Actinobacterias endofíticas aisladas de nódulos de Medicago sativaanálisis de su biodiversidad y su potencial agronómico como pgpr

Resumen

[EN]The current agriculture depends on the intensive use of agrochemicals (fertilizers and pesticides), which causes health and environmental problems. Public authorities, consumers and companies are aware of a new revolution nececidad allowing mantain agricultural productivity and eliminate the risks of current agriculture. The study of new partnerships, such as that between Micromonospora and plant roots are of great importance to design alternative methods of fertilization and biocontrol, more respectful of the environment. This doctoral thesis has studied the diversity, taxonomic relationship and biological role played by Micromonospora populations isolated from nodules of alfalfa and function, to determine their biotechnological potential in the design of biofertilizers and biocontrol agents. The most relevant conclusions of this work are: - There is great diversity among isolates intrageneric independent of geographical origin. Australia strains are phenotypically very similar to Spanish. But phenotypic characteristics of Micromonospora isolates grouped by geographic location. - Micromonospora coinoculada alone or with Sinorhizobium capable of inducing and coraloides nodules significantly increases the number of nodules in plants coinoculated with typical Sinorhizobium. Nodular ultrastructural changes in plants coinoculated regarding induced only by Sinorhizobium. - Micromonospora alone or with Sinorhizobium coinoculada improve key parameters related to growth and plant nutrition. PGPR potential as confirmed in culture conditions near the agricultural practice and their suitability for the manufacture of commercial inoculants, biotechnological interest increases. - Micromonospora produce siderophores and antifungals inhibiting the growth of phytopathogenic fungi in vitro - Micromonospora have an effect of "priming" in tomato. After treatment, the defensive response against Botrytis is different and very powerful, but only manifested in the presence of the pathogen.