Life Sciences Commons^™

Kentucky Plant Disease Management Guide For Forage Legumes, Paul C. Vincelli

Agriculture and Natural Resources Publications

This guide contains information on the biology and management of the most important diseases of forage legumes in Kentucky. Fundamental information on symptoms, disease cycle, and management is provided. For some diseases, more extensive information on biology and management is also available in other Extension publications. Additional sources of information are listed under individual diseases.

Disease management in forage legumes relies heavily on using disease-resistant varieties and employing sound agronomic practices. It is important to integrate both of these strategies into a comprehensive disease management program. Failure to consider one or the other will compromise the success of your efforts. …

Kentucky Plant Disease Management Guide For Corn And Sorghum, Paul C. Vincelli, Donald E. Hershman

Agriculture and Natural Resources Publications

This guide contains information on the biology and management of the most important diseases of corn and sorghum in Kentucky. Fundamental information on symptoms, disease cycle, and management is provided. For some diseases, more extensive information on biology and management is also available in other Extension publications. Additional sources of information are listed under individual diseases.

Disease management in corn and sorghum relies heavily on using disease-resistant hybrids and employing sound agronomic practices. It is important to integrate both of these strategies into a comprehensive disease management program. Failure to consider one or the other will compromise the success of …

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%. …

The Polymerase Chain Reaction And Plant Disease Diagnosis, Joan M. Henson, Roy C. French

Department of Plant Pathology: Faculty Publications

The polymerase chain reaction (PCR) provides a simple, ingenious method to exponentially amplify specific DNA sequences by in vitro DNA synthesis. Three essential steps to PCR (Figure 1) include (a) melting of the target (b) annealing of two oligonucleotide primers to the denatured DNA strands, and (c) primer extension by a thermostable DNA polymerase (123). Newly synthesized DNA strands serve as targets for subsequent DNA synthesis as the three steps are repeated up to 50 times. The specificity of the method derives from the synthetic oligonucleotide primers, which base-pair to and define each end of the target sequence to be …

Leptospira Genomes Are Modified At 5'-Gtac, David Ralph, Quideng Que, James L. Van Etten, Michael Mcclelland

Department of Plant Pathology: Faculty Publications

Genomic DNAs of 14 strains from seven species of the spirochete Leptospira were resistant to cleavage by the restriction endonuclease RsaI 1 (5'-GTAC). A modified base comigrating with m⁴C was detected by chromatography. Genomic DNAs from other spirochetes, Borrelia group VS461, and Serpulina strains were not resistant to h a 1 digestion. Modification at 5'-GTAm⁴C may occur in most or all strains of all species of Leptospira but not in all genera of spirochetes. Genus-wide DNA modification has rarely been observed in bacteria.

Evidence For Virus-Encoded Glycosylation Specificity, Ing-Nang Wang, Yu Li, Quideng Que, Meenakshi Bhattacharya, Leslie C. Lane, William G. Chaney, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Four spontaneously derived serologically distinct classes of mutants of the Paramecium bursaria chlorella virus (PBCV-1) were isolated using polydonal antiserum prepared against either intact PBCV-1 or PBCV-1-derived serotypes. The oligosaccharide(s) of the viral major capsid protein and two minor glycoproteins determined virus serological specificity. Normally, viral glycoproteins arise from host-specific glycosylation of viral proteins; the glycan portion can be altered only by growing the virus on another host or by mutations in glycosylation sites of the viral protein. Neither mechanism explains the changes in the glycan(s) of the PBCV-1 major capsid protein because all of the viruses were grown in …

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 …

The Future Of Agricultural Research, Roger Beachy, Susanne L. Huttner, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

We enthusiastically support Philip H. Abelson’s call for substantially increased funding for basic agricultural research (Editorial, 28 Aug., p. 1187). However, he neglects the government’s critical role as gatekeeper; some federal regulatory policies are serious impediments to progress in the agricultural sciences. A subsequent editorial by Charles Arntzen, “Regulation of transgenic plants’ (4 Sept., p 1327), points out that research on genetically engineered plants is now subject to delays and extensive assessments that result from perceptions of public concern and not from scientific evidence of risk. when government’s research and regulatory policies conflict, the public loses twice-their investment in the …

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.

Eradication Of Apple Scab, John Cripps, Ralph Doepel

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

The detection of apple scab in two orchards at Pemberton and New/ands in December 1989 ended Western Australia's 41-year, scab-free span for apple growers .

Without eradication orchardists would have had to apply up to 20 fungicidal sprays a year, at an annual cost of $1-2 million, to be able to market a high proportion of scab-free fruit. The industry chose eradication as the cheaper alternative, but the location of infected orchards at Pemberton in particular, with its high rainfall, suggested that it would be difficult .

Scab, or black spot, is the most serious fungal disease of apples in …

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 …

Pesticide Use On Sweet Corn Grown In Connecticut: 1990, James L. Turner Ii, Candace L. Bartholomew

Storrs Agricultural Experiment Station

No abstract provided.

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.

Proceedings Of The 19th Annual Meeting, Southern Soybean Disease Workers (February 19-20, 1992, St. Louis, Missouri), J. Allen Wrather, Patrick D. Colyer, Glenn R. Bowers Jr., Brian M. Anderson, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern Soybean Disease Workers 1991-1992 officers

1991-1992 Program Committee

Graduate student competition

Interactions of Macrophomina phaseolina with two soybean cultivars under four irrigation regimes. SR Kendig and JC Rupe

Influence of soybean planting dates on the incidence and severity of Sudden Death Syndrome. SS Alghamdi, PT Gibson, and MA Shenaut

The interrelationship of Heterodera glycines and Fusarium solani in sudden death syndrome of soybean. KS McLean and GW Lawrence

Frogeye leaf spot of soybean: evaluation of cultivars and isolates. PF Pace, DB Weaver, and LD Ploper

Soybean cyst nematode race symposium

SCN race scheme: a historical perspective. JA Fox …

Stubble Retention And Leaf Disease In Lupin And Cereal Crops, Mark Sweetingham, Robert Loughman, Ron Jarvis

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

Retention of cereal stubbles can reduce leaf disease in lupins but increase leaf disease in cereals. The extent of cereal disease carry-over in stubbles depends on the locality and whether multiple cropping or crop rotation is practised

Paddock Sampling For Management Of Annual Ryegrass Toxicity, Ian Riley

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

Annual ryegrass (Lolium rigidumJ seedheads containing corynetoxins, a group of bacterially produced antibiotics, are poisonous to livestock. Animals that eat affected ryegrass develop annual ryegrass toxicity (ARGT), suffer convulsive staggers and die within a few days of eating a lethal dose. ARGT is characterised by high death rates, especially where pastures are not known to be affected and where stock-owners are not expecting the problem. Fortunately, there are commercial tests that determine the levels of ARGT organisms in the paddock and the risk of getting the disease. These tests will help farmers plan their cropping and pasture programs for the …

Three New Late-Midseason Subterranean Clovers Released For High Rainfall Pastures, Phil Nichols, Donald Nicholas

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

Three new subterranean clovers - Denmark, Gou/bum and Leura - have been released in 1992 by the National Subterranean Clover Improvement Program. These subterranean clovers are black-seeded, have low oestrogen levels and improved disease resistance. Their release offers the potential for substantial improvements in pasture productivity in areas of southern Australia that have long growing seasons.

This article outlines some of the testing procedures and subsequent selection of these varieties and describes their characteristics and potential role in Western Australia.

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 …

Regulation Of Biotechnology, Henry I. Miller, Robert H. Burris, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

Greg Simon (Letters, 3 May, p. 629) makes the case that only federal regulation of releases of agricultural products will address health and safety concerns. Such a view is hardly surprising, since he drafted the federal statute for the comprehensive regulation of field research with recombinant DNA-manipulated organisms. The basic assumptions of this statute were contrary to those contained in the reports of the National Academy of Sciences (NAS) (1) and the National Research Council (NRC) (2) and also to the existing policies of government research and regulatory agencies. The statute would have regulated only those organisms that were manipulated …

Shade Tree Decline And Related Problems, John Hartman, Mary L. Witt

Agriculture and Natural Resources Publications

Shade tree decline is a complex disease situation since the cause frequently cannot be traced to one single factor. Typically, one or more primary stresses cause the health of a tree to deteriorate, and then secondary pathogens and/or insects contribute to further decline. Determining causes of decline requires careful examination of the tree and growing site as well as knowledge of the tree's history. Even then, diagnosis may be difficult because the original stress may be obscure or no longer present. Trees most commonly affected in Kentucky are Norway and sugar maples, ash and oaks (particularly pin oaks).

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 …

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 …