# Volatile Metabolome and Aroma Differences of Six Cultivars of _Prunus mume_ Blossoms
## 1 Introduction  
_Prunus mume_, belonging to Prunus in the family Rosaceae, is well known and native to central and southern China, Taiwan, and other places, and has been cultivated by the Chinese people since ancient times, mainly as an ornamental plant [1]. _P. mume_ blooms much earlier than other flowers (mostly in February to March in central and east China), and is appreciated for its cold resistance, unique floral scent, and genetic diversity of cultivars. The blossom of _P. mume_ has distinctive and refreshing floral scents compared with other Prunus species. However, long-term cultivation and domestication have resulted in a variety of _P. mume_ blossoms with different branch postures, flower colors, number of petals, and floral scent [2]. Floral scent plays an important role in the reproductive processes of many plants and enhances the aesthetic properties of ornamental plants, and is closely related to the genes and enzymes involved in the biosynthesis of floral scent volatiles. Most floral substancesbelong to one of three major groups: phenylpropanoids/benzenoids, terpenoids, and fatty acid derivatives, which originated in the shikimate pathway, the mevalonate/non-mevalonate pathway, and the malonate pathway in the plant metabolism, respectively [3]. Some researchers have studied the scent components of some _P. mume_ blossom cultivars from a better breeding point of view [4; 5; 6; 7]. [PERSON] et al. [4] analyzed the volatile constituents of five different cultivars of _P. mume_ blossoms and 45 compounds were tentatively identified; among them benzaldehyde, benzyl alcohol, and benzyl acetate originated from the shikimate pathway and were the main volatiles of the analyzed _P. mume_, while the common components of hexyl acetate, eugenol, benzyl acetate, and \(\alpha\)-pinene were considered the reason for the similar aroma of _P. mume_ blossoms. [PERSON] [5] analyzed the emitted and endogenous floral scent compounds of _Prunus mume_ and hybrids, and revealed that benzyl acetate had a stronger tendency to be volatile than the other compounds, and the volatilization rate of volatile metabolites greatly varied among different cultivars. [PERSON] et al. [6] explored the diversity of floral scents in _P. mume_ intraspecific cultivars with three different corolla colors. A total of 31 volatile metabolites were identified, in which phenylpropanoids/benzenoids accounted for over 95% of the total amounts, and the emissions of benzyl alcohol, cinnamyl alcohol, benzyl acetate, eugenol, (E)-cinnamyl acetate, and benzyl benzoate could make these intraspecific cultivars distinguishable from each other. [PERSON] et al. [7] investigated the headspace volatiles and endogenous extracts of different aroma types of _P. mume_ blossoms and 66 headspace volatiles and 74 compounds in endogenous extracts were putatively identified, of which phenylpropanoids/benzenoids were the main volatile organic compound categories. Several biomarkers including (Z)-2-hexen-1-ol, amyl acetate, cinnamaldehyde, methyl salicylate, cinnamyl alcohol, and benzoyl cyanide were found to contribute to the differences of strong-, fresh-, sweet-, and light-scented types of _P. mume_ blossoms. As a traditional ornmental plant with a unique fragrance and colorful colors, studies on _P. mume_ are generally limited. Previous studies on blossoms have been aimed at the breeding of more diverse cultivars and have paid more attention to headspace volatiles. Today, the successful cultivation of _P. mume_ on a large scale makes extensive exploration more applicable. Like many flower plants, floral metabolites of _P. mume_ blossoms could be used in perfumes, cosmetics, foods, and pharmaceuticals [8]; meanwhile, further investigation remains necessary for the applications of specific _P. mume_ blossoms due to the diversity of cultivars. In this paper, six cultivars of _P.