Emasculation and bagging are the two important steps carried during artificial hybridisation to obtain superior varieties of desired plants. Explain giving reasons, in which types of flowers and at what stages are the two processes carried out.

OR

State what is apomixis. Write its significance. How can it be commercially used?

• Artificial hybridization is used for crop improvement. In which it is important to make sure that only the desired pollen grains allow to pollination and the stigma is protected from unwanted pollen. This is achieved by emasculation and bagging techniques.

• The removal of anthers from the bisexual flower bud before the anther dehisces using a pair of forceps is referred to as emasculation.

• Emasculated flowers covered with a bag to prevent contamination of its stigma with unwanted pollen. This process is called bagging.

• By attaining receptivity of the stigma of a bagged flower, mature pollen grains collected from desirable anthers of the plant are dusted on the stigma, and the flowers are rebagged for the development of fruits.

• There is no need for emasculation in the case of unisexual flowers. The female flower buds are bagged before the flowers open. When the stigma becomes receptive, pollination is carried out using the desired pollen and the flower rebagged.

OR

• Apomixis is the form of asexual reproduction that mimics sexual reproduction and that produces seeds without fertilization.

• The problem of a hybridization technique is that they require continuous production of hybrids because the new characters can segregate and they are unable to maintain hybrid characters.

• The cost of hybrid seeds is too expensive for farmers because the production of hybrid seeds is very costly.

• But when these hybrids are converted into apomicts, there is no segregation of characters in the hybrid progeny. Thus the farmers can keep on using the hybrid seeds to raise new crops year after year.