Plant Embryo

The embryogenesis in the dicots, monocots, and gymnosperms is different. The angiosperms, which are flowering plants, produce embryos after fertilizing a haploid ovum with pollen. DNA from the egg and pollen combine to form a single-celled diploid zygote that finally develops into an embryo. The general summarized process of development of the embryo in plants is as follows: 

In Dicot Plants

• At first, the zygote divides transversely, and a basal layer along with terminal cell formation occurs. 
• Further division of the basal cell occurs transversely to form a six to the ten-celled structure called a suspensor.
• The terminal cell at the start divides longitudinally and, after that, transversally to finally form a globular structure of embryo which later on changes to a heart-shaped structure. This development is simple and primitive, shown by the Capsella bursa and hence called the crucifer type.
• The main axis in the embryo of plants is called the tigellum.
• Dicot embryo consists of two cotyledons.

In Monocot Plants

• The development in the monocots is almost similar to the embryogenesis in dicots. 
• The basal cell, in this case, does not go into division and results in the formation of a single-celled vesicular suspensor.
• Monocot embryo consists of only one cotyledon.  

The embryo derives the nutrition from the tissues of the endosperm, perisperm, and chalazosperm.

Plants that do not produce seeds but spores which include bryophytes and ferns, are involved in the formation of the embryo differently than monocots and dicots. 

Polyembryony in Plants

It is the condition in which the number of embryos formed in one seed is multiple. It is very common in gymnosperms such as Pinus and Citrus. Leeuwenhoek in citrus plants in the year 1719 first observed it.