The objective of plant breeding is to develop new crop varieties superior to the existing ones in relation to their economic use. It will give better yield and is disease resistant. It involves the following steps:
(i) Collection of variability: Genetic variability from various wild relatives of the cultivated species is collected to maintain the genetic diversity of a species. The entire collection of all the genes in a population of a plant is called the germplasm collection.
(ii) Evaluation of germplasm and selection of parents: The collected germplasm is then evaluated for the desirable genes. The plants with desirable and useful characteristics are chosen and used as parents in plant breeding experiments and are further multiplied by the process of hybridization whereas those with undesirable characteristics are hence eliminated.
(iii) Cross-hybridization among the selected parents: The next step in plant breeding is to combine the characters from different parents into one to produce hybrids. It is the most important step as one has to ensure that the mature and viable pollen grains collected from the male parent reaches the receptive stigma of the desired emasculated female parent.
(iv) Selection of superior hybrids: The choice process requires careful scientific evaluation of the progeny. The progenies of the hybrids with desirable combinations of characters are selected through scientific evaluation. The selected progenies are grown for several generations by allowing only self pollination to ensure homozygosity.
(v) Testing, release, and commercialization of new cultivars: The new varieties thus developed skilled rigorous testing. The yields, disease resistance, nutritional qualities, etc. are first evaluated by growing the developed cultivars in experimental fields and therefore the records are faithfully maintained. Once it certifies that the cultivar has passed all the essential requirements, the cultivar is commercialized.