Optimization of the production of mycorrhizal inoculum on substrate with organic fertilizer.

The system for production of inoculum of arbuscular mycorrhizal fungi (AMF) using sand and vermiculite irrigated with nutrient solution is promising. However, organic amendments added to the substrate can stimulate sporulation of AMF and replace the nutrient solution. The aim of this study was to maximize the production of AMF (Acaulospora longula, Claroideoglomus etunicatum, Dentiscutata heterogama and Gigaspora albida) using selected organic substrates (vermicompost, coir dust and Tropstrato) together with sand and vermiculite. The production of spores varied among the tested AMF and according to the organic source added to the substrate. The vermicompost promoted higher sporulation of A. longula in relation to the other AMF and substrates. The Tropstrato inhibited the sporulation of D. heterogama while the reproduction of C. etunicatum was not affected by the organic compounds. The inoculum of A. longula also showed a high number of infective propagules and promoted biomass accumulation in maize plants. The system of inoculum production using sand and vermiculite + 10% vermicompost favors the production of infective inoculum of A. longula with the fungus benefiting growth of corn plants.

Mycorrhizal technology and phosphorus in the production of primary and secondary metabolites in cebil (Anadenanthera colubrina (Vell.) Brenan) seedlings.

BACKGROUND: The application of arbuscular mycorrhizal fungi (AMF) can increase the growth and concentration of primary and secondary metabolites in several plant species. Cebil (Anadenanthera colubrina), a medicinal plant, benefits from mycorrhizal association, but the influence of the symbiosis on the production of its bioactive compounds is unknown. In this study the effect of mycorrhizal inoculation and phosphorus (P) supply on the production of primary and secondary metabolites in cebil seedlings was determined. RESULTS: The production of proteins and carbohydrates in terms of both concentration and content was enhanced by inoculation with AMF, but this benefit was mitigated at higher levels of P (30 and 50 mg dm(-3) soil). The concentration of phenols, flavonoids and total tannins was favoured by mycorrhizal inoculation even at the highest levels of P (30 and 50 mg dm(-3) soil). CONCLUSION: The production of primary and secondary metabolites in leaves of A. colubrina can be maximised by mycorrhization, with the benefit depending on supplementation of soil phosphate.