Other Plant Sciences Commons^™

Ponderosa Pine Regeneration,Wildland Fuels Management, And Habitat Conservation: Identifying Trade-Offs Following Wildfire, Victoria M. Donovan, Caleb P. Roberts, Carissa L. Wonkka, David A. Wedin, Dirac L. Twidwell

Department of Agronomy and Horticulture: Faculty Publications

Increasing wildfires in western North American conifer forests have led to debates surrounding the application of post-fire management practices. There is a lack of consensus on whether (and to what extent) post-fire management assists or hinders managers in achieving goals, particularly in under-studied regions like eastern ponderosa pine forests. This makes it difficult for forest managers to balance among competing interests. We contrast structural and community characteristics across unburned ponderosa pine forest, severely burned ponderosa pine forest, and severely burned ponderosa pine forest treated with post-fire management with respect to three management objectives: ponderosa pine regeneration, wildland fuels control, and …

Flue Gas Desulfurization Gypsum As Soil Amendment, Dinesh Panday, Richard Ferguson, Bijesh Maharjan

Department of Agronomy and Horticulture: Faculty Publications

Flue gas desulfurization (FGD) gypsum is one of the by-products of a coal-fired power generation plant. Coal is the world’s most abundant and widely distributed fossil fuel. After natural gas, coal is the second primary source of energy to generate electricity globally (more than 25%) and remains a key component of the fuel mix for power generation to meet electricity demand in most of the developing countries. The U.S., China and India are the top coal producers and consumers (for production of electricity from coal sources) in the world (OECD/IEA, 2014; IEA, 2016). However, in the U.S., its contribution to …

A Key Variant In The Cis-Regulatory Element Of Flowering Gene Ghd8 Associated With Cold Tolerance In Rice, Peng Wang, Yin Xiong, Rong Gong, Ying Yang, Kai Fan, Sibin Yu

Department of Agronomy and Horticulture: Faculty Publications

Variations in the gene promoter play critical roles in the evolution of important adaptive traits in crops, but direct links of the regulatory mutation to the adaptive change are not well understood. Here, we examine the nucleotide variations in the promoter region of a transcription factor (Ghd8) that control grain number, plant height and heading date in rice. We find that a dominant promoter type of subspecies japonica displayed a high activity for Ghd8 expression in comparison with the one in indica. Transgenic analyses revealed that higher expression levels of Ghd8 delayed heading date and enhanced cold …

Developments In Agricultural Soil Quality And Health: Reflections By The Research Committee On Soil Organic Matter Management, Michelle M. Wander, Larry J. Cihacek, Mark Coyne, Rhae A. Drijber, Julie M. Grossman, Jessica L. M. Gutknecht, William R. Horwath, Sindhu Jagadamma, Daniel C. Olk, Matt Ruark, Sieglinde S. Snapp, Lisa K. Tiemann, Ray Well, Ronald F. Turco

Department of Agronomy and Horticulture: Faculty Publications

The North Central Education and Research Activity Committee (NCERA-59) was formed in 1952 to address how soil organic matter formation and management practices affect soil structure and productivity. It is in this capacity that we comment on the science supporting soil quality and associated soil health assessment for agricultural lands with the goal of hastening progress in this important field. Even though the suite of soil quality indicators being applied by U.S. soil health efforts closely mirrors the “minimum data set” we developed and recommended in the mid-1990s, we question whether the methods or means for their selection and development …

A Tmeff2-Regulated Cell Cycle Derived Gene Signature Is Prognostic Of Recurrence Risk In Prostate Cancer, Constantin Georgescu, Joshua M. Corbin, Sandra Thibivilliers, Zachary D. Webb, Yan D. Zhao, Jan Koster, Kar-Ming Fung, Adam S. Asch, Jonathan D. Wren, Maria J. Ruiz-Echevarria

Department of Agronomy and Horticulture: Faculty Publications

Background: The clinical behavior of prostate cancer (PCa) is variable, and while the majority of cases remain indolent, 10% of patients progress to deadly forms of the disease. Current clinical predictors used at the time of diagnosis have limitations to accurately establish progression risk. Here we describe the development of a tumor suppressor regulated, cell-cycle gene expression based prognostic signature for PCa, and validate its independent contribution to risk stratification in several radical prostatectomy (RP) patient cohorts.

Methods: We used RNA interference experiments in PCa cell lines to identify a gene expression based gene signature associated with Tmeff2, an …

Impact Of Hurricane Katrina On The Coastal Systems Of Southern Louisiana, Wen-Ching Chuang, Tarsha Eason, Ahjond Garmestani, Caleb Roberts

Department of Agronomy and Horticulture: Faculty Publications

Natural disasters, such as hurricanes and forest fires, could trigger collapse and reorganization of social-ecological systems. In the face of external perturbations, a resilient system would have capacity to absorb impacts, adapt to change, learn, and if needed, reorganize within the same regime. Within this context, we asked how human and natural systems in Louisiana responded to Hurricane Katrina, and how the natural disaster altered the status of these systems. This paper discusses community resilience to natural hazards and addresses the limitations for assessing disaster resilience. Furthermore, we assessed social and environmental change in New Orleans and southern Louisiana through …

Genome-Wide Association Study For Multiple Biotic Stress Resistance In Synthetic Hexaploid Wheat, Madhav Bhatta, Alexey Morgounov, Vikas Belamkar, Stephen N. Wegulo, Abdelfattah A. Dababat, Gul Erginbas-Orakci, Mustapha El Bouhssini, Pravin Gautam, Jesse Poland, Nilufer Akci, Lutfu Demir, Ruth Wanyera, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Genetic resistance against biotic stress is a major goal in many wheat breeding programs. However, modern wheat cultivars have a limited genetic variation for disease and pest resistance and there is always a possibility of the evolution of new diseases and pests to overcome previously identified resistance genes. A total of 125 synthetic hexaploid wheats (SHWs; 2n = 6x = 42, AABBDD, Triticum aestivum L.) were characterized for resistance to fungal pathogens that cause wheat rusts (leaf; Puccinia triticina, stem; P. graminis f.sp. tritici, and stripe; P. striiformis f.sp. tritici) and crown rot (Fusarium spp.); …

Expression Of The Arabidopsis Wrinkled 1 Transcription Factor Leads To Higher Accumulation Of Palmitate In Soybean Seed, Pamela A. Vogel, Shen Bayon De Noyer, Hyunwoo Park, Hanh Nguyen, Lili Hou, Taity Changa, Hoang Le Khang, Ozan N. Ciftci, Tong Wang, Edgar B. Cahoon, Thomas Elmo Clemente

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max [L.] Merr.) is a commodity crop highly valued for its protein and oil content. The high percentage of polyunsaturated fatty acids in soybean oil results in low oxidative stability, which is a key parameter for usage in baking, high temperature frying applications, and affects shelf life of packaged products containing soybean oil. Introduction of a seed-specific expression cassette carrying the Arabidopsis transcription factor WRINKLED1 (AtWRI1) into soybean, led to seed oil with levels of palmitate up to approximately 20%. Stacking of the AtWRI1 transgenic allele with a transgenic locus harbouring the mangosteen steroyl-ACP thioesterase (GmFatA) resulted …

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …

Predicting Soil Wind Erosion Potential Under Different Corn Residue Management Scenarios In The Central Great Plains, M. K. Rakkar, Humberto Blanco-Canqui, J. Tatarko

Department of Agronomy and Horticulture: Faculty Publications

Various models and simplified equations are available to predict wind erosion potential. However, their performance can be often site-specific, depending on soil characteristics and agronomic practices, warranting sitespecific model validations. Thus, in this study, we 1) validated the wind erodible fraction (WEF) predictive equations by Fryrear et al. (1994) and López et al. (2007) and 2) estimated the total soil loss with the Singleevent Wind Erosion Evaluation Program (SWEEP) using 3-yr measured data from six experiments located across a precipitation gradient in the central Great Plains. Each site had three corn (Zea mays L.) residue removal treatments: control (no …

Molecular Marker Dissection Of Stem Rust Resistance In Nebraska Bread Wheat Germplasm, Amira M. I. Mourad, Ahmed Sallam, Vikas Belamkar, Stephen Wegulo, Guihua Bai, Ezzat Mahdy, Bahy Bakheit, Atif Abo El-Wafa, Yue Jin, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Stem rust (caused by Puccinia graminis f. sp. tritici) is a major disease of wheat. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, a set of 330 genotypes representing two nurseries (DUP2015 and TRP2015) were evaluated for resistance to a Nebraska stem rust race (QFCSC) in two replications. The TRP2015 nursery was also evaluated for its resistance to an additional 13 stem rust races. The analysis of variance revealed significant variation among genotypes in both populations for stem rust resistance. Nine stem rust genes, Sr6, Sr31, Sr1RS^Amigo, Sr24, Sr36 …

Utilizing Trait Networks And Structural Equation Models As Tools To Interpret Multi‑Trait Genome‑Wide Association Studies, Mehdi Momen, Malachy T. Campbell, Harkamal Walia, Gota Morota

Department of Agronomy and Horticulture: Faculty Publications

Background: Plant breeders seek to develop cultivars with maximal agronomic value, which is often assessed using numerous, often genetically correlated traits. As intervention on one trait will affect the value of another, breeding decisions should consider the relationships among traits in the context of putative causal structures (i.e., trait networks). While multi-trait genome-wide association studies (MTM-GWAS) can infer putative genetic signals at the multivariate scale, standard MTM-GWAS does not accommodate the network structure of phenotypes, and therefore does not address how the traits are interrelated. We extended the scope of MTM-GWAS by incorporating trait network structures into GWAS using structural …

Identification Of Quantitative Trait Loci For Plant Height, Crown Diameter, And Plant Biomass In A Pseudo-F2 Population Of Switchgrass, Megan Taylor, Carl-Erik Tornqvist, Xiongwei Zhao, R. W. Doerge, Michael D. Casler, Yiwei Jiang

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum) is a perennial warm-season grass that produces high biomass yield. Identification of mechanisms for genetic regulation of biomass traits has potential to facilitate genetic manipulation of switchgrass for enhancing biomass yield. The objective of this study was to identify quantitative trait loci for biomass-related traits in a pseudo-F₂ population of switchgrass derived from an upland cross with a lowland switchgrass cultivar. Plant height (HT), crown diameter (CD), and plant biomass (PB) were assessed in field studies in 2015 and 2016. Plant height was positively correlated with PB in both years but only correlated with …

Selection Of Bread Wheat For Low Grain Cadmium Concentration At The Seedling Stage Using Hydroponics Versus Molecular Markers, Caixia Liu, Mary J. Guttieri, Brian M. Waters, Kent M. Eskridge, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

The excessive accumulation of Cd in harvested crops grown on high-Cd soils has increased public concerns for food safety. Due to the high consumption of bread wheat (Triticum aestivum L.) per capita, high concentrations of Cd in wheat grain can significantly affect human health. Breeding is a promising way to reduce grain Cd concentration. However, a lack of efficient selection methods impedes breeding for low grain Cd concentration in bread wheat. In this study, a recombinant inbred population segregating for grain Cd concentration was used to assess the efficacy of two selection methods for decreasing grain Cd concentration in …

Joint Use Of Genome, Pedigree, And Their Interaction With Environment For Predicting The Performance Of Wheat Lines In New Environments, Réka Howard, Daniel Gianola, Osval Montesinos-Lopez, Philomin Juliana, Ravi Singh, Jesse Poland, Sandesh Shrestha, Paulino Pérez-Rodriguez, José Crossa, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

Genome-enabled prediction plays an essential role in wheat breeding because it has the potential to increase the rate of genetic gain relative to traditional phenotypic and pedigree-based selection. Since the performance of wheat lines is highly influenced by environmental stimuli, it is important to accurately model the environment and its interaction with genetic factors in prediction models. Arguably, multi-environmental best linear unbiased prediction (BLUP) may deliver better prediction performance than single-environment genomic BLUP. We evaluated pedigree and genome-based prediction using 35,403 wheat lines from the Global Wheat Breeding Program of the International Maize and Wheat Improvement Center (CIMMYT). We implemented …

A World Of Cobenefits: Solving The Global Nitrogen Challenge, Benjamin Z. Houlton, Maya Almaraz, Viney Aneja, Amy T. Austin, Edith Bai, Kenneth G. Cassman, Jana E. Compton, Eric A. Davidson, Jan Willem Erisman, James N. Galloway, Baojing Gu, Guolin Yao, Luiz A. Martinelli, Kate Scow, William H. Schlesinger, Thomas P. Tomich, Chao Wang, Xin Zhang

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen is a critical component of the economy, food security, and planetary health. Many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for (i) world hunger; (ii) soil, air, and water quality; (iii) climate change mitigation; and (iv) biodiversity conservation. Balancing the projected rise in agricultural nitrogen demands while achieving these 21st century ideals will require policies to coordinate solutions among technologies, consumer choice, and socioeconomic transformation.

Optimum Droplet Size Using A Pulse-Width Modulation Sprayer For Applications Of 2,4-D Choline Plus Glyphosate, Thomas R. Butts, Chase A. Samples, Lucas X. Franca, Darrin M. Dodds, Daniel B. Reynolds, Jason W. Adams, Richard K. Zollinger, Kirk A. Howatt, Bradley K. Fritz, W. Clint Hoffmann, Joe D. Luck, Greg Kruger

Department of Agronomy and Horticulture: Faculty Publications

The delivery of an optimum herbicide droplet size using pulse-width modulation (PWM) sprayers can reduce potential environmental contamination, maintain efficacy, and provide more flexible options for pesticide applicators. Field research was conducted in 2016, 2017, and 2018 across three locations (Mississippi, Nebraska, and North Dakota) for a total of 6 site-years. The objectives were to evaluate the efficacy of a range of droplet sizes (150 μm [Fine] to 900 μm [Ultra Coarse]) using a 2,4-D choline plus glyphosate pre-mixture and to create novel weed management recommendations using PWM sprayer technology. A pooled site-year generalized additive model explained less than 5% …

Benchmarking Irrigation Water Use In Producer Fields In The Us Central Great Plains, Katherine E. B. Gibson, Justin E. Gibson, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Efficient use of freshwater resources is necessary to balance food production and long-term sustainability of irrigated agricultural systems. Here we developed a framework to benchmark irrigation water use relative to crop yield for individual fields based on site-specific weather and soil. Subsequently, we used the framework to diagnose on-farm irrigation management, in relation to crop production, in maize and soybean producer fields in Nebraska (USA).We found actual irrigation to be similar to estimated irrigation water requirement in about half of the fields (i.e. small water surplus). Remarkably, these fields attained yields similar to fields where actual irrigation exceeded water requirements …

Comparing Infiltration Rates In Soils Managed With Conventional And Alternative Farming Methods: A Meta-Analysis, Andrea D. Basche, Marcia S. Delonge

Department of Agronomy and Horticulture: Faculty Publications

Identifying agricultural practices that enhance water cycling is critical, particularly with increased rainfall variability and greater risks of droughts and floods. Soil infiltration rates offer useful insights to water cycling in farming systems because they affect both yields (through soil water availability) and other ecosystem outcomes (such as pollution and flooding from runoff). For example, conventional agricultural practices that leave soils bare and vulnerable to degradation are believed to limit the capacity of soils to quickly absorb and retain water needed for crop growth. Further, it is widely assumed that farming methods such as no-till and cover crops can improve …

History Of Grass Breeding For Grazing Lands In The Northern Great Plains Of The Usa And Canada, Kenneth P. Vogel, John Hendrickson

Department of Agronomy and Horticulture: Faculty Publications

• In the early 1930s there were millions of acres of extensively degraded grazing lands and abandoned and eroded cropland in the Northern Plains of the United States and Canada.

• Grass breeding and plant materials programs were established by both the US and Canadian governments and cooperating universities to develop revegetation materials.

• Efforts of a small number of research locations and people resulted in grass cultivars or varieties that were used to revegetate and preserve the soil on millions of acres of land.

• This is a brief history of the people, agencies, and universities that developed these …