A New High-Yielding Red Leaf Lettuce, “Jeokdan”

A new high yield and storability lettuce (Lactuca sativa L.) cultivar Jeokdan was developed from a cross NAAES DL 114 (late bolting and high yield) and NAAES DL 108 (late bolting and disease resistance) in 1997. We selected desired characteristics in advanced lines generated by pedigree method until 2003. Especially, we advanced the second generation in 2002 and 2003 year, and we fixed good lines. These lines were evaluated for yield and stability in 7 areas (Gangwon, Kyunggi, Chungbuk, Kyungnam, Jeonnam, Jeonbuk, Jeju) for 2 years in Korea. The “Jeokdan” has gray seed color and transverse elliptic leaves. The Jeoksagye has gray seed color and transverse elliptic leaves. Compared to Ttugseom-jeokchugmyeon marketable yield of Jeokdan was heavier as a 462 g per plant, and also can be stored 3 weeks more at 4℃. The taste of Jeokdan is sweet and contains less amount of total bitter sesquiterpene lactones (BSL) of 63.8μg/g than the check variety of 109.8 μg/g dry weight.