In vitro phosphate solubilization by Aspergillus and Penicillium strains and coffee plants growth promotion

Abstract

The availability of phosphorus in the soil for the growth of plants can be increased by the action of phosphate solubilizing microorganisms. The objective of this work was to determine the potential of Aspergillus and Penicillium strains, solubilizers of phosphates in vitro, to promote the growth of coffee plants obtained by somatic embryogenesis. In vitro tests were carried out with strains of Aspergillus and Penicillium grown in Pikosvkaya culture medium (PVK) to determine their solubilization capacity of phosphates. In addition, PVK and NBRIP liquid where the pH was measured were inoculated in culture medium. Two strains were selected and cultured for 72 h in PVK culture medium. Subsequently, suspensions of conidia in the culture filtrates were applied to the substrate (soil: compost) of Coffea canephora cv. 'Red Caturra' obtained by somatic embryogenesis. After 90 days of culture the height of the plants was measured (cm), the number of leaf pairs was quantified and the dry mass (g) of the biomass was determined. All strains tested showed translucent halos around the colonies in PVK culture medium indicative of phosphate solubilization and reduced pH in liquid culture media. The inoculation of Aspegillus sp. CCIBP-Asp 32 significantly increased the height of the plants and the biomass. The potential of these strains was demonstrated for the formulation of bioproducts that can be applied in green house or nursery to promote the growth of coffee plants in vitro obtained.

Keywords

• coffea arabiga
• pikosvkaya culture medium
• phosphorus