抄録
Autotetraploid Osmunda lancea (2n=4x=88) was produced artificially by apospory. The meiotic chromosome configulation of the autotetraploid O. lancea showed the maximum 21 quadrivalent chromosomes at prophase I, in most of the spore mother cells. Their metaphase I plates additionally showed univalent, bivalent and multivalent chromosomes. Anaphase I and II plates showed frequently laggards. To make the meiosis regularly, the suppression system of multivalent chromosome formation might be obtained in the process of evolution in autoploid ferns in nature. Aposporous sporophytes could not be induced from the autotetraploid O. lancea anymore.
