化學藥劑處理改善擎天鳳梨盆花貯後品質之效果

Effects of Chemical Treatments on Poststorage Quality of Potted Guzmania (Guzmania lingulata Mez. 'Cherry')

擎天鳳梨（Guzmania lingulata Mez. 'Cherry'）盆花於貯運後經常發生葉片內捲、黃化壞疽與苞片褪色，嚴重影響品質。本研究探討化學藥劑噴施處理對15℃模擬黑暗貯運10天後之擎天鳳梨'Cherry'葉片與苞片品質與生理之影響，期能改善貯後品質。結果顯示貯運後葉片內捲與壞疽症狀多僅出現於下半部。噴施去離子水、蒸散抑制劑1%協養旺-207或3%蔗糖使貯運後葉片內捲與壞疽增加，且下位葉之光系統II（photosystem II, PS II）最大光化學利用效率Fv／Fm值降低。噴施20至100μM benzyladenine（BA）或100至500μM激勃素（gibberellic acid, GA3）皆能減少葉片內捲與壞疽。於貯運後14天，BA處理組之下位葉Fv／Fm值較GA3處理組高。BA處理可維持較佳的貯後苞片顏色；而GA3處理使貯後之苞片亮度和彩度下降、色相角度上升，苞片顏色黯淡、褪色並轉橙。建議擎天鳳梨盆花於貯運前以60μM BA噴施全株，可減少貯後之葉片內捲與壞疽數並維持苞片顏色，貯後品質較佳。 Potted Guzmanias often exhibit incurved and/or necrotic leaves, and faded color bracts after extended periods of dark shipment. This study determined the effects of prestorage spray of various chemicals on the leaf and bract quality and the physiology of Guzmania lingulata Mez. 'Cherry' after dark storage at 15℃ for 10 days. We found that incurved and necrotic symptoms appeared only in lower leaves. The number of incurved and/or necrotic leaves increased, and poststorage Fv/Fm value of lower leaves declined in plants sprayed with deionized water (control), 1% Abion antitranspirant, or 3% sucrose. Plants either sprayed with 20 to 100μM BA or with 100 to 500μM GA3 had fewer incurved and/or necrotic leaves than the control. Furthermore, BA-treated plants had fewer incurved and necrotic leaves, and higher leaf Fv/Fm values than GA3-treated plants observed 14 days after dark storge. Plants treated with BA retained normal bract color, while those treated with GA3 reduced bract lightness and chroma. The result indicated that prestorage spray with 60μM BA could significantly improve the post-storage quality or post-shipment quality of Guzmanias.