Earlier methods of plant breeding involved crossing or hybridizing pure lines...
Plant Breeding Programme
Earlier methods of plant breeding involved crossing or hybridizing pure lines, followed by artificial
Insemination to produce plants desirable traits.
The major steps in breeding a new genetic variety of a crop as follows:
i. Collection of variability
Genetic variability is the root of any breeding programme.
Pre-existing genetic variability is collected from wild varieties, species and relatives of the cultivated crops.
These are evaluated for their characteristics and preserved for effective exploitation of the natural genes.
The entire collection of diverse alleles for all genes in a given crop is called germplasm collection.
ii. Evaluation and selection of parents
Evaluation of germplasm is carried out to identify plants with desirable combination of characters.
The selected plant is multiplied and hybridized.
By self-pollination, pure line is created whenever desired.
iii. Cross hybridization among the selected parents
The cross hybridization between the parents is done who produce hybrids that genetically combine to give desired characters in one plant.
Cross hybridization is a time-consuming and tedious process because it involves emasculation and a bagging technique to transfer desired of pollen grains to the desire to plant.
iv. Selection and testing of superior recombinants
It involves the selection of plants among the progeny of the hybrids with desired combination of characters.
The hybrid are superior to both the parents. This is called hybrid vigour/heterosis.
They are self-pollinated for several generations till they reach a state of uniformity or homozygosity in order to avoid the segregation of characters in the future progeny.
v. Testing, release and commercialization of new cultivars
a. Evaluation: The newly selected lines are evaluated for their yield and other agronomic traits of quality, disease resistance, etc., by growing them in the research fields.
b. Testing: After evaluation, the hybrid line is tested in farmer’s fields.
c. Release: The material tested is then selected be certified and released in bulk as a variety.