Plant Pathology Commons^™

Semiconservative Synthesis Of Single-Stranded Rna By Bacteriophage Φ6 Rna Polymerase, James L. Van Etten, Dwight E. Burbank, Diane A. Cuppels, Leslie C. Lane, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The RNA polymerase in the nucleocapsid of seudomonas phaseolicola bacteriophage φ6 transcribed large, medium, and small single-stranded RNA from the viral double-stranded RNA genome by a semiconservative (displacement) mechanism. Approximately 23%, 63%, and 65% of the nucleocapsid particles in the assay mixture synthesized at least one round of large, medium, and small single-stranded RNA molecules, respectively. Some of these particles reinitiated synthesis such that an average of 1.5 large, 33 medium, and 24 small singlestranded RNAs were synthesized from each double-stranded RNA.

Results Of The Second High Protein-High Lysine Wheat Observation Nursery Grown In 1976, S. L. Kuhr, K. D. Wilhelmi, V. A. Johnson, P. J. Mattern

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the second report of results from a high protein-high lysine (HP-HL) observation nursery organized in 1974 by the Nebraska Agricultural Experiment Station and the Science and Education Administration, U. S. Department of Agriculture, under a contract with the Agency for International Development, U. S. Department of State. Primary objectives of this nursery are to: (1) Systematically provide breeders and cooperators with superior genetic germplasm for elevated levels of protein and/or lysine. (2) Test the degree of expression of the high protein and high lysine traits in a diverse array of environments. Funding from USAID has permitted the Nebraska …

Glutaraldehyde Nonfixation Of Isolated Viral And Yeast Rnas, Willem G. Langenberg

Department of Plant Pathology: Faculty Publications

The RNAs of brome mosaic (BMV), barley stripe mosaic (BSMV), and tobacco mosaic (TMV) viruses were inactivated by reaction with buffered glutaraldehyde. Glutaraldehyde did not fix 4% BMV-RNA, 20% t-RNA, 5% polyadenylic acid, or 5% adenosine monophosphate into water-insoluble precipitates, or gels, in distilled water or in low or high ionic strength buffers nor did it change their ultraviolet (UV) spectra. Two SDS- and phenolpurified commercial yeast RNA preparations from different sources gave UV spectra typical of pure RNA, but could not be freed of a contaminant that reacted with glutaraldehyde by forming a precipitate. The yeast RNAs did not …

Proceedings Of The 7th Annual Meeting, Southern Soybean Disease Workers (April 2-3, 1980, Fort Walton Beach, Florida)

Southern Soybean Disease Workers: Conference Proceedings

Contents

Schedule, Committees, Officers

History of the Southern Soybean Disease Workers, Glen Whitney

Presidential Address, H. Ray Smith

Global Agriculture Year 2000: A Strategic Analysis, Stuart Stearns

Attorneys Got Us Into This Mess, Attorneys Must Get Us Out, John Donley

Soybeans as a Protein Source, Kenneth Lepley

Soybeans in Human Nutrition, Ruth Patrick

Review of Plant Parasitic Nematode Problems on Soybeans, John Fulkerson

Efficacy of Nematicides for Nematode Control, Charles Baldwin

Breeding for Nematode Resistance, C. E. Caviness and R. D. Riggs

Effects of Fertility on Efficacy of Nematicides for Control of the Soybean Cyst Nematode, Al Chambers

Mississippi's Approach …

Results Of The Ninth International Winter Wheat Performance Nursery Grown In 1977, S. L. Kuhr, K. D. Wilhelmi, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the ninth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station and the Science and Education Administration (SEA), U.S. Department of Agriculture, under a contract with the Agency for International Development, U.S. Department of State. The Nursery was designed to (1) test the adaptation and stability of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes, (3) test the degree of expression …

Presence Of A Major (Storage?) Protein In Dormant Spores Of The Fungus Botryodiplodia Theobromae, James L. Van Etten, S. N. Freer, B. K. Mccune

Department of Plant Pathology: Faculty Publications

Approximately 23% of the protein isolated from dormant spores of Botryodiplodia theobromae consisted of a single polypeptide; the polypeptide is probably degraded during germination.

Proceedings Of The 6th Annual Meeting, Southern Soybean Disease Workers (March 13-15, 1979, Hot Springs, Arkansas): Healthy Beans, A Key To Profit

Southern Soybean Disease Workers: Conference Proceedings

Contents

Schedule, Committees, Officers

The Gold That Grows, John Stephens

IPM Program, Joe Good

The Role of the Ag Consultant - Dick Jensen

Seed Quality, Ron Hager

Nematode-Economic Threshold, Don Schmitt

Problems of Marketing Foliar Fungicides, Gordon Elliott and Nic Thomas

Results of Point System in Determining Application Time, Billy Moore

Disease Loss Report, R. V. Sturgeon

Seed Treatment Report, M. C. McDaniel

SSDW Financial Status Report, Sid Stephens

Update of FIFRA and RPAR, Curtis L. Mason

Needs and Effects of a Foliar Fungicide - B. C. Smale

The Effect of Bean Pod Mottle, Soybean Mosaic and Bean Yellow Mosaic …

Bacteriocin-Like Substances Produced By Rhizobium Japonicum And Other Slow-Growing Rhizobia, D. C. Gross, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

Bacteriocin-like substances were commonly produced by slow-growing Rhizobium japonicum and cowpea rhizobia on an L-arabinose medium. Antagonism between strains of R. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. Inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 R. japonicum test strains, were reproducibly detected with Corynebacterium nebraskense as an indicator. Quantitative production was not related to symbiotic properties of effective strains, since nine noninfective strains and one ineffective strain produced bacteriocin. Eight R. japonicum strains that did not produce bacteriocin nevertheless formed effective …

Results Of The Eighth International Winter Wheat Performance Nursery Grown In 1976, K. D. Wilhelmi, S. L. Kuhr, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the eighth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station and the Science and Education Administration (SEA), U.S. Department of Agriculture, under a contract with the Agency for International Development, U.S. Department of State. The Nursery was designed to (1) test the adaptation and stability of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes, (3) test the degree of expression …

Results Of The First High Protein-High Lysine Wheat Observation Nursery Grown In 1975, K. D. Wilhelmi, S. L. Kuhr, V. A. Johnson, P. J. Mattern

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the first report of results from a high protein-high lysine observation (HP-HL) nursery organized in 1974 by the Nebraska Agricultural Experiment Station and the Agricultural Research Service, U.S. Department of Agriculture, under a contract with the Agency for International Development, U.S. Department of State. Primary objectives of this nursery are to: (1) Systematically provide breeders and cooperators with superior genetic germplasm for elevated levels of protein and/or lysine. (2) Test the degree of expression of the high protein and high lysine traits in a diverse array of environments.

Simple Procedure For Disruption Of Fungal Spores, James L. Van Etten, Shelby Freer

Department of Plant Pathology: Faculty Publications

A simple, inexpensive method for disrupting dormant fungal spores is described.

Proceedings Of The 5th Annual Meeting, Southern Soybean Disease Workers (March 21-23, 1978, Fort Walton Beach, Florida): 3 P'S In A Pod - Policies, Protection, Production

Southern Soybean Disease Workers: Conference Proceedings

Contents

Farm Policies, Weldon Barton (Assistant US Secretary of Agriculture)

World Soybean Problems, Glen Whitney, Dick Ford, and Frank Ray

Interrelation of Governmental Agencies with Industry, University, and Soybean Producers
EPA: Relationship and Responsibility to Agriculture and the Public, Nathan Chandler
EPA: Problems and Requirements of Registration, Herb Harrison
State: Pesticide Impact Program, Charles Smith
Industry: View on Benefit and Risk of the Pesticide Business, Charles Gilbert
University: Role of Land Grant University in Pesticide Development, James Martin
Producer: What's Needed, "Profit or Perish," Peter Myers

DBCP Status Report and Other Nematicides
Shell Chemical, Max Sckerl
Dow Chemical, Walter Miller …

Purification Of Some Legume Carlaviruses, Venkateswarlu Veerisetty, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

Purification schemes were developed which yielded 0.7 to 1.0 mg of alfalfa latent virus (ALV) and pea streak virus (PSV) and 0.1 to 0.3 mg of red clover vein mosaic virus (RCVMV) per gram pea cullivar Lincoln plant tissue (excluding roots). The freezing of the tissue and the use of an appropriate extraction buffer were crucial. Virus from sap was precipitated by 6%(w/v) polyethylene glycol (PEG, MW 6,000) and concentrated by two cycles of differential centrifugation. Partially purified virus preparations had a single nucleoprotein component in rate-zonal sucrose and equilibrium cesium chloride density gradient centrifugation. The virus preparations did not …

Purification Of Some Legume Carlaviruses, Venkateswarlu Veerisetty, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

Purification schemes were developed which yielded 0.7 to 1.0 mg of alfalfa latent virus (ALV) and pea streak virus (PSV) and 0.1 to 0.3 mg of red clover vein mosaic virus (RCVMV) per gram pea cullivar Lincoln ) plant tissue (excluding roots). The freezing of the tissue and the use of an appropriate extraction buffer were crucial. Virus from sap was precipitated by 6%(w/v) polyethylene glycol (PEG, MW 6,000) and concentrated by two cycles of differential centrifugation. Partially purified virus preparations had a single nucleoprotein component in rate-zonal sucrose and equilibrium cesium chloride density gradient centrifugation. The virus preparations did …

Nitrogen Fixation (Acetylene Reduction) Associated With Roots Of Winter Wheat And Sorghum In Nebraska, Wayne L. Pedersen, K. Chakrabarty, R. V. Klucas, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Root segments and root-soil cores (6.5-cm diameter) from fields and nurseries of winter wheat and sorghum were tested for N₂ fixation by using the acetylene reduction assay. Wheat samples (~1,200) from 109 sites generally had low or no activity (0 to 3.1 nmol of C₂H₄ produced per h per g [dry weight] of root segments), even after 24 h of incubation. However, a commercial field of Scout 66, located in western Nebraska, exhibited appreciable activity (290 nmol of C₂H₄ produced per h per g [dry weight] of root segments). Of 400 sorghum lines …

Results Of The Seventh International Winter Wheat Performance Nursery Grown In 1975, K. D. Wilhelmi, S. L. Kuhr, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the seventh report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station and the Agricultural Research Service, U.S. Department of Agriculture, under a contract with the Agency for International Development, U.S. Department of State. The Nursery was designed to (1) test the adaptation of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management regimes, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes, and (3) test the degree of expression and stability of …

Alfalfa Latent Virus, A Naturally Occurring Carlavirus In Alfalfa, Yenkateswarlu Veerisetty, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

Alfalfa latent virus (ALV), a new member of the carlavirus group, was isolated From alfalfa (Medicago sarivo) clones from rbe University of Nebraska experimental plots and from the Farmers' fields. The pea aphid, Acvrihosiphon pisum, transmitted this virus to M. sativa, Pisum sativum, and Viria faba. but not to Trifolium pratense. It was also sap transmissible to V. faba, V. villoso, and P. sarivum, but was not seed-borne in P. sariuum. In V. Jaba sap ALV was infectious at 65 but not at 70 C in 10 min. or …

Sedimentation Coefficients Of The Virions Of Soil-Borne Wheat Mosaic Virus, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

The sedimentation coefficient of virion I of soil-borne wheat mosaic virus was estimated to be 219S, the same, within error, as the sedimentation coefficient of the dimer of virion II, estimated to be 218S. The monomer of virion II sedimented at 177S, and was 138 nm long. Another strain of the virus had a virion II (designated lIb) that was 92 nm long and sedimented at 159S. The two virus strains coexist in some fields.

Results Of The Sixth International Winter Wheat Performance Nursery Grown In 1974, K. D. Wilhelmi, S. L. Kuhr, V. A. Johnson, P. J. Mattern, J. W. Schmidt

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the sixth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station and the Agricultural Research Service, U. S. Department of Agriculture, under a contract with the Agency for International Development, U.S. Department of State. The Nursery was designed to (1) test the adaptation of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes, and (3) test the degree of expression and stability of …

Comparative Properties Of Bacteriophage Φ6 And Φ6 Nucleocapsid, James L. Van Etten, Les Lane, Carlos Gonzalez, James Partridge, Anne Vidaver

Department of Plant Pathology: Faculty Publications

Nonionic detergent treatments released a nucleocapsid from the enveloped bacteriophage φ6. The nucleocapsid sedimented at nearly the same rate as the whole phage in sucrose density gradients, but the buoyant density in Cs₂SO₄ changed from 1.22 g/cm³ for the whole phage to 1.33 g/cm³ for the nucleocapsid. The detergent completely removed the lipid and 5 of the 10 proteins from the phage. Surface labeling of the phage and nucleocapsid with ¹²⁵I revealed that protein P3 was on the outer surface of the whole phage and P8 was on the surface of the nucleocapsid. Both …

Results Of The Fifth International Winter Wheat Performance Nursery Grown In 1973, J. E. Stroike, K. D. Wilhelmi, V. A. Johnson, J. W. Schmidt, P. J. Mattern

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the fifth report of results from an International Winter Wheat Performance Nursery (IWWPN) organized in 1968 by the Nebraska Agricultural Experiment Station and the Agricultural Research Service, U. S. Department of Agriculture, under a contract with the Agency for International Development, U. S. Department of State. The Nursery was designed to (1) test the adaptation of winter wheat cultivars in a range of latitudes, daylengths, fertility conditions, water management, and disease complexes; (2) identify superior winter cultivars to serve as recipient genotypes for high protein and high lysine genes, and (3) test the degree of expression and stability …

Prospects For Control Of Phytopathogenic Bacteria By Bacteriophages And Bacteriocins, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The last review on bacteriophages and bacteriocins of phytopathogenic bacteria was that of Okabe & Goto (98). All but one (21) of the subsequent reviews (II, 12, 60, 94, 104) have dealt primarily with viruses and bacteriocins of bacteria other than phytopathogens. The most recent microbiological compendia that in­ clude bacteriophages and bacteriocins are of limited value for phytobacteriolo­ gists because the authors generally overlook or ignore such agents (29, 47, 77, 119). However, Adam's classic .book (4), the review by Bradley (II), and the bibliography of Raettig (102) are still of value to phytobacteriologists as are reviews dealing principally …

Pollution Of Surface Irrigation Waters By Plant Pathogenic Organisms, James R. Steadman, C. R. Maier, H. F. Schwartz, E. D. Kerr

Department of Plant Pathology: Faculty Publications

Systematic sampling of waterways and irrigation runoff from agricultural lands in the North Platte Project of Nebraska in July and August of 1972–1974 demonstrated that phytopathogenic organisms were disseminated. The organisms monitored included the bean common blight bacterium Xanthomonas phaseoli, the bean white mold fungus Whetzelinia sclerotiorum and various nematodes. Although many types of nematodes often were recovered from irrigation water, Heterodera sp. cysts which cause significant disease problems in the valley were found infrequently. Patterns of movement of the bacterial and fungal organisms were correlated with previous or current season infection of bean plants. The short-term survival of X. …

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 …

Intermediates In The Biosynthesis Of Double-Stranded Ribonucleic Acids Of Bacteriophage Φ6, D. L. Coplin, James L. Van Etten, James A. Koski, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

Pseudomonas phaseolicola infected with bacteriophage φ6 synthesized all three viral double-stranded RNA segments, three single-stranded RNAs, and three replicative intermediate-like RNAs in the presence of rifampin. The single-stranded RNA intermediates sedimented and electrophoresed along with melted viral double-stranded RNA, annealed with melted viral double-stranded RNA, and were transient in nature. The relative amounts of the single-stranded RNA intermediates varied during the infection cycle and were altered in the presence of chloramphenicol. The replicative intermediate-like RNAs sedimented faster than double-stranded RNA, failed to enter 2.5% polyacrylamide gels, eluted with double-stranded RNA from a CF-11 cellulose column, were precipitated with single-stranded RNA …

Survival Factors Of Plant Pathogenic Bacteria, M. L. Schuster, D. P. Coyne

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The research works discussed in this review were selected to provide a cross section of the phenomenon of survival of plant pathogenic bacteria.

Results Of The Fourth International Winter Wheat Performance Nursery, J. E. Stroike, V. A. Johnson, J. W. Schmidt, P. J. Mattern, K. D. Wilhelmi

Nebraska Agricultural Experiment Station: Historical Research Bulletins

The Fourth International Winter Wheat Performance Nursery was grown in 1972 at 44 sites in 27 countries. Data were reported from 40 sites. The 30 cultivars grown in the nursery included 15 new entries. Twenty-nine cultivars were winter wheats; one was a spring wheat. Data are reported on grain yield, test weight, plant maturity, plant height, lodging, shattering, winter survival, 1000 kernel weight, frost damage, plant diseases, grain protein and lysine content. Two-year mean data summaries also are reported. Supplemental nursery management information is reported for each nursery site.

Influence Of Molecular Weights Of Bacteriophage Φ6 Double-Stranded Ribonucleic Acids On Interferon Induction, W.J. Kleinschmidt, James L. Van Etten, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

The interferon-inducing capabilities of the three molecular segments of bacteriophage φ6 double-stranded ribonucleic acid increased with increasing molecular weight.

Purification And Characterization Of Syringacin 4-A, A Bacteriocin From Pseudomonas Syringae 4-A, William L. Haag, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Syringacin 4-A, a bacteriocin produced by Pseudomonas syrinagae 4-A, was obtained by induction with ultraviolet irradiation or mitomycin C. Approximately 1,000-fold purification of the bacteriocin was achieved by manganous chloride precipitation, differential centrifugation, and chromatography on hydroxyapatite columns. The purified syngacin was homogeneous on hydroxyapatite columns and sucrose density gradients; it also sedimented as a single entity in the analytical ultracentrifuge. The buoyant density of purified syringacin in cesium chloride was 1.294 g/ml. The sedimentation coefficient was calculated as 120S, and the diffusion coefficient was 6.49 x 10^-8 cm²/s. The molecular weight was calculated as …

Base Composition And Hybridization Studies Of The Three Double-Stranded Rna Segments Of Bacteriophage Φ6, James L. Van Etten, A. K. Vidaver, R. K. Koski, J. P. Burnett

Department of Plant Pathology: Faculty Publications

The three double-stranded ribonucleic acid (dsRNA) segments of the bacteriophage φ6 were isolated and shown to have similar melting temperatures and base compositions. RNA: RNA hybridization experiments with the isolated segments eliminate the possibility that the two smaller dsRNA segments arise from a cleavage of the large dsRNA segment. The two smaller RNA segments reanneal rapidly even at low temperatures; in contrast, the large dsRNA reannealed only at higher temperatures. Evidence is also presented which suggests that the dsRNAs may contain a short single-stranded RNA tail.