Digital Commons Network^™

Following Tetraploidy In Maize, A Short Deletion Mechanism Removed Genes Preferentially From One Of The Two Homeologs, Margaret R. Woodhouse, James C. Schnable, Brent S. Pedersen, Eric Lyons, Damon Lisch, Shabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Previous work in Arabidopsis showed that after an ancient tetraploidy event, genes were preferentially removed from one of the two homeologs, a process known as fractionation. The mechanism of fractionation is unknown. We sought to determine whether such preferential, or biased, fractionation exists in maize and, if so, whether a specific mechanism could be implicated in this process. We studied the process of fractionation using two recently sequenced grass species: sorghum and maize. The maize lineage has experienced a tetraploidy since its divergence from sorghum approximately 12 million years ago, and fragments of many knocked-out genes retain enough sequence similarity …

Good Agricultural Practices For Food Safety Of Fresh Produce, Laurie Hodges

Department of Agronomy and Horticulture: Faculty Publications

What are the guiding principles of food safety for fresh produce?

• Once contaminated, removing or killing pathogens on produce is very difficult.

• Preventing microbial contamination at all steps, from production to distribution, is strongly favored over treatments to eliminate contamination that may have occurred.

• Document the implementation of prevention programs, and educate workers at all levels of the agricultural and packing environments on food safety.

Key Signatures of a Credible Food Safety Program

The following is a condensed checklist of practices and conditions that reduce the potential for fresh produce to be exposed to pathogenic microbes. Review …

Artificial Selection For Determinate Growth Habit In Soybean, Zhixi Tian, Xiaobo Wang, Rian Lee, Yinghui Li, James E. Specht, Randall L. Nelson, Phillip E. Mcclean, Lijuan Qiu, Jianxin Ma

Department of Agronomy and Horticulture: Faculty Publications

Determinacy is an agronomically important trait associated with the domestication in soybean (Glycine max). Most soybean cultivars are classifiable into indeterminate and determinate growth habit, whereas Glycine soja, the wild progenitor of soybean, is indeterminate. Indeterminate (Dt1/Dt1) and determinate (dt1/dt1) genotypes, when mated, produce progeny that segregate in a monogenic pattern. Here, we show evidence that Dt1 is a homolog (designated as GmTfl1) of Arabidopsis terminal flower 1 (TFL1), a regulatory gene encoding a signaling protein of shoot meristems. The transition from indeterminate to determinate phenotypes in soybean is associated …

Dryland Performance Of Sweet Sorghum And Grain Crops For Biofuel In Nebraska, Charles S. Wortmann, Adam Liska, Richard B. Ferguson, Drew J. Lyon, R. N. Klein, Ismail M. Dweikat

Department of Agronomy and Horticulture: Faculty Publications

Sweet sorghum [SS; Sorghum bicolor (L.) Moench] is a potential biofuel crop for the Great Plains. Sweet sorghum was compared with corn [Zea mays (L.)] and grain sorghum for potential ethanol yield, energy use effi ciency, and greenhouse gas (GHG) emissions at seven dryland site-years in Nebraska. Seasonal rainfall ranged from approximately 340 to 660 mm. Soils were deep with medium texture at all site-years. Th e eff ects of seeding rate, N rate, and cultivar on SS performance were evaluated. Sweet sorghum sugar yield was not aff ected by seeding rate and N application at six of seven …

Crop Registration: The Pathway To Public Access Of Plant Genetic Materials To Build Crops For The Future, D. D. Ellis, K. A. Garland-Campbell, J. A. Grotenhuis, M. M. Jenderek, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Starting in 1926 and continuing for 80+ yr, 11,241 crop genetic materials have been registered as of 31 Dec. 2008. The crop registration process is an important pathway to publically describe and document new and useful genetic materials and to incorporate these into the public domain via the National Plant Germplasm System (NPGS). Crop Registration materials are now searchable via the Germplasm Resources Information Network (GRIN) and demand for registered materials remains strong with more than 9150 registered accessions distributed in the past 26 yr by the NPGS. Guidelines continue to evolve to accommodate global factors effecting germplasm exchange such …

Rna-Seq Atlas Of Glycine Max: A Guide To The Soybean Transcriptome, Andrew J. Severin, Jenna L. Woody, Yung-Tsi Bolon, Bindu Joseph, Brian W. Diers, Andrew Farmer, Gary J. Muehlbauer, Rex T. Nelson, David Grant, James E. Specht, Michelle A. Graham, Steven B. Cannon, Gregory D. May, Carroll P. Vance, Randy C. Shoemaker

Department of Agronomy and Horticulture: Faculty Publications

Background: Next generation sequencing is transforming our understanding of transcriptomes. It can determine the expression level of transcripts with a dynamic range of over six orders of magnitude from multiple tissues, developmental stages or conditions. Patterns of gene expression provide insight into functions of genes with unknown annotation.

Results: The RNA Seq-Atlas presented here provides a record of high-resolution gene expression in a set of fourteen diverse tissues. Hierarchical clustering of transcriptional profiles for these tissues suggests three clades with similar profiles: aerial, underground and seed tissues. We also investigate the relationship between gene structure and gene expression and find …

Fertilizer Rate Effects On Forage Yield Stability And Nutrient Uptake Of Midland Bermudagrass, John A. Guretzky, Maru K. Kering, Jagadeesh Mosali, Eddie Funderburg, Jon T. Biermacher

Department of Agronomy and Horticulture: Faculty Publications

Our objectives were to document effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizer rates on forage yields and uptake of N, P, and K by Midland bermudagrass [Cynodon dactylon (L.) Pers.] on a Minco fine, sandy loam in southern Oklahoma. After six years of this long-term experiment, forage yield responses to fertilization were mixed and depended on year. Stability analysis indicated forage yields responded positively to N fertilization during favorable weather conditions but negatively during poor weather conditions. Application of 112 kg N ha⁻¹ provided the best yield stability and mean annual forage yield among treatments, …

Evaluation Of The Intercom Model For Predicting Growth Of Forest Herbs, Zorica S. Popović, J. L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

The ecophysiological model INTERCOM was evaluated for its suitability in predicting the growth of perennial forest herbs. A field experiment was conducted to obtain data on photosynthesis and growth parameters of two spring flowering understorey geophytes. Results were used to parameterize the model and its performance was evaluated using the average normalized difference (AE) between predicted and observed biomass and the leaf area index. The model was assumed to provide accurate simulations if the AE was smaller than 0.4. Adjusting the photosynthetic intensity parameters in the model to reflect observed changes in photosynthesis throughout the growing period resulted in the …

Growth And Fitness Components Of Wild × Cultivated Sorghum Bicolor (Poaceae) Hybrids In Nebraska, Lilyrani Sahoo, Jared J. Schmidt, Jeffrey F. Pedersen, Donald Lee, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

• Premise of the study: Gene flow from crops to wild relatives has received considerable attention since the advent of genetically modified crops. Numerous researchers have found wild – crop hybrids to be nearly as fit as their wild parents, which suggests that crop genes may persist in wild populations. Components of the ecological fitness of cultivated sorghum, its wild relative, shattercane, and their hybrids have not been studied.

• Methods: To assess the potential for gene introgression into shattercane, we crossed cultivated sorghum to a single inbred shattercane line to produce F₁ hybrids and measured growth …

Increased Weed Diversity, Density And Above-Ground Biomass In Long-Term Organic Crop Rotations, Samuel E. Wortman, John L. Lindquist, Milton J. Haar, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

While weed management is consistently a top priority among farmers, there is also growing concern for the conservation of biodiversity. Maintaining diverse weed communities below bioeconomic thresholds may provide ecosystem services for the crop and the surrounding ecosystem. This study was conducted to determine if weed diversity, density and biomass differ within and among organic and conventional crop rotations. In 2007 and 2008, we sampled weed communities in four long-term crop rotations near Mead, Nebraska, United States using seedbank analyses (elutriation and greenhouse emergence) and above-ground biomass sampling. Two conventional crop rotations consisted of a corn (Zea mays) …

Influences Of Wind And Sandblasting On The Endangered Blowout Penstemon, James Stubbendieck, Cheryl D. Dunn, Heidi L. Hillhouse, L. M. Landholt

Department of Agronomy and Horticulture: Faculty Publications

Blowout penstemon Penstemon haydenii is a federally endangered species growing only in areas with active wind erosion in sand dunes of the central United States. This early seral species declines as the blowout habitat stabilizes, allowing later seral species to increase. Blowout penstemon populations and plant size declined in the 1990s when precipitation was higher than normal, resulting in reduced sand movement. We conducted a greenhouse experiment to determine whether blowing sand influenced vigor and persistence of blowout penstemon seedlings. Treatments were wind, sandblasting, wind with sandblasting, and a control. The wind treatment was a constant 14 km h^{–1 …}

Soydb: A Knowledge Database Of Soybean Transcription Factors, Zheng Wang, Marc Libault, Trupti Joshi, Babu Valliyodan, Henry T. Nguyen, Dong Xu, Gary Stacey, Jianlin Cheng

Department of Agronomy and Horticulture: Faculty Publications

Background: Transcription factors play the crucial rule of regulating gene expression and influence almost all biological processes. Systematically identifying and annotating transcription factors can greatly aid further understanding their functions and mechanisms. In this article, we present SoyDB, a user friendly database containing comprehensive knowledge of soybean transcription factors.

Description: The soybean genome was recently sequenced by the Department of Energy-Joint Genome Institute (DOE-JGI) and is publicly available. Mining of this sequence identified 5,671 soybean genes as putative transcription factors. These genes were comprehensively annotated as an aid to the soybean research community. We developed SoyDB - a knowledge database …

Inoculation With Arbuscular Mycorrhizal Fungi Or Crop Rotation With Mycorrhizal Plants Improves The Growth Of Maize In Limed Acid Sulfate Soil, Hasao Higo, Katsunori Isobe, Dong-Jin Kang, Kazuhiro Ujie, Rhae A. Drijber, Ryuichi Ishii

Department of Agronomy and Horticulture: Faculty Publications

Arbuscular mycorrhizal fungi (AMF) improve the uptake of immobile mineral nutrients such as phosphate, thereby improving plant growth. In acid sulfate soil (ASS), AMF spore density is generally low which impacts root colonization and phosphate uptake. Thus, inoculation may help increase AMF colonization of crops grown in ASS. AMF spore density decreases after cultivation of a non-host crop or bare fallow. In addition, preceding crops affect the growth and yield of subsequent crops. The production of AMF inocula requires AMF-compatible plants. The objective of the present study is to elucidate the effect of preceding crops on the persistence of inoculated …

Genome Sequence Of The Palaeopolyploid Soybean, Jeremy Schmutz, Steven B. Cannon, Jessica Schlueter, Jianxin Ma, Therese Mitros, William Nelson, David L. Hyten, Qijian Song, Jay J. Thelen, Jianlin Cheng, Dong Xu, Uffe Hellsten, Gregory D. May, Yeisoo Yu, Tetsuya Sakurai, Taishi Umezawa, Madan K. Bhattacharyya, Devinder Sandhu, Babu Valliyodan, Erika Lindquist, Myron Peto, David Grant, Shengqiang Shu, David Goodstein, Kerrie Barry, Montona Futrell-Griggs, Brian Abernathy, Jianchang Du, Zhixi Tian, Liucun Zhu, Navdeep Gill, Trupti Joshi, Marc Libault, Ananad Sethuraman, Xue-Cheng Zhang, Kazuo Shinozaki, Henry T. Nguyen, Rod A. Wing, Perry Cregan, James E. Specht, Jane Grimwood, Dan Rokhsar, Gary Stacey, Randy C. Shoemaker, Scott A. Jackson

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) is one of the most important crop plants for seed protein and oil content, and for its capacity to fix atmospheric nitrogen through symbioses with soil-borne microorganisms. We sequenced the 1.1-gigabase genome by a whole-genome shotgun approach and integrated it with physical and high-density genetic maps to create a chromosome-scale draft sequence assembly. We predict 46,430 protein-coding genes, 70% more than Arabidopsis and similar to the poplar genome which, like soybean, is an ancient polyploid (palaeopolyploid). About 78% of the predicted genes occur in chromosome ends, which comprise less than one-half of the genome but …

Emissions Savings In The Corn-Ethanol Life Cycle From Feeding Coproducts To Livestock, Virgil R. Bremer, Adam Liska, Terry J. Klopfenstein, Galen E. Erickson, Haishun Yang, Daniel T. Walters, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Environmental regulations on greenhouse gas (GHG) emissions from corn (Zea mays L.)-ethanol production require accurate assessment methods to determine emissions savings from coproducts that are fed to livestock. We investigated current use of coproducts in livestock diets and estimated the magnitude and variability in the GHG emissions credit for coproducts in the corn-ethanol life cycle. The coproduct GHG emissions credit varied by more than twofold, from 11.5 to 28.3 g CO₂e per MJ of ethanol produced, depending on the fraction of coproducts used without drying, the proportion of coproduct used to feed beef cattle (Bos taurus …

Factors Affecting The Alkaline Cooking Performance Of Selected Corn And Sorghum Hybrids, Weston B. Johnson, Wajira S. Ratnayake, David S. Jackson, Kyung-Min Lee, Timothy J. Herrman, Scott R. Bean, Stephen Mason

Department of Agronomy and Horticulture: Faculty Publications

Dent com (Zea mays L.) and sorghum (Sorghum hieolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for alkaline cooking performance. The influence of kernel characteristics including hardness, density, starch properties (thermal. pasting, and crystallinity). starch content. protein content. and prolamin content on alkaline cooking performance was also determined. Com nixtamal moisture content was lower for hard, dense kernels with high protein contents; sorghum nixtamal moisture content was lower for kernels with low moisture contents and low starch relative crystallinities. Statistically significant (P < 0.05) regression equations showed that com nixtamal moisture content was influenced by TADD (tangential abrasive dehulling device) index. kernel moisture content. starch content. and protein content; sorghum nixtamal moisture content was influenced by starch relative crystallinity. kernel moisture content, and abrasive hardness index. Pericarp removal was not strongly correlated with kernel characterization tests. Location (environmental) and hybrid (genetic) factors influenced most kernel characteristics and nixtamalization processing variables.

Transgenic Maize Lines With Cell-Type Specific Expression Of Fluorescent Proteins In Plastids, Amir Sattarzadeh, Jonathan Fuller, Salvador Moguel, Katia Wostrikoff, Shirley Sato, Sarah Covshoff, Tom Clemente, Maureen Hanson, David Stern

Department of Agronomy and Horticulture: Faculty Publications

Plastid number and morphology vary dramatically between cell types and at different developmental stages. Furthermore, in C4 plants such as maize, chloroplast ultrastructure and biochemical functions are specialized in mesophyll and bundle sheath cells, which differentiate acropetally from the proplastid form in the leaf base. To develop visible markers for maize plastids, we have created a series of stable transgenics expressing fluorescent proteins fused to either the maize ubiquitin promoter, the mesophyll-specific phosphoenolpyruvate carboxylase (PepC) promoter, or the bundle sheath-specific Rubisco small subunit 1 (RbcS) promoter. Multiple independent events were examined and revealed that maize codon-optimized versions of YFP and …

Fine Mapping Of The Scn Resistance Locus Rhg1-B From Pi 88788, Myungsik Kim, David L. Hyten, Andrew F. Bent, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) is the most economically damaging soybean [Glycine max (L.) Merr.] pest in the USA and genetic resistance is a key component for its control. Although SCN resistance is quantitative, the rhg1 locus on chromosome 18 (formerly known as Linkage Group G) confers a high level of resistance. The objective of this study was to fi ne-map the rhg1-b allele that is derived from plant introduction (PI) 88788. F₂ and F₃ plants and F_3:4 lines from crosses between SCN resistant and susceptible genotypes were tested with genetic markers to …

High-Throughput Snp Discovery And Assay Development In Common Bean, David L. Hyten, Qijian Song, Edward W. Fickus, Charles V. Quigley, Jong-Sung Lim, Ik-Young Choi, Eun-Young Hwang, Marcial Pastor-Corrales, Perry B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Background: Next generation sequencing has significantly increased the speed at which single nucleotide polymorphisms (SNPs) can be discovered and subsequently used as molecular markers for research. Unfortunately, for species such as common bean (Phaseolus vulgaris L.) which do not have a whole genome sequence available, the use of next generation sequencing for SNP discovery is much more difficult and costly. To this end we developed a method which couples sequences obtained from the Roche 454-FLX system (454) with the Illumina Genome Analyzer (GA) for high-throughput SNP discovery. Results: Using a multi-tier reduced representation library we discovered a total of …

Structural And Functional Divergence Of A 1-Mb Duplicated Region In The Soybean (Glycine Max) Genome And Comparison To An Orthologous Region From Phaseolus Vulgaris, Jer-Young Lin, Robert M. Stupar, Christian Hans, D. L. Hyten, Scott A. Jackson

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) has undergone at least two rounds of polyploidization, resulting in a paleopolyploid genome that is a mosaic of homoeologous regions. To determine the structural and functional impact of these duplications, we sequenced two ~1-Mb homoeologous regions of soybean, Gm8 and Gm15, derived from the most recent ~13 million year duplication event and the orthologous region from common bean (Phaseolus vulgaris), Pv5. We observed inversions leading to major structural variation and a bias between the two chromosome segments as Gm15 experienced more gene movement (gene retention rate of 81% in Gm15 versus 91% in …

Fine Mapping Of The Soybean Aphid-Resistance Gene Rag2 In Soybean Pi 200538, Ki-Seung Kim, Curtis B. Hill, Glen L. Hartman, D. L. Hyten, Matthew E. Hudson, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

The discovery of biotype diversity of soybean aphid (SA: Aphis glycines Matsumura) in North America emphasizes the necessity to identify new aphid-resistance genes. The soybean [Glycine max (L.) Merr.] plant introduction (PI) 200538 is a promising source of SA resistance because it shows a high level of resistance to a SA biotype that can overcome the SA-resistance gene Rag1 from ‘Dowling’. The SA-resistance gene Rag2 was previously mapped from PI 200538 to a 10-cM marker interval on soybean chromosome 13 [formerly linkage group (LG) F]. The objective of this study was to fine map Rag2. This fine mapping …

A High Density Integrated Genetic Linkage Map Of Soybean And The Development Of A 1536 Universal Soy Linkage Panel For Quantitative Trait Locus Mapping, D. L. Hyten, Ik-Young Choi, Qijian Song, James E. Specht, Thomas E. Carter Jr., Randy C. Shoemaker, Eun-Young Hwang, Lakshmi K. Matukumalli, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Single nucleotide polymorphisms (SNPs) are the marker of choice for many researchers due to their abundance and the high-throughput methods available for their multiplex analysis. Only recently have SNP markers been available to researchers in soybean [Glycine max (L.) Merr.] with the release of the third version of the consensus genetic linkage map that added 1141 SNP markers to the map. Our objectives were to add 2500 additional SNP markers to the soybean integrated map and select a set of 1536 SNPs to create a universal linkage panel for high-throughput soybean quantitative trait locus (QTL) mapping. The GoldenGate assay …

Fine Mapping The Soybean Aphid Resistance Gene Rag1 In Soybean, Ki-Seung Kim, Stephanie Bellendir, Karen A. Hudson, Curtis B. Hill, Glen L. Hartman, D. L. Hyten, Matthew E. Hudson, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

The soybean aphid (Aphis glycines Matsumura) is an important soybean [Glycine max (L.) Merr.] pest in North America. The dominant aphid resistance gene Rag1 was previously mapped from the cultivar ‘Dowling’ to a 12 cM marker interval on soybean chromosome 7 (formerly linkage group M). The development of additional genetic markers mapping closer to Rag1 was needed to accurately position the gene to improve the effectiveness of markerassisted selection (MAS) and to eventually clone it. The objectives of this study were to identify single nucleotide polymorphisms (SNPs) near Rag1 and to position these SNPs relative to Rag1. …

An Integrative Approach To Genomic Introgression Mapping, Andrew J. Severin, Gregory A. Peiffer, Wayne W. Xu, D. L. Hyten, Bruna Bucciarelli, Jamie A. O'Rourke, Yung-Tsi Bolon, David Grant, Andrew Farmer, Gregory D. May, Carroll P. Vance, Randy C. Shoemaker, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Near-isogenic lines (NILs) are valuable genetic resources for many crop species, including soybean (Glycine max). The development of new molecular platforms promises to accelerate the mapping of genetic introgressions in these materials. Here, we compare some existing and emerging methodologies for genetic introgression mapping: single-feature polymorphism analysis, Illumina GoldenGate single nucleotide polymorphism (SNP) genotyping, and de novo SNP discovery via RNA-Seq analysis of next-generation sequence data. We used these methods to map the introgressed regions in an iron-inefficient soybean NIL and found that the three mapping approaches are complementary when utilized in combination. The comparative RNA-Seq approach offers …

Abundance Of Ssr Motifs And Development Of Candidate Polymorphic Ssr Markers (Barcsoyssr_1.0) In Soybean, Qijian Song, Gaofeng Jia, Youlin Zhu, David Grant, Rex T. Nelson, Eun-Young Hwang, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Simple sequence repeat (SSR) genetic markers, also referred to as microsatellites, function in map-based cloning and for marker-assisted selection in plant breeding. The objectives of this study were to determine the abundance of SSRs in the soybean genome and to develop and test soybean SSR markers to create a database of locus-specific markers with a high likelihood of polymorphism. A total of 210,990 SSRs with di-, tri-, and tetranucleotide repeats of five or more were identified in the soybean whole genome sequence (WGS) which included 61,458 SSRs consisting of repeat units of di- (≥10), tri- (≥8), and tetranucleotide (≥7). Among …

Efficacy Of Singular And Stacked Brown Midrib 6 And 12 In The Modification Of Lignocellulose And Grain Chemistry, Scott E. Sattler, Deanna L. Funnell-Harris, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

In sorghum, brown midrib (bmr) 6 and 12 impair the last two steps of monolignol synthesis. bmr genes were introduced into grain sorghum to improve the digestibility of lignocellulosic tissues for grazing or bioenergy uses following grain harvest. Near-isogenic grain sorghum hybrids (AWheatland X RTx430) were developed containing bmr6, bmr12, and the bmr6 bmr12 double mutant (stacked), and their impacts were assessed in a two-year field study. The bmr genes did not significantly impact grain or lignocellulosic tissue yield. Lignocellulosic tissue from bmr6, bmr12, and stacked hybrids had reduced lignin content and increased in …

Heterosis In Sweet Sorghum And Selection Of A New Sweet Sorghum Hybrid For Use In Syrup Production In Appalachia, T. W. Pfeiffer, M. J. Bitzer, J. J. Toy, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Although heterosis is well established in grain and forage sorghum [Sorghum bicolor (L.) Moench], reports of heterosis in sweet sorghum are limited to results from grain sorghum × sweet sorghum hybrids. Recent development of cytoplasmic male-sterile sweet sorghum lines allows creation of sweet sorghum hybrids for research and industry. Male sterility may also affect allocation of photosynthate to plant parts, creating the potential to increase sugar content in stems by eliminating seed as a sink. The objectives of this study were to compare performance of A₃ cytoplasmic male-sterile lines and A₃ cytoplasmic male-sterile hybrids to fertile B …

Effect Of Nitrogen Addition And Weed Interference On Soil Nitrogen And Corn Nitrogen Nutrition, John L. Lindquist, Sean P. Evans, Charles A. Shapiro, Stevan Z. Knezevic

Department of Agronomy and Horticulture: Faculty Publications

Weeds cause crop loss indirectly by reducing the quantity of resources available for growth. Quantifying the effects of weed interference on nitrogen (N) supply, crop growth, and N nutrition may assist in making both N and weed management decisions. Experiments were conducted to quantify the effect of N addition and weed interference on soil nitrate-N (NO₃- N) over time and the dependence of corn growth on NO3-N availability, determine the corn N nutrition index (NNI) at anthesis, and evaluate if relative chlorophyll content can be utilized as a reliable predictor of NNI. Urea was applied at 0, 60, …

High-Throughput Snp Discovery Through Deep Resequencing Of A Reduced Representation Library To Anchor And Orient Scaffolds In The Soybean Whole Genome Sequence, David L. Hyten, Steven B Cannon, Qijian Song, Nathan Weeks, Edward W Fickus, Randy C Shoemaker, James E. Specht, Andrew Farmer, Gregory D May, Perry B Cregan

Department of Agronomy and Horticulture: Faculty Publications

Background: The Soybean Consensus Map 4.0 facilitated the anchoring of 95.6% of the soybean whole genome sequence developed by the Joint Genome Institute, Department of Energy, but its marker density was only sufficient to properly orient 66% of the sequence scaffolds. The discovery and genetic mapping of more single nucleotide polymorphism (SNP) markers were needed to anchor and orient the remaining genome sequence. To that end, next generation sequencing and high-throughput genotyping were combined to obtain a much higher resolution genetic map that could be used to anchor and orient most of the remaining sequence and to help validate the …

Complementary Genetic And Genomic Approaches Help Characterize The Linkage Group I Seed Protein Qtl In Soybean, Yung-Tsi Bolon, Bindu Joseph, Steven B Cannon, Michelle A Graham, Brian W. Diers, Andrew Farmer, Gregory D May, Gary J. Muehlbauer, James Specht, Zheng Jin Tu, Nathan Weeks, Wayne W Xu, Randy C. Shoemaker, Carroll P Vance

Department of Agronomy and Horticulture: Faculty Publications

Background: The nutritional and economic value of many crops is effectively a function of seed protein and oil content. Insight into the genetic and molecular control mechanisms involved in the deposition of these constituents in the developing seed is needed to guide crop improvement. A quantitative trait locus (QTL) on Linkage Group I (LG I) of soybean (Glycine max (L.) Merrill) has a striking effect on seed protein content.

Results: A soybean near-isogenic line (NIL) pair contrasting in seed protein and differing in an introgressed genomic segment containing the LG I protein QTL was used as a resource to demarcate …