Hybrid Seed Germination and Bulblet Formation in vitro in Tulip
ZHANG Yan-qiu;QU Lian-wei;XING Gui-mei;Institute of Floriculture, Liaoning Academy of Agricultural Sciences;
Tulip(Tulipa gesneriana), belonging to the Tulipeae in the family Liliaceae, is a perennial bulbous flower with high ornamental value and is used widely as cut flowers, potted plants, landscape, etc. due to their wide range of colors and flower shapes. At present, tulip varieties used in the tulip industry and research in China are mainly imported from the Netherlands or other countries, and the lack of tulip varieties with independent intellectual property rights has become a bottleneck problem that limits the development of flower industry in China. Hybridization is the main way to breed new varieties of tulip, while the hybrid seeds germination and bulblets formation are the important parts in tulip breeding process. The research on hybrid seeds germination and bulblets formation of tulip cultivars has not been reported in China until now. In this study, the hybrid seeds from the cross of tulip cultivars 'Aafke' and 'Eskimo Chief' were used as materials and the factors affecting seed germination and bulblet formation were studied. The results showed that 4℃ was the optimum temperature to break seeds dormancy and to further promote seeds germination and bulblet formation. The germination rate of the seeds treated with 0.5% KNO_3 was the highest,reaching 86.7%, and the buds were vigorous. There was no significant difference between unpeeled and peeled seeds in terms of germination rate. The optimum medium formula of bulblets formation at 4℃ was 1/2 MS + 60 g·L~(-1)sucrose and 1/2 MS + 60 g·L~(-1)sucrose + 2.8 g·L~(-1)agar, and the bulbs formation rate was 40.3%-41.7%. The bulbs newly formed were subcircular, ivory white.