Abstract: 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.

Key words: Cymbopogon citratus, volatile components, tea, fungicidal