Modern methods of Breeding plants :
(1) Plant breeding for disease resistance :- Several fungal, bacterial and viral pathogens affect the yield of cultivated crop species. In this situation, breeding and development of cultivars resistant to disease enhances food production. It also helps reduce the dependence on the use of fungicides and bacteriocides. Breeding is carried out by conventional breeding techniques or by mutation breeding. The method of breeding for disease resistance is that of hybridisation and selection. By this some crop varieties are produced which were disease resistance to bacteria and fungi. They are
Crop |
variety |
Resistance to disease |
(1) Wheat |
Himgiri |
Leaf and stripe rust, hill bunt |
(2) Cauliflower |
Pusa swarnim |
White rust |
(3) Cowpea |
Pusa komal |
Bacterial blight |
(4) Chilli |
Pusa sadabahar |
Chilly Mosaic virus Tobacco mosaic virus and leaf curl |
Mutation breeding : It is the process by which genetic information is created through changes in the base sequence within genes resulting in the creation of new character of trait not found in the parental type.
Eg : Resistance to yellow mosaic virus in Bhendi (Abelmoschus esculentus) was transferred from a wild species and develop in a new variety called Parbhani Kranti.
(2) Plant breeding for developing resistance to insect pests : Large scale destruction of crop plants and crop produce is by insect and pest infestation. Insect resistance in Host crop plants may be due to morphological morphological, biochemical biochemical or physiological physiological characteristics. Hairy leaves in several plants are resistances to insect pests.
Eg : Resistance to Jassids in cotton and cereal leaf beetle in wheat. Smooth leaved and nectar–less cotton do not attract bollworms. High aspartic acid, low nitrogen and sugar content in maize leads to resistance to maize stem borers.
Some released crop varieties bred by hybridisation and selection, for insect, pest resistance are
Crop |
Variety |
Insect pests |
(1) Brassica |
Pusa Gaurav |
Aphids |
(2) Flat bean |
Pusa sem 2
Pusa sem 3 |
Jassids, aphids
and fruit borer |
3) Okra (Bhendi) |
Pusa Sawani |
Shoot and fruit bores, pusa A-4 |
(3) Plant breeding for improved food quality : A far greater number–Three billion people-suffer from micro-nutrients, potein, and vitamin deficiencies or 'hidden hunger because they can not afford to buy enough nutritious food. Biofortification aims at breeding crops with high vitamins and minerals or higher protein and healthier fats to improve public Health. Wheat, Atlas 66 having a high protein content has been developed by this method. β carotene containing rice variety 'Golden Rice',vitamin A enriched carrots, spinach, Vitamin C enriched bitter gourd mustard, tomato, iron and Calcium rich spinach, Protein rich garden peas are released IARI, New Delhi.