Selección y evaluación de rizobacterias promotoras del crecimiento en pimentón y maíz

a group of gram negative rizobacteria able to fix atmospheric nitrogen and to solubilize inorganic phosphate was chosen from different plant rizospheric soils of táchira state. eight non-diazotrophic and seventeen dizotrophic rhizobacteria belonging to the genus azotobacter, azospirillum and rhizobium were characterized using biochemical tests. the effect of these rhizobacteria was evaluated on the germination, growth and n and p uptake of pepper (capsicum annuum) and maize (zea mays) in greenhouse conditions. the bioinoculation effect of pre-selected strains was evaluated on seedling germination. it was found that strains 17 and 20, an azotobacter sp. and a gram negative rod, respectively, promoted pepper germination; while the strains 1 and 23, another gram negative rod and an azospirillum, respectively, promoted maize germination. in greenhouse conditions the strain 1 and azospirillum 23 increased significantly (p≤0.05) the n uptake, and azospirillum 23 the p uptake in maize aerial tissue; while most of the evaluated strains increased significantly (p≤0.05) n uptake in pepper. discussion is centered on the selection of potential bioinoculants and some biological considerations related to the plant-microbe interaction.