EMBRYOLOGY OF DYPSIS DECARYI (ARECACEAE)

Abstract

The paper deals with the study of microsporogenesis and male gametophyte development, megasporogenesis and female gametophyte development in Dypsis decaryi (Jum.) Beentje et J. Dransf. The anther is tetrasporangiate and each sporangium is encircled by wall layers of an outer epidermis and an inner glandular tapetum. Immediately below the epidermis, an endothecium is present. Two middle layers are located between endothecium and tapetum. Simultaneous quadripartition in the pollen mother cells results in tetrads. The microspore tetrads are isobilateral and tetrahedral. Rarely polyspory has been noticed. The pollen grains are 2-celled when shed. The ovary is superior, tricarpellary and syncarpous. The ovules are bitegmic and crassinucellate. The sporogenous cell directly develops into megaspore mother cell. Seldom two megasporocytes are met with in a single ovule. The megaspore tetrad is linear. The development of the female gametophyte follows the Polygonum type.