Chalazogamy

A plant is a gift from nature because it provides us with food, oxygen, shelter, clothing, and other essentials. They are also referred to as “universal producers” or “primary producers.” Plants breathe, grow, develop, excrete, and reproduce in the same ways as all other living things. fertilisation is required for the reproduction of all higher plants. In the year 1884, Ralph B. Strasburger discovered that fertilisation in flowering plants is possible. To begin, let us briefly discuss the topic of fertilisation.

What is fertilisation and how does it work?

Fertilisation is a process of sexual reproduction in plants that takes place after pollination and germination have taken place.

When two male gametes (pollen) mate with two female gametes (ovum), they produce a diploid zygote, which is known as fertilisation. A physicochemical process that occurs after the pollination of the carpel is known as germination. The zygote is the site of the culmination of this process, which results in the development of a seed.

Flowers are important in the fertilisation process because they are the reproductive structures of angiosperms, which are responsible for fertilisation (flowering plants). When gametes in haploid conditions fuse to form a diploid zygote, this is the method of fertilisation used by plants.

Pollinators (honey bees, birds, bats, butterflies, and flower beetles) are responsible for the transfer of male gametes into female reproductive organs during the process of fertilisation, and the result is the formation of an embryo in a seed.

Proceedings of Fertilisation

In flowers, the pollen grain germinates after the carpel has been pollinated, and it grows into the style, which serves as a pathway for the pollen grain to travel down to the ovary and fertilise the flower.

The pollen tube enters the ovule through the micropyle and bursts into the embryo sac, releasing pollen into the environment. An ovule contains a diploid zygote, which develops into a fruit after the male nucleus joins with the nucleus of an egg to form a diploid zygote.

Sexual Reproduction In Plants

Flowers are the reproductive parts of plants, with the stamen representing the male reproductive part and the pistil representing the female reproductive part. A unisexual flower is defined as one that has only one of these reproductive organs present in its petals and leaves. Take, for example, papaya. When both the Stamen and the Pistil are present in a flower, it is referred to as bisexual flowers. As an illustration, consider the flower rose.

Pollen grains are responsible for the formation of male gametes. The pistil is made up of three parts: the style, the stigma, and the Ovary. The ovary is made up of one or more ovules, depending on the species. Ovules are the reproductive organs in which female gametes or eggs are produced. A zygote is formed when the gametes of both the male and female sex fuse together.

Pollination

Pollination is the process by which pollen is transferred from the anther to the stigma of a flower using carriers such as bees or butterflies. If pollen from the same flower or another flower of the same plant lands on the stigma of the same flower or another flower of the same plant, it may be a case of self-pollination. Cross-pollination occurs when pollen grains from a flower of a different plant, but of the same species, land on the stigma of a flower of the same species.

Fertilisation

An embryo is formed as a result of the fusion of gametes, which is formed as a result of the fusion of gametes. Fruits and seeds are formed after fertilisation has taken place. The ripened ovary eventually develops into a fruit. In the case of ovules, seeds are produced, with the embryo enclosed within a protective covering.

Different Types of Fertilisation

The process of fertilisation can be divided into three categories, which are distinguished primarily by how the pollen tube enters the ovule.

Porogamy

It is the most common type of fertilisation found in all angiosperms or flowering plants, and it is also the most expensive. In this type of fertilisation, the pollen tube enters the ovule through the micropyle, which is a small opening in the ovary.

Chalazogamy

This type of fertilisation is used on all Casuarina species of plants, and it is very effective. As a result of this arrangement, the pollen tube enters the ovule through the pollen tube.

Mesogamy

This type of fertilisation can be found in all Cucurbit plants, including pumpkins, ridge gourds, bitter gourds, and other gourd plants, as well as in other gourd species. The pollen tube can enter the ovule through its middle part or the integuments of the ovule in this type of fertilisation.

Double Fertilisation

Double Fertilisation is a term used to describe the process of fertilising twice.

Double fertilisation is a type of fertilisation in which a female gametophyte is fused with two male gametes, resulting in the formation of a fertilised egg. In this mechanism, one sperm cell fuses with the egg-producing zygote, and the other sperm cell fuses with the two polar nuclei of the endosperm to produce the endosperm. All angiosperm plants are subjected to a two-fertilisation procedure.

Conclusion

Ulmus exhibits partial chalazogamy, with the tube piercing the nucleus halfway between the chalaza and the micropyle. It was first discovered by Treub in the Casuarina tree, and it has since been discovered to occur consistently in the Betulaceae and Juglandaceae families, among other places. Instead of entering the embryo sac through the micropyle, the pollen tube enters the embryo sac through the tissue of the chalaza during the process of fecundation known as the chalaza process.