Breaking of dormancy in the narrow endemic Jasione supina Sieber subsp. supina (Campanulaceae) with small seeds that do not need light to germinate

Abstract

The germination properties of Jasione supina Sieber subsp. supina (Campanulaceae), which is endemic to Mount Uludag, Bursa, Turkey, were determined. In this study, we investigated the effects of GA(3), the combination of hormone series and short-term moist chilling (1-month), and long-term moist chilling (4-month) on the germination percentage and mean germination time in relation to seed dormancy breaking. All treatment series were incubated under continuous dark (20 degrees C, 24 h) and light/dark (20/10 degrees C, 12/12 h) conditions. Seeds were collected from specimens widespread on the alpine and subalpine grasslands and dwarf shrubs of Mount Uludag (1800-1900 m a.s.l.). Depending on the concentration, GA(3) and the combination of hormone and moist chilling treatments promoted seed germination in both dark and light/dark conditions. After 4-month-moist chilling treatment, seeds germinated 27% in a light/dark and 80% in a dark regime. Hormone and moist chilling treatments reduced the mean germination time. Our results showed that J. supina seeds have physiological dormancy, require prolonged times of moist chilling and preferentially complete germination in darkness.