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Proceedings Of The 20th Annual Meeting, Southern Soybean Disease Workers (March 28-30, 1993, Fort Walton Beach, Florida), Patrick D. Colyer, Glenn R. Bowers Jr., John C. Rupe, Brian M. Anderson, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Sustainable agriculture symposium

Sustainable Agriculture and the Soybean Industry: Building a Winning Strategy. D Hubbard and MS Fitzner

Impact of Pest Interactions on Management Programs. J Funderburke

Introducing Procedures of Sustainable Agriculture, a Team Approach. J Bradley

Sustainable Agriculture Practices and Their Impact on Plant Diseases. C Rothrock

Graduate student competition

Effect of Increasing Initial Inoculum Levels of Rotylenchus reiformis on Soybean. JJ Cornelius and GW Lawrence

Effect of Frogeye Leaf Spot on Yield of Soybean Lines Near-Isogeneic for Resistance. PF Pace, DB Weaver, LD Flopper, and PA Backman

Heritability and Genotype X Environment Interaction of Partial Resistance to …

Barley Yellow Dwarf Virus In Cereals, Simon Mckirdy, Roger Jones

Journal of the Department of Agriculture, Western Australia, Series 4

Worldwide, barley yellow dwarf virus (BYDV) is the most widespread and damaging virus disease of cereals. It infects wheat, barley, oats and grasses and is transmitted by several aphid species. The virus is not seed-borne and to persist from one growing season to the next it must survive in over-summering grasses.

Barley yellow dwarf virus decreases grain yield and also causes shrivelled grain. Yield loss is greatest from infection early in the growing season.

Sequencing Two Dna Templates In Five Channels By Digital Compression, Michaela Nelson, Yanping Zhang, David L. Steffens, Reingard Grabherr, James L. Van Etten

Department of Plant Pathology: Faculty Publications

By applying algebraic coding methods to the Sanger dideoxynucleotide procedure, DNA sequences of two templates can be determined simultaneousl in only flve reactions and data channels. A 5:2 data compression is accomplished by instantaneous source coding of nucleotide sequence pairs into one set of 5-bit block codes. A general algebraic expression, 2" - 1 ≥ 4^f, describes conditions under which f DNA templates can be sequenced using n channels. Such compression sequencing is accurate and effcient, as demonstrated by manual ³⁵S autoradiographic detection and automated on-line analysis using fluorescent-labeled primers. Symmetric 5:2 compression is especially useful when …

Mitochondrial Dna Sequence Divergence Among Meloidogyne Incognita, Romanomermis Culicivorax, Ascaris Suum, And Caenorhabditis Elegans, Thomas O. Powers, T. S. Harris, B. C. Hyman

Department of Plant Pathology: Faculty Publications

Mitochondrial DNA sequences were obtained from the NADH dehydrogenase subunit 3 (ND3), large rRNA, and cytochrome b genes from Meloidogyne incognita and Romanomermis culicivorax. Both species show considerable genetic distance within these same genes when compared with Caenorhabditis elegans or Ascaris suum, two species previously analyzed. Caenorhabditis, Ascaris, and Meloidogyne were selected as representatives of three subclasses in the nematode class Secernentea: Rhabditia, Spiruria, and Diplogasteria, respectively. Romanomermis served as a representative outgroup of the class Adenophorea. The divergence between the phytoparasitic lineage (represented by Meloidogyne) and the three other species is so great that virtually …

Role Of Endophytes In Tall Fescue, E. L. Piper, C. P. West

Journal of the Arkansas Academy of Science

Tall fescue (Festuca arundinacea Schreb.) is the most commonly grown cool season grass used for pastures in Arkansas. Most tall fescue contains a fungal endophyte (Acremonium coenophialum Morgan-Jones & Gams), which causes fescue toxicosis in livestock and costs cattle producers millions of dollars annually in lost production. Endophyte presence is known to reduce wild mammal populations in areas where tall fescue is prevalent. The endophyte spends its entire life cycle within the plant and is transmitted through the seed. The association is mutualistic with the plant providing nutrients for the endophyte and the endophyte conferring drought, insect, and nematode resistance …

A Polymerase Chain Reaction Method For Identification Of Five Major Meloidogyne Species, Thomas O. Powers, T. S. Harris

Department of Plant Pathology: Faculty Publications

A polymerase chain reaction (PCR) method for discriminating Meloidogyne incognita, M. arenaria, M. javanica, M. hapla, and M. chitwoodi was developed. Single juveniles were ruptured in a drop of water and added directly to a PCR reaction mixture in a microcentrifuge tube. Primer annealing sites were located in the 3' portion of the mitochondrial gene coding for cytochrome oxidase subunit II and in the 16S rRNA gene. Following PCR amplification, fragments of three sizes were detected. The M. incognita and M. javanica reactions produced a 1.7-kb fragment; the M. arenaria reaction, a 1.1-kb fragment; and the …

Molecular Approaches For Control Of Tomato Bushy Stunt Virus, H. B. Scholthof, M. Borja, Thomas Jack Morris, A. O. Jackson

School of Biological Sciences: Faculty Publications

I N this overview strategies are discussed that are currently being tested in our laboratory in an effort to engineer resistance against tomato bushy stunt virus (TBSV) in plants. TBSV is chosen as a model-system since this is an economically important RNA virus that is well characterized at the molecular level and the virus has some interesting and potentially useful features that can be exploited to produce resistant plants. Moreover, we anticipate that the information derived from our studies with TBSV will be applicable in developing resistance to other plant viruses. Some approaches that we are attempting to apply to …

Book Review: Genetically Engineered Organisms: Benefits And Risks, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

In the continuing debate on the introduction into the environment of genetically modified organisms, particularly those modified by recombinant DNA, there are few books suitably written for policymakers, the lay public and scientists in other fields. This book describes the current state of the science and art of genetic engineering, potential uses (particularly outside the laboratory), and the benefits that can be expected. It is particularly pertinent for examining potential risk and management of risk from the perspective of the United Kingdom.

Biological Vectors For The Dispersal Of Colletotrichum Gloeosporioides, X. B. Yang, D. O. Tebeest, E. L. Moore

Journal of the Arkansas Academy of Science

Green treefrogs (Hyla cinerea) and grasshoppers (Melanoplus differentialis and Conocephalus fasciatus) commonly observed in Arkansas rice fields, are dispersal vectors for Colletotrichum gloeosporioides f. sp. aeschynomens, a causal agent of anthracnose of northern jointvetch. Treefrogs and grasshoppers captured from rice or soybean fields with diseased northern jointvetch were placed in containers in contact with healthy northern jointvetch plants. An average of 90% of northern jointvetch plants was infected by the pathogen with up to 10 lesions per plant using treefrog vectors. Experiments were done in the greenhouse on frog dispersal by monitoring disease development from a point source in closed …

Australian Genetic Resources Of Trifolium And Ornithopus Species, Richard Snowball, Kevin Foster, Bill Collins

Journal of the Department of Agriculture, Western Australia, Series 4

The introduction of improved pasture legumes into the cereal growing areas of southern Australia changed the face of our agricultural systems.

Subterranean clover was the first pasture legume to have a major impact, and the first varieties were available commercially in the 1930s. Since then, many varieties have been released, leading to the most recent release of Denmark, Gou/bum and Leura in 1992.

The development of burr, barrel and murex medics also had an impact on the pasture production of less acid heavy soils. Yellow serradella is still being developed for the more acid sandy soils.

This development of improved …

New Leaf Rust Helps To Control Blackberry, Jonathon Dodd, Sandy Lloyd

Journal of the Department of Agriculture, Western Australia, Series 4

The release of spores of the blackbeny leaf rust in spring 1991 marked the second attempt in Western Australia at controlling weedy blackberries with a biological agent. The strain of rust now being used is expected to be more effective than the one released in the 1980s.

This article describes the techniques used for rearing and releasing the fungus and illustrates the effects of the rust on blackbeny.

Viruses And Virus-Like Particles Of Eukaryotic Algae, James L. Van Etten, Leslie C. Lane, Russel H. Meints

Department of Plant Pathology: Faculty Publications

TABLE OF CONTENTS:
INTRODUCTION
CHARACTERISTICS OF CHLORELLA SPECIES
General Properties of Chlorella Species
Symbiotic Chlorella Species
Chlorella Strains NC64A, Nla, Pbi, and SAG-241-80
DISCOVERY OF CHLORELLA VIRUSES
Initial Observations
Development of a Culturable System for PBCV-1
PROPERTIES OF CHLORELLA VIRUSES
General Characteristics of PBCV-1
Composition of PBCV-1
PBCV-1 Genome
Serology of PBCV-1
Additional Chlorella Strain NC64A Viruses
Viruses Infecting Chlorella Strain Pbi
REPLICATION OF PBCV-1
Attachment of PBCV-1 to Chlorella Strain NC64A
Intracellular Site of PBCV-1 Replication
Effect of PBCV-1 Infection on Host DNA, RNA, and Protein Syntheses
TRANSCRIPTION OF PBCV-1
VIRUSES ENCODE DNA METHYLTRANSFERASES AND DNA SITE-SPECIFIC (RESTRICTION) ENDONUCLEASES …

Β-Ionone Derivatives As Antifungal Agent, Joseph Kuc, Steven D. Salt

Plant Pathology Faculty Patents

To read this abstract, please download this patent.

Proceedings Of The 18th Annual Meeting, Southern Soybean Disease Workers (March 20-21, 1991, Lexington, Kentucky): National Perspective On Soybeans, Donald E. Hershman, J. Allen Wrather, Patrick D. Colyer, Gary W. Lawrence, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

General session

Presidential address. DE Hershman

Keynote address. P O'Connell

Invited speakers

Major Soybean Diseases of the Midwest and Their Management. TS Abney

Major Soybean Diseases of the Southeast and Their Management. WF Moore

Disease Resistance in the Defense of Yield: A Commercial Breeders Perspective. HL Gabe

Graduate student papers

Effects of potassium fertilization and weed control on the severity.of anthracnose and pod and stem blight of soybeans in Louisiana. FG Barker, GT Berggren, and JP Snow

Inheritance of soybean SDS response in segregating F₅ derived lines. WJ Matthews, VN Njiti, PT Gibson, and ML Shenaut

Selection of …

Comment On The Reinstatement Of Xanthomonas Citri (Ex Hasse 1915) Gabriel Et Al. 1989 And X. Phaseoli (Ex Smith 1897) Gabriel Et Al. 1989: Indication Of The Need For Minimal Standards For The Genus Xanthomonas, J. M. Young, J. F. Bradbury, L. Gardan, R. I. Gvozdyak, D. E. Stead, Y. Takikawa, A. K. Vidaver

Department of Plant Pathology: Faculty Publications

The proposals to reinstate Xanthomonas citri (ex Hasse 1915) Gabriel et al. 1989 and X. phaseoli (Smith 1897) Gabriel et al. 1989 are examined in terms of conventional criteria for describing new species. We suggest that the descriptions presented are insufficient in terms of modern practice for the purposes of formal classification in the genus Xanthomonas. To create guidelines for future reinstatements, the Judicial Commission of the International Committee on Systematic Bacteriology is requested to arrange for the preparation and promulgation of minimal standards for Xanthomonas. The pathovars proposed, X. campestris pv. aurantifolii Gabriel et al. 1989 …

Evaluation Of Aposphaeria Amaranthi As A Bioherbicide For Pigweed (Amaranthus Spp.), A. S. Mintz, G. J. Weidmann

Journal of the Arkansas Academy of Science

Studies were conducted to determine the potential of the fungus, Aposphaeria amaranth!, as a bioherbicide for pigweeds (Amaranthus spp.). Experiments to establish the environmental parameters necessary for control of tumble pigweed (A. albus) demonstrated that an 8-hr dew period was sufficient for control of seedlings with four to six leaves, and that temperatures ranging from 20 to 28 C were conducive for disease development. Conidial concentrations as lowas 1x 10s conidia per ml also were sufficient for plant mortality. Host range tests demonstrated pathogenicity of A. amaranthi to several other species of Amaranthus, including biotypes resistant to triazine herbicides. Disease …

Size Differences Among Root-Knot Nematodes On Resistant And Susceptible Alyceclover Genotypes, L. E. Powers, R. A. Dunn, R. Mcsorley

Department of Plant Pathology: Faculty Publications

The influence of plant resistance on the size of individual root-knot nematodes was determined in greenhouse experiments. Five genotypes of alyceclover were inoculated with second-stage juveniles of Meloidogyne incognita race 3 or M. arenaria race 1. Plants were harvested at selected intervals and stained for detection of the nematodes, which were dissected from the roots. Length, width, and sagittal-sectional area of each animal were measured using an image-analysis system, and areas of nematodes in all stages were compared at different times and across alyceclover lines. Nematodes feeding on roots of resistant lines were consistently smaller than those on susceptible plants, …

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 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 …

Origin And Evolution Of Defective Interfering Rnas Of Tomato Bushy Stunt Virus, David A. Knorr, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Viruses with defective genomes have been identified in association with virtually every major family of viruses and have been widely utilized as tools for investigating virus functions in animal cell culture systems (Perrault, 1981). It is generally thought that defective interfering viruses (DIs) arise through deletion, rearrangement, or recombination of a competent viral genome. DIs tack the ability for independent existence relying on their parental helper viruses to supply factors required for replication, maturation, and/or encapsidation (Huang and Baltimore, 1977). The interference attributed to DIs is thought to result from competition with the helper virus for factors required in trans …

Risk-Based Oversight Of Experiments In The Environment, Henry I. Miller, Robert H. Burris, Anne K. Vidaver, Nelson A. Wivel

Department of Plant Pathology: Faculty Publications

The new biology has come of age. Basic research in fields ranging from immunology to plant biology has been transformed so as to be almost unrecognizable to those whose biology education ended before 1970. The spillover into commercial development likewise has been remarkable. Hardly a week passes without news of some new advance in an area such as therapeutics, vaccines, or plants and animals for food, feed, or fiber. These uses of biotechnology in "contained" laboratories, pilot plants, greenhouses, and production facilities have engendered little controversy. The National Institutes of Health Guidelines for Research Involving Recombinant DNA have exempted from …

Towards An Improved Taxonomy Of Xanthomonas, L. Vauterin, J. Swings, K. Kersters, M. Gillis, T. W. Mew, M. N. Schroth, N. J. Palleroni, D. C. Hildebrand, D. E. Stead, E. L. Civerolo, A. C. Hayward, H. Maraîte, R. E. Stall, A. K. Vidaver, J. F. Bradbury

Department of Plant Pathology: Faculty Publications

Improvement of the taxonomy of the genus Xanthomonas and especially of Xanthomonas campestris, which is subdivided into more than 125 pathovars, is discussed. Recent contributions to the taxonomy of Xanthomonas are reviewed, and on the basis of these data and unpublished data from several laboratories, the usefulness of different phenotypic, chemotaxonomic, and genotypic techniques is discussed. The heterogeneity of several X. campestris pathovars has been demonstrated by sodium dodecyl sulfate electrophoresis of whole-cell proteins and fatty acid fingerprinting. The host selectivity of the pathovars is not correlated with their relationships as revealed by DNA-DNA hybridization experiments. In order to …

Capping Of Tobacco Mosaic Virus Rna: Analysis Of Viral-Coded Guanylyltransferase-Like Activity, David Dunigan, Milton Zaitlin

Department of Plant Pathology: Faculty Publications

The 5’ end of tobacco mosaic virus (TMV) genomic RNA is capped with 7- methylguanosine. A virus-coded polypeptide with guanylyltransferase activity has been investigated. This enzyme is responsible for forming the 5’→5’ linkage of guanosine 5’-monophosphate to the 5’- diphosphate of an acceptor RNA, thereby forming the cap. A critical step in the mechanism for cap formation in the eukaryotic nucleus is for guanylyltransferase to bind covalently to guanosine 5’- monophosphate with the hydrolysis of pyrophosphate when guanosine 5’- triphosphate is the substrate. The TMV 126-kilodalton protein, which is most probably a component of the TMV replicase, was found to …

Degradation Of Wheat Streak Mosaic Virus Capsid Protein During Leaf Senescence, Myron K. Brakke, Rose N. Skopp, L. C. Lane

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus capsid protein degraded in vivo by proteolysis as leaves senesced. The capsid protein of virus purified from young systemically infected leaves had an apparent size or 45 kDa in 12% sodium dodecyl sulfate-polyacrylamide gels with minor amounts of 43, 42, 33, and 3E kDa proteins. The proportion of smaller proteins increased with the age of the leaf. In some virus preparations only 3 1 kDa capsid protein was detected. In vitro proteolysis of virions with 45 kDa protein produced virions with 31 kDa protein. Virions with 31 kDa capsid protein sedimented slightly more slowly than those …

Identification Of Single Meloidogyne Juveniles By Polymerase Chain Reaction Amplification Of Mitochondrial Dna, T. S. Harris, L. J. Sandall, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

Polymerase chain reaction (PCR) was used to amplify a specific 1.8-kb sequence of mitochondrial DNA from single juveniles and eggs from 17 populations of Meloidogyne incognita, M. hapla, M. javanica, and M. arenaria. Approximately 2 μg amplified product were produced per reaction. Restriction digestion of the amplified product with HinfI permitted discrimination of clonal lineages of the four species. Meloidogyne javanica, however, could not be separated from M. hapla by the enzymes used in these experiments. Various amplification conditions and nematode lysis procedures were examined in order to optimize the speed and quality of …

Studies On The Giant Mealie Witchweed, Striga Forbesii Benth., In Zimbabwe, David Allen Knepper

Biological Sciences Theses & Dissertations

Of the seven species of Striga found in Zimbabwe, S. forbesii Benth. is currently the most destructive in terms of crop damage. Owing to its limited occurrence worldwide as a pest of crops, relatively little work has been done on this species.

Striga forbesii has been found to be a consistent problem on both maize and sorghum in the Hunter's Road District of KweKwe, Zimbabwe. Results of a pot study and field observations, indicate S. forbesii can successfully parasitize Urochloa panicoides Beauv., Sorghum arundinaceum (Desv.) Stapf, and Rottboellia cochinchinensis (L.) L.f., all of which are widespread weeds of arable land. …

Bulletin 4133 - Fungal Diseases Of Pasture Legumes In Western Australia, M. J. Barbetti

Bulletins 4000 -

Subterranean clover (Trifolium subterraneum L.) is the most important annual pasture legume in Western Australia, forming the basis of some 6.5 million ha of annual pastures. The success of subterranean clover may be attributed to its ability to increase soil fertility as a consequence of nitrogen fixed, to withstand heavy grazing, to control soil erosion and, with some cultivars, to tolerate waterlogging. Fungal diseases have been a major limitation to the productivity of subterranean clover, affecting both the amount of plant matter and the quantity of seed produced.

Annual medic (Medicago spp., in particular M. polymorpha L.) is also an …

Survey Of The Endogonaceae In Minnesota With Synoptic Keys To Genera And Species, F. L. Pfleger, Elwin L. Stewart

Journal of the Minnesota Academy of Science

Sixteen species in the Endogonaceae (Zygomycotina) were identified from 22 different plant species from a native prairie, an intensively cultivated vegetable field, a reclaimed iron ore tailings basin, an undisturbed site adjacent to the iron ore tailings basin, and from a Pinus resinosa plantation. Seven species of Endogonaceae identified in this study are new records for Minnesota. Synoptic keys to genera and species are presented.

Quarantine Disinfestation A Bibliography With Relevance To Ornamental Plant Material, Kevin Seaton, Daryl Joyce

Biosecurity published reports

This bibliography has been compiled as part of a programme to develop new and improved techniques for the insect disinfestation of export cut-flowers and cut-foliage. The objective of the programme is to identify the most effective disinfestation treatments. Suitable treatments should kill insects in the flowers without directly injuring the flowers or reducing their postharvest life.

The bibliography presents references relating to the disinfestation of ornamental material (i.e. cut-flowers, cut-foliage, and potted plants). However, it also includes references on disinfestation of fruit, vegetables, and stored grain where this information has some relevance to the disinfestation of ornamental materials. The bibliography …

Perspectives On Process In Plant Virology, Myron K. Brakke

Department of Plant Pathology: Faculty Publications

The editors asked that I write a chapter on landmarks in plant virology, a topic that has been covered by several authors, for example by Henderson Smith (89), Bawden (9), Holmes (51), Markham (62), Harrison (44), Black (12), and Matthews (64). In 1 938, the first of these authors, Henderson Smith (89), divided his presidential address to the Society for Applied Biology between the control of plant-virus diseases and the nature of plant viruses. Progress since then has been much more rapid in the latter than in the former area. Henderson Smith could easily understand today's literature on losses, control, …

Flora And Vegetation Of The Meadow River Wetlands, Greenbrier County, West Virginia, Alan Edward Brant

Theses, Dissertations and Capstones

The Meadow River wetlands comprise the second largest wetland complex within the state of West Virginia, containing approximately 3131 acres (1392 ha) of swamp and wet meadow (Evans et al. 1982). Plant collecting within this complex as determined by available literature and herbarium specimens has been limited in the past and apparently dealt only with the wetlands near the head of Otter Creek. Grafton et al. (1982) conducted walk-through surveys in conjunction with a statewide wetland survey and the West Virginia Department of Highways performed a rather detailed vegetation analysis in the same area as part of an environmental impact …