Question

Explain the various methods of crop improvement. Name one improved variety of Rice, Maize, Soyabean, Sunflower and Mustard.

Answer 1

Methods of crop improvement are explained below:

1. Hybridisation: It is the crossing between two genetically dissimilar plants to produce a new variety of plants.
Crossing may be between two different varieties (intervarietal cross-breeding), between two different species of the same genus (interspecific cross-breeding), and between different genera (intergeneric cross-breeding). It incorporates desirable traits of both the parents in one variety.
2. Recombinant DNA technology: It is a method of transferring genes from one organism to another to modify the genetic make-up of latter. It gives rise to transgenic plants called as genetically modified foods (GMFs). Example: Bt cotton is a genetically modified crop that carries bacterial genes that protect plants from insects.
3. Polyploidy: It refers to increasing the chromosome number of a plant that leads to increase in the plant production. Example: Potato.
4. Mutation breeding: In this method, new crop varieties are generated by inducing mutations. Example: Mexican varieties of wheat.

Improved varieties of:
(i) Rice is Jawahar.
(ii) Maize is HIM128.
(iii) Soya bean is Pusa 24.
(iv) Sunflower is MSF H 8.
(v) Mustard is Agarni.