A new lettuce (Lactuca sativa L.) with elliptic and dark green leaves, ‘Sambokhacheong’, which is tolerant to tipburn with good yield, was developed from a cross between ‘Meokchima’ (dark red leaves) and ‘Yeoreumcheongchima’ (high yield, green leaves). The crossing and selection for advanced lines was conducted by the pedigree method in 2006-2012. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon-do, Gyeonggi-do, Chungcheongbuk-do, Chungcheongnam-do, Jeollabuk-do, Gyeongnam-do, and Jeju-do) over three years starting from 2015. The evaluations revealed that this lettuce was early- and medium-maturing leaf lettuce, with a shelf-life of four weeks at 4 ℃, longer than that of ‘Yeoreumcheongchima’. ‘Sambokhacheong’ showed no symptoms of tipburn during hot seasons in the southern parts of South Korea compared ‘Yeoreumcheongchima’. The content of bitter sesquiterpene lactones (latucin, latucin+8-deoxylactucin+lactucopicrin) of ‘Sambokhacheong’ at 57.16 (μg/g, dry weight) was higher than that of ‘Yeoreumcheongchima’. Compared with ‘Yeoreumcheongchima’, the marketable yield of ‘Sambokhacheong’ was 2% higher (at 551 g per plant) and showed late bolting at 111 days after sowing in the summer cultivation season. Its leaves are better, crispier, and sweeter than those of ‘Yeoreumcheongchima’. Therefore, we recommend the new cultivar ‘Sambokhacheong’ for cultivation in hot seasons (Registration No. 6915).

Nowadays most parts of vegetable breeding in Korea have been conducted by private seed companies. However, in the beginning stages of breeding research, Horticulture Experiment Station played a crucial role. Major vegetable varieties that are distributed from Korea are produced as F₁ hybrids. Korea has developed leading techniques and human infrastructure for vegetable breeding. Such brilliant developments have resulted from three major factors: changes in the composition of varieties, the establishment of year-round vegetable production, and the development of the seed export market. First, an F₁ hybrid system increased seed performance more than traditional open pollinated (OP) varieties with respect to productivity, uniformity and disease resistance. Moreover, an F₁ hybrid system required repetitive seed production and provision, which increased the economic growth of seed companies. Second, vegetables tend to be consumed fresh instead of dried or processed. Finally, vegetable seed exports have continuously increased with the aid of R&D projects such as the Golden Seed Project (GSP). Therefore, for further progress of the vegetable industry, new varieties that can meet consumers’ demands, as well as the stable provision of fresh vegetables, are required. Contrary to the past, the future focus must be concerned with productivity and cultivation stability, the development of high value, functional, eco-friendly vegetables, and high quality vegetables. To cope with this, every breeding subject, including industry, universities, and institutes, have to collaborate with the aim of advancing vegetable breeding in Korea.