Leaf essential oil diversity of Camphora Fabr. in China

Camphora Fabr. species(CFSS) from 196 provenances in China were used as the research objects to study the distribution of leaf oil yield and the chemotypes. The results showed that: (1) the highest leaf oil yield of CFSS were in Xuzhou District of Yibin City (4.19 ± 0.30 %), the lowest leaf oil yield (0.06 ± 0.01 %) was found in three provenances: Yilong County of Sichuan Province, Guiding County of Guizhou Province, and Qiongzhong County of Hainan Province. Overall, the number of individuals with low leaf oil yield were much more than those with high leaf oil yield; leaf oil yield varied among tree species, with oil yield ranging from high to low in the order of C. longepaniculata (3.58 ± 0.43)% > C. parthenoxylon (1.87 ± 0 . 15)% > C. glandulifera (1.68 ± 0.20)% > C. officinarum (1.19 ± 0.03)% > C. bodinieri (1.12 ± 0.07)% > C. tenuipilis (0.71 ± 0.02 ) % > C. micrantha (0.54 ± 0.35)%; (2) the coefficients of variation of leaf oil yield intra and inter provenances were 51.69 % and 57.27 %, respectively, indicating that the oil yield of individuals in the same provenance were quite different. Therefore, the excellent individuals selection strategy of CFSS, differ from other species, should be based on individual plants rather than the population of the same provenance; (3) CFSS have indicated a variety of chemotypes, including citral, α-linalool, β-linalool, eucalyptol, camphor, mixed, borneol, methy isoleugenol, trans-nerolidol, etc. Mixed chemotype was predominant in most species of CFSS, while citral chemotype was predominantly found in C. bodinieri , C. officinarum , and C. parthenoxylon . Five excellent individuals of different chemotypes were obtained, which provide important raw materials for the development of CFSS in industry, spices, food and other fields.