Cultivation of Palmaria palmata (Palmariales, Rhodophyta) from isolated spores in semi-controlled conditions

摘要

Pilot scale studies were carried out to develop a methodology for the cultivation of fresh young fronds of Palmaria palmata to supply abalone hatcheries. This is the first report of cultivation of P. palmata in land-based tanks using isolated spores as seedstocks. Spores were released from field-collected tetrasporphytic fronds. A phenological study determined that tetrasporophytic fronds were fertile during the winter along the coast of northern France. This paper describes techniques for the induction of sporulation, for spore settlement and for incubation of germlings in 1.5-m-diameter tanks in semi-controlled conditions. The yield of released spores was in the range of 5000 to 25,000 g(-1) of fertile sections. Mean spore density on substrate placed in hatching tanks was 500 spores cm(-2). Spore germination occurred 3 days after inoculation and at this stage survival rate was high (80%). A few days after spore inoculation, both male and female gametophytes had germinated and a male to female ratio of approximately 1:1 was observed. Female gametophytic discs remained microscopic whereas males developed gametophytic fronds. Growth of plantlets was well correlated with the concentration of medium supplements. After 3 months of cultivation in tanks, survival rate was 35% and some plantlets measured more than 2 cm. At this stage, substrates covered with soft young fronds were transferred to an abalone hatchery to feed abalone juveniles