Abstract :
This paper reports observations of the development and cytology of this embryonic organ in the natural tetraploid Trifolium pratense L. during embryogenesis. In the natural tetraploid Trifolium pratense (var. Elçi) the division of the zygote occurs in the transverse or oblique direction, resulting in the formation of two unequal cells. The basal cell is a larger than the terminal cell. The smaller terminal cell divides further and give rise to the embryo proper. The larger basal cell develops into vacuolated suspensor. In proembryo stage, the terminal cell nucleus becomes elongated, and occupies a large part of the cell. The basal cell nucleus which contains several electron-dense regions. The growth rate of the suspensor cells is very rapid during earlier stages of embryogenesis. In the early globular embryo stage, the suspensor consists of four or six cells and contains mitochondria, ER, ribosomes, lipid droplets, small protein bodies and vacuoles. In the late globular embryo stage, the suspensor cell expanded like massive structure. During embryogenesis, the suspensor cells are usually filled with small vacuoles are less electron-dense, and fewer ribosomes than the adjoining embryo cells. The suspensor undergoes at the cotyledone stage embryo and is not present in the mature seeds.
NaturalLanguageKeyword :
Trifolium pratense , suspensor cells , embryo development , ultrastructure
