Post Fertilisation in Plant: Structures and Events - Development of Endosperm

Post Fertilization in plant: Development of Endosperm 

Endosperm-  

The triploid primary endosperm nucleus divides mitotically to form endosperm, which develops simultaneously in post-fertilization changes within the ovule. The disorganization of other embryo sac cells triggers cell division, leading to the formation of endosperm.  

Post-fertilization- In post-fertilization changes within the ovule, the embryo and endosperm are seen to develop simultaneously. 

Types of endosperms 

1) Nuclear Type: 

• It is the most common type of angiosperm in 161 families involves the primary endosperm nucleus repeatedly dividing without wall formation, producing a large number of free nuclei.  

• A central vacuole pushes the nuclei towards the periphery, and later, walls develop between the nuclei, forming multicellular endosperm.  

• However, in some cases, cell wall formation remains incomplete, such as in wheat, sunflower, and coconut. 

2) Cellular Type: 

• In some plants, division of triploid primary endospermic nucleus is immediately followed by wall formation.  

• So that the endosperm is cellular right from the beginning. It is mostly observed in 72 families of dicots as in members - Balsam, Petunia, Adoxa, etc. 

3) Helobial Type: 

• This endosperm occurs in the Helobiales order of monocotyledons, with a transverse wall dividing cells unequally.  

• The smaller cell is called chalazal cell, while the larger cell is micropylar cell. Nuclei divide by free nuclear divisions, and walls develop between nuclei in the micropylar chamber. This intermediate endosperm is similar to Asphodelus. 

Types of Endosperms