Practical Methods for Breaking Seed Dormancy in a Wild Ornamental Tulip Species <i>Tulipa thianschanica</i> Regel

oleh: Wei Zhang, Lian-Wei Qu, Jun Zhao, Li Xue, Han-Ping Dai, Gui-Mei Xing, Jia-Jun Lei

Format: Article
Diterbitkan: MDPI AG 2020-11-01

Deskripsi

The innate physiological dormancy of <i>Tulipa thianschanica</i> seeds ensures its survival and regeneration in the natural environment. However, the low percentage of germination restricts the establishment of its population and commercial breeding. To develop effective ways to break dormancy and improve germination, some important factors of seed germination of <i>T. thianschanica</i> were tested, including temperature, gibberellin (GA<sub>3</sub>) and/or kinetin (KT), cold stratification and sowing depth. The percentage of germination was as high as 80.7% at a constant temperature of 4 °C, followed by 55.6% at a fluctuating temperature of 4/16 °C, and almost no seeds germinated at 16 °C, 20 °C and 16/20 °C. Treatment with exogenous GA<sub>3</sub> significantly improved the germination of seeds, but KT had a slight effect on the germination of <i>T. thianschanica</i> seeds. The combined treatment of GA<sub>3</sub> and KT was more effective at enhancing seed germination than any individual treatment, and the optimal hormone concentration for the germination of <i>T. thianschanica</i> seeds was 100 mg/L GA<sub>3</sub> + 10 mg/L KT. In addition, it took at least 20 days of cold stratification to break the seed dormancy of <i>T. thianschanica</i>. The emergence of <i>T. thianschanica</i> seedlings was the highest with 82.4% at a sowing depth of 1.5 cm, and it decreased significantly at a depth of >3.0 cm. This study provides information on methods to break dormancy and promote the germination of <i>T. thianschanica</i> seeds.