Potential of the fast-growing Rhizobium fredii for use in soybean inoculum: physical and genetic characterization of the nitrogen-fixing symbiosis

Soybean-Rhizobium combinations with high rates of nitrogen fixation are useful in soybean breeding programs. Thirteen soybean (Glycine max L. Merr.) cultivars and wild soybean (G. soja Sieb. and Zucc.) plant introductions were inoculated with Bradyrhizobium japonicum strain 61A76 and 4 fast-growing strains of Rhizobium fredii. All fast-growing strains formed effective nodules on cultivars \u27Peking\u27, \u27Virginia\u27, \u27Hardee\u27, and the G. soja plant introductions. Three of the fast-growing strains formed ineffective nodules on the other cultivars. USDA191 formed effective nodules on all cultivars tested. No nodules were formed on \u27Harosoy rj1 rj1\u27. Combinations that produced significant acetylene reduction, nodule number, nodule fresh weight, and plant-top dry weight compared to uninoculated and ineffectively nodulated plants were B. japonicum strain 61A76 with \u27Evans\u27 and \u27Hill\u27 and the fast-growing R. fredii strains with \u27Peking\u27 and \u27Virginia\u27;A hydroponic growth system was used to study host control of nodulation by fast-growing R. fredii and slow-growing B. japonicum. Nodules were not formed on cultivars with R. fredii strains that produced ineffective nodules when soybean plants were grown in vermiculite. Nodules were formed on compatible cultivars by mutant strains that fixed little or no nitrogen. The inability to form nodules in hydroponics may be related to delays in nodule initiation;The 192 Mdal. plasmid containing symbiotic genes from R. fredii strain USDA193 (pSym193) was transferred to other species of Rhizobium, B. japonicum, Escherichia coli, and Agrobacterium tumefaciens. Host specificity genes for nodulation of soybean cultivar \u27Peking\u27 were not expressed in E. coli, but were expressed in the other genetic backgrounds. Similar results were obtained by transferring cloned DNA fragments containing host-specificity genes for Peking and early nodulation genes, demonstrating that the nod genes are unlinked. Site-specific Tn5 mutagenesis was used to locate genes on DNA fragments encoding symbiotic functions. A recombination mutant of R. fredii strain USDA193 was generated to allow complementation studies and the development of a maxi-cell system

Utilizing GIS technology for brownfields redevelopment

Typically, when developers, banks and other organizations have an interest in a piece of property they perform an extensive information search to determine if the site is worth purchasing. This search could consist of tax and title information, the location of utilities and major roadways in the area, information on population demographics and environmental contaminant data. An information search of this type could take days, weeks or even months to compile. With a geographic information system (GIS), this search could take a matter of minutes and is displayed in an easy to understand graphic or map form along with a report. GIS technology is consequently changing the way economic development organizations, states and municipalities communicate with potential purchasers of properties. With GIS technology these organizations can select brownfields or other properties based on ownership, demographics and/or predetermined zoning criteria and market the properties based on the needs of the developer. This thesis will propose development blueprints for Brownfield Pilots to consider when implementing a GIS. These blueprints or recommended strategies will be based on accepted GIS development phases, case studies that involved developing GISs for economic development and environmental applications and on responses to a questionnaire sent to Brownfield Pilots to determine their GIS development techniques and implementation status

A simple, rapid procedure for the isolation of DNA for PCR from Gibberella fujikuroi (Fusarium section Liseola)

The polymerase chain reaction (PCR) is a method for amplifying specific segments of DNA defined by the small primers used to start the reaction. Using arbitrarily chosen 10-base primers, one can generate random amplified polymorphic DNA (RAPD) markers (Williams et al. 1991 Nucl. Acids Res. 18:6531-6535). These DNA fragments, separated by electrophoresis in an agarose gel, can be used as markers for studying genetic variation within and among fungal populations

Managing Phenol Contents in Crop Plants by Phytochemical Farming and Breeding—Visions and Constraints

Two main fields of interest form the background of actual demand for optimized levels of phenolic compounds in crop plants. These are human health and plant resistance to pathogens and to biotic and abiotic stress factors. A survey of agricultural technologies influencing the biosynthesis and accumulation of phenolic compounds in crop plants is presented, including observations on the effects of light, temperature, mineral nutrition, water management, grafting, elevated atmospheric CO2, growth and differentiation of the plant and application of elicitors, stimulating agents and plant activators. The underlying mechanisms are discussed with respect to carbohydrate availability, trade-offs to competing demands as well as to regulatory elements. Outlines are given for genetic engineering and plant breeding. Constraints and possible physiological feedbacks are considered for successful and sustainable application of agricultural techniques with respect to management of plant phenol profiles and concentrations

Les sols de vignobles des Côtes de Bourg

Les travaux relatifs aux sols de vignobles sont rares, cela étant dû essentiellement à la difficulté de telles études. En effet, le but final étant de préciser le rôle des différents facteurs naturels (sol, climat...) sur la qualité du vin et de définir ainsi la notion de cru, des recherches pédologiques, climatiques et biochimiques doivent être entreprises simultanément. SEGUIN a effectué, il y a une dizaine d'années, une première approche de la connaissance des sols viticoles par des études de profils culturaux (1965). Ces travaux furent poursuivis dans le Haut-Médoc par une analyse plus approfondie reliant les données climatiques, l'alimentation en eau de la vigne et la connaissance physicochimique des zones exploitées par les racines à la maturation du raisin (1970). Une étude similaire fût réalisée dans la région des Graves par COMPAGNON (1970) et actuellement PUCHEU-PLANTÉ fait un travail comparable dans le Sauternais. Dans le cadre d'une initiation à la recherche agropédologique, nous avons effectué nous-mêmes une étude de profils culturaux dans les très grands crus classés du Haut-Médoc (1973). D'un point de vue minéralogique, LATOUCHE étudiant l'évolution des argiles de quelques sols nord-aquitains, précisa les phases argileuses essentielles des sols viticoles du Bordelais (1966)