Agricultural Science Commons^™

Estimation Of Irrigation Requirements For Drip-Irrigated Maize In A Sub-Humid Climate, Liu Yang, Hai-Shun Yang, Jiu-Sheng Li, Yan-Feng Li, Hai-Jun Yan

Department of Agronomy and Horticulture: Faculty Publications

Drip-irrigation is increasingly applied in maize (Zea mays L.) production in sub-humid region. It is critical to quantify irrigation requirements during different growth stages under diverse climatic conditions. In this study, the Hybrid-Maize model was calibrated and applied in a sub-humid Heilongjiang Province in Northeast China to estimate irrigation requirements for drip irrigated maize during different crop physiological development stages and under diverse agro-climatic conditions. Using dimensionless scales, the whole growing season of maize was divided into diverse development stages from planting to maturity. Drip-irrigation dates and irrigation amounts in each irrigation event were simulated and summarized in 30-year simulation …

Identifying Ecologically Relevant Scales Of Habitat Selection: Diel Habitat Selection In Elk, Caleb P. Roberts, James W. Cain Iii, Robert D. Cox

Department of Agronomy and Horticulture: Faculty Publications

Although organisms make resource selection decisions at multiple spatiotemporal scales, not all scales are ecologically relevant to any given organism. Ecological patterns and rhythms such as behavioral and climatic patterns may provide a consistent method for identifying ecologically relevant scales of habitat selection. Using elk (Cervus canadensis) as an example species, we sought to test the ability of behavioral patterns to empirically partition diel scales for modeling habitat selection. We used model selection to partition diel scales by shifts in dominant behavior and then used resource selection probability functions to model elk habitat selection hierarchically at diel scales within seasons. …

Effects Of Nitrogen And Phosphorus Fertilizer And Topsoil Amendment On Native Plant Cover In Roadside Revegetation Projects, Heidi L. Hillhouse, Walter H. Schacht, Jonathan M. Soper, Carol E. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction (“cut-slope soils”) is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warmseason grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and …

Control Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Glufosinate-Resistant Soybean [Glycine Max (L.) Merr], Ethann R. Barnes, Stevan Z. Knezevic, Peter H. Sikkema, John L. Lindquist, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Common ragweed emerges early in the season in Nebraska, USA and is competitive with soybean; therefore, preplant herbicides are important for effective control. Glyphosate has been used as a preplant control option; however, confirmation of glyphosate-resistant (GR) common ragweed in Nebraska necessitates evaluating other herbicide options. The objectives of this study were to (1) evaluate the efficacy of preplant (PP) herbicides followed by (fb) glufosinate alone or in tank-mixture with imazethapyr, acetochlor, or S-metolachlor applied post-emergence (POST) for control of GR common ragweed in glufosinate-resistant soybean; (2) their effect on common ragweed density, biomass, and soybean yield; and (3) the …

Impact Of Seed Protein Alleles From Three Soybean Sources On Seed Composition And Agronomic Traits, Lillian F. Brzostowski, Timothy I. Pruski, James Specht, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of seed protein alleles in soybean populations showed that an increase in protein concentration is generally associated with a decrease in oil concentration and yield.

Soybean [Glycine max (L.) Merrill] meal is one of the most important plant-based protein sources in the world. Developing cultivars high in seed protein concentration and seed yield is a difficult task because the traits have an inverse relationship. Over two decades ago, a protein quantitative trait loci (QTL) was mapped on chromosome (chr) 20, and this QTL has been mapped to the same position in several studies and given the confirmed QTL …

Molecular And Culture-Based Assessment Of Root/Crown Rot Fungal/Oomycete Complex Of Bean In Mozambique, Suzana Vanessa Ismael Fernandes

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

Dry edible beans (Phaseolus vulgaris) play an important role in food security, alleviating hunger and malnutrition and adding value to the economy in Mozambique. Recently, root/crown rot (RCR) has caused yield losses in bean fields in Mozambique. A diverse taxa of fungi and oomycetes have been associated with RCR. However, in Mozambique little information on root rot is available. The purpose of this study is to use Illumina sequencing platform, polymerase chain reaction (PCR) and culture-based methods to identify the primary pathogens associated with RCR in Mozambique. A total of 88 plants showing symptoms of RCR disease were …

Protocol For Enrichment Of The Membrane Proteome Of Mature Tomato Pollen, Puneet Paul, Palak Chaturvedi, Anida Mesihovic, Arindam Ghatak, Wolfram Weckwerth, Enrico Schleiff

Department of Agronomy and Horticulture: Faculty Publications

We established and elaborated on a method to enrich the membrane proteome of mature pollen from economically relevant crop using the example of Solanum lycopersicum (tomato). To isolate the pollen protein fraction enriched in membrane proteins, a high salt concentration (750 mM of sodium chloride) was used. The membrane protein-enriched fraction was then subjected to shotgun proteomics for identification of proteins, followed by in silico analysis to annotate and classify the detected proteins.

Transcriptomic Resources For The Medicinal Legume Mucuna Pruriens: De Novo Transcriptome Assembly, Annotation, Identification And Validation Of Est-Ssr Markers, N. Sathyanarayana, Ranjith Kumar Pittala, Pankaj Kumar Tripathi, Ratan Chopra, Heikham Russiachand Singh, Vikas Belamkar, Pardeep Kumar Bhardwaj, Jeff J. Doyle, Ashley N. Egan

Department of Agronomy and Horticulture: Faculty Publications

Background:

The medicinal legume Mucuna pruriens (L.) DC. has attracted attention worldwide as a source of the anti-Parkinson’s drug L-Dopa. It is also a popular green manure cover crop that offers many agronomic benefits including high protein content, nitrogen fixation and soil nutrients. The plant currently lacks genomic resources and there is limited knowledge on gene expression, metabolic pathways, and genetics of secondary metabolite production. Here, we present transcriptomic resources for M. pruriens, including a de novo transcriptome assembly and annotation, as well as differential transcript expression analyses between root, leaf, and pod tissues. We also develop microsatellite markers …

A Comprehensive Analysis Of Alternative Splicing In Paleopolyploid Maize, Wenbin Mei, Sanzhen Liu, James C. Schnable, Cheng-Ting Yeh, Nathan M. Springer, Patrick S. Schnable, William Brad Barbazuk

Department of Agronomy and Horticulture: Faculty Publications

Identifying and characterizing alternative splicing (AS) enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level …

Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani

Department of Geography: Dissertations, Theses, and Student Research

The gross primary production (GPP) metric is useful in determining trends in the terrestrial carbon cycle. Models that determine GPP utilizing the light use efficiency (LUE) approach in conjunction with biophysical parameters that account for local weather conditions and crop specific factors are beneficial in that they combine the accuracy of the biophysical model with the versatility of the LUE model. One such model developed using in situ data was adapted to operate with remote sensing derived leaf area index (LAI) data and gridded weather datasets. The model, known as the Light Use Efficiency GPP Model (EGM), uses a four …

Emergence, Competition, And Management Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Nebraska Soybean, Ethann R. Barnes

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

Common ragweed (Ambrosia artemisiifolia L.) is a competitive annual broadleaf weed in soybean (Glycine max) production fields throughout North America. The recent confirmation of glyphosate-resistant common ragweed in Nebraska justified the need to assess the emergence pattern and competitive ability of common ragweed in soybean and to evaluate alternative herbicide programs for effective management. The objectives of this research were to: 1) evaluate the effect of tillage and develop a predictive model for the emergence pattern of common ragweed in Nebraska; 2) model the competitive interaction between soybean and common ragweed as influenced by density and irrigation …

Proceedings Of The 44th Annual Meeting, Southern Soybean Disease Workers (March 8-9, 2017, Pensacola Beach, Florida), Terry Spurlock, Trey Price, Heather M. Kelly, Danise Beadle, Patricia Bollich, Tom Allen

Southern Soybean Disease Workers: Conference Proceedings

Contents

Agenda for March 8-9, 2017

Contributed papers

Soybean cyst nematode: current status, challenges and opportunities. G Tylka and K Bissonnette

Updates of the 2nd SCN (Soybean Cyst Nematode) Coalition. Albert Tenuta

Developing management zones for nematodes in soybean. C Overstreet, EC McGawley, DM Xavier-Mis, and M Kularathna

Microbial communities associated with long-term tillage and fertilizer management practices. AY Srour, J Hackman, RL Cook, JP Bond, and AM Fakhoury

Microbial profile of SDS-suppressive soils in soybean fields. AY Srour, LFS Leonardo, DK Malvick, JP Bond, and AM Fakhoury

Understanding the phytobiome; using strip trials and spatial analysis to determine concomitant …

The Lx Report Of The Bean Improvement Cooperative No. 60, March 2017.

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

CONTENTS

LX Annual Report of the Bean Improvement Cooperative xi

BIC Coordinating Committee Membership - 1957 to 2017 . xii

BIC Meritorious Service and Distinguished Achievement Award Recipients - 1957 to 2015 xiii

BIC Awards Nomination Request for 2017 xvi

BIC/NAPIA Meeting in 2017 . xix

In Memory of Guillermo E. Galvez-Enriquez xx

RESEARCH PAPERS FOR 2017

OPTIMIZING SPORULATION OF Pseudocercospora griseola IN VITRO • Paula F. de Pádua1, Rafael Pereira1, Luanna B. W. Gomes1 and Elaine A. de Souza1* 1

FINE MAPPING THE BROAD SPECTRUM ANTHRACNOSE RESISTANCE GENE IN AMENDOIM CAVALO 3 • Gilio, T.A.S.1, Oscar P. Hurtado-Gonzales2, Giseli …

Towards The Development Of A Sustainable Soya Bean-Based Feedstock For Aquaculture, Hyunwoo Park, Steven Weier, Fareha Razvi, Pamela A. Peña, Neil A. Sims, Jennica Lowell, Cory Hungate, Karma Kissinger, Gavin Key, Paul Fraser, Jonathan Napier, Edgar B. Cahoon, Thomas Clemente

Center for Plant Science Innovation: Faculty Publications

Soya bean (Glycine max (L.) Merr.) is sought after for both its oil and protein components. Genetic approaches to add value to either component are ongoing efforts in soya bean breeding and molecular biology programmes. The former is the primary vegetable oil consumed in the world. Hence, its primary usage is in direct human consumption. As a means to increase its utility in feed applications, thereby expanding the market of soya bean coproducts, we investigated the simultaneous displacement of marine ingredients in aquafeeds with soya bean-based protein and a high Omega-3 fatty acid soya bean oil, enriched with alpha-linolenic …

Corn Residue Use By Livestock In The United States, Marty R. Schmer, Rachael M. Brown, Virginia L. Jin, Robert B. Mitchell, Daren D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) residue grazing or harvest provides a simple and economical practice to integrate crops and livestock, but limited information is available on how widespread corn residue utilization is practiced by US producers. In 2010, the USDA Economic Research Service surveyed producers from 19 states on corn grain and residue management practices. Total corn residue grazed or harvested was 4.87 million ha. Approximately 4.06 million ha was grazed by 11.7 million livestock (primarily cattle) in 2010. The majority of grazed corn residue occurred in Nebraska (1.91 million ha), Iowa (385,000 ha), South Dakota (361,000 ha), and Kansas …

A Comprehensive Image-Based Phenomic Analysis Reveals The Complex Genetic Architecture Of Shoot Growth Dynamics In Rice (Oryza Sativa), Malachy T. Campbell, Qian Du, Kan Liu, Chris J. Brien, Bettina Berger, Chi Zhang, Harkamal Walia

Agronomy & Horticulture -- Faculty Publications

Early vigor is an important trait for many rice (Oryza sativa L.)- growing environments. However, genetic characterization and improvement for early vigor is hindered by the temporal nature of the trait and strong genotype × environment effects. We explored the genetic architecture of shoot growth dynamics during the early and active tillering stages by applying a functional modeling and genomewide association (GWAS) mapping approach on a diversity panel of ~360 rice accessions. Multiple loci with small effects on shoot growth trajectory were identified, indicating a complex polygenic architecture. Natural variation for shoot growth dynamics was assessed in a subset …

The Role Of Tre6p And Snrk1 In Maize Early Kernel Development And Events Leading To Stress-Induced Kernel Abortion, Samuel W. Bledsoe, Clémence Henry, Cara A. Griffiths, Matthew J. Paul, Regina Feil, John E. Lunn, Mark Stitt, L. Mark Lagrimini

Department of Agronomy and Horticulture: Faculty Publications

Background: Drought stress during flowering is a major contributor to yield loss in maize. Genetic and biotechnological improvement in yield sustainability requires an understanding of the mechanisms underpinning yield loss. Sucrose starvation has been proposed as the cause for kernel abortion; however, potential targets for genetic improvement have not been identified. Field and greenhouse drought studies with maize are expensive and it can be difficult to reproduce results; therefore, an in vitro kernel culture method is presented as a proxy for drought stress occurring at the time of flowering in maize (3 days after pollination). This method is used to …

Changes In Soil Microbial Communities After 10 Years Of Winter Wheat Cultivation Versus Fallow In An Organic-Poor Soil In The Loess Plateau Of China, Hui Tian, Hui Wang, Xiaoli Hui, Zhaohui Wang, Rhae A. Drijber, Jinshan Liu

Department of Agronomy and Horticulture: Faculty Publications

Agricultural management methods, such as cultivation or fallowing, have led to significant changes in soil fertility and hence, crop yield. Such changes may have stemmed from changes in soil microbial communities and associated biogeochemical processes. This phenomenon is particularly true in organic-poor soil in the Loess Plateau of China. In this study, we examined three existing soil management regimes as part of a 10-year field experiment and evaluated their effects on fungal and bacterial community structures by performing high-throughput 454 pyrosequencing. These management regimes were (i) fertilized winter wheat (Triticum aestivum L.) (FW), (ii) continuous natural fallow with weeds …

Mapping And Characterization Of The Fefe Gene That Controls Iron Uptake In Melon (Cucumis Melo L.), Raghuprakash Kastoori Ramamurthy, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) deficiency in plants limits crop growth and productivity. Molecular mechanisms that plants use to sense and respond to Fe deficiency by coordinated expression of Feuptake genes are not fully understood. The C940-fe chlorotic melon (Cucumis melo) mutant known as fefe is unable to upregulate Fe-uptake genes, however, the FeFe gene had not been identified. In this study, we used two F₂ mapping populations to map and identify the FeFe gene as bHLH38, a homolog of subgroup Ib bHLH genes from Arabidopsis thaliana that are involved in transcriptional regulation of Feuptake genes in partnership with the …

Population Structure And Genetic Diversity Of Bromus Tectorum Within The Small Grain Production Region Of The Pacific Northwest, Nevin C. Lawrence, Amber L. Hauvermale, Amit Dhingra, Ian C. Burke

Department of Agronomy and Horticulture: Faculty Publications

Bromus tectorum L. is an invasive winter annual grass naturalized across the United States. Numerous studies have investigated B. tectorum population structure and genetics in the context of B. tectorum as an ecological invader of natural areas and rangeland. Despite the wealth of information regarding B. tectorum, previous studies have not focused on, or made comparisons to, B. tectorum as it persists in individual agroecosystems. The objectives of this study were to assess the genetic diversity and structure, the occurrence of generalist and specialist genotypes, and the influence of climate on distribution of B. tectorum sourced exclusively from within …

A Transcriptome‑Snp‑Derived Linkage Map Of Apios Americana (Potato Bean) Provides Insights About Genome Re‑Organization And Synteny Conservation In The Phaseoloid Legumes, Jugpreet Singh, Scott R. Kalberer, Vikas Belamkar, Teshale Assefa, Matthew N. Nelson, Andrew D. Farmer, William J. Blackmon, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Apios (Apios americana; “apios”), a tuberous perennial legume in the Phaseoleae tribe, was widely used as a food by Native Americans. Work in the last 40 years has led to several improved breeding lines. Aspects of the pollination biology (complex floral structure and tripping mechanism) have made controlled crosses difficult, and the previous reports indicated that the plant is likely primarily an outcrosser. We used a pseudo-testcross strategy to construct a genetic map specific to the maternal parent. The map was built using single-nucleotide polymorphism markers identified by comparing the expressed sequences of individuals in the mapping population …

The Trouble With Cover Crops: Farmers’ Experiences With Overcoming Barriers To Adoption, Gabrielle E. Roesch-Mcnally, Andrea D. Basche, J. G. Arbuckle, John C. Tyndall, Fernando E. Miguez, Troy Bowman, Rebecca Clay

Department of Agronomy and Horticulture: Faculty Publications

Cover crops are known to promote many aspects of soil and water quality, yet estimates find that in 2012 only 2.3% of the total agricultural lands in the Midwestern USA were using cover crops. Focus groups were conducted across the Corn Belt state of Iowa to better understand how farmers confront barriers to cover crop adoption in highly intensive agricultural production systems. Although much prior research has focused on analyzing factors that help predict cover crop use on farms, there is limited research on how farmers navigate and overcome field-level (e.g. proper planting of a cover crop) and structural barriers …

Genetic Diversity Of Danthonia Spicata (L.) Beauv. Based On Genomic Simple Sequence Repeat Markers, Chandra S. Thammina, Keenan Amundsen, Shaun B. Bushman, Matthew H. Kramer, Scott E. Warnke

Department of Agronomy and Horticulture: Faculty Publications

Danthonia spicata (L.) Beauv., commonly known as poverty oatgrass, is a perennial bunch-type grass native to North America. D. spicata is often found in low input turfgrass areas on the East Coast of the United States and has potential for development as a new native low input turfgrass species. Roche 454 sequenced randomly sheared genomic DNA reads of D. spicata were mined for SSR markers using the MIcroSAtellite identification tool. A total of 66,553 singlet sequences (approximately 37.5 Mbp) were examined, and 3454 SSR markers were identified. Trinucleotide motifs with greater than six repeats and possessing unique PCR priming sites …

Molecular And Phenotypic Characterization Of Transgenic Wheat And Sorghum Events Expressing The Barley Alanine Aminotransferase, Pamela A. Peña, Truyen Quach, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Ismail M. Dweikat, Madhavan Soundararajan, Tom Clemente

Department of Agronomy and Horticulture: Faculty Publications

Main conclusion — The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat.

The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic …

Metabolism Of 2,4-Dichlorophenoxyacetic Acid Contributes To Resistance In A Common Waterhemp (Amaranthus Tuberculatus) Population, Marcelo R. A. Figueiredo, Lacy J. Leibhart, Zachary J. Reicher, Patrick J. Tranel, Scott J. Nissen, Philip Westra, Mark L. Bernards, Greg R. Kruger, Todd A. Gaines, Mithila Jugulam

Department of Agronomy and Horticulture: Faculty Publications

BACKGROUND: Synthetic auxins such as 2,4-D have been widely used for selective control of broadleaf weeds since the mid-1940s. In 2009, an Amaranthus tuberculatus (common waterhemp) population with 10-fold resistance to 2,4-D was found in Nebraska, USA. The 2,4-D resistance mechanism was examined by conducting [¹⁴C] 2,4-D absorption, translocation and metabolism experiments.

RESULTS: No differences were found in 2,4-D absorption or translocation between the resistant and susceptible A. tuberculatus. Resistant plants metabolized [¹⁴C] 2,4-D more rapidly than did susceptible plants. The half-life of [¹⁴C] 2,4-D in susceptible plants was 105 h, compared to …

Multisite Evaluation Of Apex For Water Quality: Ii. Regional Parameterization, Nathan O. Nelson, Claire Baffaut, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

Phosphorus (P) Index assessment requires independent estimates of long-term average annual P loss from fields, representing multiple climatic scenarios, management practices, and landscape positions. Because currently available measured data are insufficient to evaluate P Index performance, calibrated and validated process-based models have been proposed as tools to generate the required data. The objectives of this research were to develop a regional parameterization for the Agricultural Policy Environmental eXtender (APEX) model to estimate edgeof- field runoff, sediment, and P losses in restricted-layer soils of Missouri and Kansas and to assess the performance of this parameterization using monitoring data from multiple sites …

Robust Spatial Frameworks For Leveraging Research On Sustainable Crop Intensification, Patricio Grassini, Cameron M. Pittelkow, Kenneth Cassman, Haishun S. Yang, Sotirios Archontoulis, Mark Licht, Kendall R. Lamkey, Ignacio A. Ciampitti, Jeffrey A. Coulter, Sylvie M. Brouder, Jeffrey J. Volenec, Noemi Guindin-Garcia

Department of Agronomy and Horticulture: Faculty Publications

Meeting demand for food, fiber, feed, and fuel in a world with 9.7 billion people by 2050 without negative environmental impact is the greatest scientific challenge facing humanity. We hypothesize that this challenge can only be met with current and emerging technologies if guided by proactive use of a broad array of relevant data and geospatial scaling approaches to ensure local to global relevance for setting research priorities and implementing agricultural systems responsive to real-time status of weather, soils, crops, and markets. Despite increasing availability of field-scale agricultural data, robust spatial frameworks are lacking to convert these data into actionable …

The Effect Of Artificial Selection On Phenotypic Plasticity In Maize, Joseph L. Gage, Diego Jarquin, Cinta Romay, Aaron Lorenz, Edward S. Buckler, Shawn Kaeppler, Naser Alkhalifah, Martin Bohn, Darwin A. Campbell, Jode Edwards, David Ertl, Sherry Flint-Garcia, Jack Gardiner, Byron Good, Candice N. Hirsch, Jim Holland, David C. Hooker, Joseph Knoll, Judith Kolkman, Greg Kruger, Nick Lauter, Carolyn J. Lawrence-Dill, Elizabeth Lee, Jonathan Lynch, Seth C. Murray, Rebecca Nelson, Jane Petzoldt, Torbert Rocheford, James C. Schnable, Patrick S. Schnable, Brian Scully, Margaret Smith, Nathan M. Springer, Srikant Srinivasan, Renee Walton, Teclemariam Weldekidan, Randall J. Wisser, Wenwei Xu, Jianming Yu, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Remarkable productivity has been achieved in crop species through artificial selection and adaptation to modern agronomic practices. Whether intensive selection has changed the ability of improved cultivars to maintain high productivity across variable environments is unknown. Understanding the genetic control of phenotypic plasticity and genotype by environment (G × E) interaction will enhance crop performance predictions across diverse environments. Here we use data generated from the Genomes to Fields (G2F) Maize G × E project to assess the effect of selection on G × E variation and characterize polymorphisms associated with plasticity. Genomic regions putatively selected during modern temperate maize …

Allelic Variants Of Oshkt1;1 Underlie The Divergence Between Indica And Japonica Subspecies Of Rice (Oryza Sativa) For Root Sodium Content, Malachy T. Campbell, Nonoy Bandillo, Fouad Razzaq A. Al Shiblawi, Sandeep Sharma, Kan Liu, Qian Du, Aaron J. Schmitz, Chi Zhang, Anne-Alienor Very, Aaron J. Lorenz, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Salinity is a major factor limiting crop productivity. Rice (Oryza sativa), a staple crop for the majority of the world, is highly sensitive to salinity stress. To discover novel sources of genetic variation for salt tolerance-related traits in rice, we screened 390 diverse accessions under 14 days of moderate (9 dS m^-1) salinity. In this study, shoot growth responses to moderate levels of salinity were independent of tissue Na⁺ content. A significant difference in root Na+ content was observed between the major subpopulations of rice, with indica accessions displaying higher root Na⁺ and japonica …

Jasmonoyl-L-Tryptophan Disrupts Iaa Activity Through The Aux1 Auxin Permease, Paul E. Staswick, Martha Rowe, Edgar P. Spalding, Bessie L. Splitt

Department of Agronomy and Horticulture: Faculty Publications

Amide-linked conjugates between tryptophan (Trp) and jasmonic (JA) or indole-3- acetic (IAA) acids interfered with gravitropism and other auxin-dependent activities in Arabidopsis, but the mechanism was unclear. To identify structural features necessary for activity several additional Trp conjugates were synthesized. The phenylacetic acid (PAA) conjugate was active, while several others were not. Common features of active conjugates is that they have ring structures that are linked to Trp through an acetic acid side chain, while longer or shorter linkages are inactive or less active. A dominant mutant, called tryptophan conjugate response1-D that is insensitive to JA-Trp, but still sensitive …