HIGH REGENERATION RATES IN ANTHER CULTURE OF INTERSPECIFIC SUNFLOWER HYBRIDS

Optimization of anther culture with regard to the induction of callus formation and direct embryogenesis was obtained for interspecific hybr ids of H. annuus with H. tuberosus, H. laetiflorus, and H. resinosus b y investigating six different induction media and four regeneration me dia. One media combination (MS-I3, MS-R3 and MS-R4) used under differe nt culture conditions (30 degrees C/35 degrees C and different dark tr eatments) gave up to 92.7% embryogenic anthers with an average of 8.5 embryos per anther. However, direct embryogenesis as well as callus fo rmation showed a strong genotypic and treatment specific reaction. Fro m 5,600 anthers of the four investigated genotypes more than 2,000 pla nts could be regenerated. Regenerants were characterized by morphologi cal traits and isozyme analyses to prove their androgenetic origin.