## 2 Results
### Volatile Compounds of the Flower Petals of N. 'Eldorado' at Different Development Stages
'Eldorado' petals at different flowering stages (Figure 2). Twenty-seven compounds were present at all four flowering stages, but their relative contents changed dynamically at different stages. On the other hand, six volatile compounds were uniquely identified at S3, and five were unique at S1 and S4. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**NO.**} & **RI** & **RI** & \multirow{2}{*}{**Compounds**} & **Molecular** & \multirow{2}{*}{**Aroma Description 1**} & \multicolumn{4}{c}{**Relative Content (\%) 2**} \\ \cline{5-10}  & **(exp.)** & **(lit.)** & & & **Formula** & & **S1** & **S2** & **S3** & **S4** \\ \hline \multirow{3}{*}{42} & \multirow{3}{*}{1528} & \multirow{3}{*}{1531} & (E)-1-Methyl-4-(6-methyl-5-en-2-ylidene)cyclohex-1-ene & & & & & & \\  & & & & & & & & & \\  & & & & & & & & & \\  & & & & & & & & & \\  & & & & & & & & & \\
43 & 1536 & 1539 & hexadienyl]-1-methyl-1-cyclohex & & & & & & & \\  & & & & cyclohexene & & & & & \\
44 & 1602 & 1600 & Hexadecane & & & & & & \\
45 & 1612 & 1615 & Tetadecan & & & & & & \\  & & & & & & & & \\
46 & 1635 & 1630 & Trimethylpentadecane & & & & & & \\  & & & & & & & & \\  & & & & & & & & \\  & & & & & & & & & \\  & & & & & & & & \\
47 & 1658 & 1656 & cis-9-Tetradecen-1-ol & & & & & & & \\
48 & 1665 & 1667 & cis-9-Tetradecen-1-ol & & & & & & \\
49 & 1675 & 1667 & (E6,E9)-Heptadecadiene & & & & & & \\
50 & 1680 & 1672 & Cadalene & & & & & & \\
51 & 1692 & 1680 & 8-Heptadecene & & & & & & \\
52 & 1703 & 1700 & Heptadecane & & & & & & \\
53 & 1712 & 1715 & 2-Phenyl-undecane & & & & & & \\
54 & 1740 & 1745 & Dimethylmonylbenzene & & & & & & \\
55 & 1785 & 1797 & Hexadecan & & & & & & \\
56 & 1838 & 1840 & (Z)-3-Heptadecen-5-yne & & & & & & \\
57 & 1880 & 1883 & 2-Heptadecanone & & & & & & \\
58 & 1992 & 1997 & Falcarinol & & & & & & \\
59 & 2102 & 2100 & Heneicosane & & & & & & \\
60 & 2195 & 2201 & trans-Geranylgeraniol & & & & & & \\ \hline Total & & & & & & & & & \\ \hline \multicolumn{10}{c}{} & \multicolumn{10}{c}{96.01  } & 99.86  } \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 2: Venn diagram showing the numbers of volatiles at different flowering stages of \(N\). ‘Eldorado’ flowers. The concentration of the major volatile compounds varied at different flowering stages. The content of benzaldehyde, benzyl alcohol, and benzyl acetate was significantly higher at the full-flowering stage than at the other stages. At the bud stage, the aroma scent consisted mainly of trans-\(\alpha\)-bergamotene (10.52%), pentadecane (34.13%), and (Z)-5-dodecenyl-1 acetate (8.39%). At the initial flowering stage, the fragrance concentration consisted mainly of benzyl alcohol (8.69%), trans-\(\alpha\)-bergamotene (10.68%), pentadecane (22.63%), and (Z)-5-dodecenyl-1 acetate (7.88%). The content of benzaldehyde (5.78%), benzyl alcohol (23.43%), and benzyl acetate (12.15%) was significantly higher at the full-flowering stage than at the other stages (\(p<0.05\)), which resulted in a strong fragrance. At the end-flowering stage, the aroma consisted mainly of trans-\(\alpha\)-bergamotene (16.19%), pentadecane (21.21%), and (Z)-5-dodecenyl-1 acetate (10.18%), and the aroma was lighter. 2.1.2 Comparison of the Main Volatile Compounds at Different Flowering Stages in \(N\). 'Eldorado'  
The VOCs of \(N\). 'Eldorado' at different flowering stages can be grouped into seven classes of compounds, namely, alkenes, alcohols, esters, aldehydes, ketones, alkanes, and others (Figure 3). Among the seven classes, alkenes (28) accounted for the highest proportion of the total VOCs (47.07%), followed by alkanes (8); the least common were aldehydes and ketones, with only four types each. There were differences in the contents of seven types of substances at different stages in \(N\). 'Eldorado'. Among them, the relative content of alkenes was the highest at S4 (47.07%), and the relative content of alkanes was the highest at S1 (42.91%).