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

Hint: To grow high-yielding crops, farmers often use intraspecific hybridization, hybridization among strains of a single species. Continuously inbred varieties will also show inbreeding decline in maize, which is a decline in fertility and yield.

Complete answer:
The most prominent means of generating genetic variation is hybridization. In order to bring their characteristics together in the offspring, hybridization is the crossing between two or more forms between plants. This brings together valuable genetic / heritable differences on two or three lines.

The following steps are included in the process of hybridization:
- Choice of parents of desired traits: All the desired characteristics that are needed in the new variety of crops are first picked.

- Selfing: As ancestors, the chosen plants are permitted to undergo self-breeding to produce homozygotes of the desirable characteristics.

- Emasculation: Self-pollination in these flowers is avoided by the elimination of anthers (male parts) from a bisexual flower just before anthers develop (emasculation).

- Bagging: To avoid harmful pollen from getting into contact with emasculated flowers, emasculated flowers are automatically sealed by plastic, paper, or polyethene (bagging) containers.

- Artificial Pollination (Crossing): From the 'male' parents' covering flowers, pollen grains are collected. As the stigma of the female parent's emasculated flower matures, it is brushed with pollen grains. This process is known as artificial pollination.

- Picking and screening of superior recombinants: This stage includes choosing, among the descendants of the hybrids, certain plants with the desired combination of characteristics.

Note: Plants hybridize far more commonly and easily than animals do. Pollen from flowering plants is widely distributed and can fall on other types of flowers. In plants, polyploidy happens more commonly and promotes the hybrid offspring's fertility. Finally, plant variants are less tightly regulated than animal forms, and so the physiologically efficient intermediate type of a plant hybrid is more possible.