Contribution of Gluconacetobacter diazotrophicus to phosphorus nutrition in strawberry plants

Abstract

Background and Aims: Gluconacetobacter diazotrophicus (family Acetobacteraceae), is a N2-fixing bacterium with capability of mineral solubilization through organic acid production. The aim of this work was to evaluate its capacity as a phosphate solubilizing bacterium to overcome a phosphorus deficiency in phosphorus-starved strawberry plants. Methods: Strawberry plants growing with available and not available phosphorus were inoculated with the wild type G. diazotrophicus PAL5 Pi-solubilizing strain and a Tn5-derivative mutant defective in organic acid production. Growth index, root acidification, root area, MPN, greenness index, and phosphorus content were evaluated. Results: Results demonstrate that G. diazotrophicus PAL5 can increase the phosphorus content of strawberry plants (root and shoot), and revert phosphorus deficiency. Additionally, bacterial plant growth-promoting effect was represented by higher values of biomass production, root area, and growth index, as compared with the controls. Conclusions: G. diazotrophicus can increase the phosphorus content of strawberry plants, promoting the overall plant growth.