Plant Pathogenic Bacteria: Proceedings of the Sixth International Conference on Plant Pathogenic Bacteria, Maryland, June 2-7, 1985

ISBN-13: 9789024734764 / Angielski / Twarda / 1987 / 1050 str.

E. L. Civerolo; Alan Collmer; R. E. Davis

Opis

More than 270 scientists from 33 countries attended the 6th International Conference on Plant Pathogenic Bacteria in College Park, Maryland, June 2-7, 1985. The Conference was jOintly sponsored by the International Society of Plant Pathology, Bacteria Section and by the United States Department of Agriculture, Agriculture Research Service. The Conference provided an opportunity for the presentation and discussion of recent developments in phytobacteriology. The Conference was organized into five symposia, seven discussion sessions, contributed papers and poster presentations. More than 230 contributions were presented under the following topics: ice nucleating bacteria; detection, identification, nomenclature and taxonomy of phytopathogenic bacteria; applications and impact of new biotechnologies on phytobacteriology; bacterial phytotoxins; diagnostic phytobacteriology; management of bacterial plant diseases; and molecular biology, genetics and ecology, epidemiology of phytopathogenic bacteria. In addition, special sessions focused on Agrobacterium, Erwinia, Psedomonas and fastidious prokaryotes. This reflected the broad spectrum of current research activity in phytobacteriology. Furthermore, interest in this series of conferences clearly continues to increase. Key research scientists who are currently making major advances in phytobacteriology participated in the Symposia and Discussions. One of the most significant recent changes that has occurred in the field of plant pathology generally is the dynamic growth of research in which recombinant DNA technology is being applied in basic studies on bacterial plant pathogens. Results from investigations on the crown gall bacterium have stimulated expansion of research on other bacterial systems.

Spis treści

Agrobacterium.- Symposium Papers.- T-DNA Border Sequences Required for Crown Gall Tumorigenesis.- Coregulation of Promoters in the T-DNA and Virulence Region of the Agrobacterium tumefaciens Plasmid pTiC58.- Genes Involved in Indole Acetic Acid Production in Plant Pathogenic Bacteria.- Analysis of the Locus Involved in Plasmid Partitioning for the Native Agrobacterium Plasmid pTAR.- Role of Agrobacterium rhizogenes Hormone Genes in the Induction of Hairy Root.- Genetics and Molecular Biology of Agrocin Production and Sensitivity in Agrobacterium.- Ultrastructural Surveillance of the Infection Process Agrobacterium tumefaciens, Biovar Three in Grape.- Attachment of Agrobacterium tumefaciens to Host Cells.- Transfer of the T-DNA From Agrobacterium tumefaciens to Plant Cells.- Structure and Properties of Border Sequences in T-DNA Transformation.- Contributions.- Serological Study of Agrobacterium Biotypes.- Rapid Detection of Agrobacterium tumefaciens in Grapevine Propagating Material.- Control of Crown Gall in Swiss Apple Nurseries.- Biological Control of Crown Gall with an Agrocin 84-Producing Biotype 1 Transconjugant of Agrobacterium.- A Proposed Basis for Varietal Differences in Sensitivity of Grapes to Crown Gall Disease.- Host Range, Virulence and Genetic Variability of Agrobacterium tumefaciens Strains from New York Vineyards.- The Role of Membrane Atpase in Proline and Valine Transport by Agrobacterium tumefaciens.- Cloning and Nucleotide Sequence of TZS, A Cytokinin Biosynthetic Locus, from Agrobacterium tumefaciens Strain T37.- Factors Affecting the Biocontrol of Agrobacterium tumefaciens by K-84.- Biological Control of Crown Gall by Bacteriocin-Producing Bacteria.- Soft-Rot Erwinia.- Symposium Papers.- Pathogenesis by Pectolytic Erwinias.- Serology and Epidemiology of Erwinia Carotovora.- Changes in Populations of Erwinia carotovora in Relation to the Development of Soft Rot in Wounded Potato Tissue.- Molecular Cloning and Mutagenesis in Escherichia coli of Pectinase Genes from Erwinia chrysanthemi.- Erwinia Cellulases.- Possible Involvement of Outer Membrane Components in Erwinia chrysanthemi Pathogenicity.- Importance of Ketodeoxyuronate Pathway in the Degradation of Pectin in Erwinia chrysanthemi.- Assimilation: Ketouronate Pathway.- Assimilation in Soft Rot Erwinias: Cellobiose Pathway.- Genetic Systems in the Soft Rot Erwinia Group.- Development of a Chromosomal Map in Soft Rot Erwiniae.- Contributions.- Production of Cell Wall-Degrading Enzymes by Corn Stalk Rot Strains of Erwinia chrysanthemi.- Isolation and Characterization of Pectolytic Nonpathogenic Mutants of Erwinia carotovora subsp. carotovora (ECC).- Marker-Exchange Mutagenesis of the PelB Gene in Erwinia chrysanthemi CUCPB 1237.- Influence of Alkaline Salts on Growth and Pectate Degradation of Species and Subspecies of the Erwinia carotovora.- In Vitro Production of Extracellular Polysaccharides by Erwinia carotovora var. carotovora and Erwinia carotovora var. atroseptica.- The Application of Transposons to the Cloning of Genes from Erwinia carotovora.- Molecular Cloning of two Erwinia carotovora subsp. carotovora DNA Fragments which Mediate the Production of Similar Pectate Lyases.- Comparisons between Pectic Enzyme Genes from Erwinia carotovora subsp. carotovora and E. carotovora subsp. atroseptica.- Markers on a Large, Self-Transmissible Plasmid in Erwinia carotovora subsp. carotovora Strain 379.- Molecular Evidence for Linkage Between the Genes for a Polygalacturonase (peh) and a Pectate Lyase (pel) in Erwinia carotovora subsp. caro-tovora.- Cloning and Characterization of a Gene for Extracellular Protease of Erwinia carotovora subsp. carotovora.- recA-Mediated Induction of Pectin Lyase and Carotovoricin in Erwinia carotovora subsp. carotovora.- Genetics of the Damage Inducible Phenotypes of Erwinia carotovora subsp. carotovora: Characterization of Tn5 Insertional Mutants Defective in Pectin Lyase and Carotovoricin.- Chemotaxes of Erwinia carotovora subsp. carotovora and Erwinia chrysanthemi.- Pel-C is the Major Pectate Lyase Produced by Erwinia chrysanthemi (EC16) in Vitro and in Plant Tissue.- Biochemical Properties of Three Extracellular Pectate Lyases of Erwinia chrysanthemi EC16.- Regulatory Mutants Affecting the Synthesis of Pectate Lyase in Erwinia chrysanthemi.- Comparison of the Isoelectric Focusing Profiles of Pectic Enzymes Produced by Erwinia chrysanthemi, E. carotovora subs, carotovora and E. carotovora subsp. atroseptica.- Investigation of the Relatedness of Erwinia chrysanthemi Pectate Lyase Isozymes by Genetic and Protein Analysis.- Ecology and Epidemiology (Discussion Papers).- Approaches in the Diagnosis of Soft Rot Diseases of the Potato.- Soft rot Erwinias: What is Pathogenicity?.- Factors Affecting Blackleg Development.- A Rapid Method to Identify Soft Rot Erwinias Directly from Plant Material.- Antibiotic Production by Erwinia carotovora subsp. betavasculorum: Partial ‘in Vitro’ Characterization and Evidence for Activity in Potato Tubers.- Control of Bacterial Soft Rot in Potato Tubers with Hypochlorite and Certain Organic Acids.- Plant Pathogenic Biotypes of Pseudomonas Fluorescens.- The Diversity of the Pectolytic Fluorescent Pseudomonads.- Characteristics of Strains of Pseudomonas fluorescens Isolated from Soil in Relation to Ability to Macerate Plant Tissue.- Pectolytic Bacteria Associated with Post-Harvest Decays of Fruits and Vegetables with Special References to Fluorescent Pseudomonads.- Pseudomonas marginalis, an Interesting Organism for Further Research.- The Nonrandom Variation in the Distribution of Phenotypic Properties within a DNA Homology Matrix of Fluorescent Pseudomonads.- Pectolytic Fluorescent Pseudomonads Associated with Alfalfa Root and Crown Rot.- Taxonomy of the Fluorescent Pectolytic Pseudomonads.- Fastidious Prokaryotes.- Discussion Papers.- Serology of Mycoplasma-Like Organisms.- Detection of Corn Stunt Spiroplasma in Plants by ELISA Employing Monoclonal Antibodies and by Isolation of the Pathogen and its Phages in Serum-Free Medium.- Vector Relationships of Xylem- and Phloem-Limited Fastidious Prokaryotes.- Biology and Physiology of Fastidious Xylem-Limited Bacteria From Plants.- Etiology of Ratoon Stunting Disease and Host Resistance.- Detection and Control of Plant Diseases Caused by Fastidious Prokaryotes.- Contributed Papers.- Development of Monoclonal Antibodies to Spiroplasmas Utilizing a Mixture of Spiroplasma citri and Corn Stunt Spiroplasmas.- Differentiation of Strains of Spiroplasma citri with Monoclonal Antibodies.- Monoclonal Antibodies for Differentiating Some Strains of the Fastidious Gram-Negative Bacteria from Plants.- Serological Relationship Between the Xylem-Limited Bacterium Causing Sumatra Disease of Cloves in Indonesia and Pseudomonas solanacearum.- Strains of Corn Stunt Spiroplasma Defective in Helicity and Motility.- Preliminary Results on Transmission of Xylem-Limited Bacteria Causing Sumatra Disease of Cloves in Indonesia by Tube-Building Cercopoids, Hindola spp. (Homoptera: Machaerotidae).- Purification of Mycoplasma-Like Organisms from Lettuce Affected with Aster Yellows Agent.- Molecular Basis for Virulence and Pathogenicity or Phytopathogenic Bacteria.- Symposium Papers.- The Genetic Basis for Virulence, Pathogenicity and Host Range in Agrobacterium tumefaciens.- Genetics of Plant Pathogenic Coryneform Bacteria.- Pathogenicity Genes of Xanthomonas campestris.- Molecular Analysis of Pathogenicity of Pseudomonas syringae Pathovars phaseolicola and syringae.- Genetics of Virulence in the Wilt Pathogen, Pseudomonas solancearum.- Contributions.- Complementation of Avirulent Mutants of Erwinia Stewartii by Recombinant Plasmids.- Characterization of a Gene Cluster for Polysaccharide Biosynthesis in Erwinia stewartii.- Cloning of a Gene from Erwinia amylovora Involved in Induction of Hypersensitivity and Pathogenicity.- Phage Mu as a Genetic Tool to Study the Pathogenicity of Erwinia amylovora.- Use of Plasmid Vector pGS9 to Introduce Transposon Tn5 into Pathovars of Pseudomonas syringae.- Transformation of Pseudomonas solanacearum with Plasmid DNA.- Isolation and Characterization of TN5 Mutants of Pseudomonas syringae pv. phaseolicola which Fail to Elicit a Hypersensitive Response.- Cosmid Instability in Pseudomonas syringae Pathovars: Evidence for Directed Excision of a Cloned Sequence.- Integration of pMMC7105 into the Chromosome of Pseudomonas syrigae pv. phaseolicola involves the Repetitive Sequence RSII.- Transfection of Spiroplasma citri with DNA of a New Rod-Shaped Spiroplasmavirus.- Indigenous Plasmids in Xanthomonas campestris pv. pruni.- New Stable High- and Low-Copy Cloning Vectors for use in Agrobacterium and Rhizobium.- A Shuttle-Vector for Transferring Cloned DNA Between E. coli ColEl replicons and Agrobacterium virulence plasmids.- Pathogenicity Mutants of Erwinia amylovora Caused by TN5 Insertion.- Transposon Tn5 Mutagenesis of Pseudomonas syringae pv. tomato.- The Use of ? gtll Expression Vector and of Protein Sequence Derived DNA Oligomers to Clone Genes for Pilus Synthesis in Pseudomonas solancearum.- Cloning of Genes Associated with Pathogenicity and Hypersensitivity from Pseudomonas syringae pv. phaseolicola.- Molecular Analysis of Pathogenicity Specific Genes in Pseudomonas syringae pv. syringae.- Cloning Regulation and Expression of Yellow Pigment Genes from Erwinia herbicola.- Cloning and Expression of a Serratia marcescens Gene Encoding Chitinase.- Detection and Initial Characterization of Plasmids in Xanthomonas campestris pv. glycines.- Bacterial Phytotoxins (Discussion Papers).- Current Status on Mode of Action Studies with Tagetitoxin.- Cloning of Genes Encoding Phaseolotoxin.- Molecular Genetics of Phaseolotoxin Production and Immunity in Pseudomonas syringae pv. phaseolicola.- Molecular Genetics of Coronatine Production by Pseudomonas syringae pv. glycinea.- 2,5-Dihydrophenylalanine (DHP) from an Axenic Culture of Erwinia amylovora: Possible Cause of Fireblight.- Toxigenic Bacteria: Their Ecology and Biocontrol Prospects.- Physiology and Host-Parasite Interactions.- Contributions.- Characterization of Slimes Produced by Pseudomonas phaseolicola in vitro and in Planta, and the Demonstration of the Slime Polysaccharide Alginate in Seven Pseudomonas syringae Pathovars.- Leaf Necrosis Instead of Water-Soaking Due to Light Deficiency after Inoculation with Pseudomonads and Xanthomonads.- Contribution of Sugar Bacterial Components in HR of Tobacco.- Indications of a Role for Amylovorin as a Virulence Factor of Erwinia amylovora.- Factors Affecting Production of Herbicolacin 112Y by Erwinia herbicola 112Y.- Multiplication of Wild Types of Pseudomonas syringae pv. savastanoi (Smith) Young et al. and Their Indoleacetic Acid-Deficient Mutants in Olive Tissues.- On the Presence and Level of Different Cytokinins in Culture Filtrate of Pseudomonas syringae pv. savastanoi.- Activation of a Plasmalemma K+ Efflux/H+ Influx Mechanism in Tobacco by Incompatible Bacteria or Pectate Lyase.- Chromosomally Coded Pili of Pseudomonas syringae pv. phaseolicola Function as Adhesins in Early Steps of Halo Blight of Bean.- Properties of Yellow (Orange)-Pigmented Strains of Soft Rot Bacteria in the Genus Xanthomonas, Pseudomonas, Cytophaga, and Erwinia.- Phage-Induced Mutations of Histidine and Cysteine Syntheses in Xanthomonas campestris pv. citri.- Ethylene Production by the Kudzu Strains of Pseudomonas syringae pv.phaseolicola.- Function of Zinc in Toxin Production by Pseudomonas syringae pv. tabaci.- Alginic Acid as an Exopolysaccharide of Plant Pathogenic Pseudomonads.- Effects of Extracellular Polysaccharides on Bacterial Multiplication ‘in Planta’.- Involvement of Lipid Peroxidation in Bacterially induced Hypersensitive Reaction.- Cell Membrane Potential in Tissues Undergoing Bacterial Hypersensitivity.- Phytoalexin Accumulation in Congenic Cotton Lines Challenged with Different Races of Xanthomonas campestris pv. malvacearum.- In Vitro Interaction of Copper and Magnesium on Copper-Sensitive and Copper-Resistant Strains of Xanthomonas campestris pv. vesicatoria.- Properties of Clavibacter michiganense ssp. nebraskense, C. M. ssp. tessellarius and C. M. ssp. michiganense Harboring PDG101.- Cytological Observations of Leaf Spot Causing Bacteria in Susceptible and Resistant Hosts.- Hydraulic Conductivity in Sugarcane Clones as Related to Resistance to Ratoon Stunting Disease.- Avirulent Mutants of Erwinia Amylovora; Relationship Between Phage Sensitivity and Biological Properties.- Susceptibility to Erwinia amylovora of Flower Buds of Pear Trees, under Natural Conditions.- Preservation of Phytopathogenic Bacteria by Soft Agar Stab Method.- Effect of Erwinia herbicola on the Motility and Chemotaxis of Erwinia amylovora.- Electron Microscopy of Lesion Development on Wound-Inoculated Leaves of Citrus aurantifolia infected with Florida and Mexican Isolates of Xanthomonas campestris pv. citri.- Active Resistance of Cabbage to Xanthomonas campestris pv. carotae and Protection Against the Causal Agent of Black Rot, pv. campestris, by Co-inoculation.- Differential Effects of LiCl on Growth of Clavibacter michiganense ssp. nebraskense Recovered from Infected Corn Plants and Broth Cultures.- Bacterial Pustule Disease of Soybean: Electron Microscopy of Pustule Development in a Susceptible Cultivar.- Interaction Between Genotypes of Xanthomonas campestris pv. malvacearum and Gossypium hirsutum.- The Occurrence of Phytopathogenic Pseudomonas marginalis in a Latent Stage on the Phylloplane of Healthy Witloof Chicory (Cichorium intybus L. var Foliosum hegi.).- Plant Pathogenic Bacteria Identified in Spain.- Plant Diseases Caused by Bacteria in United Arab Emirates.- Xanthomonas campestris Involved in Mexican Lime Bacteriosis in Colima, Mexico.- Avocado Bacterial Blast in Mexico.- Pepper Spot of Crucifers in California.- Pathogenesis, Migration and Population Dynamics of Erwinia Amylovora in Susceptible (Jonathan) and Resistant (Red Delicious) Apple Shoots.- Isolation and Identification of Xanthotoxin and Bergapten from Celery Infected with Erwinia carotovora pv. carotovora.- Changes in the Phenol Metabolism of Ornamental Shrubs (Cotoneaster Species) Infected with Erwinia amylovora.- Disease Expression in the Leaves of Two Tomato cvs. Due to Infection of Xanthomonas campestris pv. vesicatoria (Doidge) Dye.- Certain Cell Level Changes and Chromosomal Aberrations in Tomato Seedlings Induced by Xanthomonas campestris pv. vesicatoria.- Symptoms of Pseudomonas syringae pv. tagetis Infection in Sunflower.- Invasion of the Epidermis and Cortex of Apple Roots by Actinomycetes.- The Induction of Active Resistance in Cabbage to Black Rot (Xanthomonas campestris pv. campestris) by Inoculation with Xanthomonas campestris pv. carotae.- Isolation of Soil Bacteria with Inhibitory Activity to Pseudomonas solanacearum.- Survival of Xanthomonas campestris pv. malvacearum and Performance of Seedlings from Commercially Ginned Cottonseed as Influenced by Length of Storage.- Utility of an Eclectic Approach for Obtaining Plant Growth-Promoting Rhizobacteria from New York State Apple Replant Soils.- Dispersal of Potato-Ringrot (Corynebacterium sepedonicum) in the Field.- Transfer of RP4 Plasmid on Leaf Surface of Hazelnut.- Ecology and Survival of Plant Pathogenic Bacteria in the Semi-Arid Zones of Nigeria.- Bacterial Blight of Anthurium in Venezuela.- Occurrence of Bacterial Wilt of Casuarina equisitifolia in Kerala, India.- Etiology of the Head Rot Disease of Broccoli.- Opportunistic Xanthomonads in Mixed Infections with Pseudomonas syringae in Tomato and Pepper.- Recovery of Xanthomonas campestris pv. vesicatoria from Tomato Seed.- Incidence of Biovars I and II of Pseudomonas solanacearum in two Ecological Zones of Peru.- Association of Erwinia spp. with the Rhizosphere of Crops and Weeds in the Peruvian Jungle.- Pectolytic Xanthomonas Isolates Causing Soft-Rot of Vegetables in Storage: Isolation, Characterization and Pathology.- An Inhibitor of Escherichia coli B Produced by a Sorghum Isolate of Pseudomonas andropogonis.- A Comparison of Four Methods of Inoculation Potato Tubers with the Ring Rot Bacterium, Corynebacterium sepedonicum.- Taxonomy and Nomenclature.- Discussion Papers.- Characterization of Phytopathogenic pseudomonads: An Approach to Minimal Standards for Description.- Problems with the Pathovar Concept.- Practical Problems with the Pathovar Scheme in Plant Quarantine.- Contributions.- The Taxonomy of Xanthomonas Dowson 1939.- Analysis of Strain Variation in Xanthomonas campestris pv. phaseoli.- Diagnostic Bacteriology.- Discussion Papers.- Detecting Seedborne Bacteria by Immunofluorescence.- DNA Hybridization Probes for the Identification of Phytobacteria.- Use of Selective Agar Media in Diagnosis of Plant Diseases Caused by Bacteria.- Contributions.- Determination of Fatty Acid Profiles Relevant to the Characterization of Erwinia amylovora.- Taxonomic Studies on Erwinia amylovora Isolates and Their Sensitivity to Antibiotics.- Principles and Prospects of New Serological Techniques Including Immunosorbent Immunofluorescence, Immunoaffinity Isolation and Immunosorbent Enrichment for Sensitive Detection of Phytopathogenic Bacteria.- Serological Differentiation of Strains of Erwinia ananas with Hybridoma Antibodies.- Mexican Lime Bacteriosis Examined with Monoclonal Antibodies.- Enzyme-Linked Immunosorbent Assays (Standard ELISA and Biotin/Avidin ELISA) for the Detection of Erwinia chyrsanthemi in Dahlia Stem.- Capability of Phytopathogenic Bacteria to Secrete Wall Degrading Enzymes-A Criterion for Their Identification.- The Use of Elisa for the Detection of Pseudomonas syringae pv. phaseolicola and Xanthomonas campestris pv. phaseoli in Bean Seed.- The Search for a Specific Antigen on Erwinia amylovora.- Development of ELISA for Detection of Clavibacter xyli subsp. xyli, the Causal Agent of Ratoon Stunting Disease in Sugarcane.- Dot-Immunobinding Assay for Detection of Xanthomonas campestris pv. holcicola in Sorghum.- Problems with the Detection of Latent Potato Ring Rot Infection.- Selective Isolation and Concentration of Phytopathogenic Bacteria on Immunoaffinity Columns.- A Simplified Technique for the Isolation of Clavibacter xyli subsp. xyli.- Prospects for Detecting and Controlling Potato Ring Rot in Norway.- Disease Management.- Discussion Papers.- Crown Gall of Grapevine: Disease Management Considerations.- Prospects for the Integrated Control of Bacterial Wilt (Pseudomonas solanacearum).- Management of Citrus Canker by Eradication of Xanthomonas campestris pv. citri.- Specific Detection of Corynebacterium sepedonicum in Potato with Monoclonal Antibodies as an Aid in Bacterial Ring Rot Control.- Development of a Risk-Assessment System for Fire Blight.- Contributions.- Assessment of Fire Blight Risk Assessment Systems.- Role of Amino Acids in Biological Control of Erwinia amylovora by Erwinia herbicola.- Integrated Control of Pseudomonas solanacearum in Chile.- Resistance of Chilean Potato Clones to Bacterial Wilt.- The Antagonistic Effects of Fluorescent Pseudomonas spp. on Plant Growth and the Control of Softrot and Black Leg of Potato.- Managing Pseudomonas tolaasii, Bacterial Blotch of Agaricus spp., by Integrated Biological and Chemical Practices.- Effect of Nitrogen and Plant Spacing on Bacterial leaf Blight of Rice.- Chemical Control of Bacterial Leaf Blight of Paddy Caused by Xanthomonas campestris pv. oryzae.- Effect of Sodium Hypochlorite on Lime Fruit Surface Microflora and Suspensions of Xanthomonas campestris pv. citri, as Related to Citrus Bacteriosis in Colima, Mexico.- The Efficiency and Economics of some Disinfectants Challenged in Vitro by Clavibacter michiganense subsp. michiganense.- Evaluation of an In-field Microcomputer and a Weather-based Model for Assessing Fire Blight Risk in Bloom.- Tolerance Levels of Seedborne Xanthomonas campestris pv. translucens, the Causal Agent of Black Chaff of Wheat.- Comparative Study of the Efficacy of Busan 30, Busan 72, and Bronocot for the Control of Bacterial Blight of Cotton in Northern Nigeria.- Detection of X-Disease Mycoplasma-like Organisms in Plant and Insect Hosts Using Cloned, Disease Specific DNA.- Ice Nucleating Bacteria.- Symposium Papers.- Bacterial Populations in Buds and Probability of Frost Injury on Grapevine.- Ice-Nucleation-Active Bacteria on Citrus in Florida.- Characteristics Relevant to the Question of Environmental Fate of Genetically Engineered INA- Deletion Mutant Strains of Pseudomonas.- Functional Significance of Oligonucleotide Repeats in a Bacterial Ice Nucleation Gene.- Application of Tube-Nucleation Assays to Rapid Population Estimates of Rhizobacteria Expressing Novel Ice-Nucelation Activity.- Ice-Nucleation Activity of Pseudomonas syrinage on Phaseolus vulgaris Leaflets.- Host Avoidance of Ice Nucleation Active Pseudomonas syringae on Bean.- Enhancement of Snow Production by Ice Nucleation-Active Bacteria in Air:Water Systems.- Contributions.- Reciprocal Competition Between INA+ Wild-Type and INA- Deletion Mutant Strains of Pseudomonas on Strawberry Blossoms.- Molecular Analysis of the Pseudomonas syringae pv. syringae Ice Gene and Construction and Testing of ICE- mutants for Biological Frost Control.- A Hypothetical Bioprecipitation Cycle Involving Ice-Nucleating and Dew-Condensing Bacteria, Plants and Rainfall.- New Biotechnologies: Applications to and Impact on Phytobacteriology.- Symposium Papers.- Applications and Techniques for Deficiency-Marker Exchange in Pseudomonas.- Molecular Analysis of Race-Specific Incompatibility (RSI) Genes of Pseudomonas syringae pv. glycinea Race.- Application of Novel Ice-Nucleation Activity to a Rapid Assay of Rhizobacteria Population Densities by “Tube-Freezing”.- Plasmid-Specified Host Specified Host Specificity in Xanthomonas campestris pv. vesicatoria.