Agronomy and Crop Sciences Commons^™

Predicting Phenological Development In Winter Wheat, Qingwu Xue, Albert Weiss, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Accurate prediction of phenological development is important in the winter wheat Triticum aestivum agroecosystem. From a practical perspective, applications of pesticides and fertilizers are carried out at specific phenological stages. In crop-simulation modeling, the prediction of yield components (kernel number and kernel weight) and wheat-grain yield relies on accurate prediction of phenology. In this study, a nonlinear multiplicative model by Wang & Engel (WE) for predicting phenological development in differing winter wheat cultivars was evaluated using data from a 3 yr field experiment. In the vegetative phase (emergence to anthesis) the daily development rate (r) was simulated based on the …

Using Multi-Spectral Imagery To Evaluate Corn Grown Under Nitrogen And Drought Stressed Conditions, Shannon L. Osborne, James S. Schepers, Mike R. Schlemmer

Department of Agronomy and Horticulture: Faculty Publications

The in-season estimation of crop stresses which have the potential of adversely affecting crop yield and/or quality could allow producers to make in-season management decisions to correct for the particular stress. A field study was conducted to evaluate the use of multispectral imagery for estimating corn (Zea mays L.) grain yield, in-season biomass and nitrogen (N) concentration under varying N and drought stresses. The experiment was a split-plot design with three replications using a factorial arrangement of treatments. Three irrigation (whole-plot) treatments included dry land, irrigation based on 0.5, and full evapotranspiration (ET). Sub-plot treatments included five N …

Expression Of A Putative Flavonoid 3'-Hydroxylase In Sorghum Mesocotyls Synthesizing 3-Deoxyanthocyanidin Phytoalexins, Jayanand Boddu, Catherine Svabek, Rajandeep Sekhon, Amanda Gevens, Ralph L. Nicholson, A. Daniel Jones, Jeffrey F. Pedersen, David L. Gustine, Surinder Chopra

Department of Agronomy and Horticulture: Faculty Publications

In sorghum, ingress of Cochliobolus heterostrophus stimulates the synthesis of 3-deoxyanthocyanidins that act as phytoalexins. Apigeninidin and luteolinidin are two major phytoalexins induced in the first 24 h after infection. In an attempt to understand genetic regulation of the biosynthesis of sorghum phytoalexins, we isolated a differentially expressed partial cDNA. Characterization and comparison showed that this cDNA sequence corresponds to a putative flavonoid 3’-hydroxylase. Full length sequence characterization allowed us to establish that the sorghum putative f3’h cDNA encodes a peptide of 517 amino acids that has domains conserved among cytochrome P450 proteins functioning in …

Implementation Of A Mitochondrial Mutator, Sally Mackenzie, Ricardo Vilela Abdelnoor

Department of Agronomy and Horticulture: Faculty Publications

Plant MSH1 polynucleotides and polypeptides are described. Also described are methods for the use and modulation of such MSH1 polynucleotides and polypeptides.

Mapping The Fas Locus Controlling Stearic Acid Content In Soybean, M. M. Spencer, V. R. Pantalone, E. J. Meyer, D. Landau-Ellis, D. L. Hyten Jr.

Department of Agronomy and Horticulture: Faculty Publications

Increasing the stearic acid content to improve soybean [Glycine max (L) Merr] oil quality is a desirable breeding objective for food-processing applications. Although a saturated fatty acid, stearic acid has been shown to reduce total levels of blood cholesterol and offers the potential for the production of solid fat products (such as margarine) without hydrogenation. This would result in the reduction of the level of trans fat in food products and alleviate some current health concerns. A segregating F₂ population was developed from the cross between Dare, a normal stearic acid content cultivar, and FAM94-41, a high stearic …

Registration Of Rn582 Sorghum Germplasm Line, J. F. Pedersen, J. J. Toy

Department of Agronomy and Horticulture: Faculty Publications

RN582 sorghum [Sorghum bicolor (L.)Moench] germplasm line (Reg. no. GP-591, PI 628277) was developed jointly by the USDA-ARS and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska, and was released in September 2001.

RN582 is an S₆ selection from the cross (RTx430 ms₃ms₃X E 35-1) X E 35-1. RTx430 was developed and released by the Texas Agricultural Experiment Station (Miller, 1984) and was provided to this project containing the nuclear male sterility gene ms₃ by A.B. Maunder in 1988. E 35-1 is an Ethiopian land race with white …

Single-Nucleotide Polymorphisms In Soybean, Y. L. Zhu, Q. J. Song, D. L. Hyten, C. P. Van Tassel, L. K. Matukumalli, D. R. Grimm, S. M. Hyatt, E. W. Fickus, N. D. Young, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Single-nucleotide polymorphisms (SNPs) provide an abundant source of DNA polymorphisms in a number of eukaryotic species. Information on the frequency, nature, and distribution of SNPs in plant genomes is limited. Thus, our objectives were (1) to determine SNP frequency in coding and noncoding soybean (Glycine max L. Merr.) DNA sequence amplified from genomic DNA using PCR primers designed to complete genes, cDNAs, and random genomic sequence; (2) to characterize haplotype variation in these sequences; and (3) to provide initial estimates of linkage disequilibrium (LD) in soybean. Approximately 28.7 kbp of coding sequence, 37.9 kbp of noncoding perigenic DNA, and …

Greenhouse Gas Emissions And Soil Indicators Four Years After Manure And Compost Applications, Daniel Ginting, Anabayan Kessavalou, Bahman Eghball, John W. Doran

Department of Agronomy and Horticulture: Faculty Publications

Understanding how carbon, nitrogen, and key soil attributes affect gas emissions from soil is crucial for alleviating their undesirable residual effects that can linger for years after termination of manure and compost applications. This study was conducted to evaluate the emission of soil CO₂, N₂O, and CH₄ and soil C and N indicators four years after manure and compost application had stopped. Experimental plots were treated with annual synthetic N fertilizer (FRT), annual and biennial manure (MN1 and MN2, respectively), and compost (CP1 and CP2, respectively) from 1992 to 1995 based on removal of 151 …

Forage Yield And Economic Losses Associated With The Brown-Midrib Trait In Sudangrass, M. D. Casler, Jeffrey F. Pedersen, D. J. Undersander

Department of Agronomy and Horticulture: Faculty Publications

Brown-midrib genes increase digestibility due to reduced lignification in sudangrass, Sorghum bicolor subsp. drummondii (Nees ex Steud.) de Wet & Harlan. Brown-midrib lines are known to be low in forage yield potential, but this reduction in forage yield has not been previously quantified. The objectives of this study were to quantify the increase in forage quality and decrease in forage yield and to provide an economic assessment of this dichotomy. Piper and Greenleaf (normal leaves) were compared with their brown-midrib counterparts and four highly selected brown-midrib (FG) lines at two locations for 2 yr. Brown-midrib lines averaged 9.0% lower in …

Registration Of ‘Ne422t’ Winter Triticale, P. Stephen Baenziger, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

NE422T triticale (X Triticosecale Wittmack) (Reg. no CV-27, PI 629028) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS. It was jointly released in 2001 by the developing institutions. NW422T was selected from the cross ‘Trical’/‘UB-UW26’ where Trical is most likely ‘Trical 100’ (a forage triticale developed by Resource Seed Inc., a subsidiary of Goldsmith Seed Company, Gilroy, CA) and UB-UW26 is an unknown winter triticale germplasm line given to the breeding program in the 1980s.The cross was made in 1990. The F₁ generation was grown in the greenhouse in 1990-1991. The F₂ and F …

Characterization Of Fro1, A Pea Ferric-Chelate Reductase Involved In Root Iron Acquisition, Brian M. Waters, Dale G. Blevins, David J. Eide

Department of Agronomy and Horticulture: Faculty Publications

To acquire iron, many plant species reduce soil Fe(III) to Fe(II) by Fe(III)-chelate reductases embedded in the plasma membrane of root epidermal cells. The reduced product is then taken up by Fe(II) transporter proteins. These activities are induced under Fe deficiency. We describe here the FRO₁ gene from pea (Pisum sativum), which encodes an Fe(III)-chelate reductase. Consistent with this proposed role, FRO₁ shows similarity to other oxidoreductase proteins, and expression of FRO₁ in yeast conferred increased Fe(III)-chelate reductase activity. Furthermore, FRO₁ mRNA levels in plants correlated with Fe(III)-chelate reductase activity. Sites of FRO_{1 …}

Accumulation Of Microbial Biomass Within Particulate Organic Matter Of Aging Golf Greens, Mine Kerek, Rhae A. Drijber, William L. Powers, Robert C. Shearman, Roch E. Gaussoin, Anne Streich

Department of Agronomy and Horticulture: Faculty Publications

Microbial biomass (MB) is a key variable controlling soil organic matter dynamics in soil. Currently, there is little information on the amount and significance of MB in highly managed golf greens. Our objective was to determine the amount and distribution of MB within soil structural components of golf greens and its relationship to the location of organic substrates. During 1996, 47 greens were sampled from 12 golf courses within Nebraska (USA). Microbial biomass, determined as extractable lipid phosphate on field-moist soils, increased linearly with age of green (Y = 19.39 + 3.54x; r² = 0.87, P = 0.001). In …

Combinatorial Control Of Yeast Fet4 Gene Expression By Iron, Zinc, And Oxygen, Brian M. Waters, David J. Eide

Department of Agronomy and Horticulture: Faculty Publications

Acquisition of metals such as iron, copper, and zinc by the yeast Saccharomyces cerevisiae is tightly regulated. High affinity uptake systems are induced under metal-limiting conditions to maintain an adequate supply of these essential nutrients. Low affinity uptake systems function when their substrates are in greater supply. The FET₄ gene encodes a low affinity iron and copper uptake transporter. FET₄ expression is regulated by several environmental factors. In this report, we describe the molecular mechanisms underlying this regulation. First, we found that FET₄ expression is induced in iron-limited cells by the Aft1 iron-responsive transcriptional activator. Second, FET …

Genetic Analysis Of Feed Quality And Seed Weight Of Sorghum Inbred Lines And Hybrids Using Analytical Methods And Nirs, C. Hicks, M. R. Tuinstra, Jeffrey F. Pedersen, F. E. Dowell, K. D. Kofoid

Department of Agronomy and Horticulture: Faculty Publications

Eight lines of grain sorghum and their F1 hybrids were evaluated for contents of crude protein (CP), fat (FAT), and starch (STA); protein digestibility (PD); and in vitro dry matter disappearance (IVDMD). The effect of seed weight (SW) on these traits and the potential use of near infrared reflectance spectroscopy (NIRS) to predict them also were investigated. The male lines included three normal-seeded lines (TX2737, TX435, and P954063) and two largeseeded lines (PL-1 and Eastin1). The female lines included commonU.S. seed parent lines (Wheatland, Redlan, and SA3042). The lines and their hybrids were grown under dryland conditions at Kansas State …

‘Forrest’ Resistance To The Soybean Cyst Nematode Is Bigenic: Saturation Mapping Of The Rhg1 And Rhg4 Loci, K. Meksem, P. Pantazopoulos, V. N. Njiti, D. L. Hyten, P. R. Arelli, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Field resistance to cyst nematode (SCN) race 3 (Heterodera glycines I.) in soybean [Glycine max (L.) Merr.] cv ‘Forrest’ is conditioned by two QTLs: the underlying genes are presumed to include Rhg1 on linkage group G and Rhg4 on linkage group A2. A population of recombinant inbred lines (RILs) and two populations of near-isogenic lines (NILs) derived from a cross of Forrest × Essex were used to map the loci affecting resistance to SCN. Bulked segregant analysis, with 512 AFLP primer combinations and microsatellite markers, produced a high-density genetic map for the intervals carrying Rhg …

Genomic Regions That Underlie Soybean Seed Isoflavone Content, K. Meksem, V. N. Njiti, W. J. Banz, M. J. Iqbal, My. M. Kassem, David L. Hyten, J. Yuang, T. A. Winters, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Soy products contain isoflavones (genistein, daidzein, and glycitein)that display biological effects when ingested by humans and animals, these effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key to their biological effect. Our objective was to identify loci that underlie isoflavone content in soybean seeds. The study involved 100 recombinant inbred lines (RIL)fr om the cross of ‘Essex’ by ‘Forrest,’ two cultivars that contrast for isoflavone content. Isoflavone content of seeds fromeach RIL was determined by high performance liquid chromatography (HPLC). The distribution of isoflavone content was continuous and unimodal. The …

Genetic Analysis Of Kafirins And Their Phenotypic Correlations With Feed Quality Traits, In Vitro Digestibility, And Seed Weight In Grain Sorghum, C. Hicks, S. R. Bean, G. L. Lookhart, Jeffrey F. Pedersen, K. D. Kofoid, M. R. Tuinstra

Department of Agronomy and Horticulture: Faculty Publications

Twenty-three entries of grain sorghum (Sorghum bicolor (L.) Moench), including eight inbred lines (five males and three females) and 15 hybrids, were evaluated to determine the proportion of γ, αII, and β-αI-kafirins and their association with contents of crude protein, fat, and starch; protein digestibility; in vitro dry matter disappearance; and seed weight. The male lines included three normal-seeded lines (TX2737, TX435, and P954063) and two large-seeded lines (Eastin1 and PL-1). Female lines consisted of three common U.S. seed parent lines (Wheatland, Redlan, and SA3042). The lines and their hybrids were grown under dryland conditions at two locations in …

Seed Physiology, Production & Technology: Germination, Emergence, And Yield Of 20 Plant-Color, Seed-Color Near-Isogenic Lines Of Grain Sorghum, Jeffrey F. Pedersen, J. J. Toy

Department of Agronomy and Horticulture: Faculty Publications

Although there is growing demand for sorghum [Sorghum bicolor (L.) Moench] with white seed and tan plant color, there is limited information on the overall agronomic fitness of sorghum with these characters. A set of experiments was conducted to evaluate the combined effects of plant color and seed color on sorghum germination, emergence, and agronomic performance. Twenty near-isogenic lines with red seed/tan plant (RT), red seed/purple plant (RP), white seed/ tan plant (WT), white seed/purple plant (WP) phenotypes were tested under field and laboratory conditions. Plant color X seed color interactions were not significant. Purple plant color phenotypes had higher …

High-Throughput Genotyping For A Polymorphism Linked To Soybean Cyst Nematode Resistance Gene Rhg4 By Using TaqmanTm Probes, Khalid Meksem, Eliza Ruben, David L. Hyten, Michael E. Schmidt, David A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

An individual soybean breeder can generate over one hundred thousand new genotypes each year. The efficiency of selection in these populations could be improved if these genotypes were effectively screened with one DNA marker that identified an important gene, and if laboratory throughput was high and costs were low. Our aim was to develop a rapid genotyping procedure for resistance to the soybean cyst nematode. A high-throughput genotyping method was developed with fluorogenic probes to distinguish between two insertion polymorphisms in alleles of an AFLP marker that is located about 50 kbp from the Rhg4 gene candidate. The assay uses …

Conversion Of Aflp Bands Into High-Throughput Dna Markers, K. Meksem, E. Ruben, D. L. Hyten, K. Triwitayakorn, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

The conversion of AFLP bands into polymorphic sequence-tagged-site (STS) markers is necessary for high-throughput genotype scoring. Technical hurdles that must be overcome arise from genome complexity (particularly sequence duplication), from the low-molecular- weight nature of the AFLP bands and from the location of the polymorphism within the AFLP band. We generated six STS markers from ten AFLP bands (four AFLPs were from co-dominant pairs of bands) in soybean (Glycine max). The markers were all linked to one of two loci, rhg1 on linkage group G and Rhg4 on linkage group A2, that confer resistance to the soybean cyst nematode (Heterodera …

Two Large-Insert Soybean Genomic Libraries Constructed In A Binary Vector: Applications In Chromosome Walking And Genome Wide Physical Mapping, K. Meksem, K. Zobrist, E. Ruben, D. L. Hyten, T. Quanzhou, H-B. Zhang, D. A. Lightfoot

Department of Agronomy and Horticulture: Faculty Publications

Large DNA insert libraries in binary T-DNA vectors can assist in the isolation of the gene(s) under-lying a quantitative trait locus (QTL). Binary vectors facilitate the transfer of large-insert DNA fragments containing a QTL from E. coli to Agrobacterium sp. and then to plants. We constructed two soybean large-insert libraries from cv. Forrest in the pCLD04541 (V41) binary vector after partial digestion of genomic high-molecular-weight DNA with BamHI or HindIII. The libraries contain 76,800 clones with an average insert size of 125 kb, and therefore represent 9.5-fold haploid genome equivalents. Colony hybridization using a chloroplast-specific probe infers that …

Before You Say Yes: A Planning Guide For Speakers, Charles A. Francis, Heidi Carter, Cris Carusi, James W. King

Department of Agronomy and Horticulture: Faculty Publications

We need guidelines to help us decide whether to accept invitations to speak, whether to a class on campus or a special interest group outside. As educators and workshop organizers, we could also use suggestions on how to approach potential speakers. This article describes a single-page format that can be used to guide the planning process. Essential elements include contact information, location and organization of the activity, audience, learning goals, expected content, conclusions, and evaluation. Use of this planning sheet can give organization to an often haphazard process of planning, and enhance the potential of achieving the learning goals of …

Ethylene Production, Cluster Root Formation, And Localization Of Iron(Iii) Reducing Capacity In Fe Deficient Squash Roots, Brian M. Waters, Dale G. Blevins

Department of Agronomy and Horticulture: Faculty Publications

Dicots and non-graminaceous monocots have the ability to increase root iron(III) reducing capacity in response to iron (Fe) deficiency stress. In squash (Cucurbita pepo L.) seedlings, Fe(III) reducing capacity was quantified during early vegetative growth. When plants were grown in Fe-free solution, the Fe(III) reducing capacity was greatly elevated, reached peak activity on day 4, then declined through day 6. Root ethylene production exhibited a temporal pattern that closely matched that of Fe(III) reducing capacity through day 6. On the 7th day of Fe deficiency, cluster root morphology developed, which coincided with a sharp increase in the root Fe(III) …

Crop Quality And Utilization: A Twelve-Hour In Vitro Procedure For Sorghum Grain Feed Quality Assessment, Jeffrey F. Pedersen, Todd Milton, R. A. Mass

Department of Agronomy and Horticulture: Faculty Publications

Improvedmethods for assessing cereal crop feed value are a prerequisite for the genetic improvement of sorghum [Sorghum bicolor (L.) Moench] feed value. Rate of starch digestion is now commonly believed to be the limiting factor in sorghum utilization by cattle (Bos taurus). However, techniques to assess this trait are not useful to sorghum breeders because of high labor inputs, lab error associated with starch measurement, and need for high numbers of replications. The objective of this study was to develop a simple technique capable of identifying differences in digestion between sorghum and corn (Zea mays L.) …

Effect Of Leaf Phosphorus And Potassium Concentration On Chlorophyll Meter Reading In Rice, Shaobing Peng, Arnel L. Sanico, Felipe V. Garcia, Rebecca C. Laza, Romeo M. Visperas, Josue P. Descalsota, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Chlorophyll meter (SPAD) is a convenient tool to estimate leaf nitrogen (N) concentration of rice plants. There is no information on the effects of leaf phosphorus (P) and potassium (K) concentration on SP AD readings and on the relationship between SPAD values and leaf N concentration in the literature. In 1996 dry season, cv IR72 was grown at the International Rice Research Institute (IRRI) and the Philippine Rice Research Institute (PhilRice) under various N, P and K fertilizer combinations. SPAD measurements were made on the topmost fully expanded leaves at mid-tillering and panicle initiation. The leaves were then detached, dried …

Loci Controlling Resistance To High Plains Virus And Wheat Streak Mosaic Virus In A B73 × Mo17 Population Of Maize, A. Marçon, S. M. Kaeppler, S. G. Jensen, L. Senior, C. Stuber

Department of Agronomy and Horticulture: Faculty Publications

High Plains disease has the potential to cause significant yield loss in susceptible corn (Zea mays L.) and wheat (Triticum aestivum L.) genotypes, especially in the central and western USA. The primary causal agent, High Plains virus (HPV), is vectored by wheat curl mite (WCM; Aceria tossicheila Keifer), which is also the vector of wheat streak mosaic virus (WSMV). In general, the two diseases occur together as a mixed infection in the field. The objective of this research was to characterize the inheritance of HPV and WSMV resistance using B73 (resistant to HPV and WSMV) × Mo17 (moderately …

Notes: Evaluation Of A Filter Bag System For Ndf, Adf, And Ivdmd Forage Analysis, Kenneth P. Vogel, Jeffrey F. Pedersen, Steven D. Masterson, John J. Toy

Department of Agronomy and Horticulture: Faculty Publications

A new method of determining in vitro dry matter digestibility (IVDMD) as recently developed in which the digestion is conducted with the forage samples in filter bags. Our objective was to compare the filter bag and conventional IVDMD analysis methods using smooth bromegrass (Bromus inermis Leyss.), switchgrass (Panicum virgatum L.), and forage sorghum [Sorghum bicolor (L.) Moench] samples. In addition, the filter bag analysis systems for determining non-sequential neutral and acid detergent fiber (NDF and ADF), respectively, were compared with the non-sequential conventional analysis systems. In the filter bag systems, the forage samples are sealed in filter bags and the …

Measurement Of Sorghum Stalk Strength Using The Missouri-Modified Electronic Rind Penetrometer, Jeffrey F. Pedersen, J. J. Toy

Department of Agronomy and Horticulture: Faculty Publications

Resistance to lodging is critical in sorghum [Sorghum bicolor (L.) Moench] grown for grain, yet adequate tools for plant breeders to assess this character at or before anthesis have not been developed. The objective of this study was to evaluate whether an electronic penetrometer previously shown to be an effective tool for measuring stalk strength in maize (Zea mays L.) could be usedd to differentiate among grain sorghum hybrids. Entries in three commercial grain sorghum hybrid trials were evaluated for rind penetrometer resistance (RPR) of the peduncle, the lower stalk anthesis and the lower stalk at maturity. Actual …

Growth Traits Among Sorghum Genotypes In Response To Aluminum, J. H. Bernal, R. B. Clark

Department of Agronomy and Horticulture: Faculty Publications

Aluminum (Al) has many detrimental effects on plant growth, and shoots and roots are normally affected differently. A study was conducted to determine differences among sorghum [Sorghum bicolor (L.) Moench] genotypes with broad genetic backgrounds for growth traits of plants grown at 0,200,400,600, and 800 uM Al in nutrient solutions (pH 4.0). Genotypes were categorized into "Al-sensitive", "intermediate Al-tolerant", "Al-tolerant", and SC 283 (an Al-tolerant standard). As Al increased, shoot and root dry matter (DM), net main axis root length (NMARL), and total root length (TRL) became lower than controls (0 Al). Aluminum toxicity and/or nutrient deficiency symptoms become …

Soil Temperature And Fumigation Effects On Plant Phosphorus Uptake And Related Microbial Properties, Dennis L. Mccallister, L. A. Jawson, M. D. Jawson

Department of Agronomy and Horticulture: Faculty Publications

Early season problems with growth of corn (Zea mays L.) under cool, wet conditions prompted a study of the effects of soil and environmental conditions on mineralization and plant uptake of phosphorus (P). Our objective was to determine the effect of soil test P, temperature, and soil fumigation on soil P availability and uptake during early corn growth. Corn was grown in growth chambers at temperatures of 14°C or 25°C. Soils were a high-P Hastings silty clay loam (fine, montmorillonitic, mesic Udic Argiustoll) and a low-P Sharpsburg clay loam (fine, montmorillonitic, mesic Typic Argiudoll). Plants grew for up to …