## 2 Results  
### Comparative Analysis and Evaluation of VOCs  
Table 1 showed the information about 34 germplasms. A total of 164 VOCs whose relative content were higher than 0.05% were found in these germplasms (Table S1, Supplementary Material). The number of VOCs ranged from 11 only in HTG to 38 in three germplasms, including SN, RP-RX-01 and GR-RP-02 (Figure 1). Out of the 34 samples detected, the numbers of VOCs in 27 samples were found to exceed 20, of which 10 samples were above 30; other 7 samples contained less than 20 VOCs, of which HTG, ZMG, AN were as low as 11, 11 and 12. The percentages of VOCs' relative contents accounted for 32.39% in RR to 94.28% in LL. A majority of germplasms contained high VOC contents, in which 23 samples were detected to have greater than 80%. The relative contents of all detected VOCs were present between 60% and 80% in 7 individual germplasms. Four samples, including SO, ZMG, RR and HTG-RR-02, contained VOCs with low percentages of less than 50%. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**No.** & **Code** & **Germplasm Name** & **Source 1** & **Sample Type** \\ \hline
1 & AN & ‘Ancona’ & a & Cultivar \\
2 & CAL & ‘Calvados’ & a & Cultivar \\
3 & SB & ‘Summer Beach’ & a & Cultivar \\
4 & PP & ‘Pink Passion’ & a & Cultivar \\
5 & VE & ‘Versallies’ & a & Cultivar \\
6 & HTG & ‘SN 2’ Hongtaige’ & b & Cultivar \\
7 & RX & ‘SN Ruxiang’ & b & Cultivar \\
8 & ZMG & ‘SN Zimeigui’ & b & Cultivar \\
9 & SO & ‘Soleil’ & a & Cultivar \\
10 & JHH & ‘SN Jinhuanghou’ & b & Cultivar \\
11 & FS & ‘Fragrant Sunburst’ & a & Cultivar \\
12 & LL & ‘Lovely Lavander’ & a & Cultivar \\
13 & SN & ‘Smozy’ & a & Cultivar \\
14 & HJ & ‘SN Huangjin’ & b & Cultivar \\
15 & GR & ‘Gold River’ & a & Cultivar \\
16 & WR & ‘White River’ & a & Cultivar \\
17 & RP & ‘Red Passion’ & a & Cultivar \\
18 & CA & ‘Castor’ & a & Cultivar \\
19 & MA & ‘Mandarine’ & a & Cultivar \\
20 & GRU & ‘Grumpy’ & a & Cultivar \\
21 & RR & ‘Red River’ & a & Cultivar \\
22 & TW & ‘Tweety’ & a & Cultivar \\
23 & CH & ‘SN Chenguang’ & b & Cultivar \\
24 & DXQ & ‘SN Dankueqing’ & b & Cultivar \\
25 & DH & ‘SN Dahong’ & b & Cultivar \\
26 & FT & ‘SN Faiato’ & b & Cultivar \\
27 & WR-HJ-01 & ‘White River \(\times\) SN Huangjin—01’ & b & Hybrid \\
28 & RP-RX-01 & ‘Red Passion \(\times\) SN Ruxiang—01’ & b & Hybrid \\
29 & CA-WR-01 & ‘Castor \(\times\) White River—01’ & b & Hybrid \\
30 & HTG-RR-02 & ‘SN Hongtaige \(\times\) Red River—01’ & b & Hybrid \\
31 & RR-DH-03 & ‘Red River \(\times\) SN Dahong—03’ & b & Hybrid \\
32 & GR-RP-02 & ‘Gold River \(\times\) Red Passion—02’ & b & Hybrid \\
33 & GR-RP-05 & ‘Gold River \(\times\) Red Passion—05’ & b & Hybrid \\
34 & GR-RR-06 & ‘Gold River \(\times\) Red Passion—06’ & b & Hybrid \\ \hline \hline \end{tabular}  
* a indicates the sample originated from Van den bos Co, Ltd. of Netherland; b indicates the sample originated from Shanghai Jiao Tong University.
* SN indicates cultivars bred by Shanghai Jiao Tong University.  
\end{table} 
Table 1: Sample of 34 _F. hybrida_ germplasms. Figure 1: Relative content and numbers of VOCs in 34 _F. hybrida_ germplasms. Numbers and relative contents of VOCs differed in tested freesia germplasms, and relative contents did not correspond to numbers. It was revealed that high VOC numbers did not mean high content for all germplasms. Typically, the germplasms with many VOCs were accompanied by high relative contents. However, the samples with large numbers of VOCs may contain low percentages (\(\leq\)50%), such as RR and HTG-RR-02. Conversely, some germplasms emitted few VOCs and contained high VOCs percentages, including AN, HTG, GRU and GR-RR-06. According to metabolic pathways, the VOCs could be classified into 127 terpenoids, 18 fatty acid derivatives, 9 benzenoids and phenylpropanoids and 10 other compounds (hydrocarbons, sulfur- and nitrogen-containing compounds) (Figure 2). Trepenoids, including 84 monoterenes and 43 sesquiterpenes, dominated the floral scent in the majority of germplasms.