- 學位論文
低溫貯藏對金花石蒜切花醣類含量、呼吸率及品質之影響
Low-temperature storage effects on sugar content, respiration and quality of Lycoris aurea Herb. cut flowers
摘要
金花石蒜屬於石蒜科石蒜屬，為台灣原生的球根花卉。在台灣產期集中在8月下旬至10月中旬，目前金花石蒜切花之研究報告極少，對於相關之採後處理生理變化並不清楚，因此藉由本試驗來瞭解其切花採後生理之變化。金花石蒜為繖形花序其花序中平均約有6至7朵小花苞，小花苞長度約在20 mm – 40 mm之間，在25 ℃室溫中以花序上3分之2小花萎凋為瓶插壽命約11.5天，每支切花可開放約5至6朵小花，於瓶插第6天左右會達到盛開期。 金花石蒜小花苞之長度與小花開放率、畸形小花發生率及瓶插壽命有相關性，小花苞愈短其開放率較低，畸形小花發生機率較高，包括緊蕾期與轉色期在內之瓶插壽命較長。整體而言小花苞長度達20 mm以上者，可視為具開放成熟度之基準。具開放成熟度之小花苞其盛開時由花梗至尖端花瓣的縱向長度均相似，約為65至68 mm。 金花石蒜切花呼吸率在0 –25 ℃中之花苞至盛開期間皆呈現非常穩定的趨勢，整支切花呼吸率皆隨著溫度上升而增加，25 ℃之呼吸率最高，約20 mg CO2 kg-1hr-1，於0 ℃之呼吸率最低，約4.7 mg CO2 kg-1hr-1。切花開始老化時，呼吸率會逐漸下降，直到切花花莖完全乾癟喪失貯藏價值時，呼吸率達最低。 金花石蒜切花於5 ℃下貯藏5天，移溫後瓶插於去離水中兩週，小花開放率96.7 %，畸形小花發生率17.2 %，去除花序上畸形小花之3分之2小花萎凋為觀賞瓶插壽命11.5天；貯藏10天，小花開放率降為90 %，畸形小花發生率增加至27.6 %，觀賞瓶插壽命11天；貯藏15天，小花開放率降為87.5 %，畸形小花發生率增加至57.4 %，觀賞瓶插壽命減至8.5天，由以上結果顯示貯藏時間不宜超過10天。貯藏在10 ℃以上的環境中者，於貯藏過程中小花有開放及腐爛的現象，導致瓶插時切花觀賞價值低落。小花達到盛開期之花瓣縱向長度並不受貯藏低溫而影響，約在64至70 mm左右。金花石蒜切花經貯藏後，移溫瓶插時容易發生花莖綻裂的現象，但與貯藏溫度及時間並無有明顯相關性。 金花石蒜未綻放小花苞內的醣類以蔗糖為主，隨花苞的生長發育其體內的果糖含量逐漸增加；綻放中小花內的醣類以果糖為主，蔗糖含量逐漸減少。花莖中的醣類以果糖與葡萄糖為主，僅含少量蔗糖。花莖內果糖與葡萄糖含量自貯藏開始便有明顯下降之趨勢，蔗糖含量隨貯藏溫度及時間的增加而不斷快速累積。
並列摘要
Golden spider lily (Lycoris aurea Herb.) belongs to the Lycoris genus, Amaryllidaceae. It is a flowering bulb native to Taiwan. The plant flowers from late-August to mid-October. Currently, there are very little researches carried out about this cut flower. The postharvest physiology of this flower remains to be explored. The object of this study was to understand the postharvest behaviors of this cut flower, with emphasis on the effect of storage temperature on the quality of flowering. The inflorescence of golden spider lily is an umbel, with an average of 6 – 7 flowers on the scape. The size of each flower bud ranges from 20 mm to 40 mm. When the cut flower was held in water at room temperature, it has an average vase life of 11.5 days, which was determined by the days when two third of the flowers on a scape wilted. Usually, 5 to 6 flowers will open on each scape, and the scape reaches full bloom stage on the 6th day. The lengths of flower buds bear some relationship with the ratio of flower opening, the ratio of abnormal flowers and the vase life. When the flower bud was short, it had lower opening ratio, higher abnormal flower ratio; but stayed longest on the scape. In this study, it was observed that a minimum of 20 mm was required for flower buds to possess the capacity of opening. Once opened, each fully-opened flower will reach similar sizes, the length from the pedicel to the tip of inner petal was about 65 – 68 mm. The respiration rates of golden spider lily cut flower, when held under 0 – 25 ℃, were rather stable from bud stage to fully open. The respiration rates increased as the temperature increase. The highest rate was 20 mg CO2 kg-1hr-1 when held at 25℃ and the lowest rate was 4.7 mg CO2 kg-1hr-1 when held at 0℃. The respiration rate gradually declined when the flowers began to senesce, reaching its lowest value when the scape became flat and lost it value. When the cut flowers of golden spider lily were stored at 5℃ for 5 days then held in deionized water at room temperature for two weeks, the flower opening ratio was 96.7%, abnormal flower ratio was 17.2% and the meaningful vase life, which was the vase life of normal flowers, was 11.5 days. When the cut flowers were stored at 5℃ for 10 days, the flower opening ratio was 90%, abnormal flower ratio was 27.6% and the meaningful vase life was 10 days. When the storage period extended to 15 days, the flower opening ratio was 87.5%, but the abnormal flower ratio increased to 57.4% and the meaningful vase life was reduced to 8.5 days. Therefore, it is concluded that the maximum storage period of golden spider lily cut flower at 5℃ was 10 days. When the cut flowers were held at 10℃ or higher, the flower buds opened gradually during the storage period and the incidence of decay increased, resulting lower flowering quality after storage. Cold storage did not affect the sizes of fully opened flowers, the length from the pedicel to the tip of inner petal was about 64 – 70 mm. It was observed that after cold storage the cut-end of scapes tend to crack when held in vase, the occurrence of cracking did not correlate with storage temperature or with duration. Sucrose was found to be the major carbohydrates in the flower buds of golden spider lily. As the flower bud elongates, the concentration of fructose began to increase gradually. When the flowers began to open, fructose was the major carbohydrates and sucrose gradually decreased. In the scape, fructose and glucose were the major carbohydrates, with small amount of sucrose present. During storage, the fructose and glucose in the scape decreased, and the sucrose concentration increased rapidly in parallel with storage temperature and duration.