In this essay we will discuss about:- 1. Origin and Evolution of Soybean 2. Distribution of Soybean 3. Cultivated Species 4. Reproduction and Pollination 5. Breeding Objectives 6. Breeding Procedures 7. Breeding Centres 8. Achievements.
Essay on Soybean
Essay # 1. Origin and Evolution of Soybean:
Soybean is generally accepted that soybean originated in China. From China, it spread to East and South East Asia, USA and other countries. The wild annual species G. soja is considered to be the progenitor of cultivated soybean. It is also believed that wild annual form originated either from G. tabicina or G. tomentella, because these perennial species are also found growing in area of G. soja.
Essay # 2. Distribution of Soybean:
Soybean is an important protein cum oil yielding crop of global importance. It belongs to the family Leguminosae. Seeds of soybean contain about 40% protein and 20% seed oil. Soybean is cultivated in 35 countries. Major soybean cultivating countries are USA, Brazil, China, Argentina, Canada and Japan. USA alone contributes over 60% to the global production of Soybean.
In India Madhya Pradesh, Uttar Pradesh and Maharashtra are the major soybean producing states. In India, both soybean seed and oil are used for human consumption. Soybean contributes 60% to the vegetable protein and 30% to the edible oil on global basis.
Essay # 3. Cultivated Species of Soybean:
There is only one cultivated species of soybean, i.e., Glycine max (2n = 40). This is an annual diploid species. There are eight wild species of soybean, out of which seven are perennial and one (G. soja) annual diploid. Wild species are important sources of disease and drought resistance. Soybean it cultivated in tropical and sub-tropical climates.
Essay # 4. Reproduction and Pollination of Soybean:
Cultivated soybean is seed propagated and self-pollinated. It has bisexual flowers. Cross pollination is less than 1% which occurs through insects. An isolation distance of 3 metres is quite safe for the production of foundation and certified seeds.
Essay # 5. Breeding Objectives in Soybean:
In soybean, major breeding objectives are high yield, earliness, dwarf stature, resistance to shattering, protein and oil quality, and resistance to biotic (diseases and insects) and abiotic (lodging, drought etc.) stresses. Major yield components are pods per plant, seeds per pod and seed size. Main diseases include, pod blight, yellow mosaic, bacterial blight and alternaria leaf spot. Bihar hairy caterpillar and girdle beetle are the main insects. Quality includes protein and oil% and absence of anti-nutritional factors.
Essay # 6. Breeding Procedures of Soybean:
Breeding methods which are commonly used for improvement of soybean include introduction, pure-line selection, mass selection, pedigree method, bulk method, single seed descent method and backcross method. Biotechnology is expected to play an important role in future in soybean improvement by creating vast genetic variability for various economic characters.
Somoclonal variation may be helpful in developing resistant genotypes to biotic and abiotic stresses and improving several other traits. Mutation breeding also helps in creating genetic variability for various characters. It has not been much useful in the development of improved cultivars.
Essay # 7. Breeding Centres of Soybean:
Soybean improvement work is carried out by various International and National Crop Research Centres/Institutes. International Centres where soybean breeding work is done include Asian Vegetable Research and Development Centre (AVRDC) Taiwan, and International Institute of Tropical Agriculture, (IITA), Nigeria.
AVRDC deals with breeding of tomato, Chinese cabbage, sweet potato, mungbean and soybean for Asian region. Soybean is bred for tropical and sub-tropical climates at this centre. IITA deals with improvement of cowpea, soybean, maize, rice, root tuber and plantation crops.
In India, soybean improvement work is carried out by- National Research Centre for Soybean, Indore (Madhya Pradesh) and State Agricultural Universities. New varieties are released through Coordinated Project after multi-location testing for 3-5 years. Coordinated Project is located at Indore.
Essay # 8. Practical Achievements of Soybean:
In India, several improved varieties of soybean have been developed for different states. Eight varieties (Bragg, Clark 63, Davis, Hardee, Improved Pelicon, Jupiter, Lee and Monetta) have been released through direct introduction. Some high yielding varieties have been developed by Pantnagar, Jabalpur, Ludhiana and other Agricultural universities and also by IARI, New Delhi.
These varieties include PK 262, PK 308, PK 327, PK 416, PK 472, Shilajeet and Pant Soybean 564 (Pantnagar); Durga, Gaurav, JS 75-46, JS 80-21, (Jabalpur); SL 4 and SL 96 (Ludhiana); Pusa 16 Pusa 20 and Pusa 24 (IARI, New Delhi); VL Soya 2 (Almora), Shivalik (Palampur); and MACS 13 and MACS 58 (Poona).
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