香茅草挥发物及其主要成分对3种茶树病原真菌的抑制性研究

采用固相微萃取和气相-质谱联用仪检测了香茅草鲜草茎和叶的挥发成分,分析确定了香茅草鲜草茎和叶中共51种挥发成分,主要成分为柠檬醛包含(E)-柠檬醛与(Z)-柠檬醛]和香叶醇,茎中相对含量分别为81.39%(58.48%和22.91%)和4.79%;叶片中相对含量分别为78.50%(51.63%和26.87%)和3.68%。采用菌丝生长速率法,研究了柠檬醛和香叶醇分别对茶树炭疽病病原菌(Colletotrichum gloeosporioides)、轮斑病病原菌(Pestalotiopsis theae)、褐芽病病原菌(Phoma adianticola)的抑制活性。活性初测结果表明,500 mg·L^-1处理96 h,两种成分对供试轮斑病病原菌抑制率均低于56%;而对供试茶炭疽病和褐芽病病原菌的抑制率均可达100%。进一步活性测试结果表明,柠檬醛对茶炭疽病和褐芽病病原菌的抑制中浓度(EC₅₀)值分别为(230.56±3.49) mg·L^-1和(124.79±10.29) mg·L^-1;香叶醇对两种病原菌的EC₅₀值分别为(238.38±5.51) mg·L^-1和(115.38±10.96) mg·L^-1。本研究初步明确了香茅草鲜草挥发成分及其对茶树病害病原菌抑制活性的主要物质基础,为茶园种植香茅草具有潜在防病害作用提供了理论依据。

Volatile Components from Cymbopogon citratus and the Activity Research on Their Main Elements Against Three Fungal Pathogens of Tea

The volatile components from Cymbopogon citratus (DC.) Stapf were extracted by solid phase microextraction and analyzed by gas chromatography mass spectrometry. Fifty one volatile components from stems and leaves were identified. Citral Contains two compounds (E)-citral and (Z)-citral] and geraniol were found to be the major components. Their relative contents in stems were 81.39% (58.48% and 22.91%) and 4.79%, respectively. Meanwhile, the contents in leaves were 78.50% (51.63% and 26.87%) and 3.68%, respectively. The activities of citral and geraniol to Colletotrichum gloeosporioides, Pestalotiopsis theae and Phoma adianticola were determined using mycelium growth rate method. The preliminarily test results show that the inhibition rate of the two compounds against P. theae were lower than 56% under the tested concentration of 500 mg·L^-1 for 96 h. By contrast, they exerted high activities against C. gloeosporioides and P.adianticola with a inhibition rate of 100%. Further evaluated results show that the EC₅₀ of citral to C. gloeosporioides and P.adianticola were (230.56±3.49) mg·L^-1 and (124.79±10.29) mg·L^-1, respectively. The EC₅₀ of geraniol to the two fungi were (238.38±5.51) mg·L^-1 and (115.38±10.96) mg·L^-1, respectively. The present study preliminarily revealed the volatile components of C. citratus and the main active fractions against two pathogenic Fungi on tea. The results could provide a theoretical basis for the potential disease prevention of the interplanting of C. citratus and tea.