Morphogenesis of the gametophyte of Physematium montevidensis (Woodsiaceae)

Abstract

In vitro spore culture and gametophyte characteristics may contribute understanding the life cycle in different fern taxa and also to systematic and taxonomic studies. The family Woodsiaceae contains two genera: Physematium and Woodsia. Physematium montevidensis is the only species recognized for South America, and up to now, no information has been recorded on the gametophytic phase. The aim of this work is to study the development pattern, the morphology and sexual expression of the gametophyte of Physematium montevidensis to provide information about its reproductive biology. The germination pattern was of the Vittaria-type and the gametophyte development of the Aspidium-type. Gametangia appeared 30-40 days after spore germination. Both, cordiform bisexual and spatulate-elongated male gametophytes developed in the cultures. The sporophytes emerged near 3 months after spore sowing. The gametophyte development of Physematium montevidensis and its morphological features are broadly similar to those registered in other taxa of Woodsiaceae.

Key words:
ferns; in vitro spore culture; Physematium; prothallus