| Summary: | 碩士 === 國立臺灣大學 === 園藝暨景觀學系 === 103 === Endive (Cichorium endivia L.) has high nutritional value. It contains sesquiterpene lactones incliding lactucin, 8-deoxylactucin, and lactucopicrin. Endive has been widely cultivated in Western Europe, but is not common in Taiwan. Under long day, endive switches to reproductive growth with reduced yield. The quality also differs in different seasons. This research aimed on the suitable environmental conditions for producing safe endive with good quality all year round using ‘Green Curled Ruffec’ as materials. Day/night temperatures 25℃/25℃ and electrical conductivity 1.2 dS˙m-1 in Yamazaki nutrient solution for lettuce were suitable for hydroponically grown endive ‘Green Curled Ruffec’ seedlings. After transplanting, the yield of endive grown under 23℃/20℃ and photoperiod 16 hr/8 hr was the highest. Because of the shorter cultivation period in this experiment, endive maintained vegetative growth without bolting caused by long day. The content of sesquiterpene lactones was higher at 20℃/17℃, but there was no difference among photoperiod treatments. Endive showed high fresh weight and low nitrate content in modified Yamazaki nutrient solution for lettuce with phosphorous 32 mg˙L-1, sulfur 32 mg˙L-1, magnesium 24 mg˙L-1, nitrogen 135 mg˙L-1, nitrogen-form ratio 25:75, or electrical conductivity 1.2 dS˙m-1, respectively. The contents of sesquiterpene lactones in endive were increased in modified Yamazaki nutrient solution for lettuce with phosphorous 8 mg˙L-1, sulfur 32 mg˙L-1 or magnesium 24 mg˙L-1, respectively. Among 4 seasons, spring was suitable for endive growth of 28 days in the Plastic/screen house in Taipei. The contents of free 8-deoxylactucin and total sesquiterpene lactones were increased if the cultivation extended to 56 days in spring. Endive grown in summer switched to reproductive growth, and the contents of free 8-deoxylactucin and total sesquiterpene lactones were also increased. The content of total sesquiterpene lactones was affected by free lactucopicrin in vegetative-growing endive.
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