forest inventory data on 1245 tree species, we found that although AMF-hosting trees had greater relative dominance on all soil types, with declining lithological soil fertility EMF-hosting trees became more dominant. Data on …

The Globin Gene Family In Arthropods: Evolution And Functional Diversity, Andreas Prothmann, Federico G. Hoffmann, Juan C. Opazo, Peter Herbener, Jay F. Storz, Thorsten Burmester, Thomas Hankeln

School of Biological Sciences: Faculty Publications

Globins are small heme-proteins that reversibly bind oxygen. Their most prominent roles in vertebrates are the transport and storage of O2 for oxidative energy metabolism, but recent research has suggested alternative, non-respiratory globin functions. In the species-rich and ecologically highly diverse taxon of arthropods, the coppercontaining hemocyanin is considered the main respiratory protein. However, recent studies have suggested the presence of globin genes and their proteins in arthropod taxa, including model species like Drosophila. To systematically assess the taxonomic distribution, evolution and diversity of globins in arthropods, we systematically searched transcriptome and genome sequence data and found a conserved, widespread …

Outcome Markers Of Art-Treated Hiv+ Patients With Early Stage Kaposi’S Sarcoma, Owen Ngalamika, For Yue Tso, Salum Lidenge, Sody Munsaka, Danielle Shea, Charles Wood, John West

School of Biological Sciences: Faculty Publications

HIV-associated/epidemic Kaposi’s sarcoma (EpKS) is an AIDS-defining angio-proliferative malignancy. It can be treated with antiretroviral therapy (ART) alone or with ART plus cytotoxic chemotherapy. ART-treated EpKS can either respond or worsen upon treatment. This study aimed at identifying immunological markers of ART-treatment response. We compared responders (those with clinical EpKS tumor regression) versus poor responders (those with progressive or non-responsive EpKS). We measured plasma cytokine and chemokine levels using cytometric bead assays. Kaposi’s sarcoma herpesvirus (KSHV) neutralizing antibody (nAb) responses were also quantified to test associations with treatment outcome. Interleukin (IL)-5 levels were significantly elevated in responders versus poorresponders at …

Innovative Teaching Knowledge Stays With Users, A. Kelly Lane, Jacob D. Mcalpin, Brittnee Earl, Stephanie Feola, Jennifer E. Lewis, Karl Mertens, Susan E. Shadle, John Svoretz, John P. Ziker, Brian A. Couch, Luanna B. Prevost, Marilyne Stains

School of Biological Sciences: Faculty Publications

Programs seeking to transform undergraduate science, technology, engineering, and mathematics courses often strive for participating faculty to share their knowledge of innovative teaching practices with other faculty in their home departments. Here, we provide interview, survey, and social network analyses revealing that faculty who use innovative teaching practices preferentially talk to each other, suggesting that greater steps are needed for information about innovative practices to reach faculty more broadly.

A High-Throughput Method To Quantify Feeding Rates In Aquatic Organisms: A Case Study With Daphnia, Jessica L. Hite, Alaina C. Pfenning-Butterworth, Rachel E. Vetter, Clayton E. Cressler

School of Biological Sciences: Faculty Publications

1. Food ingestion is one of the most basic features of all organisms. However, obtaining precise—and high-throughput—estimates of feeding rates remains challenging, particularly for small, aquatic herbivores such as zooplankton, snails, and tadpoles. These animals typically consume low volumes of food that are time-consuming to accurately measure.

2. We extend a standard high-throughput fluorometry technique, which uses a microplate reader and 96-well plates, as a practical tool for studies in ecology, evolution, and disease biology. We outline technical and methodological details to optimize quantification of individual feeding rates, improve accuracy, and minimize sampling error.

3. This high-throughput assay offers several …

Production Of Isoprene By Methane - Producing Archaea, Nicole Roswitha Buan Murphy, Karrie A. Weber, Jared T. Aldridge, Robert Carr

School of Biological Sciences: Faculty Publications

Plasmid vectors and use of plasmid vectors in methods for producing methane and isoprene using Archaea are disclosed . Particularly, plasmid vectors that express isoprene synthase ( ispS ) are prepared and inserted into methanogens, such as Methanosarcina acetivorans, to allow for co - production of methane and isoprene. In one embodiment , the methods of the present disclosure can be used for wastewater management.

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

Abstract

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with multiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation responded only to one or the other (but not both), resulting in unpredictable outcomes. These changes in …

Functional Responses Are Maximized At Intermediate Temperatures, Stella F. Uiterwaal, John Delong

School of Biological Sciences: Faculty Publications

Functional responses describe how consumer foraging rates change with resource density. Despite extensive research looking at the factors underlying foraging interactions, there remains ongoing controversy about how temperature and body size control the functional response parameters space clearance (or attack) rate and handling time. Here, we investigate the effects of temperature, consumer mass, and resource mass using the largest compilation of functional responses yet assembled. This compilation contains 2,083 functional response curves covering a wide range of foragers and prey types, environmental conditions, and habitats. After accounting for experimental arena size, dimensionality of the foraging interaction, and consumer taxon, we …

Engineered Clostridium Botulinum Toxin Adapted To Deliver Molecules Into Selected Cells, Benjamin J. Pavlik, Paul H. Blum, Kevin Van Cott

School of Biological Sciences: Faculty Publications

An engineered payload-delivery system includes a target cell binding unit, covalently bound to a pore forming unit, and a payload portion adapted with a region capable of non-covalently binding to the pore forming unit. The pore forming unit is derived from a particular sub-serotype of Clostridium toxin, while the payload region is derived from a different sub-serotype of Clostridium toxin. The disclosed chimeric protein-based composition is capable of specifically delivering payload to neural cells.

Longer Ubiquinone Side Chains Contribute To Enhanced Farnesol Resistance In Yeasts, Ruvini U. Pathirana, Cory Boone, Kenneth Nickerson

School of Biological Sciences: Faculty Publications

Ubiquinones (UQ) are intrinsic lipid components of many membranes. Besides their role in electron-transfer reactions there is evidence for them acting as free radical scavengers, yet their other roles in biological systems have received little study. The dimorphic fungal pathogen Candida albicans secretes farnesol as both a virulence factor and a quorum-sensing molecule. Thus, we were intrigued by the presence of UQ9 isoprenologue in farnesol-producing Candida species while other members of this genera harbor UQ7 as their major electron carrier. We examined the effect of UQ side chain length in Saccharomyces cerevisiae and C. albicans with a view towards identifying …

Effects Of Lethal Bronzing Disease, Palm Height, And Temperature On Abundance And Monitoring Of Haplaxius Crudus, De-Fen Mou, Chih-Chung Lee, Philip G. Hahn, Noemi Soto, Alessandra R. Humphries, Ericka E. Helmick, Brian W. Bahder

School of Biological Sciences: Faculty Publications

Insect vector feeding preference and behavior play important roles in pathogen transmission, especially for pathogens that solely rely on insect vector transmission. This study aims to examine the effects of the 16SrIV-D phytoplasma, the causal agent of lethal bronzing (LB) disease of palms, on associated auchenorrhynchan insects. The numbers of auchenorrhynchans collected during weekly surveys during a yearlong study using yellow sticky traps were analyzed. The cumulative number of H. crudus was 4.5 times greater on phytoplasma-infected relative to non-infected palms. Other auchenorrhynchans showed no difference between phytoplasma-infected and non-infected palms or were greater on non-infected rather than on infected …

Towards Understanding Factors Influencing The Benefit Of Diversity In Predator Communities For Prey Suppression, Amanda N. Laubmeir, Richard Rebarber, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

It is generally assumed that high biodiversity is key to sustaining critical ecosystem services, including prey suppression by natural predator guilds. Prey suppression is driven by complex interactions between members of predator and prey communities, as well as their shared environment. Because of this, empirical studies have found both positive and negative effects of high predator diversity on prey suppression. However, we lack an understanding of when these different prey suppression outcomes will occur. In this work, we use a mechanistic, trait-based model to unravel how intraguild interactions, species body mass, predator foraging area, and ambient temperature can combine to …

Benefits Of A College Stem Faculty Development Initiative: Instructors Report Increased And Sustained Implementation Of Research-Based Instructional Strategies, Mary F. Durham, Oriana R. Aragón, Meghan E. Bathgate, Aiyanan Bobrownicki, Andrew J. Cavanagh, Xinnian Chen, William M. Trochim, Jonathan K. Waterhouse, Maek J. Graham, Brian A. Couch

School of Biological Sciences: Faculty Publications

The Summer Institutes on Scientific Teaching (SI) is a faculty development workshop in which science, technology, engineering, and mathematics (STEM) instructors, particularly from biology, are trained in the Scientific Teaching (ST) pedagogy. While participants have generally reported positive experiences, we aimed to assess how the SI affected participants’ teaching practices. Building on a previously developed taxonomy of ST practices, we surveyed SI participants from the 2004–2014 SI classes regarding specific ST practices. Participants’ self-reported use and implementation of ST practices increased immediately after SI attendance as well as over a longer time frame, suggesting that implementation persisted and even increased …

How Demographic Processes Shape Animal Social Networks, Daizaburo Shizuka, Allison E. Johnson

School of Biological Sciences: Faculty Publications

Invited review

Demographic processes play a key role in shaping the patterns of social relations among individuals in a population. Social network analysis is a powerful quantitative tool for assessing the social structure formed by associations between individuals. However, demographic processes are rarely accounted for in such analyses. Here, we summarize how the structure of animal social networks is shaped by the joint effects of social behavior and turnover of individuals and suggest how a deeper understanding of these processes can open new, exciting avenues for research. Death or dispersal can have the direct effect of removing an individual and …

Invited Commentaries On Shizuka & Johnson 2020, & Response From The Authors, Adriana A. Maldonado-Chaparro, Damien R. Farine, Amiyaal Ilany, Orr Spiegel, Noa Pinter-Wollman, Ipek G. Kulahci, Eric Vander Wal, Quinn M.R. Webber, Daniel I. Rudenstein, Daizaburo Shizuka, Allison E. Johnson

School of Biological Sciences: Faculty Publications

Adriana A. Maldonado-Chaparro and Damien R. Farine, Demographic processes in animal networks are a question of time

Amiyaal Ilany, Complex societies, simple processes

Orr Spiegel and Noa Pinter-Wollman, Placing the effects of demography on networks in ecological context

Ipek G. Kulahci, Individual differences can affect how networks respond to demography

Eric Vander Wal and Quinn M.R. Webber, Density dependence and eco-evolutionary dynamics of animal social networks

Daniel I. Rubenstein, On assessing the importance of demographic change for social structure

Daizaburo Shizuka and Allison E. Johnson, The long view on demographic effects on social networks: A response to comments on Shizuka …