Embryo Culture of Helianthus Hybrids1

An embryo culture system using two modification of Gamborg's B5 medium was used to produce interspecific Helianthus hybrids. Embryos initially developed on a solid medium containing inorganic components, vitamins, amino acids, and 120g/L sucrose. For embryo germination and seedling growth the cultured embryos were transferred to a liquid medium containing only the inorganic components and 10g/L sucrose. Embryos were successfully excised and cultured 3 to 7 days after pollination. Fifty‐three combinations of species have been successfully hybridized using this system, including 21 which have not been reported using conventional methods. Embryo culture techniques avoid embryo abortion and seed dormancy. The decrease in generation time using embryo culture can be useful in breeding schemes where small numbers of plants are needed per generation.