Varietal Differences in Fruit Production and Flesh Browning of Luffa cylindrica Roem.

• Main Authors: Chia-Chen Wu, 吳佳真
• Other Authors: 曹幸之
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/79468846095545449376

碩士 === 國立臺灣大學 === 園藝學研究所 === 92 === 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.