Interspecific Hybrids of Lilium longiflorum and L. × formolongi with L. rubellum and L. japonicum through Embryo Culture

To develop pink Easter lilies through interspecific hybridization, Lilium longiflorum and L. × formolongi were crossed with L. rubellum and L. japonicum.1. Interspecific hybrids between L. longiflorum × L. rubellum, L. × formolongi × L. rubellum, and L. ×formolongi × L. japonicum were obtained by pollinating the cut surface of styles (style-cutting method) and culturing the resulting embryo in vitro. Progenies of the respective crosses were pink, pale pink, and white.2. Of the two cultivars and two selections of L. longiflorum employed as the mother parent, the largest number of ovaries and the most embryos per ovary were found in 'Georgia' pollinated with pollen from L. rubellum.3. The percentages of developed ovaries of L. × formolongi pollinated with pollen from L. rubellum or pollen of L. japonicum were higher than when L. longiflorum was used as the mother parent.4. The % fertility of pollen from interspecific hybrids was low with the exception of pollen from a hybrid between L. × formolongi and L. rubellum which attained 95.2%. This high rate of pollen fertility in this hybrid is attributed to its amphidiploid (2n =48) nature.5. Hybrids progenies between L. × formolongi and L. rubellum produced viable embryos when they were back-crossed with L. rubellum, but not when they were triple-crossed with L. longiflorum.