MALE AND FEMALE MEIOSIS IN DIPLOID AND COLCHITETRAPLOID PHLOX DRUMMONDII HOOK (POLEMONIACEAE)

Comparative studies on male and female meiosis in diploid (2n = 2x = 1 4)and colchitetraploid (2n = 4x = 28) ornamental Phlox drummondii reve al higher chiasma frequency in embryo-sac mother cells as compared wit h pollen mother cells in the diploid, and significant differences in t he pairing properties of chromosomes in the pollen mother cells and em bryo-sac mother cells of the colchitetraploid. Male meiosis in the col chicine-induced autotetraploid was abnormal with 51.70% of chromosomes associated in quadrivalents and trivalents in 96% of the cells. This was followed by discordant anaphase I disjunction. In the female meioc ytes the chromosomes formed 14 bivalents in 86.66% of the cells. Quadr ivalents (1-3) appeared only in 13.34% of the cells. It is concluded t hat meiosis in male and female cells of the colchitetraploid is govern ed and regulated by different controlling systems of gene(s). (C) 1996 The Linnean Society of London