Question

With advancements in genetics, molecular biology and tissue culture, new traits have been incorporated into crop plants. Explain the main steps in breeding a new genetic variety of a crop.

Answer 1

Hybridization is the most common method of creating genetic variation. Hybridization is crossing of two or more types of plants for bringing their traits together in the progeny. It brings about useful genetic / heritable variations of two or more lines together.

The procedure of hybridization involves the following steps.

1. Selection of parents with desired characters: All the desirable traits which are required in the new crop variety are first selected.
   
2. Selfing: The selected plants as parents are allowed to undergo self-breeding to bring about homozygotes of the desired traits.
   
3. Emasculation: The removal of anthers (male parts) from a bisexual flower, before the anthers mature (emasculation) prevents self-pollination in these flowers.
   
4. Bagging: The emasculated flowers are immediately covered by paper, plastic or polyethene bags (bagging) to prevent unwanted pollen from coming in contact with emasculated flowers.
   
5. Artificial Pollination (Crossing): Pollen grains are collected from the covered flowers of the ‘male’ parents. When the stigma of the emasculated flower of ‘female’ parent matures, it is dusted with pollen grains. This is called artificial pollination.
   
6. Selection and testing of superior recombinants: This step comprises selecting, among the progeny of the hybrids, those plants that have the desired character combination.