Other Plant Sciences Commons^™

Evaluation Of Jules-Crop Performance Against Site Observations Of Irrigated Maize From Mead, Nebraska, Karina Williams, Jemma Gornall, Anna Harper, Andy Wiltshire, Debbie Hemming, Tristan Quaife, Tim Arkebauer, David Scoby

Department of Agronomy and Horticulture: Faculty Publications

The JULES-crop model (Osborne et al., 2015) is a parametrisation of crops within the Joint UK Land Environment Simulator (JULES), which aims to simulate both the impact of weather and climate on crop productivity and the impact of croplands on weather and climate. In this evaluation paper, observations of maize at three FLUXNET sites in Nebraska (US-Ne1, US-Ne2 and US-Ne3) are used to test model assumptions and make appropriate input parameter choices. JULES runs are performed for the irrigated sites (US-Ne1 and US-Ne2) both with the crop model switched off (prescribing leaf area index (LAI) and canopy height) and with …

Science In The Supply Chain: Collaboration Opportunities For Advancing Sustainable Agriculture In The United States, Allison M. Thomson, Stewart Ramsey, Ed Barnes, Bruno Basso, Marlen Eve, Sasha Gennet, Patricio Grassini, Brandon Kliethermes, Marty Matlock, Eileen Mcclellen, Ed Spevak, Clifford S. Snyder, Mark D. Tomer, Chris Van Kessel, Tristram West, Grant Wick

Department of Agronomy and Horticulture: Faculty Publications

Consumers and corporations are increasingly interested in understanding the sustainability of agricultural supply chains and reducing the environmental impacts of food, fiber, feed, and fuel production. This emerging need to quantify environmental impacts from agricultural production creates an opportunity for collaboration with the scientific community. Without such collaboration, sustainability efforts risk failure by adopting unrealistic goals or misguided approaches. This commentary explores the role of science in Field to Market, a nonprofit organization developing a sustainability program for US commodity crops, and highlights opportunities to address emerging science challenges. We evaluate changes over the past 35 years in key environmental …

Genetic Characterization Of The Soybean Nested Association Mapping Population, Qijian Song, Long Yan, Charles Quigley, Brandon D. Jordan, Edward Fickus, Steve Schroeder, Bao-Hua Song, Yong-Qiang Charles An, David Hyten, Randall L. Nelson, Katy Rainey, William D. Beavis, Jim Specht, Brian Diers, Perry Cregan

Department of Agronomy and Horticulture: Faculty Publications

A set of nested association mapping (NAM) families was developed by crossing 40 diverse soybean [Glycine max (L.) Merr.] genotypes to the common cultivar. The 41 parents were deeply sequenced for SNP discovery. Based on the polymorphism of the single-nucleotide polymorphisms (SNPs) and other selection criteria, a set of SNPs was selected to be included in the SoyNAM6K BeadChip for genotyping the parents and 5600 RILs from the 40 families. Analysis of the SNP profiles of the RILs showed a low average recombination rate. We constructed genetic linkage maps for each family and a composite linkage map based on …

Editorial: Genomic Approaches For Improvement Of Understudied Grasses, Keenan Amundsen, Gautam Sarath, Teresa Donze-Reiner

Department of Agronomy and Horticulture: Faculty Publications

Grasses are diverse, spanning native prairies to high-yielding grain cropping systems. They are valued for their beauty and useful for soil stabilization, pollution mitigation, biofuel production, nutritional value, and forage quality; grasses encompass the most important grain crops in the world. There are thousands of distinct grass species and many have promiscuous hybridization patterns, blurring species boundaries. Resources for advancing the science and knowledgebase of individual grass species or their unique characteristics varies, often proportional to their perceived value to society. For many grasses, limited genetic information hinders research progress. Presented in this research topic is a brief snapshot of …

Expression Of The Maize Dof1 Transcription Factor In Wheat And Sorghum, Pamela A. Pena, Truyen Quach, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Taity Changa, Ismail M. Dweikat, Madhavan Soundararajan, Tom E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen is essential for plant growth and development. Improving the ability of plants to acquire and assimilate nitrogen more efficiently is a key agronomic parameter that will augment sustainability in agriculture. A transcription factor approach was pursued to address improvement of nitrogen use efficiency in two major commodity crops. To this end, the Zea mays Dof1 (ZmDof1) transcription factor was expressed in both wheat (Triticum aestivum) and sorghum (Sorghum bicolor) either constitutively, UBI4 promoter from sugarcane, or in a tissue specific fashion via the maize rbcS1 promoter. The primary transcription activation target of ZmDof1 …

High-Throughput Profiling And Analysis Of Plant Responses Over Time To Abiotic Stress, Kira M. Veley, Jeffrey C. Berry, Sarah J. Fentress, Daniel P. Schachtman, Ivan Baxter, Rebecca Bart

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor (L.) Moench) is a rapidly growing, high-biomass crop prized for abiotic stress tolerance. However, measuring genotype-by-environment (G x E) interactions remains a progress bottleneck. We subjected a panel of 30 genetically diverse sorghum genotypes to a spectrum of nitrogen deprivation and measured responses using high-throughput phenotyping technology followed by ionomic profiling. Responses were quantified using shape (16 measurable outputs), color (hue and intensity), and ionome (18 elements). We measured the speed at which specific genotypes respond to environmental conditions, in terms of both biomass and color changes, and identified individual genotypes that perform most favorably. With this …

Influence Of Tillage On Common Ragweed (Ambrosia Artemisiifolia) Emergence Pattern In Nebraska, Ethann R. Barnes, Rodrigo Werle, Lowell Sandell, John L. Lindquist, Stevan Z. Knezevic, Peter H. Sikkema, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Spring tillage is a component of an integrated weed management strategy for control of early emerging glyphosate-resistant weeds such as common ragweed; however, the effect of tillage on common ragweed emergence pattern is unknown. The objectives of this study were to evaluate whether spring tillage during emergence would influence the emergence pattern or stimulate additional emergence of common ragweed and to characterize common ragweed emergence in southeast Nebraska. A field experiment was conducted for three years (2014 to 2016) in Gage County, Nebraska in a field naturally infested with glyphosate-resistant common ragweed. Treatments consisted of a no-tillage control and three …

Can Sub-Saharan Africa Feed Itself?, Martin K. Van Ittersum, Lenny G. J. Van Bussel, Joost Wolf, Patricio Grassini, Justin Van Wart, Nicolas Guilpart, Lieven Claessens, Hugo De Groot, Keith Wiebe, Daniel Mason-D'Croz, Haishun Yang, Hendrik Boogard, Pepijn A. J. Van Oort, Marloes P. Van Loon, Kazuki Saito, Ochieng Adimo, Samuel Adjei-Nsiah, Alhassane Agali, Abdullahi Bala, Regis Chikowo, Kayuki Kaizzi, Mamoutou Kouressy, Joachim H. J. R. Makoi, Korodjouma Ouattara, Kindie Tesfaye, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Although global food demand is expected to increase 60% by 2050 compared with 2005/2007, the rise will be much greater in sub- Saharan Africa (SSA). Indeed, SSA is the region at greatest food security risk because by 2050 its population will increase 2.5-fold and demand for cereals approximately triple, whereas current levels of cereal consumption already depend on substantial imports. At issue is whether SSA can meet this vast increase in cereal demand without greater reliance on cereal imports or major expansion of agricultural area and associated biodiversity loss and greenhouse gas emissions. Recent studies indicate that the global increase …

Can Functional Traits Predict Plant Community Response To Global Change?, Sarah Kimball, Jennifer L. Funk, Marko J. Spasojevic, Katharine N. Suding, Scot Parker, Michael K. Goulden

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

One primary goal at the intersection of community ecology and global change biology is to identify functional traits that are useful for predicting plant community response to global change. We used observations of community composition from a long-term field experiment in two adjacent plant communities (grassland and coastal sage shrub) to investigate how nine key plant functional traits were related to altered water and nitrogen availability following fire. We asked whether the functional responses of species found in more than one community type were context dependent and whether community-weighted mean and functional diversity were significantly altered by water and nitrogen …

Salvinia Molesta: An Assessment Of The Effects And Methods Of Eradication, Arti Lal

Master's Projects and Capstones

Salvinia molesta is an invasive aquatic fern. It is now the second worse aquatic invader in the world. Since the 1930s, it has invaded most tropical and some temperate countries. S. molesta plants grow vegetatively and can increase in size rapidly. S. molesta can form thick mats of up to 1-meter-thick. There are a number of ways these thick mats negatively affect the environment: 1) reduce light to benthic organisms, 2) reduce oxygen in the water column for other organisms, 3) accumulate as organic matter at the bottom of the water column, 4) decrease nutrients for other organisms, and 5) …

Effect Of Smooth Bromegrass Management On Grazing Cattle Dung Decomposition, Co2 Flux, And Soil Nutrient Movement, Bradley D. Schick

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

Rapid nutrient cycling improves forage quality and livestock production in pastures. Interseeding legumes may be a strategy to enhance N cycling, but effects of dung excreted from cattle grazing pastures with legumes on dung decomposition rates and soil N cycling have not been studied. Our objective was to evaluate how dung excreted from cattle grazing legume-interseeded, N-fertilized, and unfertilized smooth bromegrass (Bromus inermis Leyss.) pastures affects dung chemical composition, dry matter decomposition, CO­₂ flux, and N availability in soil. Freshly deposited dung from yearling steers grazing legume-interseeded, N-fertilized, and unfertilized pastures was collected and placed as pats in …

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Ranae Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter J. Thorburn, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha^-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) …

Characterization And Development Mechanism Of Apios Americana Tuber Starch, Hanyu Yangchen, Vikas Belamkar, Steven B. Cannon, Jay-Lin Jane

Department of Agronomy and Horticulture: Faculty Publications

Apios americana is a wild legume-bearing plant with edible tubers. Domestication of Apios is in progress because of the superior nutritional value and health benefits of the tuber. Objectives of this study were to: (1) characterize physicochemical properties of the Apios tuber starch; and (2) understand differences in starch structures and properties between the mother (seed) and child (progeny) tubers and the mechanism of starch development. Granules of the Apios tuber starch displayed ellipsoidal, rod, or kidney shape with diameter ranges of 1–30 m. The mother tuber starches displayed greater percentage crystallinity, larger gelatinization enthalpy-changes, longer branch-chain lengths of amylopectin, …

Genomics-Assisted Characterization Of A Breeding Collection Of Apios Americana, An Edible Tuberous Legume, Vikas Belamkar, Andrew Farmer, Nathan T. Weeks, Scott R. Kalberer, William J. Blackmon, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

For species with potential as new crops, rapid improvement may be facilitated by new genomic methods. Apios (Apios americana Medik.), once a staple food source of Native American Indians, produces protein-rich tubers, tolerates a wide range of soils, and symbiotically fixes nitrogen. We report the first high-quality de novo transcriptome assembly, an expression atlas, and a set of 58,154 SNP and 39,609 gene expression markers (GEMs) for characterization of a breeding collection. Both SNPs and GEMs identify six genotypic clusters in the collection. Transcripts mapped to the Phaseolus vulgaris genome–another phaseoloid legume with the same chromosome number–provide provisional genetic …

Plants Having Increased Bomass And Methods For Making The Same, Aleel K. Grennan, Donald R. Ort, Stephen Patrick Moose, Damla D. Bilgin, Thomas Clemente, Fredy Altpeter, Stephen P. Long

Department of Agronomy and Horticulture: Faculty Publications

The impact of plastid size change in both monocot and dicot plants has been examined. In both, when plastid size is increased there is an increase in biomass relative to the parental lines. Thus, provided herein are methods for increasing the biomass of a plant, comprising decreasing the expression of at least one plastid division protein in a plant. Optionally, the level of chlorophyll in the plant is also reduced.

Variation In Leaf Wettability Traits Along A Tropical Montane Elevation Gradient, Gregory R. Goldsmith, Lisa Patrick Bentley, Alexander Shenkin, Norma Salinas, Benjamin Blonder, Roberta E. Martin, Rosa Castro-Ccossco, Percy Chambi-Porroa, Sandra Diaz, Brian J. Enquist, Gregory P. Asner, Yadvinder Malhi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

• Leaf wetting is often considered to have negative effects on plant function, such that wet environments may select for leaves with certain leaf surface, morphological, and architectural traits that reduce leaf wettability. However, there is growing recognition that leaf wetting can have positive effects.
• We measured variation in two traits, leaf drip tips and leaf water repellency, in a series of nine tropical forest communities occurring along a 3300-m elevation gradient in southern Peru. To extend this climatic gradient, we also assembled published leaf water repellency values from 17 additional sites. We then tested hypotheses for how these traits should …

Cross Species Selection Scans Identify Components Of C4 Photosynthesis In The Grasses, Pu Huang, Anthony J. Studer, James C. Schnable, Elizabeth A. Kellogg, Thomas P. Brutnell

Department of Agronomy and Horticulture: Faculty Publications

C₄ photosynthesis is perhaps one of the best examples of convergent adaptive evolution with over 25 independent origins in the grasses (Poaceae) alone. The availability of high quality grass genome sequences presents new opportunities to explore the mechanisms underlying this complex trait using evolutionary biology-based approaches. In this study, we performed genome-wide cross-species selection scans in C₄ lineages to facilitate discovery of C₄ genes. The study was enabled by the well conserved collinearity of grass genomes and the recently sequenced genome of a C₃ panicoid grass, Dichanthelium oligosanthes. This method, in contrast to previous studies, …

Herbicide Resistantsorghum Mutants, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

This disclosure provides for four different sorghum mutants that exhibit resistance to ALS-inhibiting herbicides. This dis closure also provides for methods of using such Sorghum mutants that exhibit resistance to ALS-inhibiting herbicides in breeding methods to make Sorghum hybrids, varieties, or lines. The Sorghum hybrids, varieties, and lines provided in this disclosure can be used in methods of controlling weeds.

Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse

Department of Agronomy and Horticulture: Faculty Publications

Understanding of Sandhills prairie, the most expansive sand dune region stabilized by perennial grasses in the Western Hemisphere, is limited by lack of long-term vegetation data. We used a 26-year dataset to evaluate Sandhills prairie responses to yearto- year variation in precipitation, temperature, and cattle stocking rate. Basal cover, a measurement that is constant seasonally and used to detect long-term changes in bunchgrass vegetation, was measured in 38–40 permanent plots positioned along four transects spanning 769 ha from 1979 to 2007. Across this period, total basal cover averaged 2.4 % and was dominated by warm-season grasses (81.1 %). Schizachyrium scoparium …

Regeneration: An Overlooked Aspect Of Trait-Based Plant Community Assembly Models, Julie Larson, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Despite the disproportionate influence that propagule production, dispersal, seed to seedling recruitment, and vegetative reproduction can have on plant population and community dynamics, progress has been slow in the directed collection of regeneration traits to inform community assembly outcomes.

While seed mass is globally available and linked to growth and reproductive output, there are limits to its explanatory ability. In this essay, we call for expanded efforts to integrate a more diverse set of regeneration traits into community assembly models.

First, we extend an existing community assembly framework to conceptualize regeneration as a series of transitional processes whose outcomes are …

A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna

Biological Sciences

Strong environmental gradients and varied land-use practices have generated a mosaic of habitats harboring distinct plant communities on islands on the coast of Maine. Botanical studies of Maine’s islands, however, are generally limited in number and scope. Baseline studies of Maine’s islands are necessary for assessing vegetation dynamics and changes in habitat conditions in relation to environmental impacts imposed by climate change, rising sea levels, invasive species, pests and pathogens, introduced herbivores, and human disturbance. We conducted a survey of the vascular plants and soils of forest, field, and ocean-side communities of Great Duck and Little Duck Islands, ME. These …

Evaluating Pedestrial Compaction Variation & Soil Organic C Content, Gunner B. Decker

Scholars Week

Over time, playing fields are monitored by overall appearance. However, pedestrian compaction is not evenly distributed throughout the entire surface.

Evolutionary Responses Of Invasive Grass Species To Variation In Precipitation And Soil Nitrogen, Monica A. Nguyen, Amy E. Ortega, Quoc L. Nguyen, Sarah Kimball, Michael L. Goulden, Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes.

2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and …

Information Thermodynamics Of Cytosine Dna Methylation, Robersy Sanchez Rodriguez, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Cytosine DNA methylation (CDM) is a stable epigenetic modification to the genome and a widespread regulatory process in living organisms that involves multicomponent molecular machines. Genome-wide cytosine methylation patterning participates in the epigenetic reprogramming of a cell, suggesting that the biological information contained within methylation positions may be amenable to decoding. Adaptation to a new cellular or organismal environment also implies the potential for genome-wide redistribution of CDM changes that will ensure the stability of DNA molecules. This raises the question of whether or not we would be able to sort out the regulatory methylation signals from the CDM background …

Ws-2 Introgression In A Proportion Of Arabidopsis Thaliana Col-0 Stock Seed Produces Specific Phenotypes And Highlights The Importance Of Routine Genetic Verification, Mon-Ray Shao, Vikas Shedge, Hardik Kundariya, Fredric R. Lehle, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Arabidopsis thaliana is an important model organism with a robust network of resources that has been of enormous value to the plant science research community. The use of isogenic material as a reference point or control is critical for many types of experiments in plant molecular biology and genetics. Recently, we noticed that some seed from a common source of the widely used Columbia-0 (Col-0) strain gave rise to plants showing features atypical for this strain. Whole-genome DNA-sequencing and allelespecific PCR assays confirmed that the abnormal individuals contain multiple introgressions from the ecotype Wassilewskija-2 (Ws-2), as described below. This …

Student-Conducted Farmer Video Interviews, Jenn K. Simons, Justin Van Wart, Charles Francis, Kristyn Harms

Department of Agronomy and Horticulture: Faculty Publications

High school agricultural education teachers have expressed concern about the lack of easily accessible educational materials dealing with contemporary topics in sustainable agriculture. There are numerous textbooks and monographs available for farmers and students at the college level, including the highly practical resources available from the Sustainable Agriculture Research and Education (SARE) book series on soil fertility (Magdoff and van Es, 2010), cover crops (Bowman et al., 2007) and building a farm business (DiGiacomo et al., 2003), among others. Although these are full of color photos and easily accessible graphs and tables, they are still in the print media category. …

Effect Of Green Tea On Interaction Of Lipid Oxidation Products With Sarcoplasmic And Myofibrillar Protein Homogenates Extracted From Bovine Top Round Muscle, Nahathai Stapornkul, Tatiana Prytkova, Lilian Were

Food Science Faculty Articles and Research

The interaction between lipid oxidation products and bovine sarcoplasmic (SP) and myofibrillar protein (MP) homogenates in the presence of green tea was investigated. To monitor the effect of green tea on lipid oxidation, aldehydes were measured while effect on protein was monitored via changes in myoglobin, thiols, and tryptophan fluorescence over nine days of refrigerated storage. The presence of SP and MP decreased free aldehydes in the buffers. The SP bound more aldehydes than MP. The tea compounds exhibited more favorable binding energies than aldehydes near histidine 64 close to the heme moiety of myoglobin. Addition of tea lowered tryptophan …

Corn Era Hybrid Response To Nitrogen Fertilization, Krishna P. Woli, Matthew J. Boyer, Roger Wesley Elmore, John E. Sawyer, Lori J. Abendroth, Daniel W. Barker

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) N use is of continued interest due to agronomic performance and environmental issues. This 2-yr study evaluated era hybrid response to fertilizer nitrogen (FN) rate in a factorial arrangement of one popular hybrid per five decades (1960–2000 eras) and five N rates (0–224 kg N ha^–1). An additional hybrid per era was grown at 168 kg N ha^–1. Hybrid productivity and nitrogen use efficiency (NUE) increased across the eras, but not between the 1980 and 1990 eras. Grain yield (GY) increased 65% and total plant biomass 43%, however, total plant nitrogen …

Mapping Qtls And Association Of Differentially Expressed Gene Transcripts For Multiple Agronomic Traits Under Different Nitrogen Levels In Sorghum, Malleswari Gelli, Sharon E. Mitchell, Kan Liu, Thomas E. Clemente, Donald P. Weeks, Chi Zhang, David R. Holding, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Background: Sorghum is an important C₄ crop which relies on applied Nitrogen fertilizers (N) for optimal yields, of which substantial amounts are lost into the atmosphere. Understanding the genetic variation of sorghum in response to limited nitrogen supply is important for elucidating the underlying genetic mechanisms of nitrogen utilization.

Results: A bi-parental mapping population consisting of 131 recombinant inbred lines (RILs) was used to map quantitative trait loci (QTLs) influencing different agronomic traits evaluated under normal N (100 kg.ha⁻¹ fertilizer) and low N (0 kg.ha⁻¹ fertilizer) conditions. A linkage map spanning 1614 cM was developed …

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such …