Explain the process of artificial hybridisation to get improved crop variety in:
(i) plants bearing bisexual flowers
(ii) female parent producing unisexual flowers.
If a plant breeder desires to cross a particular plant with desired pollen grains, a bisexual flower is artificially transformed into a female flower by removing its stamens in bud condition without affecting the female reproductive organs. This process is called emasculation.
The emasculated flower is immediately enclosed in a bag to prevent pollination by unwanted pollen. This process is called bagging. Then, mature and viable pollen grains are collected from the male parent, the bag is opened and the pollen grains are dusted on the stigma. The bag is replaced immediately.
The technique of emasculation is applied only when artificial pollination is carried out in a bisexual flower. If the female parent produces unisexual flowers, emasculation is not needed. The unisexual flower is bagged before the flowers open.