Question

What is plant breeding? Describe various steps involved in the classical breeding of plants.

Answer 1

• Plant breeding: it consists of the principle and the method required for favourably changing the genetic constitution of crop plants. This activity usually produces crop varieties better suited to human needs.

Following are the steps of classical breeding:

• Collection of variability: collection and preservation of all the different wild varieties, species and relatives of the cultivated species is a pre requisite for effective exploitation of natural genes available in the population.

Evaluation and selection of parents: the selected plants are multiplied and used in the process of hybridization. Pure lines are created wherever desirable and possible.

• Cross hybridization among the selected parents: the desired characters have very often to be combined from two different parents. This is possible by cross hybridizing the two parents to produce hybrids that genetically combine the desired characters in one plant. it is not necessary that the hybrid does combine the desirable characters usually only one in a few hundred to a thousand crosses shows the desirable combination.
• Selection and testing of superior recombinations: The selection process is crucial to the success of the breeding objective and requires careful scientific evaluation of the progeny. This step yields plants that are superior to both of the parents.
• Testing, release, and commercialization of new cultivars: the evaluation is done by growing these plants in the research fields and recording their performance under ideal fertilizer application, irrigation and other crop management practices. The evaluation in the research field is followed by testing the material in farmer's fields, for at least three growing seasons at several locations in the country, representing all the agro-climatic zones where the crop is usually grown.