| Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 87 === Oriental lilies can be produced in Taiwan during the winter and spring and are a potential source of export, However, cold storage often resulted in flower buds opening irregularly and yellowing of leaves. Previous studies have shown that treatment with 0.25mM STS mixed with 20% sucrose on‘Acapulco’allows the buds to open naturally and delays leaves yellowing. In this study, the effectiveness of pulsing with 0.25mM STS mixed with 20% sucrose on‘Casa Blanca’is tested. Other types of chemicals were also tested to understand the effects of pulsing on the morphology of Oriental lilies.
When Oriental lilies were pulsed with 0.25mM STS, 0.25mM STS mixed with 20% sucrose, or 0.25mM GA3 mixed with 20% sucrose for 4 hours before cold storage, flower buds opened naturally after removal from storage. Although pulsing with sucrose increased flower diameter and longevity, it caused yellowing of the leaves. GA3 and 1-MCP could delay leaf yellowing but could not improve the quality of the flower; the effects of STS were inconstant.
Ethylene production increased in‘Casablanca’after cold storage and when the leaves began to yellow but could be prevented by pulsing. Among the chemicals tested, GA3 was the most effective. The addition of 20% sucrose to GA3 caused a slight increase in ethylene levels. STS mixed with sucrose was ineffective against ethylene production, and STS displayed unstable effects. Respiration in the buds and leaves seemed to be lower by GA3 or STS but increased when sucrose was added. A higher respiration rate in flower buds causes earlier flowering, but the same occurrence in leaves causes it to senescence faster.
Before storage,‘Casa Blanca’flowers contained high concentrations of soluble sugars and starch and its leaves contained low levels of them. After storage, the sugar content increased and the starch content decreased. When sucrose was added to the pulsing, soluble sugar levels increased, particularly in the fourth flower, which also contained a greatly increased starch content. In terms of the total soluble sugar distribution throughout the plant, the larger amount of soluble sugars was found in the stem and leaves before cold storage. After storage, the content of total soluble sugars greatly increased in the flowers.
Respiration and flowering were effectively inhibited only when‘Casa Blanca’was stored at or below 5℃.A slight decline in respiration at 10℃ and the initial stages of flowering could be observed. When the flowers rewarmed to 25℃, the plants that were stored at 0℃ resumed respiration and flowering rapidly. The cold temperature preventing flowering and cell growth possibly by halted respiration.
Useful information was obtained from this two-year study on the quality of ‘Casa Blanca’cut flowers, but many assumptions could not be thoroughly proven because of the low sampling number. The environment under which cut liles were cultivated before harvesting acutely affects the quality of the flowers. Since flower supply is unknown, it is difficult to determine the cause of a decrease in flower quality.
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