The purpose of this study was to select effective arbuscular mycorrhizal fungi (AMF) on the production of yellow passionflower seedlings. The variables considered were: sterile substrates, fertility levels, and organic matter addition. Three greenhouse experiments were conducted using different mixtures as substrates: 2:1:1 - sand, soil and dairy manure, 1:1 - sand and soil , and 9:1 - soil and dairy manure. The AMF used at the two first experiments were: Acaulospora sp. (IAC-13), Gigaspora margarita, Glomus sp. (IAC-27), Acaulospora morrowae, Acaulospora sp. (IAC-44), Acaulospora scrobiculata, Scutellospora heterogama, Glomus clarum, Glomus sp. (IAC-28), Entrophospora colombiana, Glomus etunicatum and Glomus macrocarpum. In the third experiment, the following AMF were used: G. clarum, Glomus sp. (IAC-28), G. margarita, G. etunicatum and G. macrocarpum (IAC-50), a mixture of these fungal species and indigenous AMF populations obtained from a passionflower field cropping, which were multiplied in Brachiaria decumbens, passionflower and peanut. The highest mycorrhizal benefits were obtained in the substrate with no organic matter addition, which, however, did not surpass the positive effect of organic matter on plant growth. The most efficient fungi were G. clarum, G. etunicatum and G. margarita. In the substrate with organic matter addition (25 g.kg-1), Acaulospora sp. (IAC- 44) and A. morrowae were efficient to promote plant growth, while G. clarum had a parasitic effect. Plants colonized by Glomus sp. (IAC- 28) had higher growth in the substrate with 10 g.kg-1 of dairy manure added to the soil, which was comparable to the effect of those efficient fungi in the substrate with the highest organic matter addition.
arbuscular mycorrhizal fungi; arbuscular mycorrhiza; passionflower; organic matter; substrate; seedlings production
