Algae. 1994; 9(1): 21-28.

Measurement of DAPI-stained DNA in Dasysiphonia chejuensis Lee et West (Rhodophyta) by a Video Interfaced Digital Image Processor

Han-Gu Choi, Yoo Kyung Lee, In Kyu Lee

Department of biology, Seoul National University

According to the quantitative studies on DAPI-stained ANA of Dasysiphonia chejuensis by a video interfaced digital image processor, the apical cell was uninucleate polyploid and the derived ones resulted in ultimately multinucleate non-polyploid. The frequency distribution patterns of the relative nuclear DNA contents for four strains were reasonably symmetrical, and the relative nuclear DNA contents of the pericentral cells in the female, mixed-phase female and male gametophyte approximated 50% of those In those in the tetrasporophyte. The mean relative nuclear DNA content of tetrasporophyte nuclei was about twice as much as those of the female and male gametophytes, as well as the mixed-phase female plant and spermatium nuclei. Our measurements of DAPI-stained DNA by a video interfaced digital image processor have confirmed that the female and male gametophytes, and the mixed-phase female plants are haploid and that the thetrasporophytes are diploid, without having to count chromosomes. In addition, our results suggest that the mixed-phase female plants are genetically haploid and the tetraspores on these plants may be formed apomictically.

Keywords : DAPI-stained DNA, Dasysiphonia chejuensis, Rhodophyta, video interfaced digital image processor, relative nuclear DNA contents, haploid, diploid