夜來香花芽發育及花期調節之研究

Studies on the Flower Bud Development and the Regulation of the Flowering of Tuberose (Polianthes tuberosa L.)

傳統上，夜來香種球於早春挖取，經自然曝曬1.5～2個月後，於晚春種植。種球直徑2.5公分者，種植約四星期後，則其頂芽開始花芽創始。雖然夜來香可周年生產切花，但其主要花期集中於夏及早秋。本試驗乃利用乾燥種球貯藏於5°C之低溫，並不同時期種植，以觀察其產期調節之效果。直徑2.5公分之乾燥種球貯藏於5°C，經5個月後，其失重率僅4.6%。此低溫並能使大多數夜來香種球之頂芽仍維持在營養相。貯藏之種球自6月至10月分批種植，則其開花率一般均在70%以上。貯藏之種球自6月1日至10月1日種植則其自種植至開花所需日數比未貯藏種球於5月1日種植者約晚8～26天。雖然貯藏球所生產之花莖其花序較短，花蕾數較少，其花莖已達切花之標準。本試驗結果顯示，將葉來香種球貯藏於5°C之低溫下，於秋季種植則可供冬季生產夜來香切花。

Tuberose bulbs were traditionally dug out in the early spring, dried for 1 1/2 and 2 months under natural conditions, and then planted in the late spring. If the bulbs are 2.5cm in diameter, then the floral initiation at the apices of the bulbs will occur 4 weeks after planting. Although tuberose bulbs produced cut flowers all year round, major cut flower production was concentrated in the summer and early autumn seasons. Experiments are described in which dried bulbs which had been stored at 5°C low temperature, and planted at various dates, to determine whether the production period could be programmed. Storage of dried bulbs, 2.5cm in diameter, at 5°C for 5 months resulted in 4.6% weight loss. The low storage temperature (5°C) kept most of the apices of the bulbs in the vegetative phase. Dried bulbs stored at 5°C were planted from June to October. The emergence of commercially valuable floral spikes was generally above 70%. The clays to flowering in stored-bulbs planted on June 1st to October 1st were 8 to 26 days later than those unstored-bulbs planted on May 1st. Although the flower stem produced from the stored-bulbs showed shorter flower spikes and less flower buds, the flower stem were regarded as cut flowers of acceptable quality. Results demonstrate that providing bulbs stored at 5°C were planted in the autumn, mass production of cut flowers of tuberose in the winter is feasible.