Life Sciences Commons^™

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 …

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 …

Pesticide Use On Crops In Nebraska - 1987, Maurice Baker, Nancy Peterson, Shripat T. Kamble

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This is the third and most comprehensive study of pesticide use on crops in Nebraska. The first was completed in 1978 and the second one in 1982. The first study indicated that approximately 25 million pounds (11.34 million kg) of active ingredients were used on the major crops in Nebraska. This increased to approximately 30.2 million pounds (13.7 million kg) in 1982. The USDA requires accurate information to meet their responsibilities. Thus, this survey was undertaken to determine: 1) the use of pesticides on crops, pasture and rangeland and 2) to identify pest management practices.

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 …

Proceedings Of The 17th Annual Meeting, Southern Soybean Disease Workers (March 20-22, 1990, Biloxi, Mississippi): Soybean Disease Control At A Crossroad, William S. Gazaway, Donald E. Hershman, J. Allen Wrather, Gary W. Lawrence, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

Southern Soybean Disease Workers Officers 1989-1990

Southern Soybean Disease Workers Program Committee 1989-1990

Southern Soybean Disease Workers Committee Chairmen 1989-1990

General session

Presidential address. B Gazaway

Keynote address. K Smith

Invited speakers

Future Impacts of Biotechnology on Soybean Production and Uses. X Delannay

Diseases of Soybean Associated with International Seed Trade. B Moore

Impact of Regulatory Change and GLP's on New Fungicide Discovery and Development. G Hammes

Graduate student papers

Double-Stranded RNA and Virus-Like Particles From the Soybean Stem canker Pathogen, Diaporthe phaseolorum var. caulivora. Y Lee, JP Snow, GT Berggren, and RA Valverde

Development of Soybean Varieties …

Coping With Brown Spot And Root Rots Of Lupins, Mark Sweetingham

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

There is increasing concern that brown spot and root diseases may limit the long term viability of lupin cultivation in close rotations in the agricultural areas of Western Australia. Research has found several useful strategies to reduce the impact of brown spot and Pleiochaeta root rot so that losses can be kept to a minimum. Rhizoctonia has proved more difficult to combat. Although less widespread than Pleiochaeta, it has caused severe losses and appears to be increasing in incidence, particularly in the northern wheatbelt. Research has vastly expanded our knowledge of the strains of Rhizoctonia present in our soils and …

Dominance Relationships Of Cycloheximide-Resistant Mutants Of Schizophyllum Commune Fr., Marjorie Meier Eerdmans, Sally A. Amundson, Todd A. Reinhart, Keith K. Klein

Journal of the Minnesota Academy of Science

We have isolated several mutants of Schizophyllum commune Fr. able to grow on media containing cycloheximide in concentrations up to 30 mg/L. Genetic analyses of the resistant phenotypes show them to be due to the action of a single gene located on the first linkage group between the A-mating type factor and a gene for an adenine requirement (ade-ll). We have analyzed the growth and development of dikaryons made homoallelic for either the resistant or sensitive alleles as well as the heteroallelic dikaryon. These dikaryons showed different abilities to fruit when placed on media containing various concentrations of cycloheximide. Homoallelic …

Managing Diseases Of Alfalfa, Paul C. Vincelli, Garry D. Lacefield, Jimmy C. Henning

Agriculture and Natural Resources Publications

Alfalfa can be a vigorous and productive forage crop for Kentucky farmers. Like all farm crops, however, alfalfa is subject to infectious diseases that can limit forage production. Managing these diseases is an important part of economical alfalfa production.

Alfalfa diseases can cause reduced forage yield, reduced forage quality, and decreased stand persistence. Sometimes, the effects of infectious diseases can be dramatic, such as sudden stand loss in a fall-seeded crop caused by Sclerotinia crown and stem rot. Often, the effects of diseases on alfalfa are more subtle but no less important. For example, alfalfa plants with Phytophthora root rot …

Submitting Plant Specimens For Disease Diagnosis, B. C. Eshenaur, Paul R. Bachi, William C. Nesmith, John R. Hartman, Donald E. Hershman, Paul C. Vincelli, Cheryl A. Kaiser

Agriculture and Natural Resources Publications

Accurate diagnosis of a plant disease depends on having a fresh sample representative of the problem. To get an accurate diagnosis when your plant has a disease problem, you need to collect the right kind of sample.

You also need to provide complete information about the plant and its history. Since the county Extension agent and the person making a diagnosis probably won't see the problem first hand at the growing site, you need to help them create a mental picture of the disease situation. You can provide this help by filling out the information requested on various Plant Disease …

Disease Management In The Home Lawn, Paul C. Vincelli, A. J. Powell Jr.

Agriculture and Natural Resources Publications

Numerous infectious diseases can occur on lawns in Kentucky. Unless diagnosed and managed, these diseases can sometimes cause extensive damage. A sound disease management program benefits your lawn in two ways:

• reduces the severity of lawn diseases
• improves the lawn's recovery should a disease outbreak occur.

This publication describes lawn management practices that can help control diseases of turfgrasses commonly used in home lawns -- Kentucky bluegrass, tall fescue, and perennial ryegrass. You can control diseases of turfgrasses most effectively by using as many of the following lawn management practices as feasible.

The first step in improving your lawn is …

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.

Breeding Phomopsis-Resistant Lupins, John Sylvester Gladstones

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

The release of Gungurru and Yorrel lupins marks the coming of age of the narrow-leafed lupin as a crop plantt. These are the first cultivars of the species th have substantial resistance to Phomopsis stem blight, which will make the stubbles much safer for grazing stock.

This article describes the new lupins, their background, and how they were bred. It also acknowledges the contributions of colleagues who helped in important ways.

Erosion Potential Of Phomopsis-Resistant Lupins, D J. Carter, Paul Findlater

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

During lupin harvesting, up to 20 per cent of the grain remains on the ground. This non-harvested or pilt grain is a valuable feed for sheep during early summer because the pods, leaf and stem generally provide little nutrient in the stubnbles. In addition, the more efficient the weed control, the less valuable are the stubbles.

The disease lupinosis caused by Phomopsis leptostromiformis restricts the amount of grazing from the lupin stubbles, and hence the risk of wind-erosion of stubble paddocks.

However, the introduction of lupin varieties moderately resistant to Phomopsis and with reduced potential to cause lupinosis means that …

Breeding Field Peas : Screening Pea Lines, G H. Walton

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

The early use of field peas in Western Australia was as a green manure crop or to feed stock be grazing the mature crop. Varieties which produced a large bulk of green material were sown. There was no control over insects or diseases.

In 1985, the Feseral Government recognised that to realize the potential of grain legumes grown throughout Australia, more research was needed.

One of the Grain Legume Research Council's (GLRC) priorities is species evaluation and variety improvement.

Since 1983, the Western Australian Department of Agriculture has screened advanced crossbred lines from the South Australian breeding programme for its …

Distribution Of Soybean Cyst Nematode In Nebraska, Thomas O. Powers, L. J. Sandall, D. S Wysong

Department of Plant Pathology: Faculty Publications

A survey of 552 soybean fields in 20 counties in Nebraska in 1986-88 revealed 35 fields infested with the soybean cyst nematode (SCN), Heterodera glycines. Identification was confirmed with a greenhouse bioassay, using 'Lee 74' soybean, and by the application of a DNA hybridization probe derived from SCN mitochondrial DNA. Most of the SCN-infested fields were located on the Missouri River floodplain and in the southeastern corner of the state.

Chlorella Viruses Isolated In China, Yanping Zhang, Dwight Burbank, James L. Van Etten

Department of Plant Pathology: Faculty Publications

Plaque-forming viruses of the unicellular, eucaryotic, exsymbiotic, Chlorella-like green algae strain NC64A, which are common in the United States, were also present in fresh water collected in the People's Republic of China. Seven of the Chinese viruses were examined in detail and compared with the Chlorella viruses previously isolated in the United States. Like the American viruses, the Chinese viruses were large polyhedra and sensitive to chloroform. They contained numerous structural proteins and large double-stranded DNA genomes of at least 300 kilobase pairs. Each of the DNAs from the Chinese viruses contained 5-methyldeoxycytosine, which varied from 12.6 to 46.7% …

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, …

Selection And Development Of Early Maturing Varieties Of Murex Medic., D. J. Gillespie

Experimental Summaries - Plant Research

Trial 88A25, 88MO44, 88NA83, 88AL15

Location: Avondale, New Norcia, Darkan, Cranbrook, Arthur River, Kellerberrin North Quairdading, Gabalong, Merredin, Badgebup and Pingrup.

Over 300 recent overseas introductions of murex medic were evaluated in rows at South Perth in 1988. Of these 15 selections were identified with acceptable spinniness that flower in 100 days or less. Four years ago there was only one selection flowering in under 110 days and that was spiny!

These selections will be evaluated in small plot trials in several country sites in 1989.

This programme aims to identify superior varieties to Zodiac which was released in 1988.

Seed-Bourne Virus Diseases In Annual Pasture Legumes, R A C Jones

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

No abstract provided.

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 …

A Non-Capsid Protein Associated With Unencapsidated Virus Rna In Barley Infected With Barley Stripe Mosaic Virus, Myron K. Brakke, E. M. Ball, W. G. Langenberg

Department of Plant Pathology: Faculty Publications

Barley tissue with an acute systemic infection of barley stripe mosaic virus contained a large amount of unencapsidated virus RNA which was stable in extracts made in ribosome isolation buffer. The virus RNA in ribosome preparations sedimented in a broad band at 80S to 100S in sucrose gradients, which is less than the virion sedimentation rate of 180S to 200S. A protein of apparent M_r 60 000, which sedimented with the virus RNA, was present in ribosome extracts from infected plants but absent from those from uninfected plants. The protein is probably a virus protein because its apparent molecular …