Causes of Sprout Unevenness in Lilium × formolongi hort. Seeds under High Temperature

We examined the physiological factors causing reduction of seed germination under a high temperature of 24°C in Lilium × formolongi hort.. High temperature inhibited the saccharification of storage starch to glucose in the seed during germination with a reduction of α-amylase activity. Ethylene production and abscisic acid (ABA) concentration in the seed increased under a high temperature condition. Ethylene inhibitor, STS (Silver thiosulfate complex) and 1-MCP (1-methylcyclopropene), and wing removal treatments recovered the germination reduction at a high temperature. Furthermore, 1-MCP treatment during seeding in the soil was also effective in that recovering of germination reduction at a high temperature. We concluded a decrease in a-amylase activity with increases in ABA and ethylene is related to the inhibition of seed germination under high temperature in Lilium × formolongi hort.