Aspects of Gametophyte Development of Dicksonia sellowiana Hook (Dicksoniaceae): an Endangered Tree Fern Indigenous to South and Central America

Abstract

Abstract With the purpose of providing a basis for programs of sustainable management in the conservation of this endangered species, this paper presents morphological aspects on the gametophyte development of Dicksonia sellowiana (Dicksoniaceae) by light microscopy and scanning electron microscopy. Dicksonia sellowiana spores were germinated in Morh's nutrient solution modified by Dyer (1979) under a 16-hour photoperiod at 23 ± 2°C. To determine the best substrate for gametophyte and sporophyte development, 30 days after spore sowing filamentous gametophytes were transferred to different substrates: soil rich in organic matter; coxim (coconut fiber); sterilized typic hapludult soil (distroferric red nitosoil); and sterilized typic hapludult soil (distroferric red nitosoil) with the addition of organic compost. The best system for D. sellowiana growth was the red soil with the addition of compost. Fifteen days after spore sowing in mineral solution, gametophytes were filamentous. Some had attained laminar...