Other Plant Sciences Commons^™

Promoters From Chlorellavirus Genes Providing Expression Of Genes In Prokaryotic And Eukaryotic Hosts, Amitava Mitra, James L. Van Etten

Department of Plant Pathology: Faculty Publications

The invention is directed to novel promoters or mutants thereof from Chlorella virus DNA methyltransferase genes. A Chlorella virus gene promoter is operably linked to a first and/or second DNA sequence encoding a gene that is different from the Chlorella virus gene to form an expression cassette. An expression cassette can be introduced into prokaryotic and/or eukaryotic cells and can provide for a high level of expression of the gene encoded by the first and/or second DNA sequence. The invention also provides a method for screening other Chlorella virus genes for promoters that can function to express a heterologous gene …

Germplasm And Cultivar Development, M. D. Casler, Jeffrey F. Pedersen, G. C. Eizenga, S. D. Stratton

Department of Agronomy and Horticulture: Faculty Publications

Cool-season forage grasses have evolved, and continue to evolve, in natural ecosystems subject to environmental factors both in the presence and absence of human influences. The literature often lacks facts describing the evolution and domestication of forage grasses. Furthermore, the literature on this subject mainly deals with evolution of species in the broad scope, i.e., on a scale of hundreds of thousands or millions or years. Thus, some of our conclusions are necessarily speculative and are highly subject to the nature of the research that has been reported. We describe the forces of selection that act upon cool-season forage grasses …

The Complete Nucleotide Sequence And Genome Organization Of The M Rna Segment Of Peanut Bud Necrosis Tospovirus And Comparison With Other Tospoviruses, Satyanarayana Tatineni, S. E. Mitchell, D. V. R. Reddy, S. Kresovich, R. Jarret, R. A. Naidu, S. Gowda, J. W. Demski

Department of Plant Pathology: Faculty Publications

The M RNA of peanut bud necrosis virus (PBNV; synonym groundnut bud necrosis virus) is 4801 nucleotides in length. It comprised two ORFs in an ambisense organization and terminal inverted repeats. The 3' large ORF (3363 nucleotides in the virus-complementary strand) encoded a protein with a predicted size of 127.2 kDa which was identified as the glycoprotein precursor (GP) of the G1 and G2 glycoproteins. A comparison of the deduced amino acid sequence of GP revealed 37 % identity and 58-59% similarity with that of tomato spotted wilt virus (TSWV, serogroup I) and impatiens necrotic spot virus (INSV, serogroup III), …

Peanut Bud Necrosis Virus: Purification Of Nucleocapsids And Sequence Homology Of Nucleocapsid Protein And Glycoprotein Precursor With Other Tospoviruses, Satyanarayana Tatineni, S. E. Mitchell, D. V. R. Reddy, S. Brown, S. Kresovich, R. Jarret, S. Gowda, R. A. Naidu, J. W. Demski

Department of Plant Pathology: Faculty Publications

A procedure for the purification of peanut bud necrosis virus (PBNV) nucleocapsids was developed. Virus particles were treated with nonionic detergent to disrupt the envelope membrane and free nucleocapsids were separated. into three lightscattering zones after sucrose gradient centrifogation. Nucleocapsids from the top zone contained S RNA and traces ofM RNA; whereas, nucleoplasids from the middle zone contained M RNA with detectable levels of S RNA and those from the bottom zone contained L RNA with traces of M and S RNAs. Clones from a cDNA library made from the purified PBNV Sand M RNAs were characterized and sequenced. Comparison …

Diagnosis And Resistance Breeding Of Peanut Bud Necrosis Virus, D. V. R. Reddy, Satyanarayana Tatineni, S. L. Dwivedi, A. S. Ratna, A. A. M. Buiel, G. V. Ranga Rao, S. N. Nigam, R. A. Naidu, H. T. Hsu, J. W. Demski

Department of Plant Pathology: Faculty Publications

The occu!fence of peanut bud necrosis (PBN) disease in India was first reported in 1968. The high incidence ofPBN disease during the 1960s coincided with largescale imports of the peanut cultivars Asiria Mwitundae and Spanish Improved, both of which are highly susceptible to PBN. Since then, a number of reports have been published in India describing bud necrosis under at least seven different names (Reddy 1988). Crop losses due to PBN have been estimated at USD89 million per year in India during 1976-1986. The disease is also currently recognized as economically important in Nepal (Sharma 1996), in Sri Lanka, and …

Application Of The Single Kernel Wheat Characterization Technology To Sorghum Grain, Jeffrey F. Pedersen, C. R. Martin, F. C. Felker, J. L. Steele

Department of Agronomy and Horticulture: Faculty Publications

A single kernel wheat characterization system (SKWCS) was recently developed by the USDA, ARS Grain Marketing Research Laboratory and is currently being marketed by Perten Instruments North America, Inc. This device has been shown to accurately measure individual seed hardness, moisture, and size of wheat. The objective of this study was to determine if the SKWCS technology could be applied to the measurement of sorghum grain. Grains from 64 sorghum plots grown at Mead, NE in 1992 were characterized using a prototype SKWCS at the USDA, ARS Grain Marketing Research Laboratory. Problems encountered were primarily associated with the single kernel …

Molecular Diagnostics Of Three Diabrotica (Coleoptera: Chrysomelidae) Pest Species, Allen L. Szalanski, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

A 257 bp region of the mitochondrial ND4 gene was analyzed for genetic variation in three species of corn rootworm, southern corn rootworm (Diabrotica undecim punctata howardi Barber, SCR), northern corn rootworm (D. barberi Smith and Lawrence, NCR), and western corn rootworm (D. virgifera virgifera LeConte, WCR). Nucleotide sequencing revealed 26 polymorphic sites. Genetic distances averaged 8% for all pair-wise comparisons among the three species. Restriction maps were constructed from sequence data and compared to potential species specific restriction sites. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) revealed three restriction enzymes (Alu I, Apo I …

Annual Forages: New Approaches For C-4 Forages, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

The current agricultural paradigm in the U.S. is heavily biased towards the production and marketing of crops as commodities. This paradigm is kept in place by grain handling and marketing infrastructure, as well as government farm programs, designed for crops as commodities. Sorghum (Sorghum bicolor L. Moench) and maize (Zea mays L.) grown for grain certainly fit into this current paradigm.

A new approach to agricultural production and marketing, identity preserved products, is gaining in importance. This is made possible through new technologies and markets demanding products designed specifically for their needs. Examples of investment in identity preserved …

Breeding Sorghum And Pearl Millet For Forage And Fuel, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Sorghum [Sorghum bicolor (L.) Moench] and pearl millet [Pennisetum glaucum (L.) R. Br.] are unique species in their ability to be used in many forage llivestock system roles. Such flexibility has made prioritizing breeding objectives difficult and has even contributed to contradictory opinions on appropriate forage breeding objectives. Few breeding projects identified in the USDA-ARS, USDA-CREES, or at ICRISAT had forage sorghum or forage pearl millet as their sole research assignment. In the United States, it can be argued that breeding resources committed to forage sorghum improvement are probably declining. A new forage sorghum and forage pearl millet …

Media Effects On Phenotype Of Callus Cultures Initiated From Photoperiod-Insensitive, Elite Inbred Sorghum Lines, H. F. Kaeppler, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor L. Moench) is a crop of worldwide agronomic importance. Routine production of high quality (friable, embryogenic, fast growing) callus cultures is fundamental to tissue culture based genetic study and improvement of sorghum. Genotype by culture medium interactions for sorghum callus growth and morphology have been previously reported. The objective of this study was to identify tissue culture media that would support high quality callus growth across photoperiod insensitive, relatively elite genotypes. Explants from immature inflorescences of 11 sorghum genotypes were cultured on 6 tissue culture media of differing composition. After 3 and 5 months in culture, calli …

An Automated Plot Harvest System For Use With A Commercial Forage Harvester, Jeffrey F. Pedersen, Kenneth J. Moore

Department of Agronomy and Horticulture: Faculty Publications

This automated harvest system is based on minimal modification of currently available commercial forage harvesters. Using 6.8 m plots separated by 0.75 m alleys, a single operator can harvest, finely chop, and collect wet plot weights of forage sorghum [Sorghum bicolor (L.) Moench] or pearl millet [Pennisetum glaucum (L.) R. Hr.] in <1 min per plot. Harvested material is deposited in a pile in the center of each plot. Subsamples for moisture and quality analysis can easily and safely be obtained from the pile.

Brown· Midrib Sorghum Silage For Midlactation Dairy Cows, R. J. Grant, S. G. Haddad, K. J. Moore, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 ± 5 DIM were assigned to one of four diets in replicated 4 X 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 ± 20 DIM) were assigned to the same diets in a 3x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (OM basis). The DMl was greater for the corn and brown …

In Vitro Starch Disappearance Procedure Modifications, C. J. Richards, Jeffrey F. Pedersen, R. A. Britton, R. A. Stock, C. R. Krehbiel

Department of Agronomy and Horticulture: Faculty Publications

Four in vitro experiments evaluated the effects of ruminal fluid inoculum:artificial saliva ratios,

grinder type, grind size, and diet of ruminal fluid donor on in vitro starch disappearance. Experiment 1 examined rates of starch disappearance and coefficients of determination obtained by linear regression of starch disappearance using five grain sorghum (Sorghum bicolur (L.) Moench) lines, a corn (Zeu muys L.) control, and a wheat (Triticum aestivum L.) control. Grains were incubated for 4, 8, 12, 16, and 20 h with inoculum varying in proportion of ruminal fluid and artificial saliva ( l:l, 1:2, 1:3, and 1:4). In …

Proposal For Center For Grassland Studies, Ron Case, Dick Clark, Charles A. Francis, Tony Joern, Terry J. Klopfenstein, Lowell E. Moser, Bob Shearman, Ken Vogel, Steven S. Waller

Center for Grassland Studies: Newsletters

Its my pleasure, on behalf of the Grassland Studies Task Force, to forward a proposal for a Center for Grassland Studies for your consideration. The Task Force is extremely pleased with the overwhelming support from a broad base of input. The Task Force has made a major effort through internal and external listening sessions to insure that there was support and in doing so develop a coalition of partners across the University of Nebraska System, state colleges, community colleges, industry, state and federal agencies, public groups, private non-profit organizations and other educational institutions in the region.

Nebraska has a rich …

Identification And Characterization Of Aspergillus Nidulans Mutants Defective In Cytokinesis, Steven D. Harris, Jennifer L. Morrell, John E. Hamer

Department of Plant Pathology: Faculty Publications

Filamentous fungi undergo cytokinesis by forming crosswalls termed septa. Here, we describe the genetic and physiological controls governing septation in Aspergillus nidulans. Germinating conidia do not form septa until the completion of their third nuclear division. The first septum is invariantly positioned at the basal end of the germ tube. Block-and-release experiments of nuclear division with benomyl or hydroxyurea, and analysis of various nuclear division mutants demonstrated that septum formation is dependent upon the third mitotic division. Block-and-releasee xperiments with cytochalasin A and the localization of actin in germlings by indirect immunofluorescence showed that actin participated in septum formation. In …

Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max 1. Merr. vai Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. lsoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. lmmunoblot analysis demonstrated that at least part of the increased activity was dueto an increased abundance of the phosphatase protein. In situ …

Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max L.) transiently accumulates two abundant vegetative storage proteins, VSP A and VSP B, in vacuoles of above-ground vegetative tissues (Wittenbach, 1983; Staswick, 1990). As older leaves and stems become a source of exported metabolites for developing sinks, the VSPs are preferentially degraded and the resulting metabolites are presumably mobilized in the xylem and phloem stream. A striking feature of these proteins is that VSP gene expression is dramatically increased in mature leaves following the remova1 of reproductive sinks (seed pods) and the amount of these proteins increases accordingly (for review, see Staswick, 1994). Other changes …

Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Yield loss models have been developed and evaluated for irrigated rice ecosystems with respect to effects of Echinochloa crusgalli. Simple regression models that give the relation between yield loss and weed density or relative leaf area are discussed with respect to their practical value in weed management in rice. More complex eco-physiological process models have been developed and used for rice ecosystems as well. Such models can be useful as a tool in research, whereas more simple approaches are needed for practical application in weed management.

Systematic Anatomy Of Euphorbiaceae Subfamily Oldfieldioideae I. Overview, W. John Hayden

Biology Faculty Publications

The biovulate subfamily Oldfieldioideae of Euphorbiaceae, characterized by spiny pollen, is an otherwise apparently diverse assemblage of mostly Southern Hemisphere trees and shrubs that traditionally have been allied with genera of Phyllanthoideae and Porantheroideae sensu Pax and Hoffmann. Although fairly diverse anatomically, the following structures characterize the subfamily with only a few exceptions: pinnate brochidodromous venation with generally randomly organized tertiary and higher order venation; foliar and petiolar glands absent; unicellular or unbranched uniseriate trichomes; latex absent; mucilaginous epidermis or hypodermis; brachyparacytic stomata; vessel elements with simple perforation plates and alternate, often very small, intervascular pits; thick-walled nonseptate imperforate tracheary …

Stem Development, Medullary Bundles, And Wood Anatomy Of Croton Glandulosus Var. Septentrionalis (Euphorbiaceae), Sheila M. Hayden, W. John Hayden

Biology Faculty Publications

Anatomy and development of vascular tissues in the annual stems of Croton glandulosus var. septentrionalis are described. In primary stages of growth the stem possesses a eustele of bicollateral bundles; international phloem is notably more extensive than the external. In addition to a vascular cambium and secondary xylem that form in the usual fashion, additional cambia add cells to the internal phloem portion of the bicollateral bundles, forming well-marked medullary bundles at the perimeter of the pith. At first, the perimedullary cambial strands produce only internal secondary phloem; later, internal secondary xylem is present, the medullary bundles have an inverted …

Effect Of Organic Matter Decomposition Level On Bacterial Species Diversity And Composition In Relationship To Pythium Damping-Off Severity, Michael J. Boehm, L.V. Mdden, H.A.J. Hoitink

Department of Plant Pathology: Faculty Publications

Rhizosphere bacteria were isolated from root tip segments of cucumber seedlings grown in a suppressive, slightly decomposed light-colored peat mix, a conducive, more decomposed dark-colored peat mix, and a suppressive dark peat mix amended with composted hardwood bark. The bacteria were identified by a gas chromatographic fatty acid methyl ester analysis. The total number of taxa recovered from a single root tip segment ranged from 9 to 18. No single taxon predominated on all root tip segments harvested from any of the mixes. The highest relative population density reached by a given taxon on any root tip segment was 45%. …

Developmental Morphology Of Tropical Sorghum And Sorghum X Sudangrass, R. B. Mitchell, K. J. Moore, Jeffrey F. Pedersen, T. A. Peterson, L. E. Moser, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Tropical sorghum and sorghum x sudangrass are known to be efficient scavengers of soil nitrogen and are important forage crops in the U.S. Nitrate contamination of groundwater due to disposal of organic wastes and excessive fertilization is a major concern in the Central Great Plains. A common disposal method of municipal wastes is application to fallow cropland. Quantification of the developmental morphology of tropical sorghum and sorghum x sudangrass is important to developing management strategies that allow multiple applications of organic wastes to optimize nitrogen removal and dry matter production. The objective of this study was to quantify the developmental …

Genetic Manipulation Of Tall Fescue, Jeffrey F. Pedersen, D. A. Sleper

Department of Agronomy and Horticulture: Faculty Publications

Genetic manipulation of tall fescue (Festuca arnndinacea Schreb.) has not been altered by the discovery of the Acremonium coenophialum (Morgan-Jones and Gams) / grass interaction. However, tall fescue breeding programs have been affected greatly. The basic methods for genetically manipulating the grass have remained static. Tall fescue is an obligate out-crossing species, and most improvements are, therefore, captured in the form of an improved population developed through some form of mass or recurrent selection. What has changed is the breeder's ability to recognize genetic differences in the grass because of the confounding effect of A. coenophialum on plant phenotype. It …

Comparison Of Sorghum And Indiangrass Chloroplast Genomes Using Rflps, Jeffrey F. Pedersen, R. D. Lee, D. J. Lee, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor (L.) Moench) and indiangrass (Sorghastrum nutans (L.) Nash) appear closely related based on morphological and chemotaxonomic characters. Each species could potentially provide desirable traits to the other. However, traditional breeding techniques have been unsuccessful in hybridizing these two species. The objective of this study was to determine the relatedness of sorghum and indiangrass chloroplast DNA using RFLPs. Eleven sorghum lines in several cytoplasms, two indiangrass popu1ations, and a corn line were studied using 60 proberestriction enzyme combinations. Principal component analysis of the results showed sorghum to be as closely related to corn as to indiangrass, with no …

Breeding Systems For Cross-Pollinated Perennial Grasses, K. P. Vogel, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

I. Introduction

II. Reproductive and Breeding Characteristics

III. Breeding Systems

A. Ecotype Selection

B. Recurrent, RestricteclPhenotypic Selection

C. Half-sib Progeny Test

D. Between and Within Family Selection

E. Recurrent Multistep Family Selection

IV. Gains From Selection

A. Time Interval per Cycle

B. Potential Gain per Cycle .

C. Potential Inbreeding per Cycle

V. Polycrossing

VI. Hybrid Cultivars

VII. Conclusions

Literature Cited

Wood Anatomy Of Amanoa (Euphorbiaceae), W. John Hayden, Mark P. Simmons, Linda J. Swanson

Biology Faculty Publications

Wood anatomy of 29 specimens of seven species of Amanoa from tropical Africa, South America, and the Caribbean is described. The wood is diffuse-porous with most vessels in short radical multiples. Vessel elements are notably long, have simple perforation plates and small, alternative intervessel pits; tyloses are present in heartwood. Libriform wood fibres bear thick walls. Axial parenchyma distribution is diffuse and diffuse-in-aggregates. Chambered crystalliferous axial parenchyma is common. Rays are heterocellular, narrow, and very tall. The species examined, all from moist lowland forests, have similar wood structure. Wood of Amanoa resembles that of other primitive Euphorbiaceae.

Remnant Vegetation Protection Scheme 1991 Blocks, J E D Fox, P Read, J - Pg Orsini

All other publications

No abstract provided.

Jasmonate, Genes, And Fragrant Signals, Paul E. Staswick

Department of Agronomy and Horticulture: Faculty Publications

Although first recognized for its growth-inhibiting activity about 20 years ago, JA² and its fragrant methyl ester MeJA (referred to here collectively as jasmonate) are receiving renewed interest as potentially important signaling molecules in plants. This is because jasmonate markedly increases the expression of specific plant genes, some of which are wound responsive. Similarities with fatty acid-derived stress signaling molecules in animals (1) make jasmonate of general biological interest.

Review Of The Wild Oat Inflorescence And Seed: Anatomy, Development And Morphology, M. V. S. Raju, David M. Sutherland

Biology Faculty Publications

This slim volume describes a detailed study of the reproductive parts of Avena fatua, the wild oat plant-a common weed in the northern plains and the probable ancestor of the cultivated oat. The book integrates the author's own work with information from available literature and includes lengthy technical descriptions of the structure and the growth of the inflorescence, the floret, the ovule, the pollen grain, the embryo, the seed, and the young seedling. Throughout the work, the author relates the wild oat's structure and development to other grasses, other monocotyledons, and other seed plants, offering evolutionary interpretations of many of …

Inheritance Of Acid-Soil Tolerance In Sorghum (Sorghum Bicolor) Grown On An Ultisol, C. I. Flores, L. M. Gourley, Jeffrey F. Pedersen, R. B. Clark

Department of Agronomy and Horticulture: Faculty Publications

Inheritance of acid-soil tolerance (generally considered AI-toxicity tolerance) i.n sorghum [Sorghum bicolor (L.) Moench] is not clear. Forty F₁ sorghum hybrids and their 14 parents were grown two seasons in the field at relatively high (67 and 71%) and low (43 and 42%) Al saturations on an acid Ultisol in Colombia, South America to evaluate the effects of acid soil on agronomic component traits and to better understand inheritance of acid-soil tolerance of sorghum. For plants grown at the high Al saturation levels, hybrids from acid-soil tolerant [AS-T] x acid soil-sensitive [AS-S] crosses were as tolerant as hybrids from …