[Biology Class Notes] on Controlled Pollination Emasculation Tagging and Bagging Pdf

Aim: To control pollination through emasculation, tagging, and bagging.

Materials Required:

 

Theory

Emasculation is defined as the process of artificial hybridization in which female flowers’ stamens are separated from bisexual flowers in order to avoid self-fertilization. Much before the anthers mature, this process takes place. Emasculation is the method of extracting anthers from bisexual flowers before they mature. After that, the emasculated flower is bagged to keep any unwanted pollination.

 

This method aids in the development of flowers that have the desired characteristics. It is essential to have knowledge of flower structure, fertilization, flower physiology, and fertilization for this.

 

Procedure to Controlled Pollination Emasculation Tagging and Bagging:

1. Choose a flower bud and open it to extract the stamens. This is referred to as emasculation. It is the female parent vine, so make a note of it.

2. The plant is then wrapped in a plastic bag to keep unwanted pollen from pollinating it.

3. Bring it in contact with the anther of a male plant that has the desired traits. The pollen should be dusted on the stigma’s surface.

4. Cover the pollinated flower with a polythene bag and mark it with the seed parent’s name as soon as possible.

 

Pollination

Pollination is a plant reproduction process in which pollen grains are transferred from the anther to the stigma. There are two forms of pollination:

• Cross-pollination

• Self-pollination

Pollen and stigma must be compatible for pollination to be effective. Pollen grains can be rejected due to incompatibility. This is unfavorable, especially in commercial crop production. Artificial hybridization was established as a result.

 

Artificial Hybridization

For successful pollination and fertilization, pollen-stigma compatibility is important. When compatible pollen is accepted by the pistil, fertilization events begin, while incompatible pollen is rejected. The ability of a pistil to recognize its pollen is the product of long-term pollen-pistil interaction as well as chemicals released by pollen.

 

Steps in Artificial Hybridization

Hybridization proceeds in two steps:

Emasculation

Hybridization is a form of selective breeding, as we all know. Anthers must be removed from a bisexual flower before pollen grains can be released. Emasculation is the process of removing an Anther with forceps. This phase is not expected in the case of unisexual flowers.

 

Bagging

Bagging is an essential component of all pollination operations. Until anthesis, the female (receptive) flowers must be protected to protect the stigma from contamination before the desired pollen can be added. Usually, the bag is made of semi-transparent treated paper. By securing the bag over the shoot’s tip, the flowers can be secured. To make the bags more comfortable, they must be tightly fitted and fixed.

 

Bagging is a way of shielding emasculated flowers from unwanted pollen grains. Despite the fact that the flower is obscured by a bag, it achieves receptivity. Bagging is performed before the flowers open in unisexual flowers.

 

The female flower is absolutely covered from contamination thanks to emasculation and bagging.

 

The desired pollen is dusted on the stigma once the flower has achieved stigma receptivity. This has been resealed in preparation for future developments.

 

As a result, artificial hybridization ensures that the correct form of pollen is transferred to the flower’s stigma. Furthermore, there is a fair possibility of fertilization. This method allows for the production of a wide range of crop strains while also improving the quality of crops with desirable characters.

 

Emasculation & Bagging Techniques to Achieve Artificial Hybridization

• Emasculation – Emasculation is the process of artificial hybridization where the pollen and anthers of the flower are separated to prevent self-pollination.

• Bagging – Bagging involves covering the emasculated flower with a bag to prevent pollinating agents from reaching it.

The stigma of emasculated flowers can be dusted with pollen of the desired kind.

Artificial hybridization is therefore possible.

 

Control Pollination

Control-pollination is a plant enhancement technique that produces progeny with genes from each of two established parent plants. Transferring pollen from one plant to the receptive female reproductive organs of another plant while removing all other pollen is known as control pollination.

Control-pollination is necessary to:

• To establish and maintain a pedigreed breeding population, control pollination is required.

• In order to control inbreeding in the breeding population

• Hybridization and back-cross between species must be done.

Control-pollination techniques are specifically engineered and managed to generate seeds with greater genetic trait and genetic uniformity than naturally pollinated seeds, as well as eliminating pollen contamination issues.

 

Importance of Pollination

Pollination in plants can happen in two ways, self-pollination that happens within the same plant and cross-pollination that happens across the plants. Insects, water, wind etc, which facilitates pollination in plants are known as pollinating agents. However, insects were the first pollinating agents that helped the plants from their primitive stages. Pollination in plants plays a key role in the sexual reproduction of plants. It benefits not only plants but also human beings and animals by providing various fruits that we eat and flowers we use to decorate. Even today, many tribals who live in forests have fruits as their main source of nutrition. Artificial hybridizat
ion techniques have improved these chances of utilizing the plants much better. The flowers produced through pollination are a key source in the perfume industry and horticulture industry. Flowers play an important role also in the soap manufacturing and talcum powder industries. With the rise of industries and machines, humans can now process these natural gifts and store them for a longer period.