Induction of UV-B resistance in rice (Oryza sativa L. cv. ADT 43) through adaptive mutagenesis. I: Optimization of tissue culture and UV-irradiation conditions.

摘要

The depletion of stratospheric ozone layer by pollution due to human activities substantially increased the level of UV-B radiation impinging on the earth's surface. UV-B radiation affects numerous crop plants in various ways and rice (Oryza sativa) is one of them. Rice is one of the world's most important food crops and grown mostly in tropical and subtropical countries. There is a need to develop methods to produce UV-B-resistant plants with better yield for the survival of human beings. In this study, we have attempted to induce callus tissue from mature rice (cv. ADT 43) seeds on MS medium supplemented with 2 mg 2,4-dichlorophenoxyacetic acid (2,4-D) litre-1 and 0.5 mg benzylaminopurine (BAP) litre-1 in vitro. Calluses were inoculated on the medium containing 5 mg BAP litre-1 and screened for regeneration in response to different doses of UV-B irradiation which was given for 30 days and formation of UV-B selected shoots. UV-B irradiation for 10 minutes day-1 for 30 days induced the maximum frequency of shoot regeneration from calluses. UV-B selected shoots were rooted on 1 mg IBA litre-1 medium. Plantlets have been hardened in vermiculite and under shade for a specified period. Thereafter, the somaclones were planted on pots filled with garden soil to observe their growth.