Effects of Temperature and Light Condition on Seed Germination of Lilium × formolongi hort

We investigated the effects of temperature and light conditions on germination of Lilium × formolongi. The optimal germination temperatures were 20°C in early flowering cultivars ‘F1 Augusta’ and ‘Raizan No. 1’, 18°C in the medium flowering cultivar ‘Raizan No. 2’, 15°C in the late flowering cultivar ‘Raizan No. 3’. ‘F1 Augusta’ and ‘Raizan No. 1’ showed a high rate of germination at 5°C compared with ‘Raizan No. 3’. Seed germination of the all cultivars tested was inhibited by high (≧24°C) temperatures. Pre-chilling treatments, at 3, 5, or 10°C for more than 10 days, accelerated seed germination at 20°C. Germination at 30°C was accelerated by pre-chilling treatment at 10°C for more than 10 days, whereas pre-treatment at 3 or 5°C had no promotive effects. In conclusion, pre-chilling treatment at 10°C for more than 10 days is recommended to achieve uniform germination of Lilium × formolongi under high temperature conditions. There was no effect of light conditions on germination.