A new cultivar 'Hisui no Kaori' opens up a fragrant type of lettuce (Lactuca sativa L.).

Abstract

'Hisui no Kaori' is the first lettuce (Lactuca sativa L.) cultivar characterized by a sweet fragrance, attributed to 2-acetyl-1-pyrroline with the same compound as in fragrant rice and soybean cultivars, as well as edible leaves and stem. Field cultivation trials established optimal planting distances at 30 cm between seedlings, with a fertilizer requirement of N = 150 kg/ha. 'Hisui no Kaori' exhibited minimal stem burst as well as resistance to soft rot disease, proving easier to cultivate compared with prominent stem-type cultivars. Field cultivation tests at different altitudes and incubator tests revealed that an air temperature exceeding 20°C is pivotal for the development of the sweet fragrance. 'Hisui no Kaori' displayed moderately resistance to Fusarium wilt race 1 and highly resistance to race 2. In lettuce, discoloration is known to occur at the cut surface due to mechanical wounding. In a cut leaf test, 'Hisui no Kaori' was classified as having delayed discoloration. Overall, 'Hisui no Kaori' is expected to contribute to the expanding potential and the increasing market price of lettuce. This work represents a pioneering effort to open up the fragrant type of lettuce.