XVI International Botanical Congess

Monoecious isolates of Bryopsis plumosa from Maine were subcloned. The Pemaquid Point isolate (P)was from a turbulent site, the Damariscotta isolate (D) was from a calm site. Reticulated pinnae (300-1000/expt) were counted prior to the dark period. Pinnae releasing gametes following lights-on were compared with those predicted to release gametes (reticulated pinnae)in 2 treatments: continuous agitation or transiently calm conditions. Calm algae were agitated until 5 min prior to lights-on. In 4 (P) experiments, the number of pinnae in calm conditions releasing gametes was 146 (S.D.=32) % of predicted release compared to 106 (S.D.=6)% under agitation. In 2 (D) experiments, 74 (S.D.=25)% of reticulated pinnae released gametes under calm conditions and 63 (S.D.=28)% released gametes under agitation. Data on fertilization are presented from work using DAPI-stained algae.