Developmental stages of pollen and ovule in Anthemis odontostephana Boiss. Cv. Odontostephana

The study of reproductive organs development is important in taxonomy and developmental biology. In this research, developmental process of ovule and pollen grains were studies in Anthemis odontostephana. According to results of this study, anthers are tetrasporangiated type and development of anther wall is of dicotyledonus type and composed of one-layered epidermis, an endothecium, one middle layer and tapetum. ¬Tapetum layer indicated high polyploidy level that necessary for metabolism and it is of the secretory type. Microspore tetrads are tetrahedral, in the main, and tetragonal in some cases. Pollen grains are three colpated with echinated sculpturing, at the shedding time. The size of some microspores increased it seems that they showed Nemec phenomenon. Presence of asteroid crystals in the cells of endothecium layer and connective tissue is the characteristic of this species. Ovule is anatropous, unitegmic and tenuiucellate. Cell division of megaspore mother cells is of both longitudinal and transverse type and resulted to form linear, T-shaped or massive tetrads. Embryo sac development is of the Polygonum type and antipodal cells increase up to 6-8 and their nuclei become polyploidy. The polar cells are migrated toward egg apparatus and combined prior to fertilization. Formation of ovate to polygonal crystals is the characteristic of this species.