LAUSR

Abstract The histological structure of the anthers and developmental processes of the male and female gametophytes in Ocimum basilicum L. were studied for the first time. To study developmental stages of the flower, young flowers and buds at different developmental stages were embedded in paraffin, sliced with a microtome and analyzed using a photomicroscope. It was observed that sporogenous meristem is formed as a result of cellular divisions in tunica and corpus regions. The initial ring (IR) activities remarkably decreased. Successive divisions in the peripheral and surface regions of sporogenous meristem results in the stamens primordia. Petals were grown from the peripheral parts of the region. Stamens were tetrasporangiate and cytokinesis in microsporocyte is simultaneous. The tetrads were also tetrahedral and the tapetum is of the secretory type. The mature pollen grain was three-celled and composed of a vegetative cell and two sperms. The ovary in O. basilicum was observed to be hypogynous, quadri-locular with several ovules in each loculus. The ovules were anatropous, unitegmic, and tenuinucellate. Finally, the embryo sac development belonged to the Polygonum type.