Growth Promotion of Baccharis macrantha (Asteraceae) by Phosphate Solubilizing Rhizosphere Bacteria

The objectives of this research was to isolate and characterize phosphate solubilizing bacteria (BSF) associated to the rhizosphere of Baccharis macrantha and Viburnum triphyllum, and to assess their ability to solubilize phosphate under conditions in vitro. Furthermore to determine the effect of inoculation of the strains BSF more efficient on the growth of B. macrantha. Rhizosphere soil samples of B. macrantha and V. triphyllum were collected in the months of May-rainy season and September-period dry the 2012. Trypticase Soya Agar and Pikovskaya (PVK) were used for quantification of culturable heterotrophic bacteria and BSF, respectively. The phosphate solubilizing capacity of the isolated strains was estimated from the diameter of the halo around the colonies formed in the culture medium PVK after 7 days incubation at 28 degrees C. Inoculation assays were performed with more efficient BSF in B. macrantha. Inoculation of BSF Bacillus firmus and Pseudomona fluorescens individually and as inoculant combined showed a beneficial effect, significantly increasing the percentage of seed germination, seedling height, root length and dry weight of B. macrantha. Inoculation the BSF could be considered a strategy to improve the growth and development of B. macrantha in abandoned pastures.