Life Sciences Commons^™

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 …

Efficient Methods Of Estimating Switchgrass Biomass Supplies, Marty R. Schmer, Robert B. Mitchell, Kenneth P. Vogel, Walter H. Schacht, David B. Marx

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) is being developed as a biofuel feedstock for the United States. Efficient and accurate methods to estimate switchgrass biomass feedstock supply within a production area will be required by biorefineries. Our main objective was to determine the effectiveness of indirect methods for estimating biomass yields and composition of switchgrass fields. Indirect measurements were conducted in eastern Nebraska from 2003 to 2007 in which switchgrass biomass yields were manipulated using three nitrogen rates (0 kg N ha^-1, 60 kg N ha^-1, and 120 kg N ha^-1) and two harvest periods …

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, …

Economic Potential Of Substituting Legumes For Synthetic Nitrogen In Warm Season Perennial Grasses Used For Stocker Cattle Grazing, Maru Kering, John Biermacher, Ryan Reuter, Twain Butler, Job D. Springer, James Rogers, John Blanton, Joe Bouton, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

Stocker cattle grazing warm season perennial grasses is an important economic activity in the southern Great Plains. Substantial increases in the price of nitrogen fertilizer is negatively affecting forage producers‟ profitability. Two alternative nitrogen management systems that use annual and perennial legumes have been developed for bermudagrass pastures. The goal of the study is to determine if the legumes systems are more profitable than the conventional practice of applying synthetic sources of nitrogen. Results of the two-year grazing study show that the legume systems could not compete economically with the common practice.

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) …

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.

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 …

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 …

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 …

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 …}

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 …

Wheat (Triticum Aestivum) Nam Proteins Regulate The Translocation Of Iron, Zinc, And Nitrogen Compounds From Vegetative Tissues To Grain, Brian M. Waters, Cristobal Uauy, Jorge Dubcovsky, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

The NAM-B1 gene is a NAC transcription factor that affects grain nutrient concentrations in wheat (Triticum aestivum). An RNAi line with reduced expression of NAM genes has lower grain protein, iron (Fe), and zinc (Zn) concentrations. To determine whether decreased remobilization, lower plant uptake, or decreased partitioning to grain are responsible for this phenotype, mineral dynamics were quantified in wheat tissues throughout grain development. Control and RNAi wheat were grown in potting mix and hydroponics. Mineral (Ca, Cu, Fe, K, Mg, Mn, P, S, and Zn) and nitrogen (N) contents of organs were determined at regular intervals to …

Effects Of Nitrogen Supply On The Root Morphology Of Corn And Velvetleaf, Kimberly D. Bonifas, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Root morphology will affect interplant competition for soil nutrients. Research was conducted to assess fine root fraction, mean root radius, specific root length, root length density, and nitrogen (N) uptake per unit fine root biomass of corn and velvetleaf over time and in response to nitrogen supply. Pots containing either corn or velvetleaf were embedded in the ground and received one of three N treatments. Plants were destructively sampled on 10 dates during each of two years and root subsamples analyzed using root scanning software. While corn root morphology was more responsive to N supply than velvetleaf, velvetleaf N uptake …

Switchgrass For Forage And Bioenergy: Ii. Effects Of P And K Fertilization, John A. Guretzky, Maru Kering, Jon Biermacher, Billy Cook

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) has been targeted for cellulosic ethanol production. Our objective was to evaluate effects of P and K fertilization on switchgrass biomass yields. Experiments were established in switchgrass (cv. Alamo) fields planted at three Oklahoma locations in 2007. Interactions of N and P fertilizer rates were evaluated on two sites that had low soil test P (6 to 9 kg/ha). Interactions of N and K fertilizer rates and harvest system were evaluated on a site that had low soil test K (134 kg/ha). In the N and P rate experiments, biomass yields during establishment …

Grazing Lands And Soil Carbon Storage, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

On March 31, 2009, a draft discussion of the American Clean Energy and Security Act of 2009 was released to the public. The bill contains four sections addressing:

1. clean energy;
2. energy efficiency;
3. reducing global warming pollution; and
4. transitioning to a clean energy economy.

Section 3 contains a description of the proposed cap-and-trade program designed to reduce industrial emissions of greenhouse gases (GHG) including carbon dioxide (CO₂), methane (CH4), nitrous oxide (N₂O), hydro-fluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6) and nitrogen trifluoride (NF3). Agricultural sources, although largely diffuse and not regulated directly by the bill, account for …

Switchgrass For Forage And Bioenergy: I. Effects Of Nitrogen Rate And Harvest System, Maru Kering, J. T. Biermacher, Billy Cook, John A. Guretzky

Department of Agronomy and Horticulture: Faculty Publications

Switchgrass (Panicum virgatum L.) has been targeted for cellulosic ethanol production. Our objective was to evaluate effects of location, harvest system, and N fertilizer rates on switchgrass biomass yield and N, P, and K removal. Randomized complete block experiments with four replications were established on one-year old stands of ‘Alamo’ switchgrass at two Oklahoma locations in 2008. Harvest system and N rate interactions affected total annual yield. Biomass yields ranged from 9020 to 10530 kg/ha across harvest systems when no N was applied. With application of 179 kg N/ha, biomass yields averaged 10715, 13912, and 16516 kg/ha when harvested at …

Bulked Segregant Analysis Using The Goldengate Assay To Locate The Rpp3 Locus That Confers Resistance To Soybean Rust In Soybean, D. L. Hyten, James R. Smith, Reid D. Frederick, Mark L. Tucker, Qijian Song, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Few resistance loci to soybean rust (SBR), caused by Phakopsora pachyrhizi Syd., have been genetically mapped and linked to molecular markers that can be used for marker assisted selection. New technologies are available for single nucleotide polymorphism (SNP) genotyping that can be used to rapidly map traits controlled by single loci such as resistance to SBR. Our objective was to demonstrate that the highthroughput SNP genotyping method known as the GoldenGate assay can be used to perform bulked segregant analysis (BSA) to fi nd candidate regions to facilitate effi cient mapping of a dominant resistant locus to SBR designated Rpp3 …

Mapping And Confirmation Of A New Allele At Rpp1 From Soybean Pi 594538a Conferring Rb Lesion–Type Resistance To Soybean Rust, Nanda Chakraborty, Joe Curley, Reid D. Frederick, D. L. Hyten, Randall L. Nelson, Glen L. Hartman, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean rust, caused by Phakopsora pachyrhizi (H. Sydow & Sydow), is a destructive soybean [Glycine max (L.) Merr.] disease and identification of new resistance genes is essential for effective rust management. Our research objectives were to map and confirm the location of resistance gene(s) in PI 594538A using a population of 98 F_3:4 lines from across between PI 594538A (reddish-brown [RB] lesions) and the susceptible cultivar Loda (tan [TAN] lesions). The lines were inoculated with the P. pachyrhizi isolate ZM01-1 from Zimbabwe. The RB resistance in PI 594538A mapped on linkage group G as a single dominant gene. …

Non-Destructive Determination Of Maize Leaf And Canopy Chlorophyll Content, Veronica Ciganda, Anatoly A. Gitelson, James S. Schepers

Department of Agronomy and Horticulture: Faculty Publications

The objective of this study was to develop a rapid non-destructive technique to estimate total chlorophyll (Chl) content in a maize canopy using Chl content in a single leaf. The approach was (1) to calibrate and validate a reflectance-based nondestructive technique to estimate leaf Chl in maize; (2) to quantify the relative contribution of each leaf Chl to the total Chl in the canopy; and (3) to establish a relationship between leaf Chl content and total Chl in a maize canopy. The Red Edge Chlorophyll Index Cl_{red edge} = (R_NIR/R_{red edge})-1 based on …

Limits To Maize Productivity In The Western Corn-Belt: A Simulation Analysis For Fully Irrigated And Rainfed Conditions, Patricio Grassini, Haishun Yang, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Unlike the Central and Eastern U.S. Corn-Belt where maize is grown almost entirely under rainfed conditions, maize in the Western Corn-Belt is produced under both irrigated (3.2 million ha) and rainfed (4.1 million ha) conditions. Simulation modeling, regression, and boundary-function analysis were used to assess constraints to maize productivity in the Western Corn-Belt. Aboveground biomass, grain yield, and water balance were simulated for fully irrigated and rainfed crops, using 20-year weather records from 18 locations in combination with actual soil, planting date, plant population, and hybrid-maturity data. Mean values of meteorological variables were estimated for three growth periods (pre- and …

A Nonsense Mutation In A Cinnamyl Alcohol Dehydrogenase Gene Is Responsible For The Sorghum Brown Midrib6 Phenotype1[W][Oa], Scott E. Sattler, Aaron J. Saathoff, Eric J. Haas, Nathan A. Palmer, Deanna L. Funnell, Gautam Sarath, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Recently, bmr6 plants were shown to have limited cinnamyl alcohol dehydrogenase activity (CAD; EC 1.1.1.195), the enzyme that catalyzes the conversion of hydroxycinnamoyl aldehydes (monolignals) to monolignols. A candidate gene approach was taken to identify Bmr6. Two CAD genes (Sb02g024190 and Sb04g005950) were identified in the sorghum genome based on similarity to known CAD genes and through DNA sequencing a nonsense mutation was discovered in Sb04g005950 that results in a truncated protein lacking the NADPH-binding and C-terminal catalytic domains. Immunoblotting confirmed that the Bmr6 protein was absent in protein extracts from bmr6 plants. Phylogenetic analysis indicated that Bmr6 is …

Evaluation Of Glyphosate-Tolerant And Conventional Alfalfa Weed Control Systems During The First Year Of Establishment, Robert Wilson Jr., Paul Burgener

Department of Agronomy and Horticulture: Faculty Publications

A field trial was conducted for 3 yr (2005 through 2007) near Scottsbluff, NE, to examine weed control, crop safety, forage production, and economics of glyphosate-tolerant and conventional alfalfa establishment systems. Glyphosate applied to alfalfa at the unifoliate growth stage provided 67% weed control and was similar to imazamox applied at the two-trifoliate leaf stage. Delaying glyphosate application until alfalfa had reached the two-trifoliate growth stage improved weed control to 83%, and weed control was similar to imazamox plus 2,4-DB and imazethapyr plus 2,4-DB. Imazamox and imazethapyr caused minor crop injury, and the addition of bromoxynil or 2,4-DB to both …

Quantum Simulation Of High-Order Harmonic Spectra Of The Hydrogen Atom, A. D. Bandrauk, S. Chelkowski, Dennis J. Diestler, J. Manz, K.-J. Yuan

Department of Agronomy and Horticulture: Faculty Publications

Three alternative forms of harmonic spectra, based on the dipole moment, dipole velocity, and dipole acceleration, are compared by a numerical solution of the Schrödinger equation for a hydrogen atom interacting with a linearly polarized laser pulse, whose electric field is given by E(t)= E₀f(t)cos(ω₀t + η) with Gaussian carrier envelope f(t) = exp(−t² /δ²). The carrier frequency ω₀ is fixed to correspond to a wavelength of 800 nm. Spectra for a selection of pulses, for which the intensity I₀=cε₀E²₀, duration T∞ δ, …

Farmers And Nature Conservation: What Is Known About Attitudes, Context Factors And Actions Affecting Conservation?, Johan Ahnström, Jenny Höckert, Hanna L. Bergea, Charles A. Francis, Peter Skelton, Lars Hallgren

Department of Agronomy and Horticulture: Faculty Publications

Farmers’ attitudes towards viability of specific conservation practices or actions strongly impact their decisions on adoption and change. This review of ‘attitude’ information reveals a wide range of perceptions about what conservation means and what the impacts of adoption will mean in economic and environmental terms. Farmers operate in a tight financial situation, and in parts of the world they are highly dependent on government subsidies, and cannot afford to risk losing that support. Use of conservation practices is most effective when these are understood in the context of the individual farm, and decisions are rooted in land and resource …

Farming Systems Education: Case Study Of Swedish Test Pilots, Lennart Salomonsson, Anna Nilsson, Sofia Palmer, Adam Roigart, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

We describe and analyze a pedagogical experiment that introduced a broad and holistic perspective on complete farming systems, systemic learning tools, and a participatory learning strategy at an early stage in agronomy education. The paper describes the adventure of three students, who came from a conventional agronomy program at the Swedish University of Agricultural Sciences (SLU), who were frustrated with the lack of integrated approaches to the study of agricultural systems and a strong focus on molecular-level processes in their first year of education. They encountered a narrow focus in most courses and the overall curricula of agricultural education that …

Evaluation Of The Waxy Endosperm Trait In Proso Millet (Panicum Miliaceum), Robert A. Graybosch, D. D. Baltensperger

Department of Agronomy and Horticulture: Faculty Publications

The entire USDA-ARS maintained collection of 650 accessions of proso millet (Panicum miliaceum L.) was evaluated for the presence of accessions with waxy (amylose-free) endosperm starch. Six accessions, five of which derived from mainland China, were identified. Segregation ratios for waxy endosperm were evaluated in F₂ and F₃ populations derived from crosses between two waxy accessions, PI 436625 (Lung Shu 16) and PI 436626 (Lung Shu 18), and several wildtype accessions. The waxy trait was found to be under the control of duplicate recessive alleles at two loci, herein designated wx-1 and wx-2. Wild-type alleles at …