Male and female meiosis in diploid and colchitetraploid Phlox drummondii Hook. (Polemoniaceae)

Comparative studies on male and female meiosis in diploid (2n = 2x = 14) and colchitetraploid (2N = 4x = 28) ornamental Phlox drummondii reveal higher chiasma frequency in embryo-sac mother cells as compared with pollen mother cells in the diploid, and significant differences in the pairing properties of chromosomes in the pollen mother cells and embryo-sac mother cells of the colchitetraploid. Male meiosis in the colchicine-induced autotetraploid was abnormal with 51.70% of chromosomes associated in quadrivalents and tridents in 96% of the cells. This was followed by discordant anaphase I disjunction. In the female meiocytes the chromosomes formed 14 bivalents in 86.66% of the cells. Quadrivalents (1–3) appeared only in 13.34% of the cells. It is concluded that meiosis in male and female cells of the colchitetraploid is governed and regulated by different controlling systems of gene(s).