Chilling Injury Symptoms and Ethylene Synthesis of Wax Apple Fruits

Abstract

The objectives of this study were to investigate the physical changes of wax apple fruits, symptoms of chilling injury and induced ethylene synthetic rate after exposing to low temperature. Result indicated chilling injury occurred when wax apple were stored below 10 ℃. Visible symptoms of chilling injury included surface pitting, color-fading, water soaking of pulp, mold infection and decay of fruit. The respiration and ethylene production rates of wax apple fruit stored below 5 ℃ were very low but rose and fell abruptly again after transferring to an environment of 25 ℃. Ethylene production reached a peak and maintained the highest value for 8 hrs at 25 ℃. The large amount of ethylene produced under the chilling condition was a result of stress which led to the biosynthesis of ACC synthase and EFE after fruits were transferred to room temperature (25℃).本試驗調查蓮霧果實採收後低溫逆境所引起寒害，造成果實外觀的變化及誘發乙烯生合成。結果顯示，蓮霧果實貯藏在低於10℃以下的溫度即會發生寒害，其寒害徵狀首先在果實表面形成許多凹陷小病斑、果皮顏色變淡、果肉呈水浸狀、嚴重者果實發霉腐爛。於5℃下貯藏，其呼吸率及乙烯釋放率都非常低，但隨果實移至室溫(25℃)時間的延長，二者皆上升，之後再下降。於回溫8小時，乙烯釋放率達到高峰；而呼吸率則無明顯呼吸高峰產生。寒害果實在回溫後所產生的大量乙烯屬於逆境。乙烯大量產生是因低溫誘發果實在回溫後ACC synthase及EFE，而促進ACC合成，進而使乙烯大量生成