Plant Biology Commons^™

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 …

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 …

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 …

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 …

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 …

The Pollen Exostructure Of Striga (Scrophulariaceae), Mark A. Deleonardis

Biological Sciences Theses & Dissertations

In this survey, the pollen exostructure of 13 Striga species was examined using light microscopy and scanning electron microscopy. Two of the 13 species were also observed by transmission electron microscopy to assess major differences in exine composition. Striga pollen is consistently spherical to oblate, isopolar, tectate, and three or four colpate. Sculpturing may be psilate, psilate-perforate, finely rugulate, or coarsely rugulate. The equatorial width of the species surveyed ranged from 15 to 30 micrometers. It is concluded that variation in Striga pollen sculpturing, aperture structure, and size support the current taxonomy of the genus.

Differential Effects Of Lithium Chloride On In Vitro Growth Of Clavibacter Michiganense Subsp. Nebraskense Depending Upon Inoculum Source, Mary L. Smidt, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The bacterium Clavibacter michiganense subsp. nebraskense (Corynebacterium michiganense subsp. nebraskense) was grown in broth cultures and inoculated into corn plants. The plating efficiency of cells from broth cultures was essentially the same on nutrient broth-yeast extract and the semiselective medium for this bacterium, CNS. However, when cells were isolated from Goss bacterial wilt- and blight-infected corn, very few were recovered on CNS compared with the amount recovered on nutrient broth-yeast extract agar. When lithium chloride was omitted from the CNS, recoveries from infected corn were nearly the same as on nutrient broth-yeast extract agar. No other ingredient of CNS …

Effects Of Two Species Of Va Mycorrhizal Fungi On Drought Tolerance Of Winter Wheat, Michael F. Allen, Michael G. Boosalis

Department of Plant Pathology: Faculty Publications

Roots and soils from western Nebraska fields of native and planted grasslands, and winter wheat of varied fallow-wheat cultivation duration, were evaluated for vesicular-arbuscular (VA) mycorrhizal root infection and spore numbers and types. Increased cultivation decreased percentage mycorrhizal infection in wheat and reduced spore numbers of Glomus fasciculatus, the dominant VA mycorrhizal fungus in these soils. Spore numbers of other VA mycorrhizal fungi did not change significantly with cultivation although mean numbers of G. mosseae increased with continued wheat production. Water relations and growth were determined for greenhouse-grown non-mycorrhizal, G. fasciculatus-infected, and G. mosseae-infected wheat in wet …

Influence Of Vesicular-Arbuscular Mycorrhizae On Water Movement Through Bouteloua Gracilis (H.B.K.) Lag Ex Steud, Michael F. Allen

Department of Plant Pathology: Faculty Publications

Root growth characteristics and water transport were compared between non-mycorrhizal Bouteloua gracilis and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus. Mycorrhizal plants did not have significantly different leaf area or root length from non-mycorrhizal plants, hut did have significantly fewer and shorter root hairs. Mycorrhizal plants had 50% lower leaf resistance with no change in leaf or root water potentials; thus transpiration was increased 100% with a 50% reduction in whole-plant, soil-to-root and root-to-leaf resistance. Assuming that the difference in water uptake was due to transport via the mycorrhizal hyphae, estimated fungus-to-root transport was 2◦8 x 10^{-5 …}

The Plant Pathogenic Corynebacteria, Anne K. Vidaver

Department of Plant Pathology: Faculty Publications

The plant pathogenic corynebacteria are a fascinating group of bacteria that produce effects as diverse as any in the microbial world, ranging from wilts to abnormal growths. Several new pathogens have been discovered since this group was reviewed by Jensen (75), Starr (157), and Lelliott (96). Most subsequent reviews have dealt with taxonomy. The areas covered in this review necessarily reflect my biases and limitations. However, this review attempts to be comprehensive in some areas, and it calls attention to other areas that would benefit from more detailed investigation.

Influence Of Phosphate Source On Vesicular-Arbuscular Mycorrhizae Of Bouteloua Gracilis, Michael F. Allen, James C. Sexton, Thomas S. Moore Jr., Martha Christensen

Department of Plant Pathology: Faculty Publications

Non-mycorrhizal and vesicular-arbuscular mycorrhizal Bouteloua gracilis infected with Glomus fasciculatus were grown in defined media containing different phosphate sources and compared with respect to phosphate content and form, biomass, chlorophyll concentration, and root phosphatase activity. The phosphate sources were sodium monobasic phosphate, a mixture of sodium monobasic phosphate and calcium phytate, and calcium phytate. Inositol and inositol plus calcium were added to the sodium phosphate medium as additional treatments. Mycorrhizal infection was highest in roots of plants grown in the presence of phytate (75%). Lower root infection levels were noted in plants from the sodium phosphate (19%) and mixed phosphate …

Effects Of Reduced Tillage And Multiple Cropping On Plant Diseases, Donald R. Sumner, Ben Doupnik Jr., M. G. Boosalis

Department of Plant Pathology: Faculty Publications

In the past, tillage research on plant diseases was concerned primarily with practices that buried plant residues in single-crop production systems. The burial of plant debris to destroy pathogens is an ancient agricultural prac­ tice (34). Each crop was tested as a single entity, and most crop rotations were based on one crop per year. Interest in notill and conservation tillage systems and mUltiple cropping has increased in the past two decades be­ cause of the scarcity and increased cost of fossil fuels, periodic world food shortages, and the concern over soil erosion (73,110). These concerns are of such paramount …

Comparative Water Relations And Photosynthesis Of Mycorrhizal And Non-Mycorrhizal Bouteloua Gracilis H.B.K. Lag Ex Steud., Michael F. Allen, William K. Smith, Thomas S. Moore Jr., Martha Christensen

Department of Plant Pathology: Faculty Publications

The rangeland grass, Bouteloua gracilis was inoculated with its mycorrhizal symbiont, Glomus fasciculatus, to determine the influence of vesicular-arhuscular mycorrhizae on water status, stomatal behaviour and photosynthesis as well as gross plant morphology, biomass and phosphorus content. Mycorrhizal infection increased transpiration rates by over 100% with 50 to 70% lower leaf resistances to water vapour diffusion. Leaf xylem pressure was not different between mycorrhizal and non-mycorrhizal plants indicating that whole-plant resistance to water transport was reduced by more than 50%. Photosynthetic rates under saturating light conditions increased 68% with infection as a consequence of a 33% reduction in stomatal …

Ryegrass Toxicity Organism Found On Other Grasses, D L. Chatel, J. L. Wise, A. G. Marfleet

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

Yellow slime disease caused by Corynebacterium sp. has recently been found in three grass species.

The diseased grasses were found in the field growing with each other and with affected toxic annual ryegrass.

A Study Of Vascular Plants On Rock Outcrops In Southwestern West Virginia, Sheila Kay Adkins Zeto

Theses, Dissertations and Capstones

A total of 223 species of vascular plants representing 66 families were collected from rock outcrops at five study sites in Cabell, Wayne and Lincoln Counties, southwestern West Virginia. Eighteen species (8.07 percent) were present at all five sites with little regard for site conditions. One hundred seventeen species (52,4 percent) were restricted to only one of the five sites. The outcrop flora included nine species (5.03 percent) that are considered introduced elements, Forty-eight species were new additions to the flora of one or more of the counties studied, Floristic similarity coefficients of five sites range .from .347 to .512. …

Bulletin No 3863 - Plants Which Cause Kimberley Horse Disease, A. L. Payne

Bulletins - 3000 - 3999

Crotalaria crispata and Crotalaria retusa (Rattlepod), two plants responsible for Kimberley horse disease*, are, unfortunately, fairly widespread throughout the Kimberleys. Both species are apparently toxic in all stages of growth.

This bulletin is to assist pastoralists to:-

• Identify the two plants;

• Recognise the type of country and conditions under which they grow; and

• Locate horse paddocks on country where the plants are least likely to occur.

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 …

Survival Mechanisms Of Phytopathogenic Bacteria, M. L. Schuster, D. P. Coyne

Department of Plant Pathology: Faculty Publications

Natural habitats usually do not provide bacteria the continuity of agricultural crops. With continuous culture. perpetuation of pathogen is no problem. Although agricul­ tural practices provide some discontinuity between crops. it is less than that in nature. Uniformity of crop germ plasm also favors inoculum buildup and perhaps perpetuation of the pathogens.

Learning To Live With Clover Scorch, A Bokor, D. L. Chatel

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

Recent research has increased our understanding of clover scorch disease in Western Australia.

An economic control has yet to be developed but it appears that management can be adjusted to reduce damage to pastures and there is scope for using resistant species and less susceptible cultivars to escape the disease.

A major research programme is in progress.

Smooth-Stemmed Turnip, B J. Quinlivan, A. C. Devitt

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

Cruciferous weeds are common throughout the agricultural areas of Western Australia. They include wild turnip, wild mustard, wild radish, charlock and raphistrum weed or short fruited turnip.

Another one—tentatively named smooth-stemmed turnip—has recently been sighted. Its exact weed potential will not be known for some years, but it is likely to spread through the south coastal districts where the climate and sandy surfaced soils favour its growth.

Bulletin No 3861 - Kimberley Research Station - Progress Report 1972, J. R. Mcalpine, R. H. Gunn, P. Jakobsen, R. Wetselaar, J. J. Basinski, N. J. Thomson, A. G. L. Wilson, D. H. Mackenzie, A. J. Millington, D. F. Beech, P. C. Owen, B. G. Williams, C. G. Blunt, A. Mcr Holm

Bulletins - 3000 - 3999

The systematic investigations of the potential of the Ord area for irrigated farming began during the Second World War when the possibilities of damming the river were first examined, initial soil survey was carried out, and agricultural experiments started. The Kimberley Research Station was established on its present site in 1945. A year later the State and Commonwealth Governments agreed to finance and operate the Station jointly, with CSIRO and the Western Australian Department of Agriculture being responsible for research.

The construction of the main dam designed to store 5,675 million m" ( 4.6 million acre feet) was completed in …

The Effect Of Antibiotics On Thermophilic Blue-Green Algae, Erleen Blanche Christenson

Dissertations and Theses

The nature of the action of penicillin on the cell walls of bacteria is reviewed. The composition of bacterial cell walls is compared to cell walls of blue-green algae.

The test organisms used were thermophilic: Anacystis nidulans grew optimally at 35⁰C, whereas Synechococcus lividus grew best at 45⁰ C. Growth was recorded by reading optical densities.

Cells of these two thermophilic blue-green algae were treated with varying dosages of penicillin and streptomycin. Penicillin inhibited growth of Anacystis nidulans and Synechococcus lividus in concentrations of 3.0 µg/ml and 0.03 µg/ml respectively. However, when 0.3 µg/ml of penicillin was added to Anacystis …

Bulletin No 3768 - Submitting Plants For Disease Identification, M D. Marcley

Bulletins - 3000 - 3999

THERE are several important points to remember when submitting plant material for disease identification by the Department of Agriculture's Plant Pathology Branch.

Firstly it is very important to collect a suitable sample because it is very difficult to determine the cause of a plant disease by looking at a completely dead plant. The sample should include the entire plant (before it is completely dead) including roots and soil. Then all the effects of the disease can be seen. For example leaf yellowing, dead areas of the stem, collar rot, root rot, eelworm damage, and disease of the water and food …

Observations On The Establishment Of Seedlings Of Phoradendron Californicum On Prosopis Juliflora, Richard L. Null

Dissertations and Theses

The mistletoe Phoradendron californicum is a common parasite on the mesquite plant Prosopis juliflora. Seeds of the parasite are deposited upon the host plant by birds and perhaps other agents. Normally seedlings of the parasite become established when the elongating radicle of the embryo comes into contact with a host branch and forms a holdfast. From the underside of the holdfast the primary haustorium enters the host tissue and establishes the parasitic union. Later the aerial portion of the parasite develops. Some seeds of P. californicum follow a different sequence; they stimulate the host to produce gum in the tissue …

Growing Barley For Grain In Western Australia : Barley Quality, J A. Parish

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

Plumpness and absence of pinched grain are desirable for both malting and feed barley.

This is a brief discussion of various Quality standards in barley and how they may not be met.

Dehulling And Scarifying Serradella Seed, J R. Weeldenburg, R. W. Smith

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

YELLOW FLOWERED SERRADELLA is growing in popularity as a pasture legume on coastal sandy soils in Western Australia, and its use may increase further when new selections become available.

However, its rate of entry into commerce has been limited by the poor germination of the seed available.

Pasture Seed Production In Western Australia, B J. Quinlivan

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

Pasture seed production in Western Australia is an industry with a somewhat turbulent past. Booms and slumps have been the rule rather than the exception.

However, during the past few years there has been some degree of "stability"—if not in price, at least in terms of total production.

Northern Corn Leaf Blight (Helminthosporium Turcicum Pass.) On Susceptible And Resistant Corn, Saffet Baydar

Open Access Master's Theses (through 2010)

The objectives of the research reported herein were to (1) become familiar with the technique of inoculating corn with Helminthosporium turcicum, (2) become familiar with a technique of evaluating the susceptibility of corn lines to H. turcicum, (3) become familiar with plant reaction and organism development in the various types of corn and (4) evaluate Turkish corn susceptibility in relation to various types of germ plasm in American corn lines in order to assist in combating the serious disease of Northern corn left blight in Turkey.

Comparative reactions of 10 Turkish, 5 multigenic resistant, 2 heterozygous monogenic …

The Effect Of Straw On The Emergence Of Wheat Seedlings, W A. Shipton, W. R. Tweedie

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

The emergence of wheat seedlings was decreased substantially when seed was planted close to oaten straw.

When the grain was placed a 1/4 inch above a straw layer emergence was depressed by more than half.