Observations On The Nuclear Division Characterization Of Porphyra (Bangiales, Rhodophyta)

Nuclear divisions of vegetative cells, spermatia, carpospores, conchocelisfilamentous cells, conchosporangial branch cells, sporangial cells of Porphyrayezoensis, P. haitanensis and conchospores of Porphyra yezoensis, P. haitanensis, P.katadai var. hemiphylla and P. oligospermatangia from China were investigated. Theaim was to investigate the nuclear division characterizations of Porphyra and theirinfluences on the researches of meiosis and life history ploidy of the alga. Ourobservations indicate that for P. yezoensis and P. oligospermatangia n=3, 2n=6, andn=5, 2n=10 for P. haitanensis and P. katadai var. hemiphylla. Nuclear divisions ofvegetative cells and spermatia of P. yezoensis and P. haitanensis were haploid mitosis.In carpospores, conchocelis filamentous cells, conchosporangial branch cells andsporangial cells (conchospore formation), somatic pairing of chromosome sets in lateprophase were observed and sister chromosomes separated at anaphase as mitosistook place. Chromosome configurations of tetrad and ring-shaped in conchosporesgermination were observed in all four species, demonstrating the occurrence ofmeiosis. The characteristics of nuclear division in 2n=6 species are the same as thoseof 2n=10 species. The influence of somatic pairing on nuclear division of diploid cellsin Porphyra was discussed.