| 摘要： 本研究之目的為比較更年性與非更年性番石榴果實發育期間果實性狀與糖類代謝之差異。調查結果顯示所有分析的番石榴品種果實生長過程中累積的糖類均以蔗糖和果糖的累積量較高，而葡萄糖累積量較低。糖類代謝相關酵素活性於果實發育後期蔗糖含量增加時，蔗糖合成&;#37238;(sucrose synthase)及蔗糖磷酸合成&;#37238;(sucrose phosphate synthase)活性也上升。果糖及葡萄糖的累積量在果實發育後期增加較快速，而中性轉化&;#37238;(neutral invertase)的活性也有增加的趨勢，但酸性轉化&;#37238;(acid invertase)的活性則沒有顯著的差異。因此，蔗糖合成&;#37238;與蔗糖磷酸合成&;#37238;應該是番石榴果實發育後期蔗糖累積之關鍵酵素，而中性轉化&;#37238;則可能與單糖的累積有關。 以益收(ethephon)處理成熟期番石榴果實，結果顯示益收處理使果實可滴定酸和硬度下降，並使果皮顏色由暗綠色轉變成黃綠色或白綠色。果重與可溶性固形物則不受益收處理影響。更年性品種(&;apos;&;apos;黃拔&;apos;&;apos;與&;apos;&;apos;巴基斯坦&;apos;&;apos;)皆可觀察到益收處理之果實蔗糖含量較高，但非更年性品種(&;apos;&;apos;珍珠拔&;apos;&;apos;與&;apos;&;apos;世紀拔&;apos;&;apos;)之蔗糖含量則沒有顯著差異。然而非更年性品種益收處理之果實其單糖含量有較高之趨勢，顯示更年性果實與非更年性果實於後熟期間糖類代謝機制可能有所不同。 以RAPD (Random Amplified Polymorphism DNA)分子標誌分析番石榴更年性品種&;apos;&;apos;黃拔&;apos;&;apos;、&;apos;&;apos;巴基斯坦&;apos;&;apos;及&;apos;&;apos;梨拔&;apos;&;apos;與非更年性品種&;apos;&;apos;珍珠拔&;apos;&;apos;、&;apos;&;apos;水晶拔&;apos;&;apos;及&;apos;&;apos;世紀拔&;apos;&;apos;，其相似度樹狀圖顯示非更年性品種可分在同一群內，其中&;apos;&;apos;珍珠拔&;apos;&;apos;和&;apos;&;apos;水晶拔&;apos;&;apos;的相似度最高達0.90。另外，以OPN-15、OPR-11、OPW-7和OPU-1等4支引子均於更年性品種出現一條明顯的特異條帶，這些條帶將可用於分析上述品種之雜交後代。The objective of this study was to compare differences in fruit characteristics and sugar metabolism during development between climacteric and non-climacteric guavas. Results indicated that all the guava cultivars analyzed had higher sucrose and fructose contents than glucose. Determination of activities of sugar metabolism related enzymes during fruit growth and development showed that with the raising of sucrose content, sucrose synthase and sucrose phosphate synthase activities also increased. The cumulative amount of fructose and glucose increased more rapidly during the late stage of fruit maturation and the neutral invertase activity also increased. However, the acid invertase activity showed non-significant difference. As a result, the sucrose synthase and sucrose phosphate synthase should be the key enzymes for sucrose accumulation in guava fruits during development, while neutral invertase may be related to the accumulation of hexoses. With the treatment of ethephon, it resulted in the decrease in titratable acid and firmness of guava fruits and also turned the skin of fruit from dark green to yellow-green or white-green. However, fruit weights and total soluble solids were not affected by the ethephon treatment. The ethephon treatment on climacteric guava fruits, ''Huang Bar'' and ''Pakistani'', caused an increase in sucrose content, while on non-climacteric guava fruits, ''Jen-Ju Bar'' and ''Shy-Jii Bar'', the sucrose content had no significant difference. In addition, the hexose contents in non-climacteric guava fruits were increased by the ethephon treatment, which indicated that sugar metabolism mechanism may be different between climacteric and non-climacteric guava fruits during ripening stage. After analyzing the climacteric guava cultivars, ''Huang Bar'', ''Pakistani'', ''Li Bar'', and non-climacteric cultivars, ''Jen-Ju Bar'', ''Shui-Jing Bar'', ''Shy-Jii Bar'', by RAPD (Random Amplified Polymorphism DNA), the dendrogram showed that non-climacteric cultivars was in the same cluster and ''Jen-Ju Bar'' and ''Shy-Jii Bar'' had the highest similarity of 0.90. In addition, OPN-15, OPR-11, OPW-7 and OPU-1 all generated a polymorphic band in climacteric cultivars, which was not found in non-climacteric cultivars. Those bands could be used to analyze the hybrid progenies from crosses between the alove cultivars. |
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