執行成果摘要
Plant volatile organic compounds (VOCs) typically occur as a complex mixture of low molecular weight compounds derived from different biosynthetic pathways, the preeminent roles of VOCs is their repellent or cytotoxic activity, which helps the plant against biotic and abiotic stress, as well as contributing to various physiological functions of the producer organism. We analysis the essential oils and VOCs extracted from the leaves of five precious conifers (Taiwania cryptomerioides, Chamaecyparis formosensis, Chamaecyparis obtusa var. formosana, Cunninghamia lanceolata, and Cunninghamia konishii) in Taiwan. Chemical diversity was observed, the components of essential oils and VOCs with some species-specific and could be used to discriminate five species in PCA plot. The T. cryptomerioides oils and VOCs was dominated by α-Pinene and Limonene, while C. formosensis primarily contained α-Pinene; Sabinene and Thujopsene were the characteristic compounds belong to C. obtusa var. formosana. As to C. lanceolata, which were characterized by high levels of β-Selinene and α-Selinene both in oils and VOCs, while α-Pinene, trans-β-Caryophyllene and β-Myrcene were the dominant compounds in C. konishii leaves. Two monoterpenes (α-Pinene and Limonene) and a sesquiterpenes - β-Caryophyllene, which are known to have cytotoxic and deterrent effects, were the most frequent compounds in the sampled species. Furthermore, the interspecific variation in chemical diversity was caused mostly by variation in sesquiterpenes. The optimum sampling temperature and SPME fiber were examined and their performance is discussed.