Introduction of Floral Scent Traits into Asiatic Hybrid Lilies (Unscented) by Crossbreeding with <i>Lilium cernuum</i> (Scented)

Abstract

Although a strong floral scent is typical of hybrid lilies, Asiatic hybrid lilies (Lilium spp.) have only a weak scent. Therefore, developing new cultivars with pleasant floral scents is an important objective in Asiatic hybrid lily breeding programs. Among the wild species contributing to Asiatic hybrid lily establishment, L. cernuum has a characteristic scent that the nose can perceive. We crossed Asiatic hybrid lily cultivars twice with L. cernuum to introduce floral scent traits into Asiatic hybrid lilies, and scent emission in the F1 plants and their progeny lines was evaluated instrumentally. Flowers of L. cernuum emitted benzenoids/phenylpropanoids (mainly 2-phenylethanol and benzaldehyde), monoterpenes (predominantly linalool and linalool oxides), and a fatty acid (iso-valeric acid). Lilium cernuum gave off unpleasant odors mainly because of iso-valeric acid emission. The F1 flowers also emitted these three chemical classes. Among the lines derived from the crosses between Asiatic hybrid lily cultivars and the F1 plant, lines that emitted all three chemical classes and lines that released one or two of the three chemical classes were segregated, and some lines emitted benzenoids/phenylpropanoids or terpenoids without emitting fatty acids. We successfully selected elite breeding lines that predominantly emitted pleasant scents. Therefore, this study demonstrated the introduction of pleasant scent production capability into Asiatic hybrid lilies using interspecific hybridization with L. cernuum.