- 學位論文
圓筒絲瓜結果特性及果肉褐化之品種差異
Varietal Differences in Fruit Production and Flesh Browning of Luffa cylindrica Roem.
摘要
利用人工氣候室及移動植物到不同夜溫的方式，探討五種日夜溫度處理(35/30℃、35/25℃、30/25℃、30/20℃、25/20℃)對短日結果型’七美’絲瓜花性表現的影響。夏作(2002,7 ~ 2002,11)結果顯示，溫度25/20℃處理的植株最早出現花芽，雄花芽在處理後(即定植於人候室後)57天發生於蔓上(單蔓)第39節，可見雌花芽在處理後88天，蔓上第66節發生。兩個花性出現時間相差31天，21節位; 35/30℃處理只有雄花芽發生，沒有雌花芽發生; 而35/25℃處理之雄花芽發生於定植後71天，第88節，雌花芽發生於定植後115天，第138節，兩種花性相距44天， 50節位。春作(2003,4 ~ 2003,6)也以25/20℃處理最早發生花芽，雄花芽約在處理後70天，蔓上第45節發生，雌花著生約在82天，第58節。兩種花性相距12天，13節位，其餘4組處理均無雌花著生，雄花僅發生於30/25℃、25/20℃處理，顯示夏作日長低於12 ~12.5小時下，日均溫(average daily temperature, ADT )22.5 ~ 27.5℃’七美’能開雌花，低溫25/20 ℃提早其雄雌花的分化及發育。春作日長在12.5小時以上，只有25/20℃處理有雌花形成，其他較高溫處理及日夜溫差10℃(30/20 ℃)不能改善對日長的敏感，即抑制雌花的問題。由田間四絲瓜品種夏作及春作試驗結果，春作雌花發生於定植後106 ~ 126天，比夏作處理之24 ~31天分化晚，顯示對長日亦屬敏感類型。 比較四個絲瓜品種’阿順’、’鳥寮’、’大陸八號’與’銀光’果實切塊置於室溫0、1、3小時後，果皮及果肉總酚含量與褐化速率之關係。果皮總酚含量比果肉高；四個品種秋作之果肉總酚含量在0 ~ 1小時會隨著時間增加，’鳥寮’果肉酚含量最高，為266.6µg/g，’阿順’、’銀光’依次為138.4µg/g及162.9µg/g， 1小時後，以’鳥寮’增加酚含量幅度最大，增為748.6µg/g，高於其他三個品種。在3小時後，仍以’鳥寮’的總酚含量最高，果肉變成暗褐色(L值46.6)，果肉酚含量達618.7µg/g，’大陸八號’與’阿順’的酚含量隨暴露時間增長而少量增加; ’鳥寮’和’銀光’的酚量在果實切開後1小時快速增加，1至3小時期間酚量則減少，切開3小時’銀光’總酚含量365.7µg/g，果肉變淡褐色(L值62.7) 。’阿順’與’大陸八號’總酚增加不多，分別增為223.4µg/g及216.2µg/g色澤維持白亮(L值80)，果肉褐化與總酚含量相關性高(r=0.8897)(剛切開)；夏作四品種只’鳥寮’果肉總酚含量在0 ~ 3小時會隨著時間增加而增加，最高為393.0µg/g，果肉為淡褐色(L值51.5)，其他三個品種則增加量不大，約44.3µg/g ~ 103.6µg/g，果肉維持白色，果肉色澤與總酚含量的相關性不顯著(r=0.791)。各絲瓜品種在兩個期作表現褐化的程度不同。擴大利用農試所提供之夏作16品系及秋作21品系之絲瓜果實進行果肉總酚含量與L值之測定，夏作果肉酚含量介於138 ~ 267µg/g，秋作果肉酚含量介於121µg/g ~ 262µg/g，兩期作果肉酚含量與果肉亮度L值均有顯著相關性(r=0.766與r=0.731)，再利用秋作21品系測定果肉均質後、離心後及煮後色澤與褐化的關係。均質法及離心法可快速檢測絲瓜褐化與否。
關鍵字
褐化並列摘要
To study the temperature effect on sex expression and flowering of loofah (Luffa cylindrica Roem.), a long day sensitive cv ‘Seven Beauty’, was grown in a phytotron with five day/night temperature (35/30℃、35/25℃、30/25℃、30/20℃、25/20℃)treatments. The 35/25℃ and 30/20℃ treatments were achieved by moving the plants on a trolley twice a day to respective rooms which were designed with only a 5℃ day and night difference. In the fall crop(2002,7 ~ 2002,11) 25/20℃ treatment had the earliest flower, the first staminate flower bud developed on 39th node, 57 days after transplanting, and the first pistillate flower bud developed on 88 days, 66th node of the vine. The temporal difference between this two sex expression was 31days and 21 nodes. The 35/30℃ treatment only had staminate flower bud , but no pistillate flower bud. The staminate flower bud in 35/25℃ treatment developed on 71 days after transplanting, on 88th node of the vine. The temporal and location difference between this two sex expression was 44 days, 50 nodes. In spring(2003,4 ~ 2003,6) the 25/20℃ treatment also had the earliest flower, the staminate flower developed on 70 days after transplanting, 45th node and the pistillate flower developed on 82 days, 58th node on the vine. The temporal difference between this two sex expression was 12 days and 13 nodes. The staminate flowers developed only with 30/25℃and 25/20℃ treatments. It showed that ‘Seven Beauty’ developed pistillate flower when the daylength not exceeding 12 to 12.5 hr and the average daily temperature was between 22.5 to 27.5℃. Lower temperature (25/20℃) treatment could enhance the differentiation and development of staminate and pistillate flower. In the spring crop, with daylength exceeding 12.5 hr, only 25/20℃ treatment plant had pistillate flower ; and higher temperatures with 10℃ day/night difference (30/20℃) could not ameliorate the suppression of pistillate flower. The results from both fall and spring crops of four varieties grown on the experimental farm showed that the female bud developed on 106 ~126 days after transplanting in spring crop, while the pistillate bud developed on 24 to 31 days after transplanting in fall crop. All four varieties showed sensitivity to day length. To study the relationship between fruit phenolics content and fruit browning, four loofah cvs. ‘A-Shun’、‘Bird-Hut’、‘Continental No.8’ and ‘Silver Light’ were tested. Fruits were cut , separated into rind and flesh, and were exposed to the air for 0、1、3 hr. Rind browning was attributed more to wounding rather than the total phenolics content. In the fall crop, ‘Bird-Hut’ had the highest phenolics content, 266.6µg/g and the flesh turned dark brown, The total fruit phenolics contents of ‘A-Shun’ and ‘Silver Light’ were 138.4µg/g and 162.9µg/g, respectively. Within 1hr of cut, ‘Bird-Hut’ had the most rapid increase in phenolics content, reaching 748.6µg/g, much higher than three other varieties. At 3 hrs of cut, ‘Bird-Hut’ still had the highest phenolics content of 618.7µg/g and the fruit remained dark brown(L value=46.6). While ‘Silver Light’ had phenolics content of 365.7µg/g, and the fruit flesh was light brown(L value=62.7). Cultivars ‘A-Shun’ and ‘Continental No.8’ increased only a little in phenolics content to 223.4µg/g and 216.2µg/g, respectively and the fruit flesh remained white(L value=80). The total phenolics content of fruit had a higher correlation with fruit flesh browning(r=0.8897)( at cut). In spring crop, only phenolics content of cv. ‘Bird-Hut’ increased with time from 0-3 hr, to the highest of 393.2µg/g and turned light brown(L value=51.5). The other three varieties increased a little in phenolics content of 44.3µg/g ~103.6µg/g. The total phenolics content of fruit had no significant correlation with fruit flesh browning(r=0.791). Different varieties showed different degree of browning in different seasons. Varietal difference in fruit browning was further tested to TARI breeding lines, (16 in spring crop and 21 in fall crop). The phenolics contents ranged from 138µg/g ~267µg/g in fall crop and 121µg/g ~262µg/g in spring crop . The total phenolics content of fruit in both spring and fall crop showed significant correlation with fruit flesh browning(r=0.766 and r=0.731, respectively). Furthermore, the fruit browning of 21 loofah lines after boiling was correlated with the color of suspension after homogenizing、centrifuge. Fruit homogenizing and centrifuging could serve as a quick test for fruit browning.