Question

Explain the process of emasculation and bagging of flowers. State their importance in breeding experiments

Answer 1

Hint: These techniques are used to prevent self-pollination. In a plant breeding programme only desired pollen grains are practised for pollination. Protection of the stigma from the contamination of undesired pollen is compulsory.

Complete answer : Emasculation: The process of extracting anthers from bisexual flowers without harming the female reproductive part pistil is called emasculation. If the female parent has bisexual flowers, anthers are removed from the flower’s bud using a pair of forceps. This process eliminates the ability of a flower to self pollinate. Self-pollination can be stopped by shifting its pollen from another into its own stigma. This process of emasculation is done during artificial hybridisation. Plant breeders perform emasculation process in bisexual flowers by crossing a particular variety of a plant with desired pollen grain. This entire process helps to achieve beneficial variation.

Bagging:
After the emasculation process, the emasculated flowers are covered with a bag, usually a butter paper. This process is bagging. This is done to inhibit contamination of its stigma with undesired pollen. Yes, this helps to keep flowers away from pollinating insects and stray pollen. The fertilization of stigma from unwanted pollen can be prevented.

Importance in Breeding: The mature pollen grains have to be collected from the anther of the male parent before the stigma of bagged flower attains receptivity. If the female parent breeds unisexual flowers, emasculation is not required. Once, the stigma becomes receptive, pollination starts to happen with the help of unwanted pollen. This leads to rebagging of flowers.

Note:You should remember in short that in the emasculation process, basically, you are eliminating the chance of undesired pollination. Only after emasculation, bagging is done in the hybridization process.