The study of anther and pollen developmental stages in Petunia hybrida

The pollen grains and anther developmental characteristics of Petunia hybrida were studied in this research. Petunia plants were grown in green house under experimental conditions. The flowers and buds, in different developmental stages, were removed, fixed in FAA70, stored in 70% ethanol, and following dehydration and embedding in paraffin, the specimens were sliced by a rotary microtome. Staining was carried out with Hematoxylin-Eosine and prepared specimens were studied under a light microscope. Results indicated that anthers are tetrasporangiate and each pollen sac, due to progress in placentoeid tissue, are crescent-shaped. The sporogenous tissue was surrounded by dimorphic secretory tapetum. The pollen grains, in this plant, are spherical in polar view and fusiform in equatorial view; mature pollen grains are prolate, tricolporate/tricolporoidate with furrows disposed along polar axis. The disposition of the microspore in the tetrads is tetrahedral. The pollen grains are 2-celled when shed. The pattern of wall formation is dicotyledonous type. Stomium is formed by the differentiation of epidermal cells within the anther, to form a single cell region, the location of which determines the position of anther opening. In the final stages of pollen grains maturation unusual tissue formation in anther septum and causes deformation of the pollen sac.