不同發育階段番木瓜果實採後呼吸及乙烯產生行為之探討

Postharvest Behavior of Respiration and Ethylene Production of Papaya Fruits (Carica papaya L.) Harvested at Different Developmental Stages

為瞭解番木瓜‘台農二號’、‘日陞’及種苗改良繁殖場屏東種苗研究中心新育成之‘種苗七號’全兩性品系之果實，在個體發育（ontogeny）過程之呼吸及乙烯產生行為，乃於人工授粉後30、60、90、105、120及130天，分別採收果實於20℃進行呼吸率及乙烯產生率之連續測定。同時測定不同採收成熟度‘台農二號’番木瓜果實在不同貯藏溫度（5℃、10℃、15℃、20℃及25℃）之呼吸率及乙烯產生率之連續變化。結果顯示，番木瓜果實，不論是‘台農二號’、‘日陞’或全兩性之‘種苗七號’品系，在果實個體發育之不同階段，果實採收後在20℃均會出現呼吸更年性特性，且乙烯產生亦呈相同的趨勢。但果實採收後至更年峰出現之時間，在不同果齡之果實並不相同，三個品種均以果齡90天之果實，採收後到出現更年峰之時間最長（約14-16天），果齡較90天低或高，其更年峰出現之時間均較果齡90天之果實短，且果齡較90天愈低或愈高之果實，在更年峰之呼吸率及乙烯產生率，均有愈高之趨勢。而番木瓜乙烯更年峰出現之時間較呼吸更年峰晚1-2天之趨勢。至於果實生長發育過程，果腔內乙烯及CO2之含量變化，在本研究之供試三品種（‘台農二號’、‘日陞’及‘種苗七號’），在授粉後30-105天之果實果腔內氣體，均測不到CO2和乙烯濃度，一直到授粉後120天時，才明顯測到果腔中之CO2和乙烯氣體成分，內生乙烯濃度均在0.1ppm以下，而在授粉後130-135天，果腔內之CO2及乙烯濃度達到最高，果實成熟度再提高，CO2及乙烯濃度反而下降。而果腔CO2及乙烯可偵測到之時間（授粉後120天）與果皮顏色急速轉變（由綠開始轉黃）之時間相吻合。不同採收成熟度之‘台農二號’番木瓜果實，在不同貯藏溫度（5℃、10℃、15℃、20℃、25℃）下，均呈典型更年性水果，且溫度愈高呼吸率愈高，且呼吸更年上升之時間愈早，乙烯產生率亦呈類似趨勢。果實成熟度愈高，其呼吸及乙烯更年峰出現之時間愈早，且在更年峰時之呼吸率及乙烯產生率，亦有成熟度愈高，其產生率愈高之趨勢。 A series of studies were conducted to elucidate the postharvest behavior of respiration and ethylene production of papaya fruits (Carica papaya L.) during growth and development. Fruits of three cultivars named｀Tanung No. 2＇, ｀Sunrise＇and｀TSS No.7＇(a newly selected line of hermaphrodite papaya), were harvested at 30, 60, 90, 105, 120 and 130 days after hand pollination for measuring respiration rate and ethylene production at 20℃. Results showed that papaya fruits of three cultivars harvested at different developmental stages of ontogeny, all exhibited respiratory climacteric pattern and ethylene production also showed similar trend. However, the period to climacteric peak after harvest differed among different ages of fruits. The longest pre-climacteric period (about 14-16 days) was observed in fruits harvested at 90 days. While fruits harvested earlier or later showed shortened pre-climacteric period. The peak rate of respiratory and ethylene production increased as fruits harvedted earlier or later than 90 days. The peak of ethylene production occurred about 1-2 days after the respiratory climacteric. The concentration of CO2 and ethylene in fruit cavities of three papaya cultivars were not detectable before 105 days after pollination. CO2 and ethylene were clearly detected only until 120 days after pollination with internal ethylene concentration below 0.1ppm. The peak of internal CO2 and ethylene were found at 130-135 days after pollination and then declined with fruits more mature. The time of CO2 and ethylene emanation coincided with the rapid peel color breakage from green to yellowing. In different storage temperatures (5-25℃), fruits of｀Tainung NO.2＇at different maturities exhibited typical climacteric pattern. The higher storage temperature the higher respiration rate. The time for climacteric rise of respiration and ethylene production were also shorter. In addition, the higher maturity of the fruits, the time for the peak of respiratory climacteric and ethylene production were earlier, and the rate at peak were higher with more mature fruits.