DEVELOPMENT OF THE INTEGUMENT IN TRIFOLIUM PRATENSE L. (EL AYIRü GüLü-FABACEAE)

This study aims to reveal the histological and cytological changes undergone by integument cells in natural tetraploid Trifolium pratense L. (El i ay rü gülü) in the stages of proembryo, zygote, mature embryo sac and throughout ovule development.Female organs of flowers buds and flowers sampled from those at different developmental stages were embedded both in paraffin and epon 812. The structure of integument cells was examined in the stage of mature embryo sac and throughout ovule development by a light and a transmission electron microscopy.The ovules in natural tetraploid Trifolium pratense L. (El i ay rü gülü) have two integuments, namely inner and outer integuments. The primordia of both integuments start to appear from the medial part, chalaza. While the megaspore mother cell is in earlier stage of Prophase I, integuments start to develop. In the stage of mature embryo sac, the inner integument is two-cells thick and it fully covers the nucellus. The outer integument becomes thicker and thicker, and one of the cells grown faster covers the junction of inner integuments and joins with the other outer integument.It was concluded that necessary nutrients were sufficiently stored and transmitted in integumentcells during the stages of ovule, embryo sac, zygote and proembryo development in natural tetraploidTrifolium pratense L. (El i ay rü gülü).