Abstract

The pomegranate (Punica granatum) is a fruit tree with medicinal potential due to the presence of bioactive compounds with pharmacological characteristics. Arbuscular mycorrhizal fungi (AMF), when in symbiosis, optimize the production of metabolites with medicinal potential. The objective of this study was to select efficient AMF to maximize the growth and the production of foliar metabolites with medicinal characteristics in P. granatum seedlings. The experimental design was completely randomized, with three inoculation treatments (inoculated with Gigaspora albida, inoculated with Acaulospora longula and a non-inoculated control) and 7 repetitions, totaling 21 experimental units. Pomegranate plantlets with two definitive leaves were transferred to pots with soil containing 3 mg P dm^-3 and were inoculated at the root region with soil-inoculum supplying 200 spores/pot of G. albida or A. longula. 120 days after inoculation, the following parameters were evaluated: height, number of leaves, stem diameter, fresh and dry matter of the aerial part and fresh matter of the subterranean part and mycorrhizal colonization. On the leaves, the concentration of total proteins, soluble carbohydrates, total phenols, total tannins and total flavonoids was determined. Pomegranate seedlings associated with G. albida accumulate more proteins (213, 36%), carbohydrates (246, 75%), phenols (198, 40%), flavonoids (410, 81%) and tannins (59, 92%) compared to the non-inoculated control. Similar behavior was found for the other parameters of vegetal growth, with the exception of stem growth and of the mycorrhizal colonization. It can be concluded that pomegranate seedlings benefit from inoculation with AMF in terms of growth and production of bioactive compounds, depending on the species of fungus that was used.

Key words: Glomeromycota, bioactive compounds, arbuscular mycorrhizal fungi (AMF).