Ovule and Megagametophyte Development in Adonis flammea Jacqu: Report of Ovule and Embryo Abortion

Since applied and molecular studies are increasing in Ranunculaceae، the study and understanding of the flower development in the family is necessary. In this research ovule developmental stages in Adonis flammea were studied. The young flowers and buds were sampled in different developmental stages، fixed in FAA70 and kept in 70% ethanol. Samples were embedded in paraffin after dehydration and sliced using microtome. Staining was carried out with PAS and Hematoxylin. Prepared slides of different developmental stages were studied using light microscope and are photographed. Results showed that ova in A. flammea are anatropous، bitegumic and crassinucellate. Micropylar channel was constructed with inner integument. Megasporocyte produces both linear and nonlinear arrangement of tetrads after meiosis. Embryo sac development follows to the Polygonum type. Antipodal cells are persistent that degenerate at the cellular endosperm stage. Cytoplasmic connections of embryonic sac cells، degeneration of some ova، consciously abortion of ovules and embryo were also observed. The patterns of ovule and embryo sac development are accordance with the Angiosperms and Polygonum type. But antipodal cells persistence، nucellar cap formation، cytoplasmic connections between embryo sac cells، fertilization failure and embryotocia in some ova are characters of the studied species that can due to genetical or environmental factors.