Digital Commons Network^™

Tissue‑ And Time‑Dependent Metabolite Profiles During Early Grain Development Under Normal And High Night‑Time Temperature Conditions, Nathan Abshire, Andrew L. Hauck, Harkamal Walia, Toshihiro Obata

Department of Agronomy and Horticulture: Faculty Publications

Background Wheat grain development in the first few days after pollination determines the number of endosperm cells that influence grain yield potential and is susceptible to various environmental conditions, including high night temperatures (HNTs). Flag leaves and seed-associated bracts (glumes, awn, palea, and lemma) provide nutrients to the developing seed. However, the specific metabolic roles of these tissues are uncertain, especially their dynamics at different developmental stages and the time in a day. Tissue- and time-dependent metabolite profiling may hint at the metabolic roles of tissues and the mechanisms of how HNTs affect daytime metabolic status in early grain development. …

Adding Value To Crop Production Systems By Integrating Forage Cover Crop Grazing, Robert B. Mitchell, Daren D. Redfearn, Kenneth P. Vogel, Terry J. Klopfenstein, Galen Erickson, P. Steven Baenziger, Bruce E. Anderson, Mary E. Drewnoski, Jay Parsons, Steven D. Masterson, Marty R. Schmer, Virginia L. Jin

Department of Agronomy and Horticulture: Faculty Publications

In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, Nebraska, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for …

Gene Expression Changes Linked To Phenylpropanoid-Based Resistance To Fusarium Head Blight Of Wheat, Shiv Singla

Department of Plant Pathology: Dissertations, Theses, and Student Research

Fusarium graminearum is a devastating pathogen of wheat that causes Fusarium head blight (FHB) and contaminates the grain with the mycotoxin deoxynivalenol (DON). Resistance to FHB is quantitative and it is important to identify additional genes conferring resistance against it. The goal of this thesis was to examine if the constitutive expression of two sorghum phenylpropanoid pathway genes, SbCCoAOMT (encoding caffeoyl-CoA O-methyltransferase) and SbC3’H (encoding p-coumarate 3-hydroxylase), in the moderately-susceptible spring wheat CB037 can provide Type-I and Type-II resistance to F. graminearum and determine the underlying mechanisms of the enhanced resistance. The constitutive expression lines (CCoAOMT413, CCoAOMT421, C3H112, …

Predicting Site‑Specific Economic Optimal Nitrogen Rate Using Machine Learning Methods And On‑Farm Precision Experimentation, Alfonso De Lara, Taro Mieno, Joe D. Luck, Laila A. Puntel

Department of Agronomy and Horticulture: Faculty Publications

Applying at the economic optimal nitrogen rate (EONR) has the potential to increase nitrogen (N) fertilization efficiency and profits while reducing negative environmental impacts. On-farm precision experimentation (OFPE) provides the opportunity to collect large amounts of data to estimate the EONR. Machine learning (ML) methods such as generalized additive models (GAM) and random forest (RF) are promising methods for estimating yields and EONR. Twenty OFPE N trials in wheat and barley were conducted and analyzed with soil, terrain and remote-sensed variables to address the following objectives: (1) to quantify the spatial variability of winter crops yield and the yield response …

6k1, Nia-Vpg, Nia-Pro, And Cp Ofwheat Streak Mosaic Virus Are Collective Determinants Of Wheat Streak Mosaic Disease In Wheat, Satyanarayana Tatineni, Jeffrey Alexander, Haritha Nunna

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) is the causal agent of the most economically important wheat streak mosaic disease of wheat (Triticum aestivum) in the Great Plains region of theUnited States.WSMVdeterminants responsible forwheat streak mosaic disease in wheat are unknown. Triticum mosaic virus (TriMV), a wheatinfecting virus,was used as an expression vector for the transient expression of each of the WSMV-encoded cistrons in wheat. WSMV-encoded 6K1, NIa-VPg, NIa-Pro, and CP cistrons in TriMV elicited symptoms specific to different stages of wheat streak mosaic disease without significantly affecting the genomic RNA accumulation. WSMV 6K1 …

6k1, Nia-Vpg, Nia-Pro, And Cp Ofwheat Streak Mosaic Virus Are Collective Determinants Of Wheat Streak Mosaic Disease In Wheat, Satyanarayana Tatineni, Jeffrey Alexander, Haritha Nunna

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) is the causal agent of the most economically important wheat streak mosaic disease of wheat (Triticum aestivum) in the Great Plains region of theUnited States.WSMVdeterminants responsible forwheat streak mosaic disease in wheat are unknown. Triticum mosaic virus (TriMV), a wheatinfecting virus,was used as an expression vector for the transient expression of each of the WSMV-encoded cistrons in wheat. WSMV-encoded 6K1, NIa-VPg, NIa-Pro, and CP cistrons in TriMV elicited symptoms specific to different stages of wheat streak mosaic disease without significantly affecting the genomic RNA accumulation. WSMV 6K1 …

Editorial: Genomics-Enabled Triticeae Improvement, Xue-Feng Ma, Xianchun Xia, Shuyu Liu, P. Stephen Baenziger, Hakan Özkan

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Source Of Off-Type Frequencies In Winter Wheat Varieties, Michaela Benes

Honors Theses

The enzyme polyphenol oxidase (PPO) is undesirable in most wheat products due to the discoloration it causes. Purifying wheat varieties through selective breeding is the best way at getting rid of PPO in a variety. The variety NW15443 was planted in both a field in McCook, NE, and in a greenhouse in Lincoln, NE. Individual heads were snapped from the field and the greenhouse seed was harvested in bulk. After completing a PPO test of the seed, it was determined that the percentages of off-type frequencies from the field seed and the greenhouse seed were 11% and 3.6%, respectively. Using …

Coleoptile Length Comparison Of Three Winter Small Grain Cereals Adapted To The Great Plains, M. Alam, M. Kashif, Amanda Easterly, F. Wang, J. D. Boehm Jr., P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Successful crop stand establishment is critical to realize high yield potential, which is dependent on depth of seed placement to access soil moisture. The coleoptile determines sowing depth by its length and ability to emerge from depth. This study was conducted to assess coleoptile length among three sets of three Great Plains winter small grain cereals—wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and triticale (X triticosecale Wittm.)—and to evaluate the effect of the Rht-B1b dwarfing allele on coleoptile length in wheat and triticale. Fifty seeds of each genotype were sown in wet germination paper in two …

Intervention Of Climate-Smart Practices In Wheat Under Rice-Wheat Cropping System In Nepal, Janma Jaya Gairhe, Mandeep Adhikari, Deepak Ghimire, Arun Khatri-Chhetri, Dinesh Panday

Department of Agronomy and Horticulture: Faculty Publications

Besides a proper agronomic management followed by Nepalese farmers, wheat (Triticum aestivum L.) production has been severely affected by changing climate. There are many interventions, including climate-smart practices, to cope with this situation and possibly enhance crop and soil productivity. Field experiments were set up in a randomized complete block design with six treatments (TRT) with four replications in three locations (LOC) during wheat-growing seasons in Nepal from 2014 to 2016. Treatments included (i) Controlled Practice (CP), (ii) Improved Low (IL), (iii) Improved High (IH), (iv) Climate Smart Agriculture Low (CSAL), (v) Climate Smart Agriculture Medium (CSAM), and (vi) …

High Plains Wheat Mosaic Virus: An Enigmatic Disease Of Wheat And Corn Causing The High Plains Disease, Satyanarayana Tatineni, Gary Hein

Department of Entomology: Faculty Publications

Brief history: In 1993, severe mosaic and necrosis symptoms were observed on corn (maize) and wheat from several Great Plains states of the USA. Based on the geographical location of infections, the disease was named High Plains disease and the causal agent was tentatively named High Plains virus. Subsequently, researchers renamed this virus as maize red stripe virus and wheat mosaic virus to represent the host and symptom phenotype of the virus. After sequencing the genome of the pathogen, the causal agent of High Plains disease was officially named as High Plains wheat mosaic virus. Hence, High Plains virus, …

Wheat Growth Monitoring And Yield Estimation Based On Multi-Rotor Unmanned Aerial Vehicle, Zhaopeng Fu, Jie Jang, Yang Gao, Brian Krienke, Meng Wang, Kaitai Zhong, Qiang Cao, Yongchao Tian, Yan Zhu, Weixing Cao, Xiaojun Liu

Department of Agronomy and Horticulture: Faculty Publications

Leaf area index (LAI) and leaf dry matter (LDM) are important indices of crop growth. Real-time, nondestructive monitoring of crop growth is instructive for the diagnosis of crop growth and prediction of grain yield. Unmanned aerial vehicle (UAV)-based remote sensing is widely used in precision agriculture due to its unique advantages in flexibility and resolution. This study was carried out on wheat trials treated with different nitrogen levels and seeding densities in three regions of Jiangsu Province in 2018–2019. Canopy spectral images were collected by the UAV equipped with a multi-spectral camera during key wheat growth stages. To verify the …

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 …

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 E. Clemente, Paul E. 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 …

Effects Of Different Water And Nitrogen Regimens On Yield Of Winter Wheat Produced In Nebraska, Joseph Emory Davis

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

Wheat is the 3rd most prominent crop in the USA and approximately 50% is exported annually. Nebraska wheat production is 11^th in the country, and it plays a major role in the state's agricultural economy, especially in western NE. Generally, wheat is grown under dryland conditions and the region grows much more wheat on unirrigated land than it does on irrigated. However, deficit irrigation has shown great value in producing high yielding wheat with much less water than needed for other crops. Finding new ways to leverage irrigation in wheat production may help address the need to produce food …

Addressing The Challenges Facing Wheat Production: Nebraska And International Breeding Efforts, Sarah Blecha

Doctor of Plant Health Program: Dissertations and Student Research

Bread wheat, Triticum aestivum L., provides 20 percent of the global daily calorie intake. It is the third most important food crop, after rice and corn. Biotic challenges significantly reduce wheat yield; chemical control can be a solution but can be cost prohibitive for subsistence farmers. For many farmers, genetic resistance to biotic stresses can be the most cost effective solution.

The International Center for Agricultural Research in the Dry Areas (ICARDA) and the Nebraska Small Grains Breeding Program have been addressing these wheat production challenges. ICARDA is part of an international research consortium to increase wheat yield and tolerance …

Estimating Percentages Of Fusarium-Damaged Kernels In Hard Wheat By Near-Infrared Hyperspectral Imaging, Stephen R. Delwiche, I. Torres Rodriguez, S. R. Rausch, R. A. Graybosch

Department of Agronomy and Horticulture: Faculty Publications

Fusarium head blight (FHB) is among the most common fungal diseases affecting wheat, resulting in decreased yield, low-density kernels, and production of the mycotoxin deoxynivalenol, a compound toxic to humans and livestock. Human visual analysis of representative wheat samples has been the traditional method for FHB assessment in both official inspection and plant breeding operations. While not requiring specialized equipment, visual analysis is dependent on a trained and consistent workforce, such that in the absence of these aspects, biases may arise among inspectors and evaluation dates. This research was intended to avoid such pitfalls by using longer wavelength radiation than …

Water Productivity Of Rainfed Maize And Wheat: A Local To Global Perspective, Juan I. Rattalino Edreira, Nicolas Guilpart, Victor Sadras, Kenneth G. Cassman, Martin K. Van Ittersum, Rene L.M. Schils, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Water productivity (WP) is a robust benchmark for crop production in relation to available water supply across spatial scales. Quantifying water-limited potential (WPw) and actual on-farm (WPa) WP to estimate WP gaps is an essential first step to identify the most sensitive factors influencing production capacity with limited water supply. This study combines local weather, soil, and agronomic data, and crop modeling in a spatial framework to determine WPw and WPa at local and regional levels for rainfed cropping systems in 17 (maize) and 18 (wheat) major grain-producing countries representing a wide range of cropping systems, from intensive, highyield maize …

Wheat Streak Mosaic Virus Coat Protein Is A Host-Specific Long-Distance Transport Determinant In Oat, Satyanarayana Tatineni

Department of Plant Pathology: Faculty Publications

Viral determinants involved in systemic infection of hosts by monocot-infecting plant viruses are poorly understood. Wheat streak mosaic virus (WSMV, genus Tritimovirus, family Potyviridae) exclusively infects monocotyledonous crops such as wheat, oat, barley, maize, triticale, and rye. Previously, we reported that WSMV CP amino acids 36–84 are expendable for systemic infection of wheat, maize, barley and rye. In this study, the role of coat protein (CP) in systemic infection of oat by WSMV was examined by using a series of viable deletion mutants. WSMV bearing deletions within or encompassing all of amino acids 36–57 efficiently infected oat, indicating that …

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 …

Reducing The Potential For Acrylamide Formation In Wheat Products, Amy Hauver, P. Stephen Baenziger, Mary J. Guttieri

UCARE Research Products

Acrylamide, a chemical formed from free asparagine and reducing sugars during high-temperature cooking via the Maillard reaction (i.e. frying or baking) of high starch foods is deemed ‘probably carcinogenic to humans’ based on its affect in mice. In April of 2002, a group of Swedish researchers reported findings that presented evidence that heat-treated, starch-rich foods contained high levels of acrylamide, later linking the production of acrylamide to the Maillard reaction. A number of other studies have been done to link dietary intake of acrylamide to human cancers and other health effects, although many have had inconclusive results. Nevertheless, the World …

Impact Of Derived Global Weather Data On Simulated Crop Yields, Justin Van Wart, Patricio Grassini, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Crop simulation models can be used to estimate impact of current and future climates on crop yields and food security, but require long-term historical daily weather data to obtain robust simulations. In many regions where crops are grown, daily weather data are not available. Alternatively, gridded weather databases (GWD) with complete terrestrial coverage are available, typically derived from: (i) global circulation computer models; (ii) interpolated weather station data; or (iii) remotely sensed surface data from satellites. The present study’s objective is to evaluate capacity of GWDs to simulate crop yield potential (Yp) or water-limited yield potential (Yw), which can serve …

Potential For Crop Production Increase In Argentina Through Closure Of Existing Yield Gaps, Fernando Aramburu Merlos, Juan Pablo Monzon, Jorge L. Mercau, Miguel Taboada, Fernando H. Andrade, Antonio J. Hall, Esteban Jobbagy, Kenneth Cassman, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Favorable climate and soils for rainfed crop production, together with a relatively low population density,results in 70–90% of Argentina grain production being exported. No assessment to date has tried to estimate the potential for extra grain production for soybean, wheat and maize, which account for 78%of total harvested area, by yield gap closure on existing cropland area and its impact at a global scale.The objectives of this paper are (i) to estimate how much additional grain could be produced without expanding crop area by closing yield gaps in Argentina, (ii) to investigate how this production and yield gaps varies across …

Population Dynamics Of Triticum Mosaic Virus In Various Host Species, Melissa S. Bartels

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

It has been established that RNA viruses should be genetically diverse, due to the high error rate of their RNA-dependent RNA polymerases and the lack of proof-reading capabilities. Plant RNA viruses are not as genetically diverse as expected. Evolutionary factors, such as purifying selection and bottlenecks that favor genetic stability, might be affecting plant viral populations. Otherwise RNA virus populations, with their potential for extreme diversity, might acquire a lethal number of mutations leading to the collapse of the population.

Triticum mosaic virus (TriMV) populations maintained in a controlled greenhouse environment displayed genetic stability. The mutation frequency per nucleotide of …

Nutrient Partitioning And Grain Yield Of Tanam-Rnai Wheat Under Abiotic Stress, Mary J. Guttieri, Ricardo J. Stein, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Aims — Decreased expression of TaNAM genes by RNAi results in delayed senescence and decreased grain protein, iron, and zinc concentrations. Here, we determined whether NAM expression level alters onset of senescence under stress conditions, whether delayed senescence in the TaNAM-RNAi line resulted in improved tolerance to post-anthesis abiotic stress, and determined the effects of post-anthesis abiotic stress on N and mineral remobilization and partitioning to grain.

Methods — Greenhouse-grown WT and TaNAM-RNAi wheat were characterized in two studies: three levels of N fertility or water limitation during grain fill. Studies were conducted under both optimal and heat stress …

Estimating Crop Yield Potential At Regional To National Scales, Justin Van Wart, Kurt Christian Kersebaum, Shaobing Peng, Maribeth Milner, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

World population will increase 35% by 2050, which may require doubling crop yields on existing farm land to minimize expansion of agriculture into remaining rainforests, wetlands, and grasslands. Whether this is possible depends on closing the gap between yield potential (Yp, yield without pest, disease, nutrient or water stresses, or Yw under water-limited rainfed conditions) and current average farm yields in both developed and developing countries. Quantifying the yield gap is therefore essential to inform policies and prioritize research to achieve food security without environmental degradation. Previous attempts to estimate Yp and Yw at a global level have been too …

Modulation Of Kernel Storage Proteins In Grain Sorghum (Sorghum Bicolor (L.) Moench), Tejinder Kumar, Ismail M. Dweikat, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Han Chen, Thomas Elthon, Scott Bean, Brian P. Ioerger, Mike Tilley, Thomas E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Sorghum prolamins, termed kafirins, are categorized into subgroups α, β, and γ. The kafirins are co-translationally translocated to the endoplasmic reticulum (ER) where they are assembled into discrete protein bodies that tend to be poorly digestible with low functionality in food and feed applications. As a means to address the issues surrounding functionality and digestibility in sorghum, we employed a biotechnology approach that is designed to alter protein body structure, with the concomitant synthesis of a co-protein in the endosperm fraction of the grain. Wherein perturbation of protein body architecture may provide a route to impact digestibility by reducing disulphide …

Comparing Cropping System Productivity Between Fixed Rotations And A Flexible Fallow System Using Modeling And Historical Weather Data In The Semi-Arid Central Great Plains, Juan Jose Miceli-Garcia

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

In the Central Great Plains, the predominant crop rotation is winter wheat (Triticum aestivum L.)-fallow. Producers are looking to add diversity and intensity to their cropping systems by adding summer crops, however, the elimination of summer fallow may increase crop production risk. The objective of this study was to use crop simulation modeling to compare the productivity of two fixed rotations [winter wheat-corn (Zea mays L.)-fallow and winter wheat-corn-spring triticale (X Triticosecale Wittmack)] with simulated flexible fallow rotations. The flexible fallow rotations made the decision to plant triticale or use summer fallow prior to winter wheat seeding based …

Fusarium Head Blight: Winter Wheat Cultivar Responses And Characterization Of Pathogen Isolates, John Fredy Hernandez Nopsa

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

Fusarium head blight (FHB) is a destructive disease of wheat (Triticum aestivum L). FHB reduces yield and grain quality and causes accumulation of the mycotoxin deoxynivalenol (DON) in grain. Cultivar resistance is one of the most effective management strategies for FHB. Experiments were conducted to 1) identify winter wheat cultivars with resistance to FHB and DON accumulation, 2) determine the effect of winter wheat cultivar on the relationship between FHB and DON concentration, and 3) identify the major species of Fusarium causing FHB in Nebraska and characterize its isolates. Differences (P ≤ 0.05) were detected among cultivars in FHB …

Grain Yield And Yield-Related Qtl Validation Using Reciprocal Recombinant Inbred Chromosome Lines In Wheat, Neway C. Mengistu

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

Grain yield and yield-related traits are the most important economic factors for bread wheat (Triticum aestivum L.) improvement. Grain yield (GYLD) and yield-related quantitative trait loci (QTLs) were previously identified by using a population of recombinant inbred chromosome lines (RICLs) developed from cultivar ‘Cheyenne’ (CNN) and its substitution line CNN(WI3A), where the 3A chromosome of cultivar ‘Wichita’ (WI) was substituted for the CNN chromosome 3A. The objectives of this study were to identify and validate GYLD and yield-related QTLs previously identified in CNN(RICLs-3A) studies by using the mirror population WI(RICLs-3A), where chromosome 3A of CNN and WI were now …