Essential oil diversity of Cinnamomum parthenoxylon (Jack) Meisner from China

Abstract

The yield and chemical components of Cinnamomum parthenoxylon (Jack) Meisner essential oil from 564 individual plants across 20 natural populations in five provinces in China were examined in this study. The leaf essential oil yield varied greatly among populations and individual plants (1.15–23.6 mg/g and 0.2–41.3 mg/g, respectively). A total of 117 chemical constituents, which included 51 types of monoterpenes, 46 types of sesquiterpenes, and 20 types of non-terpenoids, were detected from the essential oil of C. parthenoxylon leaves. A total of 14 chemotypes were identified, and eucalyptol chemotypes, camphor chemotypes, and linalool chemotypes were the most common. The 20 natural populations of C. parthenoxylon were divided into four categories based on their main chemical components, including eucalyptol, camphor, linalool, and elemol. The first category included Guangxi populations, which had a high essential oil yield and a high frequency of the eucalyptol chemotype. The second category included Yunnan populations, which had a high frequency of the camphor chemotype. The third category included Hunan and Jiangxi populations, which had a high frequency of the elemol chemotype. The fourth category included Guangdong and Jiangxi populations, which were characterized by a high diversity of chemotypes. The classification of populations was consistent with the geographical distance between them. The main environmental factors affecting variation in essential oil yield and components of C. parthenoxylon leaves were longitude, latitude, altitude, and annual average temperature. The yield of leaf essential oil showed a significant geographical gradient and was negatively correlated with longitude and latitude. The correlation coefficient between essential oil yield and latitude was -0.826, and the correlation coefficient between essential oil yield and longitude was -0.610. The linalool content was positively correlated with annual average temperature. The camphor content was negatively correlated with longitude and latitude and positively correlated with altitude.