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Biosystematics And Diversification In The Genus Striga Lour. (Scrophulariaceae) In Africa, Kamal-Eldin Ibrahim Mohamed

Biological Sciences Theses & Dissertations

Of the 34 taxa of Striga (29 species) that occur in Africa, 25 are endemic. Species diversity differs from region to region. The subtropical zone has 74% of the taxa including 41% endemics. Within this region, the West African part (from Senegal to eastern Nigeria) has 62% of the total taxa including 24% endemics. South of the equator the number of taxa is 56% of the total with 21% endemics, a proportion slightly less than that for West Africa. I recognize 29 species based on extensive herbarium and field studies. A new species from Angola is described. Striga yemenica previously …

Proceedings Of The 21st Annual Meeting, Southern Soybean Disease Workers (March 6-8, 1994, Tulsa, Oklahoma), Glenn Bowers, John Rupe, Brian M. Anderson, Gabe Sciumbato, Glenn G. Hammes

Southern Soybean Disease Workers: Conference Proceedings

Contents

1993-94 SSDW Committee Chairs

1993-94 SSDW Officers

Graduate student competition

Resistance of Soybean Cultivars in Maturity Group IV-VIII to Rotylenchulus reniformis. JJ Cornelius and GW Lawrence

Evaluation of Susceptibility of Soybean to Red Crown Rot caused by Calonectria crotalariae in the Field. KD Kim, JS Russin, and JP Snow

Contributed papers

Soybean Disease Loss Estimate for the Southern United States During 1993, Table 1. Estimated percent Joss of soybean yields in 1993 to disease, Table 2. Estimated reduction of soybean yields in 1993 to disease, and Table 3. Southern states soybean disease loss estimate total in bushels and …

Meloidogyne Javanica Parasitic On Peanut, E. K. Tomaszewski, M. A. M. Khalil, A. A. El-Deeb, Thomas O. Powers, J. L. Starr

Department of Plant Pathology: Faculty Publications

Peanut fields in four governorates of Egypt were surveyed to identify species of Meloidogyne present. Fourteen populations obtained from peanut roots were all identified as M. javanica based on perineal patterns, stylet and body lengths of second-stage juveniles, esterase phenotypes, and restriction fragment length polymorphisms of mtDNA. Three of 14 populations, all from contiguous fields in the Behara governorate, had individuals with a unique two-isozyme esterase phenotype. All populations of M. javanica tested on peanut had levels of reproduction on the M. arenaria-susceptible peanut cultivar Florunner that were not different from M. arenaria (P = 0.05), and had lower …

Characterization Of Heterorhabditis Isolates By Pcr Amplification Of Segments Of Mtdna And Rdna Genes, Susan A. Joyce, Ann M. Burnell, Thomas O. Powers

Department of Plant Pathology: Faculty Publications

Restriction digests of amplified DNA from the mitochondrial genome and the nuclear ribosomal internally transcribed spacer region have been evaluated as genetic markers for species groups in Heterorhabditis. Six RFLP profiles have been identified. These profiles supported groupings determined by cross-breeding studies and were in agreement with less definitive groupings based on other biochemical and molecular methods. Digestion patterns of both amplification products provided strong evidence for the recognition of species groups, which include Irish, NW European, tropical, and a H. bacteriophora complex. The H. bacteriophora complex could be further resolved into three genotypes represented by H. zealandica, …

Merging Conservation With Production In Remnant Bush, Anne Morgan, Alison Fuss

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

Exports of cutflowers and foliage from Western Australia are now worth about $17 million a year. A third of this is picked from the bush, either on Crown Land or areas of remnant bush on private property. While the industry's future lies in cultivation, bush picking is likely to remain important for some years. This can provide both extra income for farmers and benefit the environment - as long as care is taken

Identification And Characterization Of Aspergillus Nidulans Mutants Defective In Cytokinesis, Steven D. Harris, Jennifer L. Morrell, John E. Hamer

Department of Plant Pathology: Faculty Publications

Filamentous fungi undergo cytokinesis by forming crosswalls termed septa. Here, we describe the genetic and physiological controls governing septation in Aspergillus nidulans. Germinating conidia do not form septa until the completion of their third nuclear division. The first septum is invariantly positioned at the basal end of the germ tube. Block-and-release experiments of nuclear division with benomyl or hydroxyurea, and analysis of various nuclear division mutants demonstrated that septum formation is dependent upon the third mitotic division. Block-and-releasee xperiments with cytochalasin A and the localization of actin in germlings by indirect immunofluorescence showed that actin participated in septum formation. In …

Developing Improved Varieties Of Subterranean Clover, Phil Nichols, Bill Collins, Dennis Gillespie, Martin Barbetti

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

Subterranean clover is widely recognised as the most important pasture legume species in southern Australia, having been sown over about 20 million hectares.

Together with superphosphate and trace elements, it has been a key factor in improving and maintaining soil fertility, and has resulted in dramatic increases in crop, livestock and wool production.

While the value of subterranean clover is well established, it does have some shortcomings.

Many varieties grown today are not sufficiently adapted to the environments and management systems in use. Others lack sufficient pest and disease resistance.

Improved subterranean clovers are being bred with better adaptation and …

1993-94 Progress Report, Warren Hedstrom, James D. Leiby, Michele C. Marra, John M. Smagula, Scott Dunham, Paul E. Capiello, Delmont Emerson, David E. Yarborough, Alfred A. Bushway, Rodney J. Bushway, Lixin Tian, Mary Ellen Camire, Susan Ismail Flint, Youzhi Chen, Richard Work, Therese M. Work, Linda J. Irvine, Francis A. Drummond, Constance S. Stubbs, H Y. Forsythe Jr, Judith A. Collins, Edward R. Huff, David H. Lambert, David E. Yarborough, Timothy M. Hess, Marjorie Hundhammer, Roland Dupuis, Sue Hill, Dick Vervill, Bill Seekins, Kim Mitchell, John Jemison

Wild Blueberry Research Reports

The 1993 edition of the Progress Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:

1. Effects of irrigation on lowbush blueberry yield and quality

2. The Economics of investigating irrigation for lowbush blueberries

3. Phosphorus dose/response curve

4. Winter injury protection by potassium

5. Multiple cropping of wild stands

6. Effect of Boron and Calcium on lowbush blueberry fruit set and yield

7. Comparison of N, NP, and NPK fertilizers to correct nitrogen and phosphorus deficiency

8. …

Biological Control Of Doublegee : Israeli Weevil Could Help Fight Doublegee, John Scott, Paul Yeoh

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

Since its deliberate introduction from South Africa as a salad vegetable in 1830 the doublegee has spread to become a major weed throughout much of Australia.

It is one of the most serious weeds of crops and pastures in Western Australia, smothering other more useful plants while young, and troubling both humans and animals with its sharp spiny seeds when mature.

Using biological control techniques, scientists are now attacking it and related docks in three ways - with an aphid, a weevil and a fungus.

Within a few years it is hoped that while still present, the doublegee will be …

Biological Control Of Doublegee : Doublegee Decline And The Dock Aphid, John Scott, Francoise Berlandier, Kristy Hollis

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

Since 1990 farmers in the Western Australian wheatbelt have been reporting doublegee plants that appear to be diseased, stunted and producing poorly formed fruit (the spiny casing around the single doublegee seed). Often no obvious cause of this decline in plant health is apparent. Experiments carried out in 1990 showed that an aphid, which feeds hidden in the growing tips of doublegee stems and in young distorted leaves, is the most likely cause. This North American aphid, the dock aphid (Brachycaudus rumexicolens), arrived in WA in 1987. It appears to only feed on docks, doublegees and related plants and is …

Biological Control Of Doublegee : Fungi May Be Another Weapon, Roger Shivas, John Scott

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

A fungus has been assessed both in Australia and South Africa since 1989 for its potential to control doublegee.

Under optimal environmental conditions it causes a severe stem blight which ultimately kills the plant. It also infects seeds, and caused up to 30 per cent mortality at a field site near Badgingarra.

Hopes to develop the fungus as a mycoherbicide (fungal killer of plants) have had to be dropped because it produces a potent toxin but it is still contributing to control in the field.