The document summarizes the development of dicot and monocot embryos. It begins by defining embryogenesis as the process after fertilization that produces a fully developed plant embryo. It then describes the development of dicot embryos, starting with the zygote dividing into two cells, one forming the suspensor and one the embryo proper. The embryo cell divides further to form the octant stage with eight cells that develop into various embryo parts. For monocot embryos, the zygote also divides into two cells but the basal cell does not divide further and forms the suspensor directly while the embryo cell divides to form the plumule, hypocotyl, and radicle.

1. Development of
embryo
Dambar Singh Khatri

2. Behavioral objectives
• At the end of season, students will be able to
• Define the term embryogenesis.
• Understand the concept of development of dicot embryo.
• Describe the development of dicot embryo.
• Explain the development of monocot embryo.

3. What is embryogenesis..
• Embryogenesis is a process that occurs after the fertilization of an ovule to
produce a fully developed plant embryo.

4. Development of dicot embryo
• The zygote divides transversely forming two cells, a terminal cell and basal
cell.
• The cell towards the micropylar end of the embryo sac is the suspensor cell
(i.e., basal cell) and the other one makes to the embryo cell (i.e., terminal
cell).
• The terminal cell by subsequent divisions gives rise to the embryo while the
basal cell contributes the formation of suspensor.

5. Cont …
• The terminal cell divides by a vertical division forming a 4-celled shaped
embryo.
• The terminal cells of the four-celled pro-embryo divide vertically at right
angle to the first vertical wall forming four cells.
• Now each of the four cells divides transversely forming the octant stage (8-
celled) of the embryo.

6. Conti ….
• The octant cell divides in many tires of cell.
• The upper tires gives epidermis.
• Next to this, the layer of cell gives, plumule and cotyledons.
• The layer of cells, which are connected with suspensor gives hypocotyl.
• At the same time, the cell of suspensor which is connected to proembro called
hypophysis.
• It divides into 8 cell. Lower 4 cell forms root tip and upper 4 cell forms cortex of
root.

7. Dicot and monocot embryo development

8. Development of monocot embryo
• The zygote divides transversely forming the terminal cell and the basal cell.
• The basal cell, which is the larger and lies towards the micropylar end, does not
divide again but becomes transformed directly into a large vesicular cell.
• The terminal cell divides transversely forming the two cells. of these, the lower cell
divides vertically into two cell and the middle cell divides transversely into two cells.
• After that, a repeated division takes in both top cell and middle cell.
• The top cell forms the cotyledon and plumule while repeated division of middle
layer gives the hypocotyle and radicle.

9. Thank you