We observed chromosome behavior during meiosis of Arabidopsis thaliana justafter polyploidization. Two strains of A. thaliana, Columbia (Col) and Landsberg erecta(Ler), were treated with colchicine to induce polyploid lines, and the treated generationswere analyzed. Flow cytometric analysis revealed that a tetraploid line was obtained fromthe treated Col and an octoploid line from the treated Ler. Meiotic chromosomes of pollenmother cells of these polyploid lines were visualized by DAPI staining and observed. Bothlines underwent meiosis as normal, as did most of the established tetraploid lines on thewhole. At metaphase I, however, their numbers of bivalent chromosomes were fewer thanexpected and chromosome alignment of the octoploid was occasionally disturbed. Therewas no significant difference between the fertility of diploid and tetraploid, but that ofoctoploid was significantly reduced, which might be correlated with the disturbance ofchromosome configuration
