Sexual reproduction ofStilophora rhizodes(Phaeophyceae, Chordariales) in culture

Abstract
Stilophora rhizodes from western Sweden was studied in laboratory culture. Meiospores develop into filamentous microthalli which at higher temperatures (17–20°C) reproduce directly by means of plurispores. At lower temperatures (5–9°C), the microthalli act as dioecious gametophytes forming isogametes. The zygote develops into a few-celled protonema which forms a primary apex. The macrothallus as known from the field is produced by differentiation of a secondary apex. Unfused gametes develop into gametophytes or sporophytes.