Spore Germination and Early Gametophyte Development in Stromatopteris

Abstract

Spores of Stromatopteris moniliformis (Gleicheniaceae) germinated after three months in the dark on a nutrient medium containing minerals and 0.5% glucose. Small cylindrical ga- metophytes with apical cells and septate rhizoids were grown under these conditions. The pattern of cell divisions for early gametophyte development is that of the Gleicheniaceae. Spores from species of eusporangiate pteridophytes with mycorrhizal ga- metophytes germinate in the dark (Whittier, 1973, 1981, 1983; Gifford and Brandon, 1978; Whittier and Braggins, 1994). The dark-germination of spores from the Ophioglossaceae, Psilotaceae, and those taxa of the Lycopodiaceae with subterranean gametophytes insures that the mycorrhizal gametophytes will develop in the soil. This study was undertaken to determine if the dark- germination of spores from species with mycorrhizal gametophytes is a more general phenomenon in the pteridophytes. Stromatopteris spores were used to investigate if spores from a leptosporangiate species with subterranean game- tophytes (Bierhorst, 1968) will germinate and initiate gametophyte develop- ment in the dark. Also, it would be of interest to know if the early develop- mental stages of Stromatopteris gametophytes have any similarity to those stages of the eusporangiate pteridophytes.