Fertilisation in plants is defined as the union of the male and female gametes, which results in the development of a diploid zygote (a plant embryo). Following fertilisation, a succession of events takes place in the zygote that eventually results in the formation of a seed. Let us have a look at the post-fertilisation, endosperm and embryo development processes in further detail.
What is the meaning of post fertilisation?
An ovary produces a seed, and a seed produces a fruit. Post-fertilisation is a series of activities that take place after fertilisation in order for the seed to develop into a fruit. After a successful fertilisation, the following events take place.
- Endosperm development
- Embryogeny
Endosperm
A form of tissue found in flowering plants’ seeds during the period of fertilisation, the endosperm is a type of tissue that helps the seed to germinate. The cells of endosperm tissue are filled with food materials that have been set aside. It offers starch to the growing embryo, which helps it to grow and develop properly. The development of the endosperm can be divided into three categories. These are the ones to look out for:
- Nuclear endosperm formation: During this process, the original nucleus of endosperm divides frequently, resulting in the formation of free nuclei without the formation of walls
- Cellular endosperm formation: During nuclear division, the creation of the cell wall takes place, which ultimately results in the production of the cellular endosperm
- Helobial endosperm formation: Helobial endosperm formation is a type of endosperm formation that occurs between cellular and nuclear types
Seed germination occurs when the endosperm is totally utilised by the developing embryo during seed maturation or in the mature seed. The endosperm is also utilised by the seed during seed germination.
Embryogeny
Flowering plants go through an embryogenic phase, which is described as the process of the growth and development of an embryo from a zygote. The phases of embryonic development are the same in both monocot and dicot plant species.
An embryonal axis as well as two cotyledons are present in the embryo of a dicot plant embryo. In the embryonal axis, there are two distinct components. The following are examples:
- Located above the cotyledon level, the epicotyl is referred to as the root of the plant
- Located below the cotyledon, the hypocotyl is referred to as the hypocotyl
Only one cotyledon is present in the embryo of a monocot plant. If you are talking about grass, the cotyledon is referred to as scutellum. In the grass, the root cap is protected by an undifferentiated sheath, which is referred to as coleorhiza. In embryology, the epicotyl is defined as the section of the embryonic axis that is above the scutellum. The apex of the shoot and coleoptiles make up the epicotyl.