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A Synopsis Of The Ferns And Fern Allies Of Nebraska, With Maps Of Their Distribution, Steven B. Rolfsmeier, Robert B. Kaul, David M. Sutherland

School of Biological Sciences: Faculty Publications

An annotated list and country-by-country distribution maps are presented for the 32 species of ferns and fern allies native to Nebraska, based upon field and herbarium studies and critical evaluation of the literature. Native to the state are Isoëtes melanopoda, Selaginella rupestris, five species of Equisetum, and 25 species in 18 genera of ferns. Three native species are here verified for the first time, based upon recent collections: Matteuccia struthiopteris var. pensylvanica, Ophioglossum engelmannii, and Pellacaglabella ssp. glabella. Isoëtes melanopoda was rediscovered in 2000, the first record since 1941. Rejected are published reports of …

Polyacrylamide For Surface Irrigation To Increase Nutrient-Use Efficiency And Protectwater Quality, Rodrick D. Lentz, Robert E. Sojka, Charles W. Robbins, Dennis C. Kincaid, Dale T. Westermann

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Furrow irrigation systems have a greater application capacity, are less costly, and use less energy than sprinkler systems but furrow irrigation produces greater runoff, erosion, and deep percolation losses. Phosphorus (P) and nitrogen (N) losses are associated with runoff sediment, and can be minimized by eliminating irrigationinduced erosion. Excessive leaching of inorganic and organic solutes commonly occurs at the inflow region of furrow irrigated fields where infiltration opportunity times are longer. In one conservation practice, a high molecular weight, anionic polyacrylamide (PAM) is applied to advancing furrow stream flows at a concentration of 10 mg L^-1. Because PAM …

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 …

Uneasy Unions: Quality Effects Of Rye Chromatin Transfers To Wheat, Robert A. Graybosch

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A number of genes of agronomic importance have been transferred from rye (Seale cereale L.) to its close relative, common bread wheat (Triticum aestivum L). Largely through the production of interspecific chromosomal translocation and substitution lines, rye chromatin now rides within the genome of a large number of wheat breeding lines and cultivars. Rye chromosomal materials have been used to transfer resistance genes to fungal pathogens, especially rusts and powdery mildew, resistance to insect pests, and in some cases, may enhance grain yield, grain yield stability, and grain protein content. Unfortunately, the transfer of some rye chromosomal materials …

Net Grassland Carbon Flux Over A Subambient To Superambient Co2 Gradient, P. C. Mielnick, W. A. Dugas, H. B. Johnson, H. W. Polley, J. Sanabria

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Increasing atmospheric CO₂ concentrations may have a profound effect on the structure and function of plant communities. A previously grazed, central Texas grassland was exposed to a 200-µmol mol^-1 to 550 µmol mol^-1 CO₂ gradient from March to mid-December in 1998 and 1999 using two, 60-m long, polyethylene-covered chambers built directly onto the site. One chamber was operated at subambient CO₂ concentrations (200-360 µmol mol^-1 daytime) and the other was regulated at superambient concentrations (360-550 µmol mol^-1). Continuous CO₂ gradients were maintained in each chamber by photosynthesis during the day and …

Research Needs Concerning Non-Target Impacts Of Biological Control Introductions, K.R. Hopper

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two workshops were held in 1999 on research needs concerning non-target impacts of biological control introductions. One took place on the Internet for 9 months, and the other in Montpellier, France, for 1 day. Altogether, over 200 researchers from over 30 countries participated, representing a wide variety of viewpoints on the issues involved. The deliberations of these workshops are summarized here. Both workshops highlighted the need for retrospective studies to: (i) identify cases of significant non-target impacts; (ii) explore mechanisms involved when such impacts are found; (iii) evaluate the reliability of host-range testing protocols; and (iv) determine whether and under …

Oxidative Metabolism In Plant/Bacteria Interactions: Characterization Of The Oxygen Uptake Response Of Bacteria, C. Jacyn Baker, Norton Mock, Kenneth L. Deahl, Bryan Bailey, Daniel P. Roberts

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

An increase in oxygen uptake has been previously described in plant cell suspensions treated with bacteria or bacterial elicitors. These studies, regarding oxygen uptake, have all been undertaken from the perspective of the host plant cell reacting to the invading pathogen. In contrast, here we describe and characterize an increase in oxygen uptake by bacterial cells in response to plant suspensions or autoclaved plant cell filtrates. Autoclaved plant cell filtrates stimulated bacterial oxygen uptake by as much as sevenfold within a few minutes after addition. This oxygen uptake response was proportional to both the concentration of the plant cell filtrate …

Oxidative Metabolism In Plant/Bacteria Interactions: Characterization Of A Unique Oxygen Uptake Response Of Potato Suspension Cells, C. Jacyn Baker, E. W. Orlandi, Kenneth L. Deahl

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Plant suspension cells have been shown to respond to bacteria or microbial elicitors by producing active oxygen as well as increasing oxygen uptake. Here we characterize a unique two stage oxygen uptake response of potato suspension cells to heat-killed bacteria. Stage 1 occurred within minutes after the addition of heat-killed bacteria; the potato suspension cells responded with a rapid increase in oxygen uptake and reached a steady state approximately 50 % greater than the initial basal rate. Stage 2 began 20-30 min after this new steady state was achieved and was characterized by a slow increase in the oxygen uptake …

Induction Of Defense Responses In Tobacco By The Protein Nep1 From Fusarium Oxysporum, James C. Jennings, Patricia C. Apel-Birkhold, Norton M. Mock, C. Jacyn Baker, James D. Anderson, Bryan A. Bailey

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Fusarium oxysporum produces a 24-kDa protein, Nep1, which induces necrosis and ethylene production in leaves of many dicot plant species. Detached Nicotiana tabacum L. cv. Xanthi leaves respond with concentration-dependent necrosis after infiltration with Nep1 or when Nep1 is taken up by the vascular tissue. This response follows the induction of ethylene biosynthesis and accumulation of ACC synthase and ACC oxidase transcripts. Pretreating the leaves with 100 µl/l ethylene prior to elicitation enhanced Nep1-induced ethylene production. Nep1 (208 nM) causes extensive necrosis of mature tobacco leaf tissue when applied to Xanthi tobacco as a foliar spray (129 ml/m²). …

Conservation And Evaluation Of Natural Enemies In Ipm Systems For Bemisia Tabaci, Steven E. Naranjo

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Conservation biological control emphasizes the preservation and enhancement of natural enemies and is the cornerstone of all approaches to biological control. This review critically examines recent and current research efforts in conservation biological control by predators and parasitoids of Bemisia tabaci worldwide. A large number of natural enemy species have been identified from many agricultural systems. Further research has demonstrated that these natural enemies may act along with other mortality agents to inflict high levels of mortality on populations of B. tabaci. Less effort has been placed on determining the factors constraining or potentially enhancing biological control. The widespread …

Managing Crop Residue With Green Manure, Urea, And Tillage In A Rice–Wheat Rotation, Milkha S. Aulakh, T. S. Khera, John W. Doran, Kevin F. Bronson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Most double-crop grain farmers in South Asia remove or burn cropresidue to facilitate seedbed preparation and to avoid possible yield reductions. This results in loss of soil organic matter (SOM) and nutrients. In this study, we determined whether incorporating wheat (Triticum aestivum L.) residue, rice (Oryza sativa L.) residue, and sesbania (Sesbania aculeta L.) green manure with urea fertilizer N in a rice–wheat cropping system can improve grain yields, N use efficiency, and SOM. We incorporated wheat residue (6 Mg ha^-1, C/N = 94), rice residue (6 Mg ha^-1, C/N = 63), or …

Measures Of Denitrification In Selected South Dakota Semi-Permanent Prairie Pothole Wetlands, Beverly S. Klein

Electronic Theses and Dissertations

Wetlands are an integral part of agricultural systems in the prairie pothole regions of the North Central United States and Canadian Provinces. Little research has been done on denitrification in prairie potholes, and a better understanding of their denitrifying capability could aide in optimizing management practices near pothole areas. Most probable number (MPN) and denitrifying enzyme activity (DEA or Phase I) assays were conducted. Most probable number (MPN) measures were used to give an estimate of dissimilatory nitrate reduction to ammonia (DNRA) and denitrifying populations present in the wetlands. This study involved 3 selected semi-permanent prairie pothole wetlands near Madison, …

Early Evaluation Of Banana Cultivars For Fusarium Wilt Tolerance, Abdulkadir Aden Mohamed

Student Works (2000-2009)

Field evaluation of banana plants for disease tolerance in soil infested with Fusarium oxysporum f. sp. cubense is commonly used. The process is slow as disease expression usually takes 4-5 months, while inoculum concentration, edaphic conditions, temperature and other variables that may affect disease expression are difficult to control. An alternative method of screening plantlets at the nursery stage was developed. The technique consisted of a double tray set up; a perforated inner tray containing sterilized river sand or a sand-clay mixture (4 sand : I clay) on which hardened tissue-cultured plantlets were grown, and a larger outer containment tray …

The Genus Striga (Scrophulariaceae) In Africa, Kamal I. Mohamed, Lytton John Musselman, Charles R. Riches

Biological Sciences Faculty Publications

Twenty-eight species and six subspecies of the hemiparasitic genus Striga Lour., witchweed, occur in Africa. Twenty-two species are endemic. Witchweeds occur throughout the continent with greatest diversity in the grasslands and savannas north of the equator. Striga gesnerioides (Willd.) Vatke and S. hermonthica (Del.) Benth. have developed host-specific strains that may have distinct morphotypes. me accord these no formal taxonomic status. Striga hermonthica and S. asiatica (L.) Kuntze, limited to agroecosystems, may be recently derived from non-ruderal species. Striga hirsuta Benth. and S. lutea Lour., sometimes treated as conspecific with S. asiatica, are recognized as distinct species restricted …

Farmers’ Perceptions Of Importance, Control Methods And Natural Enemies Of Maize Stemborers At The Kenya Coast, M. J. Bonhof, A. Van Huis, F. G. Kiros, N. Dlbogo

All Peer-Reviewed Publications

A survey among 240 resource-poor farmers at the Kenya coast indicated that insect pests were considered to be the main production constraint. Over 70% of respondents mentioned stemborers to be the most important insect pest. Unlike the eggs and adults, stemborer larvae and pupae were frequently seen by farmers. Alternative gramineous host plants for pests were common near maize fields and were often not destroyed until after the first rains. Nearly all farmers left dry stems and stubble in the field after harvest. Farmers knew of many methods for controlling stemborers, but only 32 and 56% of farmers in Kilifi …

Distribution And Abundance, In Maize And Sorghum, Of Lepidopteran Stemborers And Associated Indigenous Parasitoids In Zanzibar, E. I. Nlyibigira, Z. S. Abdallah, W. A. Overholt

All Peer-Reviewed Publications

Studies to determine the relative abundance and distribution of stemborer species and their associated parasitoids in maize and sorghum were carried out during the 1995-1996 and 19992000 cropping seasons on Unguja and Pemba, the two main islands of Zanzibar. Three stemborer species were found on both islands in maize and sorghum, with the exotic species Chilo partellns (Swinhoe) (Crambidae) being the most abundant and widely distributed species, accounting for 75.3 % of stemborer attack. It was followed by Sesamia calamistis Hampson (Noctuidae) and C/i. oriclialcociliellus Strand (Crambidae). Stemborer abundance was significantly higher in Pemba (1.47 ± 0.20) than Unguja (0.85 …

Greenhouse Trials Of New Bacillus Thuringiensis Isolates For Control Of Chilo Partellus Larvae In Sorghum, Michael Brownbridge

All Peer-Reviewed Publications

Eight new Bacillus thuringiensis Berliner (Bt) isolates originally recovered from different source materials and geographic locations in Kenya were tested against Chilo partellus (Swinhoe) on sorghum grown in a greenhouse. All isolates had been demonstrated previously to be toxic to this pest. Bt strains were cultured in a liquid growth medium and preserved as powders for experimental application. Three-week-old sorghum plants (4-6 leaves) were artificially infested with 20 neonate C. partellus and sprayed 24 h later with Bt suspensions. Non-infested sorghum and infested non-treated sorghum served as the comparative checks within each experimental trial. Plant development and dead-heart formation were …

Investigations On The Environmental Significance And The Bioavailability Of Heavy Metals In Soils, Inaam Ali Abdallah Saad

Student Works (2000-2009)

Heavy metals contaminated soils pose a continuing and increasing threat to human health, the increased inputs of heavy metals from the widespread disposal of industrial wastes have created an Increased attention on the issue of their fate. bioavailability and environmental significance. These Investigations were carried mainly to study the solid - solution phase distribution, chemical speciation and plant uptake of cadmium (Cd), lead (Pb), nickel (Ni) and zinc (Zn) in three contrasting soils amended with Cd, Pb. Ni and Zn nitrate sails at rates of 5-40 mmol/kg for incubation time varied between 3-15 month. Although heavy metal cations adsorbed to …

Currents, A 'Berry' Good Addition To Your Garden, Dennis Hinkamp

All Current Publications

No abstract provided.

Insecticides: Ask Questions First, Shoot Later, Dennis Hinkamp

All Current Publications

No abstract provided.

D13c Signatures Of Flora, Macrofauna And Sediment Of A Mangrove Forest Partly Affected By Sewage Wastes, J F Machiwa

Tanzania Journal of Science

Stable carbon isotope ratios (d13C) of sediments, suspended particulate matter, and crab gut content from Maruhubi mangrove forest, Zanzibar, were determined. Stable carbon isotope ratios were used to determine sources of organic matter in the forest. Mangrove organic carbon (d13C±SD = - 27.97±0.25) was found to be an important component of the sediment organic matter except at the marine fringe zone (d13C±SD = - 17.26±0.83). The areal distribution of d13C values show that the marine fringe zone was rich in organic carbon of marine origin. The terrestrial fringe zone was dominated by a mixed source of sediment organic carbon (d13C±SD …

The Prairie Naturalist Volume 32, No.4 December 2000

The Prairie Naturalist

LOCATING NESTS OF BIRDS IN GRASSLANDS FROM A MOBILE TOWER BLIND ▪ . T. F. Fondell, S. T. Hoekman, and L J. Ball

OBSERVATIONS ON SMALL MAMMALS RECOVERED FROM OWL PELLETS FROM NEBRASKA ▪ J J Huebschman, P. W Freeman, H. H. Genoways, and J A. Gubanyi

DlSTRIBUTION, HABITAT USE, AND NESTING SUCCESS OF HENSLOW'S SPARROW IN OKLAHOMA ▪ D. L. Reinking, D. A. Wiedenfeld, D. H. Wolfe, and R. W. Rohrbaugh, Jr.

REPRODUCTIVE SUCCESS OF PIPING PLOVERS ON ALKALI LAKES IN NORTH DAKOTA AND MONTANA ▪ R. K. Murphy, M. J. Rabenberg, M. L. Sondreal, B. R. Casler, and …

An Enhancer Trap Line Associated With A D-Class Cyclin Gene In Arabidopsis, Kankshita Swaminathan, Yingzhen Yang, Natasha Grotz, Lauren Campisi, Thomas Jack

Dartmouth Scholarship

In yeast and animals, cyclins have been demonstrated to be important regulators of cell cycle progression. In recent years, a large number of A-, B-, and D-class cyclins have been isolated from a variety of plant species. One class of cyclins, the D-class cyclins, is important for progression through G1 phase of the cell cycle. In Arabidopsis, four D-class cyclins have been isolated and characterized (CYCLIN-D1;1, CYCLIN-D2;1,CYCLIN-D3;1, and CYCLIN-D4;1). In this report we describe the characterization of a fifth D-class cyclin gene,CYCLIN-D3;2 (CYCD3;2), from Arabidopsis. An enhancer trap line, line 5580, …

Comparative Phenology Of Acacia Berlandieri, A. Minuata, A. Rigidula, A. Schaffneri, And Chloroleucon Ebano In The Lower Rio Grande Valley Of Texas, Melissa R. Eddy

Theses and Dissertations - UTB/UTPA

A phenological study of Acacia berlandieri, A. minuata, A. rigidula, A. schaffneri, and Chloroleucon ebano was conducted at three sites in the lower Rio Grande Valley of Texas from July 1998 to August 1999. Flowering in Acacia species occurred between January and April 1999, and was influenced by precipitation only in A. minuata . The timing of flowering appears to be influenced by the amount of time needed for fruit maturation. Precipitation, photoperiod, and temperature influenced the timing of fruiting in all species except A. berlandieri . Shoot elongation and leaf maturation in Acacia species were positively correlated with …

The Vascular Flora Of Prentice Cooper State Forest And Wildlife Management Area, Tennessee, John Trevor Beck

Masters Theses and Doctoral Dissertations

The vascular plants of Tennessee's Prentice Cooper State Forest and Wildlife Management Area were gathered from 112 collection trips made during the growing seasons of 1998 and 1999. Prentice Cooper has an interesting and a rich flora. I collected 2,313 specimens and examined 110 herbarium specimens. The flora is comprised of 139 families, 512 genera, and 1,038 species and lesser taxa. The four largest families are Asteraceae (128 species-12% of the flora), Poaceae (106 species-10%), Cyperaceae (64 species-6%), and Fabaceae (57 species-5%). These four families represent approximately 34% of the total flora. Numerous county extensions, as well as rare, threatened, …

Transgene And Transposon Silencing In Chlamydomonas Reinhardtii By A Deah-Box Rna Helicase, Dancia Wu-Scharf, Byeong-Ryool Jeong, Chaomei Zhang, Heriberto D. Cerutti

Center for Plant Science Innovation: Faculty Publications

The molecular mechanism(s) responsible for posttranscriptional gene silencing and RNA interference remain poorly understood. We have cloned a gene (Mut6) from the unicellular green alga Chlamydomonas reinhardtii that is required for the silencing of a transgene and two transposon families. Mut6 encodes a protein that is highly homologous to RNA helicases of the DEAH-box family. This protein is necessary for the degradation of certain aberrant RNAs, such as improperly processed transcripts, which are often produced by transposons and some transgenes.

How To Set Up A Mediterranean Fruit Fly Community Baiting Scheme, Sonya Broughton

Biosecurity published reports

Second edition.

The Mediterranean fruit fly (Medfly) is one of the most serious economic pests, infesting over 300 fruit and vegetable species worldwide. Medfly is thought to originate from Africa and is a pest in many countries including North America, Central America, South Africa, Europe and Australia. In Australia, Medfly is present only in Western Australia where it is considered to be naturalised. Although Medfly are occasionally detected in eastern Australia, these outbreaks are eradicated at considerable expense by local agricultural departments.

For Western Australia, Medfly poses a serious threat to backyard and commercial fruit production, and restricts access to …

Mortality Of Escherichia Coli O157:H7 In Two Soils With Different Physical And Chemical Properties, D. N. Mubiru, Mark S. Coyne, John H. Grove

Plant and Soil Sciences Faculty Publications

Wild and domesticated animals can harbor a pathogenic Escherichia coli strain designated as O157:H7. Potential health problems could occur if strain O157:H7 is a more robust survivor in defecated waste than commonly used indicator bacteria. A laboratory study was conducted to assess E. coli O157:H7 survival relative to a nonpathogenie E. coli strain in two soils with different physical and chemical characteristics. Bacteria in the inoculated soils were enumerated on a weekly basis for 8 wk using a most probable number (MPN) technique. First-order decay models were used to describe bacteria mortality in the soils. Decay series were described slightly …

Botanizing With Darwin, Duncan M. Porter

Virginia Journal of Science

Note: Sidney S. Negus Memorial Lecture, Radford University, May 25, 2000

From the introduction: In this paper, I will take a look at Darwin's life and some of his botanical and other interests. I will also indicate where his and my paths have crossed during my own career as a botanist.

Ornamental And Turf Pest Control, Larry A. Sagers

All Archived Publications

No abstract provided.