To select AMF and substrates that enhance production of micropropagated seedlings of Alpinia purpurata and Zingiber spectabile, tropical ornamental species, seedlings were inoculated with 1,500 infective propagules of Gigaspora albida, Glomus etunicatum and Acaulospora longula, in pots containing: (a) soil; (b) soil and vermicompost (3:1); (c) soil, sand and vermicompost (2:2:1). The experimental design was completely randomized in a factorial of: four inoculation treatments (three with AMF and uninoculated control), three substrates, with eight replicates for each plant species. After 70 (Z. spectabile) and 100 (A. purpurata) days of inoculation, plant growth parameters such as height, leaf and offshoots number, dry mass of shoots and roots, leaf area, as well as mycorrhizal colonization, AMF sporulation were evaluated. Significant interactions were not observed between AMF and substrates. In A. purpurata, the two substrates with vermicompost promoted growth, while in Z. spectabile only the substrate with higher proportion of this compound enhanced plant growth. Use of vermicompost reduced mycorrhizal colonization in both hosts and the sporulation of A. longula. During the acclimatization period, application of organic amendment is useful to induce formation of healthy seedlings of A. purpurata and Z. spectabile but it may be harmful to the AMF community.
micropropagation; Glomeromycota; tropical flowers
