Identification and Evaluation of Aromatic Volatile Compounds in 26 Cultivars and 8 Hybrids of _Freesia_ hybrida  
[PERSON]  
1 School of Design, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS] (S.W.); [EMAIL_ADDRESS] (X.F.); [EMAIL_ADDRESS] (T.L.); [EMAIL_ADDRESS] (Y.S)  
2 Instrumental Analy Center, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS]  
[PERSON]  
1 School of Design, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS] (X.F.); [EMAIL_ADDRESS] (T.L.); [EMAIL_ADDRESS] (Y.S)  
[PERSON]  
2 Instrumental Analy Center, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS] 2  
[PERSON]  
1 School of Design, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS] (S.W.); [EMAIL_ADDRESS] (X.F.); [EMAIL_ADDRESS] (T.L.); [EMAIL_ADDRESS] (Y.S)  
[PERSON]  
1 School of Design, Shanghai Jiao Tong University, Shanghai 200240, China; [EMAIL_ADDRESS] (S.W.); [EMAIL_ADDRESS] (X.  
scent. The fragrant oriental lily was found to emit predominantly monoterreponoids and benzenoids for its special scent [13]. Moreover, the living scent or essential oil extracted from flowers has health functions. The 3,5-di-methoxytoluene that effectively contributes to the rose scent has a strong sedative and relaxing effect [14].  
_Freesia_ (Iridaceae) originates from South Africa and has been artificially planted for 18 centuries. _Freesia hybrida_, the modern cultivar population, is formally regarded as the offspring of _Freesia corymbosa_ and _Freesia leichtulini_ in the anfractousity of breeding [15; 16; 17]. The fusion of diverse varieties' genetic resources led to the complex genetic background of _F. hybrida_. It is an excellent bulb flower with various colors and an abundant aroma. Thus far, there have been some studies which have identified the VOCs of the scent of _F. hybrida_. The cultivar 'Rijnvelds Golden Yellow' was firstly found that the principal compound linalool accounted for 67.96% in 31 VOCs [18]. Subsequent studies also demonstrated that terpenoids, in which linalool was critical, dominated the scent of _F. hybrida_[19; 20]. However, these studies usually focused on limited cultivars, leading to an unrepresentative summary of scent characteristics of plenty of freesia germplasms. More rapid cultivar innovation provides newer demand to summarize the recent situation of the floral scent of _F. hybrida_, which is valuable for the cut flower and essential oil industries. In addition, as the most important commercial breeding method, intervarietal crossing is generally applied to breeding new _F. hybrida_ cultivars. Studying the VOCs of hybrids plays a fundamental role in breeding new fragrant cultivars. It has been found that the hybrid generations would synthesize some novel scent traits or evidently lost parental chemical compounds [21]. More data are still required to explore the changes which occur during cultivating and breeding.  
Based on our previous persistent breeding and germplasms collection, we selected 34 germplasms to identify the VOCs in these fresh _F. hybrida_ flowers. Compared to other methods, HS-SPME-GC-MS is rapid, solvent-free, inexpensive and accurate when used to identify VOCs. [22; 23]. PCA and HCA were then performed to analyze the floral scent pattern of these germplasms. Moreover, we screened some hybrids to explore the inheritance and variation of VOCs between parents and hybrids. This study aims to comprehensively analyze the characteristic of _F. hybrida_, and form a theoretical basis for scent breeding in _F. hybrida_.