保鮮劑對萬代蘭切花瓶插壽命之影響

Abstract

本研究採用萬代蘭‘巨輪紫’ (Vanda Pachara Delight)為主要試驗材料，探討蔗糖、殺菌劑、免疫反應誘導藥劑、1-methylcyclopropene (1-MCP)、奈米金及奈米銀對切花保鮮之效益。研究方法為調查不同處理下之瓶插壽命、花梗基部褐化程度、最上位花萎凋及瓶插液吸收能力，嘗試改善產業現有萬代蘭切花保鮮之處理方式。本研究另解剖萬代蘭，觀察各部位構造及基部褐化後之花梗構造。 瓶插液單獨添加2%蔗糖或搭配593 µM 8-HQC均可顯著增長萬代蘭切花瓶插壽命8-10日、延後花梗基部褐化6-8日、使最上位花延後7-10日萎凋及延緩瓶插液產生混濁5-10日。 瓶插處理2900 µM水楊酸加2%蔗糖比單獨處理2%蔗糖多延長瓶插壽命7-10日，且能有效提高切花的瓶插液吸收能力；但造成花梗基部於4日內產生褐化。水楊酸處理下褐化花梗木質化次生細胞壁數量較對照組多。故此花梗基部褐化現象應屬藥劑誘導之免疫反應。短時間(12-48小時)處理2900-5800 µM水楊酸即可延長切花3.6-7.2日瓶插壽命、減緩上位花萎凋及增加瓶插液吸收能力。噴施725 µM 水楊酸於萬代蘭花朵，亦可延長瓶插壽命4.6日，且花梗基部不會產生提早褐化之現象。於蔗糖瓶插液中添加同為誘發植物免疫反應藥劑之茶皂素180 µM，其切花瓶插壽命較2900 µM水楊酸處理多2.1日；但切花瓶插前期(花朵萎凋率達40%之前)瓶插品質以水楊酸處理較佳。以2%蔗糖加2900 µM水楊酸為瓶插液處理Vanda Pachara Delight切花，瓶插壽命較200× 可麗鮮(Chrysal Professional 2)處理多3.0日。以2%蔗糖加2900 µM水楊酸處理Vanda Siriporn Pink切花，瓶插壽命較200× 可麗鮮處理多1.9日。以2%蔗糖加2900 µM水楊酸處理Vanda Pachara Delight切花及Vanda Siriporn Pink切花皆能顯著提升瓶插前期之花朵品質。 萬代蘭切花遭遇2 µL·L-1乙烯逆境會造成下位花朵提早萎凋，瓶插壽命較對照組提早5.3日結束。相對於下位花，上位花對乙烯較不敏感。以0.025、0.05或0.2 µL·L-1 1-MCP前處理2小時，可降低萬代蘭切花瓶插前期之花朵萎凋率。萬代蘭切花噴施處理60、180、540、2700 nM奈米金、瓶插處理180 nM奈米金或同時瓶插180 nM奈米金及噴施540 nM奈米金，可分別較對照組延長瓶插壽命3.6、4.6、6.2、5.3、5.1或6.3日。萬代蘭切花噴施80或240 ppm奈米銀，相較於對照組，可延長切花瓶插壽命4.3-5.8或4.0-5.0日。 本研究中，瓶插液單獨添加2%蔗糖可延長萬代蘭瓶插壽命70%，處理成本最低。540 nM奈米金噴施處理可延長瓶插壽命66%；80 ppm 奈米銀噴施處理延長瓶插壽命59%，兩者雖成本較高，但施用方式最簡便。以0.025 µL·L-1 1-MCP前處理2小時，可減少萬代蘭切花遭受乙烯逆境所受之傷害。本研究中，以2%蔗糖+ 2900 µM水楊酸處理效果最佳，相較於對照組，雖會造成花梗基部提早褐化，但具延長切花瓶插壽命85%-127%之能力。

Vanda orchids have become an important crop in Taiwan, which are exported to Japan as cut flowers. In this study, cut flowers were treated with sucrose, antibacterials, immune response-induced chemicals, 1-methylcyclopropene (1-MCP), nano gold, or nano silver. The flowering quality, including vase life, days to spike base browing, days to top flower wilting, and vase solution uptake capacity were investigated. The purposes of this study were to observe senescence phenemenon of cut Vanda and to improve the postharvest handling methods of the cut flowers. This study also observed the structures of different organ parts and various base-browned spikes of Vanda by dissection. Treatment of 2% sucrose or 2% sucrose + 593 µM 8-HQC both extended vase life for 8-10 days, delayed spike base browing for 6-8 days, prolonged top flower life for 7-10 days, slowed vase solution became turbid for 5-10 days, and increased vase solution uptake capacity of Vanda cut flowers. With 2% sucrose + 2900 µM salicylic acid, the vase life of cut flowers was extended for 7-10 days, longer than that of with 2% sucrose alone, vase solution uptake was increased, but it also led to spike base browing within 4 days. Sections of browned spike base showed that there were more lignified secondary walls than control. This browing reaction seems to be a chemical-induced plant immune response. A short-term (12-48 h) treatment of 2900-5800 µM salicylic acid to Vanda cut flower increased vase life, days to top flower wilting, and vase solution uptake. Spraying 725 µM salicylic acid to Vanda cut flowers extended vase life for 4.6 days without spike base browing. Treatment with tea-seed saponins at 180 µM further extended vase life for 2.1 days, compared with that of 2900 µM salicylic acid treatment. But 2900 µM salicylic acid treatment still had better flowering quality in early vase time (flower wilting rate below 40%). Treatment of 2% sucrose + 2900 µM salicylic acid extended vase life for 3 days, compared with that of 200× Chrysal Professional 2 in Vanda Pachara Delight. Applying 2% sucrose + 2900 µM salicylic acid extended vase life for 1.9 days in Vanda Siriporn Pink, longer than that of 200× Chrysal Professional 2. Adding 2% sucrose + 2900 µM salicylic acid in vase significantly increased cut flower quality in the early vase time in both Vanda Pachara Delight and Vanda Siriporn Pink. Flowers at the lower positions of Vanda Pachara Delight were more sensitivie to ethylene than those at the upper positions. Wilting of lower-position flowers was induced by 2 µL·L-1 ethylene, of which vase life were reduceed by 5.3 days. Data showed that pretreated Vanda Pachara Delight with 0.025, 0.05, or 0.2 µL·L-1 1-MCP for 2 hours delayed wilting of flowers at lower positions. Flowers treated with nano gold by spray at concentrations of 60, 180, 540, or 2700 nM, or with 180 nM nano gold in vase, or with 180 nM nano gold in vase and 540 nM nano gold by spray extended vase life for 3.6, 4.6, 6.2, 5.3, 5.1, or 6.3 days, respectively, compared with the controls. Among them, sprayed with 540 nM nano gold had the best result. Flower sprayed with nano silver at concentrations of 80 or 240 ppm extended vase life for 4.3-5.7 or 4.0-5.0 days, respectively. In this study, treated Vanda cut flowers with 2% sucrose in vase extended vase life for 70%; this treatment had the lowest cost. Spraying 540 nM nano gold or 80 ppm nano silver to Vanda cut flowers extended vase life for 66% or 59%, respectively. Although the costs of nano particles are higher, they are easier to apply. Fumigated with 0.025 µL·L-1 1-MCP for 2 h was effective in inhibiting ethylene-induced wilting in Vanda cut flowers. The most effective treatment in this research was 2% sucrose + 2900 µM salicylic acid in vase. Altough it caused earlier spike base browing, it extended the vase life of Vanda cut flowers by 85%-127%, compare with the controls.