伯利恆之星切花採後處理技術之研究

Abstract

本次研究以百合科聖星百合屬的伯利恆之星（Ornithogalum saundersiae Bak.）切花為材料，探討切花瓶插特性與採收後處理之技術之方法。 伯利恆之星切花瓶插時平均每日開放小花0 至10 朵，每支切花 可開放40 朵左右之小花。每朵小花壽命約7 天。瓶插第5 天至第14 天期間，花序上之盛開小花數目大於15 朵，此時具有最佳觀賞價值。 切花之呼吸速率在25℃最高，可達約80mg CO2 kg-1hr-1，隨溫度 之下降而降低，0℃之呼吸率低至約20mg CO2 kg-1hr-1。在25℃下乙 烯生成率約1.5μl kg-1hr-1，第5 天左右生成率最大，隨後逐漸下降； 在15℃以下的溫度中，乙烯生成率大概在0.5μl kg-1hr-1 左右。 切花使用1ppm 乙烯處理，會使小花總開放數增加，瓶插壽命也 較對照組長；10ppm 乙烯處理後，對低成熟度之切花可使小花開放數 增加，瓶插壽命也延長，但對高成熟度之切花則使小花總開花數與瓶 插壽命減少。另外，乙烯處理後的切花之萼片前端容易出現枯黃現 象，影響切花之瓶插過程之觀賞價值。 切花之上部不以塑膠袋包覆者在低溫貯藏比塑膠袋包覆者，有較 佳之小花總開放數與瓶插壽命，且其貯藏過程花序保持乾燥，不易出 現發黴現象，是較適合的貯藏方式。 以0℃貯藏小花梗因低溫使生長緩慢，使室溫瓶插時小花花梗向 上生長，花型略呈杯狀，影響品質。5℃貯藏者，總開花數與瓶插壽 命次於0℃貯藏者，但花型較緊緻優美，與未貯藏者之球狀花型較接 近，是最適合貯藏之溫度。10℃貯藏者小花梗於貯藏過程中有伸長現 象，導致瓶插時切花花型較鬆散，觀賞價值下降。15℃不適合貯藏， 其小花開花總數與瓶插壽命表現均較差，且小花花梗於貯藏過程參差 伸長，影響切花外型。 預措浸插處理以5%蔗糖溶液＋8HQS+STS 預措處理效果較佳， 能提高開花數目並延長切花瓶插壽命，但萼片有明顯黃化情形。BA 預措噴灑不僅能提高小花總開花數，且可明顯抑制切花萼片黃化。 伯利恆之星切花開花過程花莖之可溶性糖類含量以葡萄糖與果 糖為主，蔗糖含量幾乎偵測不到。開花過程中葡萄糖含量隨時間下降。

In this research we investigated the postharvest technology of Star-of-Bethlehem cut flower (Ornithogalum saundersiae Bak.) The length of the stem of Star-of-Bethlehem cut flower ranges from 70 cm to more than 100 cm, with a corymb at the top consisting of 30 to 40 florets. When it was held in a vase at 25 , the inflorescence opened at ℃ the rate of 1~5 florets per day. Average life time of each floret is about 7 days. The inflorescence forms a perfect flower ball after 7 days, and the vase life can last about two weeks. The respiration rate of cut flower was the highest at 25℃. It is about 80mg CO2 kg-1hr-1 and decreased with the storage temperature. At 0℃, the respiration rate reached the lowest point of 20mg CO2 kg-1hr-1. The ethylene production was 1.5µl kg-1hr-1 at 25℃. Maximum production occurred at the 5th day and decreased with time. Below 15℃, ethylene production was about 0.5µl kg-1hr-1. When we treated the cut flowers with 1ppm ethylene, the total number of florets increased and the vase life was extended in comparison to that of the control group. On the other hand, 10ppm ethylene had the similar effects on the low mature florets but not on the high mature florets. In addition, ethylene treatment makes calyx of cut flower wilted and lowers the appreciation value. At low storage temperature, the cut flowers without plastic wrapping on the upper portion had greater total number of florets and longer vase life as opposed to the group with wrapping. Throughout the storing process, the inflorescence was kept dry and less likely to mold. It is considered as a promising storage method. With less than three weeks of the storage time, the flowers held at 0 had the longest vase life and the most opened florets. However, florets ℃ at the lower position had elongated pedicels and thus the flower assumed the shape of a cup rather than a ball. Flowers stored at 5 and 10 had ℃ ℃ better outcome. Flowers stored at 5 for three weeks had shorter vase ℃ life, yet they produced superior appearance. In the storage condition of 5 and during the three week period, the flowers had slightly less ℃ opened florets than that of 10 group, but looked solid and exquisite. ℃ When the flowers was held at 15 , its floret stalk elongated unevenly ℃ during the storage period, and there were nectar secreted at the base of the floret, which reduced its quality of decoration. In conclusion, 5 was the ℃ most suitable temperature for Star-of-Bethlehem cut flower to be stored. The pulsing treatment process with 5% sucrose solution＋ 8HQS+STS had a better performance in increasing the total number of florets and the vase life time. But the calyx were observed to be significantly yellow and wilted. BA treatment can help increase the total number of florets and ease the problem of yellowing. During the blooming process of the cut flowers, glucose and fructose are the major components of the solvable sugar in the stem. Sucrose is hardly detectable, and the amount of glucose decreases with time.