CBSE Class 12-science Answered
(i) Plant breeding is the manipulation of plant species to create desired plant types which are better suited for cultivation, give better yields and are disease resistant. Classical plant breeding involves the following steps:
(a) Hybridisation of pure lines
(b) Artificial selection to produce plants with desirable traits
(ii) Inducing mutation in plants helps in producing desirable genes for disease resistance. Plants having desirable genes can either be multiplied directly or can be used in breeding. For example, in mung bean, resistance to yellow mosaic virus and powdery mildew were induced by mutations.
(iii) Biofortification is the technology which has helped in improving public nutritional health by breeding crops with higher levels of vitamins and minerals or higher protein and healthier fats. In biofortification, protein, oil, vitamin, micronutrient and mineral content and their qualities are improved.
For example,
(a) Maize hybrids with more quantity of amino acids such as lysine and tryptophan were developed.
(b) To increase wheat cultivation, an improved variety, Atlas 66, has been used as the donor for having a high protein content.