Biology · Sexual Reproduction in Flowering Plants · NEET
Emasculation is the removal of anthers (the male parts) from a bisexual flower bud using forceps, before the anthers dehisce (split open). It is done so the flower cannot pollinate itself. This makes the flower act as a pure female parent, so the breeder can later add only the desired pollen. It must be done at the bud stage because once the anther dehisces, self-pollen is already released.
A unisexual flower is either male or female, not both. The female flower has no anthers at all, so there is nothing to remove. Therefore emasculation is skipped. But bagging is still needed: the female flower buds are bagged before they open to keep out unwanted pollen. This is a very common NEET point.
Bagging is covering the emasculated (or female) flower with a bag of suitable size to stop unwanted pollen from landing on the stigma. NCERT specifically says the bag is generally made of butter paper. Bagging protects the stigma until the breeder dusts on the chosen pollen.
After the stigma becomes receptive, mature pollen from the chosen male parent is dusted on the stigma. The flower is then covered again with the bag. This second covering is called rebagging. It protects the freshly pollinated stigma so the fruit develops only from the desired cross.
Order: (1) Emasculation - remove anthers from the bud before dehiscence, (2) Bagging - cover with butter-paper bag, (3) when stigma is receptive, dust desired pollen on stigma, (4) Rebagging - cover again and let the fruit develop. Remember: Emasculate before Bag; unisexual flowers skip only the emasculation step.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Before. The anthers are removed from the flower bud before the anther dehisces, otherwise self-pollen is already released and the cross is spoiled.
Unisexual female flowers. They have no anthers to remove, so only bagging (before the flower opens) is done.
A bag of suitable size generally made of butter paper, as stated in NCERT.
It lets breeders combine desirable characters from different plants (even different species or genera) to produce commercially superior crop varieties. It is a major approach in crop improvement.
The flower is rebagged (covered again) and the fruit is allowed to develop, so only the desired cross produces seeds.
