Multi-dimensional metabolomic analysis of aroma and bitterness reshaping driven by hybridization between lettuce and...

Loose-leaf lettuce and Youmaicai (a Chinese leaf lettuce) each have unique aromas and tastes, and hybridization between the two is an effective method for creating new materials. This study explores the effects of hybridization on appearance, taste, and metabolomic characteristics by comparing red loose-leaf lettuce (RL) and green Youmaicai (GL) along with their F₁ hybrid (H). The H exhibits significant hybrid vigor in agronomic traits such as plant height and fresh weight, as well as in certain metabolites, with its color lying between those of the two parental types. Remodeling key aroma components enriches the H's "green-fruity" flavor characteristics. High flavonoid levels in RL directly account for its red color. RL is crunchy and sweet, while GL exhibits bitterness. The balance of lactucin and lactucopicrin optimizes the bitter profile of H, resulting in a richer taste experience. This study provides theoretical support for achieving high-quality lettuce breeding in the future.