Inheritance of bulb dormancy and early flowering ability in F₁ progenies of intra- And interspecific crosses of lilium formosanum and L. longiflorum

One-year-old seedlings of the northern populations of Lilium longiflorum in the Ryukyu Archipelago have deep dormancy in summer, whereas those of the southern populations of L. longiflorum and L. formosanum show lack or reduction of dormancy. Dormancy status of the F₁ progenies of intraspecific hybrids among L. longiflorum with different degrees of dormancy and interspecific hybrids between L. formosanum and L. longiflorum was studied in an open field condition. Three populations of L. longiflorum, Yakushima (LYA) and Kikai Jima (LKI) in the Ryukyu Archipelago, Japan and Pitouchiao (LPI), Taiwan and two populations of L. formosanum, Wulai (FWU), Taiwan and Fukuoka (FFU), Japan were used. FFU, FWU, LPI and hybrids of FFU × FWU, FFU × LPI and FWU × LPI continued developing leaves in summer and flowered in a year after seed sowing, while LYA and LKI and the hybrids with them did not. Since FFU, FWU and LPI are categorized as non-dormant populations and LKI and LYA as deep dormant, the bulb dormancy seems to be dominant, while early flowering ability is recessive in the F₁ progenies.