Question

Briefly explain the steps involved in plant breeding.

Answer 1

Plant breeding is the purposeful manipulation of plant species in order to create desired plant types that are better suited for cultivation, give better yields and are disease resistant.

The main steps in breeding a new genetic variety of a crop are:

(i) Collection of variability: A single crop might have different varieties grown in different places which have some unique qualities of its own. To bring them together, we need to collect the seeds or germplasm (the part that contains its DNA).

(ii) Evaluation and selection of parents: Among the numerous varieties, the seeds which have the best quality or the desired quality is selected and is opted as the parent. Cross breeding might not work for the first time itself, so the parent is multiplied so that we can use it.

(iii) Cross hybridisation among the selected parents: The parents are bred between them to produce new seeds which might or might not contain the desired characteristics. So the cross-breeding is also done in large quantity.

(iv) Selection and testing of superior recombinants: Usually only one in few hundred to a thousand crosses shows the desirable combination. So, among the numerous cross-bred seeds, the one with the desired quality is found by continuous testing and evaluation. Once they are found, they are made homozygous by self-pollinating them for several generations.

(iv) Testing, release and commercialisation of new cultivars: The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance, etc. This evaluation is done by growing these in the research fields and recording their performance under ideal conditions of fertilizers etc and the farmer's field to make sure that it grows perfectly.