Algae. 2003; 18(1): 21-28.
Physiological Responses of Blade and Conchocelis of Porphyra vietnamensis Tanaka et Pham-Hoang Ho (Bangiales, Rhodophyta) from Thailand in Culture
Rapeeporn Ruangchuay and Masahiro Notoya*
Laboratory of Applied Phycology, Tokyo University of Fisheries, 5-7 Konan 4, Minato-Ku, Tokyo 108-8477, Japan
The effects of temperature (10-30°C), photon flux density (10-80 μmol ·m?2· s?1), salinity (10-40 ppt) and photoperiod (14L: 10D and 10L: 14D) on the growth and maturation for the conchocelis and blade phase of Porphyra vietnamensis Tanaka et Pham-Hoang Ho from Thailand were examined under laboratory conditions to investigate data of tropical species. Maximum growth rate of the conchocelis showed at 25°C, 80 μmol ·m?2· s?1 under 35 ppt and 14L: 10D without formation of conchosporangial branch during 6 weeks of culture period. An early formation of conchosporangial branch was observed at 30°C, 20-40 ppt under 80 μmol ·m?2· s?1 of both photoperiods after 2 weeks in culture. Early conchospore release occurred at 20-35 ppt and 10L: 14D under 30°C and 80 μmol ·m?2· s?1 at 4th weeks of culture. Fast growth of the conchospore germlings was observed at 25°C under the both of photoperiods in 35 ppt and 80 μmol ·m?2· s?1. The blades culture at 30°C produced only archeospores after 2 weeks throughout the culture period. Under the optimum culture conditions of 25 ppt and 14L: 10D at 25°C and 80 μmol ·m?2· s?1, the blades matured and liberated zygotospores within 6 weeks. In good combinations of conditions at the four factors, the life cycle was completed within 12 weeks in culture.
Keywords : Bangiales, blade and conchocelis phase, life cycle, photon flux density, photoperoid, physiological