2004 Volume 44 Issue 2 Pages 68-75
We developed a culture system of Osmunda banksiifolia (Pr.) Kuhn with the lowest chromosome number of 2 n = 44 among Filicales and examined its usefulness as a teaching material.
On the 1/2 Murashige-Skoog (MS) agar medium, spores germinated within a week. Sexual organ matured and fertilized within 7 months and young sporophytes were formed within 8 months. Then, young sporophyte was transplanted onto 1/4 MS agar medium in a flask and cultured continuously. After 4 months of transplantation, sporophyte formed fertile fronds. The frond formation repeated about ten times in a year.
For the observation of cell division, young roots and young sporangium of sporophytes were used. In the mitotic cell division of root tip, we could count 44 chromosomes at metaphase stage. In the meiotic cell division of spore mother cells, we could count 22 bivalent chromosomes (2n = 44 = 22 II) at metaphase I.
These results show the usefulness of culture system of Osmunda banksiifolia as a teaching material for the topics of “Cell”, “Reproduction and Development” and others in the biology class of the secondary schools.