Characteristics of floral scent compounds in a new fragrant petunia cultivar TX-794 ‘evening scentsation’

Abstract

A new blue petunia cultivar, TX-794 bred by Takii & Co., Ltd, has a sweet floral fragrance different from conventional petunia cultivars that typically have no odor or have a somewhat unfavorable smell. Since fragrant bedding plants suitable for summer cultivation are rare, we expect that the fragrance will enhance the value of TX-794. The characteristics of emitted scent compounds from TX-794 were evaluated in this study. The major scent compound was phenylacetaldehyde, a C6-C2 aromatic compound that was emitted at higher levels in TX-794 compared to conventional petunia cultivars. iso-Eugenol, a C6-C3 aromatic compound, is the major scent compound in conventional petunia cultivars. These results suggest that TX-794 has a high capacity to biosynthesize C6-C2 aromatic compounds, resulting in a significantly different scent compound composition compared to conventional petunia cultivars. Time-course analysis of scent compound emission revealed that the largest release of scent compounds by TX-794 occurs during the switch from light periods to dark periods. Soon after flowering, that is, in the light period on the day of anthesis, the major scent compound was p-cresol. Thereafter, the primary scent compound was phenylacetaldehyde or methyl benzoate with 2-phenylethanol occupying the next position. Since a bed or a container of petunias has flowers that are primarily over 2-days old, the basic fragrance of TX-794 plants is derived from phenylacetaldehyde, which has a hyacinth-like scent, 2-phenylethanol, which has a rose-like scent, and methyl benzoate, which has a dry fruit-like scent.