Life Sciences Commons^™

Genetic Control Of Photoprotection And Photosystem Ii Operating Efficiency In Plants, Seema Sahay, Marcin Grzybowski, James Schnable, Katarzyna Głowacka

Department of Biochemistry: Faculty Publications

• Photoprotection against excess light via nonphotochemical quenching (NPQ) is indispensable for plant survival. However, slow NPQ relaxation under low light conditions can decrease yield of field-grown crops up to 40%.

• Using semi-high-throughput assay, we quantified the kinetics of NPQ and photosystem II operating efficiency (ΦPSII) in a replicated field trial of more than 700 maize (Zea mays) genotypes across 2 yr. Parametrized kinetics data were used to conduct genome-wide association studies.

• For six candidate genes involved in NPQ and ΦPSII kinetics in maize the loss of function alleles of orthologous genes in Arabidopsis (Arabidopsis thaliana) …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to …

Clavibacter Nebraskensis Causing Goss's Wilt Of Maize: Five Decades Of Detaining The Enemy In The New World, Ebrahim Osdaghi, Alison E. Robertson, Tamra A. Jackson-Ziems, Hamid Abachi, Xiang Li, Robert M. Harveson

Department of Plant Pathology: Faculty Publications

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram-positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high-risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to maize production …

A Glass Bead Semi‑Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares4, Daniel P. Schachtman, Sophie Alvarez, Karin Van Dijk

Department of Biochemistry: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage.

Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl …

Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2018, Katharine A. Swoboda-Bhattarai, Samantha R. Daniel, Julie A. Peterson

West Central Research and Extension Center, North Platte

The objectives of this field trial were to evaluate the efficacy of single applications of foliar insecticides at preventing feeding damage by the western bean cutworm (WBC), an important pest of corn and dry beans that has undergone a rapid range expansion into the eastern Corn Belt during the last 18 yr. This study was conducted within the historic range of WBC, at the University of Nebraska-Lincoln’s Henry J. Stumpf International Wheat Center in Perkins County, NE (40.856851°N, −101.701335°W). An RCB design with a total of 16 treatments (including an untreated check) and four replications was used. Plots measured 20 …

Susceptibility Of Corn To Stink Bug (Dichelops Melacanthus) And Its Management Through Seed Treatment, Paulo Roberta Da Silva, Ademar Novais Istchuk, Thomas E. Hunt, Cristina Schetino Bastos, Jorge Braz Torres, Karolayne Lopes Campos, Josemar Foresti

Department of Entomology: Faculty Publications

We determined the susceptibility of vegetative corn stages to Dichelops melacanthus damage, and how seed treatment can reduce damage and yield loss. Two field trials were carried out. In the first, corn plants were artificially infested with D. melacanthus male/female pairs at rate of 0.5 pair per plant at different vegetative stages and infestation periods lasting 7-28 days (V1-V3, V1-V5, V1-V7, V1-V9, V3-V5, V3-V7, V3-V9, V5-V7, V5-V9, and V7-V9), plus a control without infestation. In the second, corn plants were artificially infested at a rate of one male/female pair per plant at different vegetative stages and infestation periods (V1-V3, V1-V5, …

Evaluation Of Seed Treatments And At-Plant Soil Insecticides For The Control Of Wireworms (Coleoptera: Elateridae) In Field Corn, 2015, Kayla A. Mollet, Jonas Victor De Macedo, Grace E. Hirzel, C. Oliveira-Hofman, Julie A. Peterson

Department of Entomology: Faculty Publications

Wireworms are an important pest of corn, other field crop seedlings, and vegetables and can cause significant damage if not controlled. This field trial was established to evaluate the efficacy of neonicotinoid seed treatments and in-furrow soil insecticides to protect seedling field corn under a heavy wireworm pressure scenario. The trial was conducted on a commercial production field in Perkins County near Madrid, NE (40.781993° N, −101.463666° W). The field was selected for its likelihood to have heavy wireworm pressure due to the following: 1) past farmer observations of crop damage when planted to field corn in 2012; 2) sandy …

Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2017, Katharine A. Swoboda-Bhattarai, Grace E. Hirzel, Julie A. Peterson

Department of Entomology: Faculty Publications

The objective of this field trial was to evaluate the efficacy of a single application of foliar insecticides at preventing feeding damage by the western bean cutworm (WBC), an important pest of corn and dry beans. Direct feeding by WBC larvae on developing kernels in the ear can result in yield loss, whereas WBC infestation can also lead to secondary fungal infections. WBC has undergone a rapid range expansion into the eastern Corn Belt within the last 16 yr. This study was conducted within the historic range of WBC, at the University of Nebraska-Lincoln’s Henry J. Stumpf International Wheat Center …

Performance Of Seed Treatments And In-Furrow At-Plant Insecticides For Protection Against Cry3bb1-Resistant Western Corn Rootworm, 2015, Jonas Victor De Macedo,, Kayla A. Mollet, Julie A. Peterson

Department of Entomology: Faculty Publications

The western corn rootworm is an important pest of corn that can compromise yield by feeding on plant roots during its larval stage. WCRW management has been complicated by the development of resistance in some regions, including Nebraska, to transgenic Bacillus thuringiensis (Bt) traits, particularly the protein Cry3Bb1, which confers cross-resistance to mCry3A. A field trial was established to evaluate the efficacy of neonicotinoid seed treatments in combination with in-furrow insecticides on a corn hybrid expressing mCry3A Bt proteins against corn rootworm in an area with a history of rootworm resistance. The trial was conducted in a farmer’s field in …

Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2015, Débora G. Montezano, Kayla A. Mollet, Grace E. Hirzel, Julie A. Peterson

Department of Entomology: Faculty Publications

The western bean cutworm (WBC) is an important pest of corn and dry beans. This study was conducted within the historic range of WBC in western Nebraska; however, it has undergone a rapid range expansion into the eastern Corn Belt within the last 16 years. This field trial was established to evaluate the efficacy of a single application of foliar insecticides against this pest to prevent feeding damage to non-Bt corn ears. The trial was located at the University of Nebraska-Lincoln’s West Central Water Resources Field Laboratory in Keith County, Nebraska, USA (41.160246° N, –102.035695° W). A RCB design with …

Evaluation Of Foliar Insecticides For The Control Of Western Bean Cutworm In Field Corn, 2016, Débora G. Montezano, Kayla A. Mollet, Grace E. Hirzel, Julie A. Peterson

Department of Entomology: Faculty Publications

The western bean cutworm (WBC) is an important pest of corn and dry beans. In addition to yield loss due to direct feeding on developing kernels in the ear, WBC infestation can also lead to secondary fungal infections. This study was conducted within the historic range of WBC in western Nebraska; however, it has undergone a rapid range expansion into the eastern Corn Belt within the last 16 years. This field trial was established to evaluate the efficacy of a single application of foliar insecticides against this pest to prevent feeding damage to non-Bt corn ears. The trial was located …

Hybrid And Environment Effects On Popcorn Kernel Physiochemical Properties And Their Relationship To Microwave Popping Performance, Jess C. Sweley, Devin J. Rose, David S. Jackson

Department of Food Science and Technology: Faculty Publications

The objective of this study was to characterize the effect of hybrid and environment on physical and chemical characteristics of popcorn kernels that have shown importance in predicting end-use quality. Three popcorn hybrids grown in three different environments were tested for physiochemical attributes and popping performance. Hybrid had a significant effect on kernel sphericity, time-to-grind, dietary fiber, sugars, and starch. Environment effect alone affected total mineral content. Hybrid and environment main effects influenced test weight, tangential abrasive dehulling device index, thousand-kernel weight, total carbohydrates, and kernel protein content. Oil adherence to the bag averaged 15.8% and was proportional to oil …

Using Sex Pheromone Traps In The Decision-Making Process For Pesticide Application Against Fall Armyworm (Spodoptera Frugiperda [Smith] [Lepidoptera: Noctuidae]) Larvae In Maize, Ivan Cruz, Maria De Lourdes Corrêa Figueiredo, Rafael Braga Da Silva, Ivana Fernandes Da Silva, Cristiane De Souza Paula, John E. Foster

Department of Entomology: Faculty Publications

The fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), is a major pest of maize and frequently demands control measures. The timing of insecticide application is a key factor in determining its efficiency, so an experiment was designed to investigate this. Application of insecticide was based on three criteria: (i) the number of trap-caught moths in a Delta-type trap with a commercial sex pheromone lure placed in the center of the target area, soon after plant emergence; (ii) the percentage of plants exhibiting pinhole-type damage (10% or 20%), and (iii) the percentage of plants exhibiting shot hole–type damage (10% or 20%) …

Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood

West Central Research and Extension Center, North Platte

Dietary diversification, including consumption of plant tissues such as pollen, can enhance the fecundity of generalist predators, resulting in improved control of pest prey. Supplemental pollen feeding has been observed in many natural enemies, including sheet-web spiders (Araneae: Linyphiidae), which represent a major component of food webs in agroecosystems. Their horizontal, ground-based webs have the potential to intercept pollen grains during anthesis of crop plants, providing the opportunity for consumption of pollen to occur. In laboratory feeding trials, Frontinella communis and Tennesseellum formicum (Araneae: Linyphiidae) readily fed on pollen grains dusted on their webs, with 82 and 92% of spiders …

Western Corn Rootworm ( Diabrotica Virgifera Virgifera Leconte) Population Dynamics, Lance Meinke, Thomas W. Sappington, David W. Onstad, Thomas Guillemaud, Nicholas Miller, Judit Komáromi, Nora Levay, Lorenzo Furlan, József Kiss, Ferenc Toth

Department of Entomology: Faculty Publications

1 The western corn rootworm Diabrotica virgifera virgifera LeConte is a major insect pest of field maize, Zea mays L. Larvae can cause substantial injury by feeding on maize roots. Larval feeding may destroy individual roots or root nodes, and reduce plant growth, stability, and yield. Costs associated with managing corn rootworms in continuous maize are annually one of the largest expenditures for insect management in the United States Corn Belt.

2 Even though D. virgifera virgifera has been studied intensively for over 50 years, there is renewed interest in the biology, ecology, and genetics of this species because of …

Mitochondrial Dna Variation And Range Expansion In Western Bean Cutworm (Lepidoptera: Noctuidae): No Evidence For A Recent Population Bottleneck, Nicholas Miller, David L. Dorhout, Marlin E. Rice, Thomas W. Sappington

Department of Entomology: Faculty Publications

The western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a pest of both corn and dry bean crops. At the beginning of the 21st century, the species began to extend its range out of the Great Plains, eastward through the Corn Belt. This rapid range expansion is remarkable because the species distribution had been stable for at least the previous half century, despite the apparent abundance of suitable habitat (i.e., cornfields) immediately to the east. We hypothesized that if the western bean cutworm had to overcome a stable barrier to movement before starting the current range expansion, it probably …

In-Field Labeling Of Western Corn Rootworm Adults (Coleoptera: Chrysomelidae) With Rubidium, Timothy M. Nowatzki, Bradley Niimi, Kelli J. Warren, Sean Putnam, Lance J. Meinke, David C. Gosselin, F. Edwin Harvey, Thomas E. Hunt, Blair D. Siegfried

Department of Entomology: Faculty Publications

Field and laboratory studies were conducted in 2000 and 2001 to determine the feasibility of mass marking western corn rootworm adults, Diabrotica virgifera virgifera LeConte, with RbCl in the field. Results showed that application of rubidium (Rb) in solution to both the soil (1 g Rb/plant) and whorl (1 g Rb/plant) of corn plants was optimal for labeling western corn rootworm adults during larval development. Development of larvae on Rb-enriched corn with this technique did not significantly influence adult dry weight or survival. Rb was also highly mobile in the plant. Application of Rb to both the soil and the …

Cultivar-Dependent Expression Of A Maize Lipoxygenase Responsive To Seed Infesting Fungi, Richard A. Wilson, Harold W. Gardner, Nancy P. Keller

Fungal Molecular Plant-Microbe Interactions

Maize kernels are highly susceptible to Aspergillus spp. infection and aflatoxin (AF) contamination. Fatty acid signaling molecules appear to mediate the plant–fungal interaction by affecting the growth, development, and AF production of the fungus. In particular, fatty acid derivatives of the plant lipoxygenase (LOX) pathway are implicated in the Aspergillus spp.-seed interaction. The 9(S)-hydroperoxide derivative of linoleic acid promotes transcription of AF genes, whereas the 13(S)-hydroperoxide derivative decreases AF gene expression and production; both are sporulation factors. Our goal was to identify LOX genes responsive to Aspergillus spp. colonization and determine their specificities, 9(S)- …

Sterol Composition Of The Corn Root Lesion Nematode, Pratylenchus Agilis, And Corn Root Cultures, David J. Chitwood, William R. Lusby

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Sterols from mixed stages of the com root lesion nematode, Pratylenchus agilis, and uninfected corn root cultures were analyzed by gas chromatography-mass spectrometry. Twenty-eight sterols were identified in P. agilis, including nine not previously detected in nematodes. The major sterols were 24-ethylcholest-22-enol, 24-ethylcholesta-5,22-dienol, 24-methy1cholestanol, 24-ethylcholestanol, isofucostanol, and 24-ethylcholesterol. The principal corn root sterols were 24-ethylcholesta-5,22-dienol, 24-methylcholesterol, 24-ethylcholesterol, isofucosterol, and cycloartenol. Therefore, the major metabolic transformation of sterols by P. agilis was saturation of the sterol nucleus. In addition, very small amounts of 4α-methylsterols were biosynthesized by P. agilis. The 4-methylation pathway is unique to nematodes and was …

Concentration Of Maize Chlorotic Mottle Virus Increased In Mixed Infections With Maize Dwarf Mosaic Virus, Strain B, Karen-Beth Goldberg, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

The concentration of maize chlorotic mottle virus (MCMV) was up to 5.4 times higher in plants infected with both MCMV and maize dwarf mosaic virus. strain R (MDMV-BE. rhan in plants infected with MCMY only. The concentration of MDMV-B was the same in doubly and singly infected plants. Plants infected with both viruses had a reduced level of chlorophyIl and a lower than normal ratio of chloroplast to cytoplasmic rRNA. Purified MCMV had an extinction coefficient of 6.7 cm² mg^-1 at 260 nm, an absorption maximum at 258 nm, minimum at 240 nm, and 25% RNA.

Simulation Studies Of Corn Hybrid-Climate Response In Nebraska, R. E. Neild, N. H. Richman

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Crop development models can be used to determine the expected phenological responses of corn hybrids to different planting dates and locations. The number of days from planting to maturity for a particular hybrid varies considerably between different dates of planting at a single location and between locations at the same planting date.

Growing Degree Days Predictions For Corn And Sorghum Development And Some Applications To Crop Production In Nebraska, R. E. Neild, M. W. Seeley

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The concept of growing degree days (GDD) originated with observations by Reamur (1735) that plant development is more closely related to the temperature accumulated to a given stage than with time alone. It was not until nearly 200 years later, however, that Merriam (1894), Livingston (1916) and Klages (1942) began to use temperature accumulations in plant distribution studies and in crop geography. In the early 1950's, a system involving growing degree days became widely used in the canning industry to schedule plantings and thus control time of harvest of rapidly maturing vegetables. This system provided a more precise control of …

Leaf Freckles And Wilt Of Corn Incited By Corynebacterium Nebraskense Schuster, Hoff, Mandel, Lazar, 1972, M. L. Schuster

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The new bacterial disease Leaf Freckles and Wilt (LFW) of corn (Zea mays L.) was first observed in 1969 on two farms in southcentral Nebraska. Since then it has spread to other areas in the state. LFW is a serious disease on farms in six Nebraska counties (Clay, Custer, Dawson, Furnas, Hall and Phelps) and has been found in isolated cases in at least 28 other counties. In 1971 LFW was found in a seedcorn field in western Iowa, in 1973 in two Kansas counties, and in 1974 in South Dakota and Colorado. Because of its explosive nature, several …

European Corn Borer, Ostrinia Nubilalis (Hbn.) Populations In Field Corn, Zea Mays (L.) In The North Central United States, R. E. Hill, A. N. Sparks, C. C. Burkhardt, H. C. Chiang, M. L. Fairchild, W. D. Guthrie

Nebraska Agricultural Experiment Station: Historical Research Bulletins

A long-range study of the annual changes in corn borer populations in the North Central States was started in Minnesota, Iowa, Kansas and Nebraska in 1955 and in Missouri and Ohio in 1956. This investigation was a phase of a broader Regional Project, NC-20, entitled "Factors Influencing Corn Borer Populations" and was undertaken to measure by standardized procedures the seasonal changes in abundance of the European corn borer, Ostrinia nubilalis (Hbn.), under cropping procedures in different locations within, the North Central States. Much valuable information has been accumulated on the abundance and effects of various physical and biotic factors on …

The Effects Of Irradiating Dormant Maize Seeds With Xrays And Thermal Neutrons, Rosalind Morris, E. F. Frolik

Nebraska Agricultural Experiment Station: Historical Research Bulletins

In 1951 a research program was started at the University of Nebraska to compare the developmental effects of thermal neutrons and X rays on different crop seeds. Three crops, barley, tomato and maize, were chosen for additional information involving induced chromosomal aberrations and seedling mutations. The maize investigations are presented in this bulletin, along with a comparison among the three crops with respect to irradiation effects.

Progress From Recurrent Selection Procedures For The Improvement Of Corn Populations, John H. Lonnquist

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The possibilities of developing synthetic varieties suitable for the fringe areas of the corn belt, where cost of hybrid seed is high relative to the value of the expected crop, and in areas where hybrid corn might not be a feasible approach for other reasons, made it seem a worthwhile objective for study. Effort has been made in recent years to increase the productivity of hybrid combinations through selection of new superior lines using standard breeding procedures. The limited progress realized has resulted in an increased interest in the possible use of alternate methods for the development of superior germplasm …

The Significance Of Xenia Effects On The Kernel Weight Of Corn, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The purpose of this paper is to appraise the xenia effects of the pollen parent on the kernel weight of corn (Zea mays L.), and to interpret so far as possible their genetic, physiologic and applied significance. The conclusions will be based on local experiments and a review of the literature.

Progressive Development And Seasonal Variations Of The Corn Crop, T. A. Kiesselbach

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The chief purpose of these studies has been to determine the normal growth changes that occur in the corn plant at successive intervals when growing in the field, and to observe annual yield variations in relation to prevailing weather conditions. Aside from supplying information regarding the physiology of this crop, the data are of interest to the corn grower because they indicate comparative yields, shelling percentages, moisture contents, and feed constituents at various stages of development. Some data also are presented concerning the effects of frost, drouth, day length, and the economic value of tillers and seminal roots.