Botany Commons^™

Reaction Of Tepary Beans To Eight Virulent Races Of The Rust Pathogen That Overcomes All Known Common Bean Rust Resistance Genes, Santos Barrera Lemus, Prabin Tamang, Carlos A. Urrea, Marcial A. Pastor-Corrales

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

Bean rust, caused by Uromyces appendiculatus, is a major disease of common and snap bean (Phaseolus vulgaris) worldwide (Stavely, 1984). Although host resistance is an important component of rust management (Mmbaga et al., 1996), populations of the rust pathogen comprise an extensive and shifting virulence diversity that could render susceptible all known rust resistance genes in common bean. Conversely, it has been suggested that certain tepary bean (Phaseolus acutifolius) accessions are broadly resistant to bean rust (Miklas & Stavely, 1998). The objectives of this study were to verify if tepary beans are resistant to …

Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell

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

This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.

Variance Heterogeneity Genome-Wide Mapping For Cadmium In Bread Wheat Reveals Novel Genomic Loci And Epistatic Interactions, Waseem Hussain, Malachy T. Campbell, Diego Jarquin, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Genome-wide association mapping identifies quantitative trait loci (QTL) that influence the mean differences between the marker genotypes for a given trait. While most loci influence the mean value of a trait, certain loci, known as variance heterogeneity QTL (vQTL) determine the variability of the trait instead of the mean trait value (mQTL). In the present study, we performed a variance heterogeneity genome-wide association study (vGWAS) for grain cadmium (Cd) concentration in bread wheat. We used double generalized linear model and hierarchical generalized linear model to identify vQTL associated with grain Cd. We identified novel vQTL regions on chromosomes 2A and …

Florida Mangroves Show No Evidence Of Thermal Acclimation Of Leaf Respiration: Implications For Coastal Carbon Cycling And Future Climate, Kylie Harris, Jeff Chieppa, Matt Sturchio, Michael Aspinwall

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Temperature controls of physiological processes that regulate C cycling in mangrove ecosystems remain understudied. New studies that investigate mangrove sensitivity to temperature could improve representation of coastal C cycling in global scale models. Respiration represents the second largest C flux between vegetation and the atmosphere, and roughly 50% of plant respiration comes from leaves. Leaf respiration increases with temperature, but thermal acclimation can dampen this response, and mitigate the positive feedback between temperature, respiration, and atmospheric CO2. We tested whether thermal acclimation of leaf respiration (R) to seasonal temperature changes and experimental warming is similar among three common mangrove species …

Great Bay Estuary Subtidal Seaweed And Seagrass Sampling Photographs 2019, David M. Burdick, Gregg Moore

Jackson Estuarine Laboratory

Led by Dr. Gregg Moore, cover of sub-tidal seaweed and eelgrass was sampled using remote video. Nine images were clipped for each of three sample areas (replicates) for four locations around Great Bay and herein is a record of the photographs.

Great Bay Estuary Intertidal Seaweed Plot Photographs 2019, David M. Burdick

Jackson Estuarine Laboratory

Records of photographs of intertidal seaweed sampling plots for cover (50 by 50 cm) and biomass (25 by 25 cm) collected by Jackson Estuarine Laboratory staff and volunteers in June, August and October 2019. Many of the photos were taken by Coastal Research Volunteers, a SeaGrant Extension project led by Wells Costello.

A Global Perspective On Sustainable Intensification Research, Kenneth Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Despite general agreement that meeting food demand without further loss of natural ecosystems requires sustainable intensification, there is little dialogue about the research agenda needed to achieve it. To that end, we evaluate current trajectories towards sustainable intensification, review published research on the topic, identify missing links, and propose a prioritization framework to fill gaps. Although progress towards sustainable intensification is behind schedule, we are optimistic that current trends can get back on course assuming a well-prioritized and adequately funded research portfolio and appropriate policies and institutions to support it.

Assessment Of Pollinator Preference Of Native And Nonnative Perennial Flowering Plants In South Dakota’S Grasslands, Bryanna Chipley

Schultz-Werth Award Papers

With global pollinator decline continually worsening as a result of human action, concerned citizens and scientists alike have been looking for answers as to what can be done to help, and the question of whether native or non-native plants provide more benefit to pollinating insects has been long discussed in the scientific community. This research is intended to help answer that question by attempting to determine whether pollinators have a distinct preference between native and non-native plants when presented with both options. The hypothesis at outset of this project was that native plants would provide greater benefit to pollinators, whom …

Herbicide Injury From Dicamba And 2,4-D: How Much Is Too Much In Lettuce?, Xinzheng Chen, Amit J. Jhala, Stevan Z. Knezevic, Samuel E. Wortman

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

Off-target herbicide injury from dicamba and 2,4-D is an increasingly common problem for specialty crop growers in the Midwest United States. Lettuce (Lactuca sativa L.) is a common specialty crops grown in Nebraska, but proximity to corn and soybean production leaves growers vulnerable to crop injury and significant economic loss. The goal of this study was to quantify crop injury and yield loss in greenhouse grown lettuce after exposure to simulated sub-lethal drift rates of 2,4-D and dicamba. Sublethal doses were determined based on a percentage of the maximum labeled rate and ranged from 25% to 0.01%. Tested lettuce …

Spring Meadow Management Practices: What’S A Rancher To Do?, Tara M. Harms, Jerry D. Volesky, Mitchell B. Stephenson

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

Subirrigated meadows are a valuable forage resource to ranching operations in the Nebraska Sandhills, being used for both hay production and livestock grazing.

The water table of these meadows is within one meter of the soil surface during the growing season.

In some years, wet conditions hinder meadow utilization, resulting in a buildup of standing dead and litter plant material which can lower forage production.

Investigate if burning and mowing are effective strategies to remove dead plant material from meadows • Determine if burning or mowing interact with grazing to influence end of season forage production

Burning or mowing effectively …

Wildflower Of The Year—Cymes, Not Corymbs!, W. John Hayden

Biology Faculty Publications

I hit a snag while composing the text for this year’s wildflower of the year brochure on Wild Geranium, Geranium maculatum. The problem concerned the proper descriptive term for its inflorescence, i.e., the pattern in which its flowers are grouped. In more than one source, I read that, for the family Geraniaceae, inflorescences are cymes (Figures 1 and 2), but those same sources indicated that inflorescences of Geranium maculatum are corymbs (Figure 4). That conflict caused me to scratch my head because cymes and corymbs are fundamentally different kinds of inflorescences.

Difficult Creek, Difficult Management Choices, W. John Hayden

Biology Faculty Publications

Virginia is blessed with many botanical wonderlands; see Chapter 4 of the Flora of Virginia (Weakley et al. 2012) for thumbnail sketches describing 50 of these special places. One such treasure, Difficult Creek Natural Area Preserve, is home to a thriving population of the 2019 VNPS Wildflower of the year, Ceanothus americanus (New Jersey Tea). Paradoxically, however, our featured wildflower of last year is inextricably linked to a difficult conservation management decision.

Diversity And Ethnobotanical Importance Of Pine Species From Sub-Tropical Forests, Azad Jammu And Kashmir, Kishwar Sultana, Sher Wali Khan, Safdar Ali Shah

Journal of Bioresource Management

A general investigation of sub-tropical forests, from Pir Chinasi National Park, Tolipir National Park, Dhirkot Nature Reserve and Banjosa Game Reserve was carried out during different months from February 2008 to May 2010. The relative abundance of species was calculated using line transects of 50m. A total of five different species (Abies pindrow. Cedrus deodara, Pinus wallichiana, Pinus roxburgii and Picea smithiana) from the Pinaceae family were recorded. The main reported use of Cedrus deodara and Pinus wallichiana by the local people was for furniture and construction purposes. Pinus wallichiana was observed as the dominant …

De Novo Sequencing And Analysis Of Salvia Hispanica Tissue-Specific Transcriptome And Identification Of Genes Involved In Terpenoid Biosynthesis, James Wimberley, Joseph Cahill, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Salvia hispanica (commonly known as chia) is gaining popularity worldwide as a healthy food supplement due to its low saturated fatty acid and high polyunsaturated fatty acid content, in addition to being rich in protein, fiber, and antioxidants. Chia leaves contain plethora of secondary metabolites with medicinal properties. In this study, we sequenced chia leaf and root transcriptomes using the Illumina platform. The short reads were assembled into contigs using the Trinity software and annotated against the Uniprot database. The reads were de novo assembled into 103,367 contigs, which represented 92.8% transcriptome completeness and a diverse set of Gene Ontology …

Optimum Rates Of Surface-Applied Coal Char Decreased Soil Ammonia Volatilization Loss, Dinesh Panday, Maysoon M. Mikha, Harold P. Collins, Virginia L. Jin, Michael Kaiser, Jennifer Cooper, Arindam Malakar, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Fertilizer N losses from agricultural systems have economic and environmental implications. Soil amendment with high C materials, such as coal char, may mitigate N losses. Char, a coal combustion residue, obtained from a sugar factory in Scottsbluff, NE, contained 29% C by weight. A 30-d laboratory study was conducted to evaluate the effects of char addition on N losses via nitrous oxide (N₂O) emission, ammonia (NH₃) volatilization, and nitrate (NO₃–N) leaching from fertilized loam and sandy loam soils. Char was applied at five different rates (0, 6.7, 10.1, 13.4, and 26.8 Mg C ha …

Landscape Performance Of Buck Roses Under Minimal-Input Conditions In North-Central Texas, Derald A. Harp, Gaye Hammond, David C. Zlesak, Greg Church, Mark Chamblee, Steve George

Faculty Publications

Griffith Buck (Iowa State University) bred roses (Rosa sp.) to survive long, cold winters and hot, humid summers yet still retain their foliage without fungicides. Unfortunately, there is little known about the performance of Buck roses in the southern United States. Thirty-eight Buck rose cultivars were evaluated for flowering, disease resistance, drought tolerance, and overall landscape performance in alkaline soils with no fertilizer, no pesticides, and only limited irrigation. Flowering occurred on a bimodal basis, with the highest per plant mean bloom number (16.3 blooms) and bloom coverage (9.7%) in April, and a second flowering in the fall, with …

Using Ndvi To Differentiate Wheat Genotypes Productivity Under Dryland And Irrigated Conditions, Mohammed A. Naser, Raj Khosla, Louis Longchamps, Subash Dahal

Department of Agronomy and Horticulture: Faculty Publications

Crop breeders are looking for tools to facilitate the screening of genotypes in field trials. Remote sensing-based indices such as normalized difference vegetative index (NDVI) are sensitive to biomass and nitrogen (N) variability in crop canopies. The objectives of this study were (i) to determine if proximal sensor-based NDVI readings can differentiate the yield of winter wheat (Triticum aestivum L.) genotypes and (ii) to determine if NDVI readings can be used to classify wheat genotypes into grain yield productivity classes. This study was conducted in northeastern Colorado in 2010 and 2011. The NDVI readings were acquired weekly from March to …

A Checklist Of Vascular Plants Endemic To California, James P. Smith Jr

Botanical Studies

No abstract provided.

A History Of Zinnias: Flower For The Ages, Eric Grissell

Purdue University Press Book Previews

A History of Zinnias brings forward the fascinating adventure of zinnias and the spirit of civilization. With colorful illustrations, this book is a cultural and horticultural history documenting the development of garden zinnias—one of the top ten garden annuals grown in the United States today.

The deep and exciting history of garden zinnias pieces together a tale involving Aztecs, Spanish conquistadors, people of faith, people of medicine, explorers, scientists, writers, botanists, painters, and gardeners. The trail leads from the halls of Moctezuma to a cliff-diving prime minister; from Handel, Mozart, and Rossini to Gilbert and Sullivan; from a little-known confession …

Arkansas Cotton Variety Test 2019, F. Bourland, A. Beach, E. Brown, C. Kennedy, L. Martin, B. Robertson

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). Entries in the 2019 Arkansas Cotton Variety Test …

Vascular Plant Families Of The United States (With Common Names And Numerical Summary), James P. Smith Jr

Botanical Studies

No abstract provided.

Impacts Of Invasive Rats On Hawaiian Cave Resources, Francis G. Howarth, Fred D. Stone

International Journal of Speleology

Although there are no published studies and limited data documenting damage by rodents in Hawaiian caves, our incidental observations during more than 40 years of surveying caves indicate that introduced rodents, especially the roof rat, Rattus rattus, pose significant threats to vulnerable cave resources. Caves, with their nearly constant and predictable physical environment often house important natural and cultural features including biological, paleontological, geological, climatic, mineralogical, cultural, and archaeological resources. All four invasive rodents in Hawai‘i commonly nest in cave entrances and rock shelters, but only the roof rat (Rattus rattus) habitually enters caves and utilizes areas …

The State Of Sustainable Agriculture And Agroecology Research And Impacts: A Survey Of U.S. Scientists, Marcia Delonge, Tali Robbins, Andrea Basche, Lindsey Haynes-Maslow

Department of Agronomy and Horticulture: Faculty Publications

A growing body of research suggests that although sustainable agriculture, particularly agroecology, can address challenges such as those related to climate change, ecosystem services, food insecurity, and farmer livelihoods, the transition to such systems remains limited. To gain insight into the state of U.S. sustainable agriculture and agroecology, we developed a 28-question mixed-method survey that was administered to scientists in these fields. Respondents (N=168) represented diverse locations, institutions, and career stages. They offered varied definitions of sustainable agriculture, with 40% considering economic and social well-being to be core components. Respondents identified the amount and duration of public research funding as …

Ecological Strategies Begin At Germination: Traits, Plasticity, And Survival In The First Four Days Of Plant Life, Julie E. Larson, Brian L. Anacker, Sara Wanous, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1. We commonly use trait variation to characterize plant function within and among species and understand how vegetation responds to the environment. Seedling emergence is an especially vulnerable window affecting population and community dynamics, yet trait‐based frameworks often bypass this earliest stage of plant life. Here we assess whether traits vary in ecologically‐meaningful ways when seedlings are just days old. How do shared evolutionary history and environmental conditions shape trait expression, and can traits explain which seedlings endure drought?.
2. We measured seedling traits in the first four days of life for 16 annual plant species under two water treatments, exploring trait …

Restoring The Fire–Grazing Interaction Promotes Tree–Grass Coexistence By Controlling Woody Encroachment, Jane F. Capozzelli, James R. Miller, Diane M. Debinski, Walter H. Schacht

Department of Agronomy and Horticulture: Faculty Publications

Woody encroachment can convert grasslands and savannas to shrublands and woodlands, so understanding the processes which regulate woody encroachment is necessary to conserve or restore these ecosystems.We hypothesized that recreating the fire–grazing interaction would limit woody encroachment because focal grazing increases fuel accumulation on unburned areas and increases browsing on emergent woody plants in burned areas. This study was conducted in the Grand River Grasslands of Iowa and Missouri (USA) on 11 sites (15.4–35.0 ha). Each site was assigned to one treatment: patch-burn-graze (n = 4), with spatially discrete prescribed fires and free access by cattle (the fire–grazing interaction); graze-andburn …

Combination Of Biological And Chemical Soil Tests Best Predict Maize Nitrogen Response, M. D. Mcdaniel, Daniel T. Walters, L. G. Bundy, Xiaofei Li, Rhae A. Drijber, John E. Sawyer, Michael J. Castellano, C. A.M. Laboski, Peter C. Scharf

Department of Agronomy and Horticulture: Faculty Publications

Soil tests can help optimize nitrogen (N) fertilizer rates, thereby improving farmer profitability and environmental performance. In US Midwest maize (Zea mays) production, however, most soil N tests have limited accuracy to predict N fertilizer requirements. Here we tested the individual and combined ability of 30 soil tests (12 rapid N extractions, seven biological carbon or N tests, six long-term incubation kinetic parameters, and five other routine soil tests), as well as environmental and management data, to predict maize response to N fertilizer across 56 site-years in the US Midwest. Out of 30 soil tests, and across all …

Soybean Response To Water: Trait Identification And Prediction, Shawn Jenkins

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

The rising demand for soybean [Glycine Max (L.) Merrill] taken in consideration with current climatic trends accentuates the importance of improving soybean seed yield response per unit water (WP). To further our understanding of the quantitative WP trait, a multi-omic approach was implemented for improved trait identification and predictive modeling opportunities. Through the evaluation of two recombinant inbred line populations jointly totaling 439 lines subjected to contrasting irrigation treatments, informative agronomic, phenomic, and genomic associations were identified. Across both populations, relationships were identified between lodging at maturity (r = -0.58, H = 0.86), canopy to air temperature differential …

Availability Of Soil Mutualists May Not Limit Non‐Native Acacia Invasion But Could Increase Their Impact On Native Soil Communities, Elizabeth M. Wandrag, Christina Birnbaum, Metha M. Klock, Luke G. Barrett, Peter H. Thrall

Faculty Publications, Environmental Studies

1. The availability of compatible mutualistic soil microbes could influence the invasion success of non-native plant species. Specifically, there may be spatial variation in the distribution of compatible microbes, and species-specific variation in plant host ability to associate with available microbes. Although either or both factors could promote or limit invasion, the scale over which most studies are conducted makes it difficult to examine these two possibilities simultaneously. However, this is critical to identifying a role of soil microbes in invasion.
2. A series of recent research projects focused on interactions between Australian Acacia and nitrogen-fixing bacteria (rhizobia) at multiple spatial scales, …

Enhancing Hybrid Prediction In Pearl Millet Using Genomic And/Or Multi- Environment Phenotypic Information Of Inbreds, Diego Jarquin, Reka Howard, Zhikai Liang, Shashi K. Gupta, James C. Schnable, Jose Crossa

Department of Agronomy and Horticulture: Faculty Publications

Genomic selection (GS) is an emerging methodology that helps select superior lines among experimental cultivars in plant breeding programs. It offers the opportunity to increase the productivity of cultivars by delivering increased genetic gains and reducing the breeding cycles. This methodology requires inexpensive and sufficiently dense marker information to be successful, and with whole genome sequencing, it has become an important tool in many crops. The recent assembly of the pearl millet genome has made it possible to employ GS models to improve the selection procedure in pearl millet breeding programs. Here, three GS models were implemented and compared using …

A List Of The Rare, Endangered, & Threatened Vascular Plants Of California, James P. Smith Jr

Botanical Studies

No abstract provided.