In vitro somatic embryogenesis of high yielding varieties of rice (Oryza sativa L.)

Rice (Oryza sativa L.) belongs to the family Gramineae and is the staple food for half of the world’s population and occupies almost one-fifth of the total land area covered under cereals. Now-a-days, the production of rice is hampered due to climatic changes. Therefore, it is essential to develop variety which is tolerant to abiotic and biotic stresses. The present investigation was conducted to establish an efficient and simple protocol for regeneration of four agronomically important indica rice varieties (Khandagiri, Udayagiri, Swarna and Pratikhya). Somatic embryogenesis were achieved from immature zygotic embryos on Murashige and Skoog (MS) medium supplemented with 3 mg/l 2,4-D (2,4-dichlorophenoxyacetic acid), 1.0 mg/l kinetin and 3% (w/v) sucrose within 4 weeks of culture. The secondary somatic embryogenesis was also achieved in subsequent subculture on MS medium supplemented with 2 mg/l 2,4-D and 2.0 mg/l kinetin and 200 mg/l L-proline. The percentage of embryogenic calli proliferation were 82.4, 83.7, 88.4 and 84.4 in variety Khandagiri, Udayagiri, Swarna and Pratikhya respectively on MS basal medium supplemented with 3.0 mg/l 2,4-D, 2.0 mg/l Kinetin and 200 mg/l L-proline. Inclusion of higher concentration of L-proline (400 mg/l) in the induction medium, the growth of calli was reduced. The maximum percentage of somatic embryo germination took place in medium supplemented with 2.0 mg/l kinetin, 0.25 mg/l NAA and 50 mg/l adenine sulfate within 4 weeks of culture. The regenerated plantlets were transferred to pots for acclimatization. About 80% of plants were survived in the greenhouse condition.Keywords: Somatic embryogenesis, immature zygotic embryos, Indica rice, plant regenerationAfrican Journal of Biotechnology Vol. 12(42), pp. 6113-611