Plant Biology Commons^™

Evaluation Of Application Timing On Stratego Yld Efficacy Of Field Corn In Nebraska, 2012, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide timing trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 64-83, rating of “good” (6 out of 9) for gray leaf spot (GLS), “very good” (4 out of 9) for common rust (CR), and “good” (5 out of 9) for southern rust (SR), was planted on 26 Apr in 30-in. rows at a target population of 30,600 plants/A. The trial area was disked with corn as the previous year’s crop. Five foliar fungicide treatments and a non-treated control were replicated six times in a randomized complete …

Efficacy Evaluation Of Foliar Fungicide Products On Diseases Of Field Corn In Nebraska, 2012, C. M. Schleicher, T. A. Jackson-Ziems

Department of Plant Pathology: Faculty Publications

A foliar fungicide efficacy trial was conducted at the University of Nebraska-Lincoln South Central Agricultural Laboratory near Clay Center, NE. DeKalb corn hybrid DKC 64-83, rating of “good” (6 out of 9) for gray leaf spot (GLS), “very good” (4 out of 9) for common rust (CR), and “good” (5 out of 9) for southern rust (SR), was planted on 26 Apr in 30-in. rows at a target population of 30,600 plants/A. The trial area was disked with soybean as the previous year’s crop. Five foliar fungicide treatments and a nontreated control were replicated six times in a randomized complete …

Foliar Treatment Timing Trials For Management Of Goss’S Bacterial Wilt And Blight Of Field Corn In Nebraska, 2012, H. H. Oser, T. A. Jackson-Ziems, J. L. Brungardt

Department of Plant Pathology: Faculty Publications

One experimental hybrid, DKC 37-38, with a Goss’s wilt rating of 7 out of 9 (“poor”), was planted at the University of Nebraska Agricultural Research and Development Center (ARDC) near Mead, NE on 2 Jun. Corn was planted at 32,000 seeds per acre in a field that received minimum tillage. The previous year’s crop was corn. Each plot was 30 ft long and contained two rows spaced 30-in. apart. Alleys were cut between plots reducing plot length to 28 ft. All plots were irrigated with an overhead sprinkler center pivot irrigation system. . . . There were no significant differences …

Major Fusarium Diseases On Corn, Wheat, And Soybeans In Nebraska, Bo Liu, Loren J. Giesler, Tamra A. Jackson-Ziems, Stephen N. Wegulo, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Fusarium species have been associated with many important diseases of corn, wheat, and soybean, causing significant yield loss in Nebraska; some produce mycotoxins that are harmful to both human and animal consumers. These pathogens are very common in agricultural field soil across the Midwest and cause numerous types of diseases.

Corn Disease Update, Tamra A. Jackson-Ziems, Craig B. Langemeier, Greg R. Kruger

Department of Plant Pathology: Faculty Publications

Goss's Bacterial Wilt and Blight ... Symptoms ... 2011 Survey results ... New alternate hosts identified ... Goss's Wilt Management Strategies ... More Resources ... Literature Cited

Aspergillus Ear Rot and Aflatoxin Contaminated Grain ... Table 1. FDA Action Levels for Aflatoxin in Feed and Food ... Testing for Aflatoxin ... High risk factors for aflatoxin contamination in corn ... Scouting for Aspergillus Ear Rot ... Harvest and Storage ... More Resources

Stalk Rot Diseases ... Scouting for Stalk Rot Diseases ... Management ... More Resources

Immunodetection Of Triticum Mosaic Virus By Das- And Dac-Elisa Using Antibodies Produced Against Coat Protein Expressed In Escherichia Coli: Potential For High-Throughput Diagnostic Methods, Satyanarayana Tatineni, Gautam Sarath, Dallas Seifers, Roy C. French

Department of Agronomy and Horticulture: Faculty Publications

Triticum mosaic virus (TriMV), an economically important virus infecting wheat in the Great Plains region of the USA, is the type species of the Poacevirus genus in the family Potyviridae. Sensitive and high-throughput serology-based detection methods are crucial for the management of TriMV and germplasm screening in wheat breeding programs. In this study, TriMV coat protein (CP) was expressed in Escherichia coli, and polyclonal antibodies were generated against purified soluble native form recombinant CP (rCP) in rabbits. Specificity and sensitivity of resulting antibodies were tested in Western immuno-blot and enzyme-linked immunosorbent assays (ELISA). In direct antigen coating (DAC)-ELISA, …

Soil Sorptivity Enhancement With Crop Residue Accumulation In Semiarid Dryland No-Till Agroecosystems, T.M. Shaver, G. A. Peterson, Laj R. Ahuja, D.G. Westfall

Department of Agronomy and Horticulture: Faculty Publications

Water capture and precipitation use efficiency are of great importance in dryland cropping systems because the world's dependence on food produced in dryland areas continues to increase. Growing season evapotranspiration potential greatly exceeds growing season precipitation rates in dryland areas, creating a water deficit for crops. Management practices that positively impact soil physical properties increase the potential for soils to capture water. One way to assess the ability of soils to capture water is through the measurement of sorptivity. Sorptivity is defined as the cumulative infiltration proportionality constant and is governed by surface soil physical properties such as texture, degree …

Enzyme Activity In Wheat Breeding Lines Derived From Matings Of Low Polyphenol Oxidase Parents, Somrudee Nilthong, Robert A. Graybosch, P. Stephen Baenziger

Department of Agronomy and Horticulture: Faculty Publications

Polyphenol oxidase (PPO) in grain plays a major role in time-dependent discoloration of wheat (Triticum aestivum L.) products, especially fresh noodles. Breeding wheat cultivars with low or nil PPO activity can reduce undesirable product darkening. The low PPO line PI 117635 was crossed to two low PPO wheats, IDO580 and ‘IDO377s’, to determine whether matings between wheats with low levels of grain PPO would result in complementation, such that lines with still lower or nil PPO would be generated. Progeny in a population derived from PI 117635/ IDO580 displayed no variation in PPO activity. In the F_3:4 populations …

Evaluation Of Public Sweet Sorghum A-Lines For Use In Hybrid Production, Jeffrey F. Pedersen, Scott E. Sattler, William F. Anderson

Department of Agronomy and Horticulture: Faculty Publications

A fundamental need for commercialization of sweet sorghum [Sorghum bicolor (L.) Moench] as a bioenergy crop is an adequate seed supply, which will require development of hybrid varieties using dwarf seed-parent lines. A set of six public sweet sorghum A-lines (Dwarf Kansas Sourless, KS9, N36, N38, N39, and N4692) were crossed with a set of six public sweet sorghum cultivars (Brawley, Kansas Collier, Dale, Sugar Drip, Waconia, and Wray). Grain, fiber, and sugar yields were determined, and conversion formulas were applied to estimate ethanol yields. Hybrids were grown in fields at Ithaca, NE, USA, in 1983– 1984 fertilized with …

Functional Characterization Of Cinnamyl Alcohol Dehydrogenase And Caffeic Acid O-Methyltransferase In Brachypodium Distachyon, Gina M. Trabucco, Dominick A. Matos, Scott J. Lee, Aaron J. Saathoff, Henry D. Priest, Todd C. Mockler, Gautam Sarath, Samuel P. Hazen

Department of Agronomy and Horticulture: Faculty Publications

Background: Lignin is a significant barrier in the conversion of plant biomass to bioethanol. Cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O-methyltransferase (COMT) catalyze key steps in the pathway of lignin monomer biosynthesis. Brown midrib mutants in Zea mays and Sorghum bicolor with impaired CAD or COMT activity have attracted considerable agronomic interest for their altered lignin composition and improved digestibility. Here, we identified and functionally characterized candidate genes encoding CAD and COMT enzymes in the grass model species Brachypodium distachyon with the aim of improving crops for efficient biofuel production.

Results: We developed transgenic plants overexpressing artificial microRNA designed …

Transcriptome Analysis Of Two Buffalograss Cultivars, Michael Wachholtz, Tiffany Heng-Moss, Paul Twigg, Lisa Baird, Guoqing Lu, Keenan Amundsen

Department of Agronomy and Horticulture: Faculty Publications

Background: Buffalograss [Buchloë dactyloides (Nutt.) Engel. syn. Bouteloua dactyloides (Nutt.) Columbus] is a United States native turfgrass species that requires less irrigation, fungicides and pesticides compared to more commonly used turfgrass species. In areas where water is limited, interest in this grass species for lawns is increasing. While several buffalograss cultivars have been developed through buffalograss breeding, the timeframe for new cultivar development is long and is limited by a lack of useful genetic resources. Two high throughput next-generation sequencing techniques were used to increase the genomic resources available for buffalograss.

Results: Total RNA was extracted and …

Complete Plastid Genomes From Ophioglossum Californicum, Psilotum Nudum, And Equisetum Hyemale Reveal An Ancestral Land Plant Genome Structure And Resolve The Position Of Equisetales Among Monilophytes, Felix Grewe, Wenhu Guo, Emily A. Gubbels, A Katie Hansen, Jeffrey P. Mower

Department of Agronomy and Horticulture: Faculty Publications

Background: Plastid genome structure and content is remarkably conserved in land plants. This widespread conservation has facilitated taxon-rich phylogenetic analyses that have resolved organismal relationships among many land plant groups. However, the relationships among major fern lineages, especially the placement of Equisetales, remain enigmatic.

Results: In order to understand the evolution of plastid genomes and to establish phylogenetic relationships among ferns, we sequenced the plastid genomes from three early diverging species: Equisetum hyemale (Equisetales), Ophioglossum californicum (Ophioglossales), and Psilotum nudum (Psilotales). A comparison of fern plastid genomes showed that some lineages have retained inverted repeat (IR) boundaries originating …

Indoor Application Of Attractive Toxic Sugar Bait (Atsb) In Combination With Mosquito Nets For Control Of Pyrethroid-Resistant Mosquitoes, Zachary P. Stewart, Richard M. Oxborough, Patrick K. Tungu, Matthew J. Kirby, Mark W. Rowland, Seth R. Irish

Department of Agronomy and Horticulture: Faculty Publications

Background: Attractive toxic sugar bait (ATSB) sprayed onto vegetation has been successful in controlling Anopheles mosquitoes outdoors. Indoor application of ATSB has yet to be explored. The purpose of this study was to determine whether ATSB stations positioned indoors have the potential to kill host-seeking mosquitoes and constitute a new approach to control of mosquito-borne diseases.

Methods: Insecticides were mixed with dyed sugar solution and tested as toxic baits against Anopheles arabiensis, An. Gambiae s.s. and Culex quinquefasciatus in feeding bioassay tests to identify suitable attractant-insecticide combinations. The most promising ATSB candidates were then trialed in experimental …

Nutrient Partitioning And Grain Yield Of Tanam-Rnai Wheat Under Abiotic Stress, Mary J. Guttieri, Ricardo J. Stein, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Aims — Decreased expression of TaNAM genes by RNAi results in delayed senescence and decreased grain protein, iron, and zinc concentrations. Here, we determined whether NAM expression level alters onset of senescence under stress conditions, whether delayed senescence in the TaNAM-RNAi line resulted in improved tolerance to post-anthesis abiotic stress, and determined the effects of post-anthesis abiotic stress on N and mineral remobilization and partitioning to grain.

Methods — Greenhouse-grown WT and TaNAM-RNAi wheat were characterized in two studies: three levels of N fertility or water limitation during grain fill. Studies were conducted under both optimal and heat stress …

Genetic Mapping And Confirmation Of Quantitative Trait Loci For Seed Protein And Oil Contents And Seed Weight In Soybean, Safiullah M. Pathan, Tri Vuong, Kerry Clark, Jeong-Dong Lee, J. Grover Shannon, Craig A. Roberts, Mark R. Ellersieck, Joseph W. Burton, P. B. Cregan, David L. Hyten, Henry T. Nguyen, David A. Sleper

Department of Agronomy and Horticulture: Faculty Publications

Demand for soybean [Glycine max (L.) Merr.] meal has increased worldwide and soybean importers often offer premiums for soybean containing higher contents of protein and oil. Objectives were to detect quantitative trait loci (QTL) associated with soybean seed protein, oil, and seed weight in a soybean mapping population and confirm detected QTL across genetic backgrounds and environments. Two populations of 216 and 156 recombinant inbred lines were developed from Magellan × PI 438489B and Magellan × PI 567516C crosses, respectively, and grown in two Missouri environments in 2008. More than 900 simple sequence repeat (SSR) and single nucleotide polymorphism …

Soybean Seed Amino Acid Content Qtl Detected Using The Universal Soy Linkage Panel 1.0 With 1,536 Snps, Benjamin D. Fallen, Catherine N. Hatcher, Fred L. Allen, Dean A. Kopsell, Arnold M. Saxton, Pengyin Chen, Stella K. Kantartzi, P. B. Cregan, D. L. Hyten, Vincent R. Pantalone

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is the primary source of meal used in animal feed in the U.S. However, few studies have been conducted to evaluate genomic regions controlling amino acid composition is soybean. Designing soybean seed compositions that will benefit animal production is essential. The objective of this study was to identify genomic regions controlling essential and non-essential amino acid composition in soybean seed proteins. To achieve this objective, 282 F_5:9 recombinant inbred lines (RILs) developed from a cross of Essex × Williams 82 were used. Ground soybean seed samples were analyzed for amino acids and statistically …

Development And Evaluation Of Soysnp50k, A High-Density Genotyping Array For Soybean, Qijian Song, D. L. Hyten, Gaofeng Jia, Charles V. Quigley, Edward W. Fickus, Randall L. Nelson, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

The objective of this research was to identify single nucleotide polymorphisms (SNPs) and to develop an Illumina Infinium BeadChip that contained over 50,000 SNPs from soybean (Glycine max L. Merr.). A total of 498,921,777 reads 35–45 bp in length were obtained from DNA sequence analysis of reduced representation libraries from several soybean accessions which included six cultivated and two wild soybean (G. soja Sieb. et Zucc.) genotypes. These reads were mapped to the soybean whole genome sequence and 209,903 SNPs were identified. After applying several filters, a total of 146,161 of the 209,903 SNPs were determined to be …

The Plant Science Decadal Vision: Response To The Martin Commentary, David Stern, Sally Ann Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

The plant science community is being called upon as never before to carry out research that addresses challenges in food, climate, and health, to educate a populace inundated with science misinformation, and to excite and recruit a new generation of scientists from among that populace, all while investments in basic research are stagnant or even declining in many countries. The Decadal Vision (Plant Science Research Summit, 2013) represents a response from that community, one that launches a meaningful and ongoing dialogue about how best to accomplish these goals. In that spirit, we welcome this thoughtful commentary by Cathie Martin (Martin, …

Chloroplast Division Protein Arc3 Regulates Chloroplast Ftsz-Ring Assembly And Positioning In Arabidopsis Through Interaction With Ftsz2, Min Zhang, Aaron J. Schmitz, Deena K. Kadirjan-Kalbach, Allan D. Terbush, Katherine W. Osteryoung

Department of Agronomy and Horticulture: Faculty Publications

Chloroplast division is initiated by assembly of a mid-chloroplast FtsZ (Z) ring comprising two cytoskeletal proteins, FtsZ1 and FtsZ2. The division-site regulators ACCUMULATION AND REPLICATION OF CHLOROPLASTS3 (ARC3), MinD1, and MinE1 restrict division to the mid-plastid, but their roles are poorly understood. Using genetic analyses in Arabidopsis thaliana, we show that ARC3 mediates division-site placement by inhibiting Z-ring assembly, and MinD1 and MinE1 function through ARC3. ftsZ1 null mutants exhibited some mid-plastid FtsZ2 rings and constrictions, whereas neither constrictions nor FtsZ1 rings were observed in mutants lacking FtsZ2, suggesting FtsZ2 is the primary determinant of Z-ring assembly in vivo. arc3 …

Resource Allocation For Maximizing Prediction Accuracy And Genetic Gain Of Genomic Selection In Plant Breeding: A Simulation Experiment, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

Allocating resources between population size and replication affects both genetic gain through phenotypic selection and quantitative trait loci detection power and effect estimation accuracy for marker-assisted selection (MAS). It is well known that because alleles are replicated across individuals in quantitative trait loci mapping and MAS, more resources should be allocated to increasing population size compared with phenotypic selection. Genomic selection is a form of MAS using all marker information simultaneously to predict individual genetic values for complex traits and has widely been found superior to MAS. No studies have explicitly investigated how resource allocation decisions affect success of genomic …

Evaluation Of Public Sweet Sorghum A-Lines For Use In Hybrid Production, Jeffrey F. Pedersen, Scott E. Sattler, William F. Anderson

Department of Agronomy and Horticulture: Faculty Publications

A fundamental need for commercialization of sweet sorghum [Sorghum bicolor (L.) Moench] as a bioenergy crop is an adequate seed supply, which will require development of hybrid varieties using dwarf seed-parent lines. A set of six public sweet sorghum A-lines (Dwarf Kansas Sourless, KS9, N36, N38, N39, and N4692) were crossed with a set of six public sweet sorghum cultivars (Brawley, Kansas Collier, Dale, Sugar Drip, Waconia, and Wray). Grain, fiber, and sugar yields were determined, and conversion formulas were applied to estimate ethanol yields. Hybrids were grown in fields at Ithaca, NE, USA, in 1983– 1984 fertilized with …

Yield Gap Analysis—Rationale, Methods And Applications—Introduction To The Special Issue, M.K. Van Ittersum, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Yield gap analysis is an increasingly popular concept. It is a powerful method to reveal and understand the biophysical opportunities to meet the projected increase in demand for agricultural products towards 2050, and to support decision making on research, policies, development and investment that is needed. This Special Issue presents the state-of-the-art about concepts, methods and applications of yield gap analysis. The methodological papers emphasize the need for agronomically sound and relevant analyses, from local to global scales. The fourteen papers provide examples of applications to different crops, climate zones and production conditions, at various spatial extents and with different …

Agricultural Innovation To Protect The Environment, Jeffrey Sayer, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

In a world of 9.5 billion people, global demand for food, fiber, and biofuels has to be met with minimal possible increases in land, water, fossil fuels, and the minerals used to produce fertilizers (1–4). The problem is debated at three levels: first, that agriculture will not be able to produce enough because it will come up against both biophysical and environmental limits that restrict yields (3, 5, 6); second, that the need to expand and intensify agriculture will destroy the broader environmental values of forests, wetlands, marine systems, and their associated biodiversity (7–9); and third, that there are institutional …

New Technologies Reduce Greenhouse Gas Emissions From Nitrogenous Fertilizer In China, Wei-Feng Feng, Zheng-Xia Dou, Pan He, Xiao-Tang Ju, David Powlson, Dave Chadwick, David Norse, Yue-Lai Lu, Ying Zhang, Liang Wu, Xin-Ping Chen, Kenneth Cassman, Fu-Suo Zhang

Department of Agronomy and Horticulture: Faculty Publications

Synthetic nitrogen (N) fertilizer has played a key role in enhancing food production and keeping half of the world’s population adequately fed. However, decades of N fertilizer overuse in many parts of the world have contributed to soil, water, and air pollution; reducing excessive N losses and emissions is a central environmental challenge in the 21st century. China’s participation is essential to global efforts in reducing N-related greenhouse gas (GHG) emissions because China is the largest producer and consumer of fertilizer N. To evaluate the impact of China’s use of N fertilizer, we quantify the carbon footprint of China’s N …

Influence Of Two Herbicides On Soybean Cyst Nematode (Heterodera Glycines) Reproduction On Henbit (Lamium Amplexicaule) Roots, Rodrigo Werle, Mark L. Bernards, Loren J. Giesler, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Soybean cyst nematode (SCN) is the most yield-limiting pathogen of soybean in the United States. Henbit is a prevalent winter annual weed species in no-till fields and is reported to be an alternative host of SCN. A greenhouse study was conducted to evaluate how the development of SCN on henbit roots was affected by herbicide mode of action and time of herbicide application. Henbit plants were grown in watertight pots placed in a water bath bench that kept soil temperature constant (27 6 1 C) during the study. Ten d after transplanting, pots were inoculated with approximately 1,000 SCN eggs. …

Maternal Environment Effects On Phenolic Defenses In Abutilon Theophrasti Seeds, Brian J. Schutte, Sam E. Wortman, John L. Lindquist, Adam S. Davis

Department of Agronomy and Horticulture: Faculty Publications

A class of phenolic compounds, ortho-dihydroxyphenols (hereafter “o-DHP”), has been implicated with seed survival. Based on expectations of the growth-differentiation balance hypothesis, we predicted that seed o-DHP concentration exhibits a curvilinear response to increasing resource availability in the maternal environment, with maximum o-DHP occurring at moderate resource levels. To test this hypothesis, Abutilon theophrasti seeds were produced under field conditions at two locations. Each location included twelve maternal environments established through factorial combinations of soil compost (+/−), species assemblage (A. theophrasti with and without maize), and soil nitrogen fertilizer (0, 0.5× or 1× local …

Seed Burial Physical Environment Explains Departures From Regional Hydrothermal Model Of Giant Ragweed (Ambrosia Trifida) Seedling Emergence In U.S. Midwest, Adam S. Davis, Sharon Clay, John Cardina, Anita Dille, Frank Forcella, John Lindquist, Christy Sprague

Department of Agronomy and Horticulture: Faculty Publications

Robust predictions of weed seedling emergence from the soil seedbank are needed to aid weed management. A common seed accession (Illinois) of giant ragweed was buried in replicate experimental gardens over 18 site years in Illinois, Michigan, Kansas, Nebraska, Ohio, and South Dakota to examine the importance of site and climate variability by year on seedling emergence. In a nonlinear mixed-effects modeling approach, we used a flexible sigmoidal function (Weibull) to model giant ragweed cumulative seedling emergence in relation to hydrothermal time accumulated in each site-year. An iterative search method across a range of base temperature (T_b) …