Temperature Responses of Porphyra tenera Kjellman and P. Yezoensis Ueda (Bangiales, Rhodophyta) from Korea

Algae > Volume 12(3); 1997 > Article

Algae 1997;12(3): 207-213.

Mi-Sook Hwang, Ik-Kyo Chung, Yoon-Sik Oh

Department of Marine Science, Pusan National University, Department of Biology, Gyeongsan National University

ABSTRACT

Temperature responses of the conchosporophytes and gametophytes of Porphyra tenera and P. yezoensis were investigated in culture. The growth of conchosporophytes and the formation of conchosporangial branches were high at 20℃ in both species. The conchospore release was high at 10℃ and 15℃ in P. tenera and at 10℃ in P. yezoensis. Conchosporophytes were tolerant at -1.5℃ for 4 weeks in both species and tolerant up to 32℃ in P. tenera and 30℃ in P. yezoensis for 2 weeks. The relative growth rates (RGRs) of the gametophytes decreased as they grew. The temperature for the highest RGR of gametophytes was changed from 20℃ at the 1st stage (2-4week) to 5℃ and 10℃ in P. tenera and 5℃ in P. yezoensis at the 3rd stage (8-10 week). The reproductive structures developed early as temperature increased. Monospores were released not only from the early stage of gametophytes at the condition above 15℃ or 20℃ but also from mature plants at the same time of spermatium release at lower temperature. It is apparent that P. tenera and P. yezoensis are well adapted to the temperature variation in nature for the alternation of generations and the growth and reproduction of each generation.

Key words: conchosporophyte, gametophyte, Porphyra tenera, relative growth rate, temperature, response