番荔枝果實IAA類似物質之研究

Studies on the IAA-like Substance of Sugar Apple Fruits

番荔枝為具有更年性之果實，然乙烯之發生量甚低。因以IAA（indole-3-aceticacid）可促進果實軟化等後熟現象，故本試驗探討IAA與果實後熟生理之相關性。果實於20°C貯藏時，IAA類似物質（lAA-like substance）含量變化均與乙烯發生量變化呈平行，IAA類似物質於第4天，乙烯發生於第5天達一高峰，此時值果實後熟軟化之時期。果實於室溫（25°±2°C），20°C及16°C貯藏，發現室溫與20°C貯藏者在貯藏期間有IAA類似物質含量之高峰出現，然16°C者則沒有明顯高峰。以色氨酸（tryptophan; IAA生合成之前驅物）處理果實，並未能促使IAA類似物質含量增加，但其呼吸量（CO2放出量）均增加。CHI（cycloheximide）處理之果實IAA類似物質生成較少。但至貯藏後期其含量並未降低，顯示其分解較慢。

Sugar apple (Annona squamosa L.) is reported as a climacteric fruit, while the amount of ethylene evolutiong during ripening is quite low. An indoleacetic acid (IAA) treatment to the fruit induces some ripening behaviors such as, flesh softening that lead us to research its concerning on ripening. Changes in IAA - like substance content parallelled well with that of ethylene evolution. And both of them reached a peak at 4 or 5 days after harvesting respectively that coincided with the stage of fruit ripening. The IAA-like substance content had a peak during storage at ambient temperature (25° ±2°C) or 20°C, while no maximum appeared when stored at 16°C. A tryptophan (precusor of IAA) treatment did not induce the increases of IAA - like substance content, but enhanced the carbon dioxide production. It seemed that the administered tryptophan disintegrated .into carbon dioxide. Cycloheximide (CHI) seemed inhibited enzymes for IAA biosynthesis and also the IAA- oxidase.