An experiment was carried out under green house conditions to evaluate the effects of the inoculation with arbuscular mycorrhizal fungi (AMF), associated with the addition of formononetin (5, 10 µ mol L¹), quercetin and morin (5, 10 and 15 µ mol L¹), on the growth and nutrient content of passion fruit plants in the phase of seedlings cultivated in sterile substrate and after transplanting to a non-sterile substrate. The fungi utilized were Glomus clarum (Gc), Glomus fasciculatum (Gf) and a population of native fungi (IN), which was isolated from a passion fruit plantation in the region of São João da Barra (RJ). Significant effects on the growth and mineral nutrition of the passion fruit plants were observed for all the AMF utilized (Gc, Gf and IN), during the seedling development and after transplanting to a non-sterile substrata. The phenolic compounds had effects on root colonization and plant growth during the phase of seedling grown only in the phase of seedlings cultivated in a non-sterile substrata, where a beneficial effect of the flavonols quercetin and morin, and the isoflavonoid formononetin (5 µ mol L-1) on root colonization by AMF, was observed for the non-inoculated seedlings, indicating that these compounds stimulated the native AMF present in the substrata. For the inoculated seedlings with AMF, the flavonoids did not affect the root colonization, but had a positive effect on some variables analyzed.
mycorrhizae; formononetin; quercetin; morin