1980 Volume 45 Issue 4 Pages 809-817
The mode of meiosis in PMCs was studied in two members of Chionographis. C. japonica was found to have n=12 chromosomes, and C. japonica var. hisauchiana n=21 chromosomes. No localized kinetochore was observed in the chromosomes at various stages of meiosis. The bivalents at mid diakinesis showed various characteristic configurations, due to the presence of chiasma or chiasmata. Each bivalent at prometaphase I and metaphase I consisted of 2 homologous chromosomes connected end to end. Somewhat rectangular bivalents (in side view) were oriented axially with regard to the spindle at metaphase I. This mode of orientation of bivalents (axial orientation) differs from the one reported in some species of Luzula and some other organisms with holocentric chromosomes. Each pollen tetrad cell developed into a single mature pollen grain.