短日照处理天数对一品红开花和观赏品质的影响

 短日照处理不同天数后转到自然长日照下, 研究短日照处理对促成栽培的‘千禧’和‘早生天鹅绒’一品红生长开花的影响。结果表明短日照处理天数对其发育进程、苞片着色和观赏品质有显著影响。苞片转色后结束短日照处理, 节数与连续短日照相似, 但开花显著延迟; 现蕾时结束短日照处理, 开花时间、冠幅与连续短日照相似; 过渡性叶片面积在短日照处理至现蕾后13～14 d才与连续短日照相似。一品红对短日照处理天数的反应存在品种差异。现蕾前结束短日照处理导致一品红过渡性叶片的节间和花梗伸长、苞片着色变差, 出现开花逆转现象。为了保证观赏品质, 短日照处理要持续到现蕾以后。

Effect of Number of Short-day on Flowering and Visual Quality of Poinsettia

The effect of number of short-days on development and flowering of ‘Millennium’and‘Velveteen’poinsettia was studied by transferring plants from short-day to natural long days. The results showed that the number of short-day significantly affected the development, bract pigmentation and visual quality of poinsettia. When terminating short-day at bract colour change, the plants produced similar number of nodes below inflorescence to those under continued short-day, but flowering was delayed. Flowering time and canopysize did not change when transferred at or after visible bud stage. Until 13 - 14 d after visible bud, transitional leaf area remained equal to continued short-day. Poinsettia responded differently to number of short-days among cultivars. When terminating short-day before visible buds, poinsettia showed flower reversion with worse pigmentation of bract, longer node of transitional leaves and pedicle. As a conclusion, short-day should continue to visible buds in order to produce quality flowers.