Adventitious shoot regeneration from immature embryos of sorghum

Eleven genotypes of sorghum were examined for their response in tissue cult ure, and the tissue culture system was optimized. The cultures were initiat ed from immature embryos taken approximately two weeks after flowering. The response of immature embryos varied with the genotype. 'C. Kafir' and 'PE9 32 025' showed the highest frequency of callus induction and regenerable ca llus formation under appropriate culture conditions. Regeneration occurred at high frequencies when cytokinins (kinetin or 6-benzyladenine) had been a dded in the callus induction medium, followed by regeneration medium devoid of growth regulators. The addition of proline and polyvinylpyrrolidone als o enhanced shoot formation, but the addition of cytokinins to regeneration media did not improve shoot formation. On the revised culture medium, plant s were regenerated from up to 100% of sorghum immature embryos.