# Volatile Metabolome and Aroma Differences of Six Cultivars of _Prunus mume_ Blossoms
## 2 Results and Discussion
### Analysis of Volatile Metabolite Differences in Six Cultivars of P. mume Blossoms
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & & & & & & \\ \cline{3-10}
**Number** & **Compound Name** & **CAS-** & **VIP** & \multicolumn{3}{c}{**VTD**} & \multicolumn{3}{c}{**JJM**} & \multicolumn{3}{c}{**CLH**} & \multicolumn{3}{c}{**LE**} & \multicolumn{3}{c}{**DFZS**} & \multicolumn{3}{c}{**GF**} \\ \hline
1 & Benzaldehyde & 100-52.7 & 3.606 & 157.00 \(\pm\) 9.21 & 112.00 \(\pm\) 4.21 & 108.02 \(\pm\) 6.00 & 126.76 \(\pm\) 9.83 & 62.61 \(\pm\) 7.60 & 149.91 \(\pm\) 8.06 \\
2 & Methyl benzoate & 94-58.3 & 3.085 & 172.36 \(\pm\) 7.23 & 207.26 \(\pm\) 6.85 & 166.90 \(\pm\) 5.90 & 120.76 \(\pm\) 11.67 & 212.02 \(\pm\) 6.35 & 157.84 \(\pm\) 8.82 \\
3 & Ethly benzoate & 93-89.0 & 1.002 & 0.28 \(\pm\) 0.11 & 1.13 \(\pm\) 3.08 & 2.38 \(\pm\) 0.49 & 0.54 \(\pm\) 0.27 & 0.46 \(\pm\) 0.14 & 1.21 \(\pm\) 0.79 \\
4 & Benzyl acetate & 140-11.4 & 1.762 & 15.99 \(\pm\) 1.21 & 8.69 \(\pm\) 2.15 & 4.34 \(\pm\) 0.38 & 112.99 \(\pm\) 1.62 & 0.84 \(\pm\) 0.15 & 5.80 \(\pm\) 1.16 \\
5 & Benzyl alcohol & 100-51.6 & 2.202 & 41.41 \(\pm\) 5.73 & 13.81 \(\pm\) 2.66 & 196.88 \(\pm\) 3.19 & 23.67 \(\pm\) 3.49 & 6.82 \(\pm\) 1.33 & 22.68 \(\pm\) 2.73 \\
6 & Methylogenized & 919-51.2 & 1.392 & 5.11 \(\pm\) 0.57 & 1.53 \(\pm\) 0.38 & 4.83 \(\pm\) 0.30 & 1.97 \(\pm\) 0.87 & 2.60 \(\pm\) 0.58 & 2.06 \(\pm\) 0.33 \\
7 & (E)-Cimmaaldehyde & 1437-10.9 & 1.797 & 0.91 \(\pm\) 0.30 & 0.26 \(\pm\) 0.09 & 27.52 \(\pm\) 7.41 & 0.29 \(\pm\) 1.66 & 1.89 \(\pm\) 0.31 & 25.09 \(\pm\) 2.48 \\
8 & (E)-Cimamy acetate & 2104-54.9 & 2.336 & 1.28 \(\pm\) 0.48 & 1.48 \(\pm\) 0.84 & 50.96 \(\pm\) 8.52 & 0.43 \(\pm\) 0.15 & 0.42 \(\pm\) 0.08 & 52.22 \(\pm\) 3.68 \\
9 & Eugen & 97-53.0 & 2.580 & 64.87 \(\pm\) 3.39 & 43.03 \(\pm\) 3.47 & 48.80 \(\pm\) 3.25 & 45.79 \(\pm\) 5.18 & 56.94 \(\pm\) 5.06 & 34.62 \(\pm\) 4.05 \\
10 & (E)-Methyl isoquemol & 6379-72.2 & 1.244 & 0.73 \(\pm\) 0.16 & 1.51 \(\pm\) 0.27 & 0.61 \(\pm\) 0.37 & 0.56 \(\pm\) 0.17 & 0.75 \(\pm\) 0.11 & 0.49 \(\pm\) 0.10 \\
11 & Alkanen3 & 1.442 & 14.10 \(\pm\) 2.72 & 4.92 \(\pm\) 0.86 & 6.30 \(\pm\) 1.00 & 91.32 \(\pm\) 2.75 & 8.86 \(\pm\) 2.65 & 3.97 \(\pm\) 0.99 \\
12 & (E)-Cimma alcohol & 4407-36.7 & 2.107 & 0.44 \(\pm\) 0.08 & 0.18 \(\pm\) 0.09 & 36.33 To further investigate how these fifteen compounds differentiate among the six _P. mume_ blossoms, Hierarchical Cluster Analysis (HCA) was simultaneously performed on these fifteen compounds and samples, as shown in Figure 3. From the similarity among samples, GLH was more similar to GF, and LE was similar to JM, which is consistent with the results of PCA and PLS-DA analysis. The contents of three compounds of (E)-cinnamaldehyde, (E)-cinnamic alcohol, and (E)-cinnamyl acetate were much higher in GLH and GF cultivars than in the other four cultivars, making GLH and GF similar to each other and dissimilar from others. A previous study [6] also found that (E)-cinnamic alcohol and (E)-cinnamyl acetate were only synthesized in pink flowers. However, in this study, these three compounds were also found in other cultivars of _P. mume_ blossoms, with very low content. According to existing research on flowers and fruits [12; 13], (E)-cinnamic acid is converted to cinnamoyl-CoA by (E)-cinnamic acid: CoA ligase in flowers and fruits, and the latter is catalyzed by cinnamoyl CoA reductase (CCR) to generate cinnamaldehyde; after a series of reactions, other phenylpropene compounds including (E)-cinnamyl acetate are generated. Higher concentrations of (E)-cinnamaldehyde, (E)-cinnamic alcohol, and (E)-cinnamyl acetate indicated that, compared with the other four cultivars, GLH and GF _P. mume_ are likely to have differences in related metabolic regulation. Similarly, benzaldehyde, benzyl alcohol, and benzyl acetate, among these 15 compounds, belong to the same metabolic branch in plant metabolism [14; 15]. When HCA was performed with compounds, benzyl alcohol, benzyl acetate, and benzaldehyde were also closer together, indicating the similarity of the variation among samples for these three compounds.