Microsporogenesis: Definition, Diagram, Process, Types, Structure and Process

What Is Microsporogenesis?

Microsporogenesis in flowering plants is the process by which microspores are formed within their anthers, the precursory cells leading to the formation of pollen grains. There is a meiotic division of one diploid microsporocyte that gives rise to four haploid microspores. In the process, each microspore undergoes mitosis to form a pollen grain with a vegetative cell and a generative cell.

Microsporogenesis is, therefore, of prime importance for plant reproduction as it ensures the production of viable pollen grains. These are highly essential in carrying genetic material through fertilisation, resulting in seeds, and thus allowing the continuation of species.

Structure And Function Of The Anther

The structure and function of the anther is described below-

Anther Anatomy

The anther is the pollen-forming part of the stamen of flowering plants. It is bilobed, and each lobe is further divided into two microsporangia or pollen sacs. It is attached to the filament and forms a very crucial part of producing and releasing the pollen grains for the fertilisation process.

Microsporangia

These are specialized structures within the anther lobes. They contain sporogenous tissue in which the process of pollen development takes place and is, therefore, significant in the formation of microspores via meiosis.

The Process Of Microsporogenesis

The process includes:

Stages Of Microsporogenesis

The whole process of microsporogenesis commences when sporogenous tissue develops within a microsporangium. This kind of tissue develops into microspore mother cells, otherwise known as microsporocytes, which undergo meiosis to form haploid microspores.

Meiosis in microsporocytes

During meiosis I the microsporocytes undergo division, after which two haploid cells are produced. These cells undergo further division to enter meiosis II and produce a tetrad of four haploid microspores — precursors to pollen grains.

Formation of microspores (tetrads)

Undergo a series of cellular and molecular changes to develop into mature pollen grains which can fertilise ovules.

Microspore maturation

In developing a tough outer wall, it biochemically equips itself with the view to succeed in fertilisation.

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