Q.70 You are a Botanist working in the area of plant breeding. Describe the various steps that you

will undertake to release a new variety.

Plant breeding programmes are carried out in a systematic way world wide-in government

institutions and commercial companias.

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

(i)Collection of Variability Genetic variability is the root of any breeding programme. In

many crops pre-existing genetic variabilly is available from wild relatives of the crop.

Collection and preservation of ail the different wild varieties, species and relatives of the

cultivated species (followed by their evaluation for their characteristics) is a pre-requisite

or effective exploitation of natural genes available in the populations.

The entire collection (of plants/seeds) having all the diverse alleles for all genes in a

given crop is called germplasm collection.

(ii) Evaluation and Selection of Parents The germplasm is evaluated so as to identity

plants with desirable combination of’ characters. The selected plants are multiplied and

used in the process of hybridisation, Purelines are created wherever desirable and

possible.

(iii) Cross Hybridisation Among the Selected Parents The desired characters have very

often to bo combined from two different plants (parents), e.9., high prolwin quality of

‘one parent may need to be combined with disease resistance trom another parent.

Ihis is possible by cross hybridising the two parents lo produce hybrids that genetically

‘combine the desired characters in one plant. This is a very time-consuming and tedious

process since the pollen grains from the desirable plant chosen as male parent have to

be collected grid placed on the stigma of the flowers selected as female parent.

Also, it is not necessary that the hybrids do combine the desirable characters, usually

only one in few hundred to a thousand crosses shows the desirable combination.

(iv) Selection and Testing of Superior Recombinants This step consists of selecting,

among the progeny of the hybrids, those plants thal have the desired character

Combination. 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 (very often more than one

superior progeny plant may become available). These are self-polinated for several

generations til they reach a state of uniformity (homozygosity), so that the characters

will not segregate in the progeny.

(v) Testing, Release and Commercialisation of New Cultivars The nawly selected lines

fare evaluated for their yiek! and other ayronuinic bails of quallly, disease resistance, etc.

This evaluation is done by growing these in the research fields and recording their

performance under ideal fertliser application, irrigation and other crop management practices.

The evaluation in research fields is followed by testing the materials in farmers’ fields

for at least three growing seasons at several locations in the country, representing all the

agraclimatic zones when the eiup is usually grown.

The material is evaluated in comparison to the best available local crop. Alter evaluation

the variety can be relased for the farmers.