7. Briefly describe various steps involved in plant breeding.
Plant breeding is the process in which two genetically dissimilar varieties
are purposely crossed to produce a new hybrid variety. As a result,
characteristics from both parents can be obtained in the hybrid plant variety.
Thus, it involves the production of a new variety with the desired
characteristics such as resistance to diseases, climatic adaptability, and
better productivity. The various steps involved in plant breeding are as
follows:
Collection of genetic variability: Genetic variability from various
wild relatives of the cultivated species are collected to maintain the
genetic diversity of a species. The entire collection of the diverse
alleles of a gene in a crop is called the germplasm collection.
Evaluation of germplasm and selection of parents: The germplasm
collected is then evaluated for the desirable genes. The selected plants
with the desired genes are then used as parents in plant breeding
experiments and are multiplied by the process of hybridization.
Cross-hybridization between selected parents: The next step in plant
breeding is to combine the desirable characters present in two
different parents to produce hybrids. It is a tedious job as one has to
ensure that the pollen grains collected from the male parent reach the
stigma of the female parent.
Selection of superior hybrids: The progenies of the hybrids having the
desired characteristics are selected through scientific evaluation. The
selected progenies are then self-pollinated for several generations to
ensure homozygosity.
Testing, release, and commercialization of new cultivars: The
selected progenies are evaluated for characters such as yield,
resistance to diseases, performance, etc. by growing them in research
fields for at least three growing seasons in different parts of the
country. After thorough testing and evaluation, the selected varieties
are given to the farmers for growing in fields for a large-scale
production.