蘿蔓萵苣為歐美國家主要沙拉食材，亦為臺灣重要生食、烹煮兼用及供應外銷用蔬菜。雖然現有品種於春季及秋季之溫暖環境栽培具有低頂燒症發生率優點，但不耐貯藏為主要缺失。為克服本問題，本研究策略為引入長葉型(Cos-type) 及迷你型(Gem-type) 二種蘿蔓萵苣商業品種進行比較，以篩選具耐熱性及耐貯性品種。結果顯示在長葉型蘿蔓以‘EX3308’ 具最高株重，其次為‘LE4712’ 及‘TC101’，最低為‘TC103’，且無頂燒症發生；耐貯性由高至低依序為‘LE4712’、‘TC103’、‘TC101’、‘EX3308’。迷你型蘿蔓評估結果以‘長生62 號’ 具最高株重，其次為‘長生61 號’ 及‘長生60 號’，最低為‘長生65 號’，且無頂燒症發生：耐貯性由高至低依序為‘長生62 號’、‘長生61 號’、‘長生65 號’、‘長生60 號’。本引種試驗顯示長葉型蘿蔓以‘LE4712’、迷你型蘿蔓以‘長生62 號’ 為兼具耐熱及耐貯性之候選品種。現有技術： 現行品種於溫暖環境栽培雖具低頂燒率優點，但不耐貯藏，主要問題為採收後於低溫貯藏期間易出現葉脈紅化及鏽斑等生理障害，故需引入新品種，篩選優良品種以供產業應用。創新內容： 藉由引種於晚春溫暖環境栽培，採收後經貯藏二個月進行評估，評選出長葉型蘿蔓‘LE4712’ 及迷你型蘿蔓‘長生62 號’ 二品種，兼具耐熱及耐貯性。對產業影響： 若萵苣生產團體採用本項引種試驗所評選出兼具耐熱及耐貯性品種，應有機會促進產品銷售至更遠國外市場及提升產業國際競爭力。

Romaine lettuce is a vegetable eaten raw as salad and sandwiches in western countries. However it is both eaten raw and cooked in Taiwan, and becoming an important export crop. The current cultivars can be grown during the warm climate of spring and autumn with low rates of tipburn but short storage life. To overcome this problem, new cultivars of Cos-type and Gem-type in romaine were selected in trials based on heat tolerance and storage life. The results of the Costype romaine trials showed that ‘EX-3308’ has the highest weight followed by ‘LE4712’, ‘TC101’, and then ‘TC103’ with no tip-burn. In addition, the storage life results showed that ‘LE4712’ has the highest storability followed by ‘TC103’, ‘TC101’, and then ‘EX3308’. In the Gem-type romaine trials, ‘Acegreen 62’ has the highest weight followed by ‘Acegreen 61’ and ‘Acegreen 60’, and then ‘Acegreen 65’. In addition, the storage life results showed that ‘Acegreen 62’ has highest storability followed by ‘Acegreen 61’, ‘Acegreen 65’, and then ‘Acegreen 60’. This research has shown that the ‘LE4712’ is a good candidate for cultivating Cos-type romaine and ‘Acegreen 62’ for Gem-type romaine due to their heat tolerance and storage life. What is already known on this subject? The current cultivars have low tipburn rates when they are cultivated in a warm environment, but with a short storage life. The main problem that they are prone to are leaf vein redness and brown spots during low temperature storage after harvest. It is necessary to screen out excellent cultivars for economic production. What are the new findings? After variety trials in late spring and low temperature storage for two months, ‘LE4712’ was determined to be a good candidate for Cos-type romaine and ‘Acegreen 62’ for Gem-type romaine due to their heat tolerance and storage life. What is the expected impact on this field? If the industry adopts these two cultivars, the lettuce can be exported to farther markets and improve its international competitiveness.