Breeding of New type Red Butterhead Lettuce ‘Sunny Red Butter’

A new lettuce (Lactuca sativa L.) variety ‘Sunny Red Butter’ that belongs to butter-head type has transverse broad elliptical leaf with red color. Crossbreeding of ‘Oriana’ and ‘Cardinale’ was made to obtain seeds of the F1 generation. Subsequent generations were selected using in pedigree methods until 2011, resulting in ‘Sunny Red Butter’. The new variety ‘Sunny Red Butter’ is brown in seeds and the upper part of the leaf is light red and glossy. The leaf stalk is white. It can be harvested from 30 days after planting. The average harvested leaf number is 51 leaves per plant. The average weight is 556.5g per plant, which is 44% higher than a control lettuce variety ‘Germania’. It showed that 30.9 tons/ha production was made in spring, summer, and autumn cultivations for 3 years in 6 areas (Daegwanryeong, Gyeonggi, Chungbuk, Jeonbuk, Gyeongnam, and Jeju) than the control variety ‘Germania’. The shelf-life of ‘Sunny Red Butter’ was 4 weeks for storage at 4°C. Anthocyanin amount (10.3 mg/100g) of ‘Sunny Red Butter’ was lower than that of ‘Germania’. BSL (latucin+8-deoxylactucin+lactucopicrin) amount of ‘Sunny Red Butter’, the bitter ingredients was 26.1 μg/g and higher than BSL amount of ‘Germania’. Leaf hardness of ‘Sunny Red Butter’ was 1,554 kg/cm 2 , which was thicker than ‘Germania’. ‘Sunny Red Butter’ showed better taste (more crispy and sweeter) than ‘Germania’. The new variety ‘Sunny Red Butter’ can be used as lettuce productions during spring and autumn in most area and in summer in highland of Korea.