The Rhizosphere and plant growth : papers presented at a symposium held May 8-11, 1989, at the Beltsville Agricultural Research Center (BARC), Beltsville, Maryland (1991)

1: Progress in Rhizosphere Research.- Rhizosphere Research - 85 Years of Progress and Frustration.- Substrate Flow in the Rhizosphere.- Microbial Dynamics in the Rhizosphere. Possible strategies in Managing Rhizosphere Populations.- Root Colonization by Indigenous and Introduced Microorgamisms.- Genetic Approaches for Studying Rhizosphere Colonization.- Living Plant Cells Released from the Root Cap: A Regulator of Microbial Populations in the Rhizosphere?.- Root Growth and Development.- The Development of a Conceptual Model of Root Growth.- Methods for Microbial Autecology in the Soil Rhizosphere.- Applications and Limitations of Rhizotrons and Minirhizotrons for Root Studies.- Conversion Factors Relating Thymidine Uptake to Growth Rate with Rhizosphere Bacteria.- Short Papers.- Growth Rate of Rhizosphere Bacteria as Measured by the Thymidine Method.- Chromosome and Symbiotic Plasmid Diversity within a Naturally-Occurring Population of Clover Rhizobia.- Stability of Antibiotic-Resistance Markers in Bacillus Cereus Uw85.- Bacterial Characteristics Important to Rhizosphere Competence.- Growth of Genetically Altered Pseudomonas Solanacearum in Soil and Rhizosphere.- Growth of Genetically-Engineered Pseudomonas Aeruginosa and Pseudomonas Putida In Soil and Rhizosphere.- Soil Invertebrates are Concentrated on Roots.- Distribution of Assimilated Carbon within the Plant and Rhizosphere of Lolium Perenne: Comparison of Field and Laboratory Grown Plants.- Rhizosphere Effect on Soil Organic Matter Decomposition.- Influence of Nitrogen Fertilization on Photosynthate Distribution and Utilization by Rhizosphere Micro-Organisms in Wheat.- In Vitro Studies on the Interactions of Agrobacterium SPP. And Pseudomonas SPP. Isolated from Opine Environments.- Colonization of Wheat Roots by Pseudomonas Fluorescens: Scanning Electron Microscopy and Biochemical Analysis.- Pectic Enzymes of Azospirillum Brasilense.- Water Uptake Patterns in Loblolly Pines as Seen with Magnetic Resonance Microscopy.- The Occurrence of Cluster Roots in Actinorhizal Plants.- 2: The Rhizobium-Legume Symbiosis.- Legume Inoculation: Successes and Failures.- Importance of Saprophytic Competence for Introduced Rhizobia.- Genetic Stability in Rhizobia in the Field.- Rhizosphere Flavonoids Released by Alfalfa.- Chemotaxis, Induced Gene Expression and Competitiveness in the Rhizosphere.- Gene-For-Gene Interaction in the Legume-Rhizobium Symbiosis.- Microbial Influence on Gene-For-Gene Interactions in Legume-Rhizobium Symbioses.- Short Papers.- Extracellular Polysaccharide-Deficient Mutants of Rhizobium Strain Ciat899 Induce Chlorosis in Beans.- Rhizosphere Interactions Between Rhizobia and Nonlegumes.- Photosynthetic N2-Fixing Rhizobia.- Physiological Comparisons Between Root and Stem Nodules of Aeschynomene Scabra and Sesbania Rostrata.- Isolation and Characterization of Cowpea (Vigna Unguiculata) Lectin.- Rapid Plate Assay for Hydrolytic Enzymes of Rhizobium.- Evaluation of Rhizobium Meliloti Strains Indigenous to Sonoran Desert Soils by Plasmid Profile and Intrinsic Antibiotic Resistance.- Enhancing Rhizobial Colonization in the Rhizosphere of Legumes by a Systemic Fungicide.- Mapping and Subcloning of Genes Involved in Nodulation Competitiveness from Rhizobium Leguminosarumbv. TrifollT24.- Competition for Nodulation of Soybean by Bradyrhizobium Japonicum 123 and 138 In Missouri Soil.- Effect of Acidified Soil on Symbiosis in Soybeans.- Distribution of P Metabolites and Compartmentation in Soybean Nodules As Studied By Electron Microscopy and 31P NMR Spectroscopy.- 3: Rhizosphere Interactions and Plant Rest Control.- Exudate Molecules Initiating Fungal Responses to Seeds and Roots.- Beneficial and Deleterious Effects of HCN-Producing Pseudomonads on Rhizosphere Interactions.- Induction of Rhizosphere Competence in the Biocontrol Fungus Trichoderma.- Mechanisms of Biocontrol of Soil-Born Plant Pathogens by Rhizobacteria.- Biocontrol of Soilborne Plant Pathogens with Fungi.- Role of Antibiotics and Siderophores in Biocontrol of Take-All Disease of Wheat.- Factors Influencing Siderophore-Mediated Biocontrol Activity of Rhizosphere Pseudomonas SPP..- Rhizosphere Interactions and Siderophores.- Genetics of Iron Transport in Plant Growth-Promoting Pseudomonas Putida Wcs358.- Formulation and Delivery Systems of Biocontrol Agents with Emphasis on Fungi.- Formulation, Delivery Systems and Marketing of Biocontrol Agents and Plant Growth Promoting Rhizobacteria (PGPR).- Short Papers.- Effect of a Fluorescent-Pigment Producing Rhizobium on the Severity of Rhizoctonia Solani Seed and Root Rot of Phaseolus Vulgaris.- Role of Ammonia and Calcium in Lysis of Zoospores of Phytophthora SPP. by bacillus cereus strain UW.- Deleterious Rhizobacteria for Biocontrol of Weed Seeds and Seedlings in Soil.- An Improved, in Vitro Technique for Rapidly Assaying Rhizosphere Bacteria for the Production of Compounds Inhibitory to Rhizoctonia Solani andGaeumannomyces Graminisvar. Tritici.- Improved Rhizosphere Competence of Trichoderma Harzianumby Protoplast Fusion.- Sick Pathogens Make Poor Pests in Biological Control of Corn Diseases.- Mutational Changes in the O-Antigenic Side Chains of the Lipopolysaccharides of Pseudomonas SPP. Affect Colonization of but not Adhesion to Potato Roots.- Fungal Antagonists of Pythium Ultimum from a Suppressive Sphagnum Peat.- Siderophore-Producing Bacteria Isolated From Roots of Iron-Efficient and Inefficient Grasses.- Production of Siderophore-Like Iron Chelators by Ericoid and Ectomycorrhizal Fungi.- Genetic Improvement of Siderophore Production Aimed At Enhancing Biocontrol in Pseudomonas Strains.- Bioinorganic and Bio-Organic Studies of Rhizobactin, A Structurally Novel Siderophore Related to the Opines.- Uptake of Bradyrhizobiumjaponicum Siderophores By Soybean Cells in Culture.- 4: Rhizosphere Interactions and Plant Growth Promotion.- Plant Growth Promotion Mediated by Bacterial Rhizosphere Colonizers.- Microbial Production of Plant Hormones.- Characterization and Use of Vesicular-Arbuscular Mycorrhizae in Agricultural Production Systems.- Mycorrhizal Interactions in the Rhizosphere.- Agro-Ecological Aspects of the Mycorrhizal, Nitrogen-Fixing Legume Symbiosis.- Field Management of VA Mycorrhizal Fungi.- Short Papers.- Characterization of Cultivar Specific Growth Promotion of Spring Wheat by Bacillus SP..- Effect of Bacillus Strains on Growth of Pine (Pinus Contorta Dougl), Spruce (Picea Glauca Voss.), And Douglas-Fir (Pseudotsuga Menziesll (Mirb. Franco)).- Sulfur Oxidizing Microorganisms for Growth Promotion of Canola.- Microbe Enhanced P Uptake by Corn under no Till and Conventional Till.- Exposure of Phleum Pratenseto SO2 and Its Subsequent Effect on Vam Root Infectivity.- Promotion of Maize Growth by Legume Soil Factors.- Variation in VA Mycorrhizal Strain Interactions with Rhizobium on Pigeon Pea.- Use of Histochemical Techniques to Quantify Mass/Activity Relations of Mycorrhizal Roots and Soil.- Genetic Transformation of Protoplasts From an Ectomycorrhizal Fungus.- Response of Two Acacia Species to Drought and Inoculation with an Ectomycorrhizal Fungus.- Specific Interactions of Bradyrhizobium and Four VA-Mycorrhizal Isolates in Soybean.- Ozone-Induced Alteration of Biomass Allocation and Nitrogen Derived From Air in the Leguminous Plant-Rhizobium-Vam System.- Strategy for Inoculating Nursery-Grown Sea Oats with Vesicular- Arbuscular Mycorrhizal Fungi.- Evaluation of the Effects of Biocontrol Agents on Mycorrhizal Fungi.- A Misting Apparatus for Studying Plant-Microbe Interactions and Nutrient Utilization.- Increasing VA-Mycorrhization with Applications of Rhizosphere Bacteria.- Mycorrhizal Fungi Increase Yields of Winter Wheat.