Algae. 1989; 4(2): 111-119.
Mixed Phase Reproduction of Platythamnion yezoense Inagaki in Culture
Gwang Hoon Kim, In Kyu Lee
Department of Botany, Seoul National University
Life history and sex differentiation of Platythamnion yezoense Inagaki from three sites in Korea were studied in culture. The spores released from tetrasporangiate and cystocarpic plants were cultured under various environmental conditions. The strains from all sites showed a Polysiphonia-type of life history, while exhibited mixed phases and bisexuality in addition. Some (2-28%) of female plants bore spermatangia and tetrasporangia additionally, and some of carpospore germlings grew to mixed phases plants bearing spermatangia and tetrasporangia. The ratio of mixed phases plants to normal ones differed remarkably according to environmental conditions. The most favorable condition for occurrence of mixed phases was also most favorable for growth and reproduction of this species. The chromosome number was as n=ca. 30 and 2n=ca. 60. The gametophytes and bisexual mixed phases plants were haploid, whereas the tetrasporophyte was diploid.
Keywords : bisexuality, chromosome, environmental condition, mixed phases, platythamnion yezoense