Study On The Interaction Between The Endophytic Fungi And Saussurea Involucrata Kar. Et Kir.

The roots of Saussurea involucrata Kar. et Kir. (Compositae) were examined for fungal symbiont colonization. Typical structures of dark septate fungal endophytes (hyphae and microsclerotia), and arbuscular mycorrhizas (arbuscule, coils, vesicles) were found in the roots of nearly all the individuals examined.40 strains of endophytic fungi were isloted from S. involucrata , 9 strains of fungi from roots and 3 from leaves were cultured together with seedlings of S. involucrate respectively. In agar medium, EF-11,15, 27, 38, 40, 41 killed the seedlings quickly; In vermiculite medium, EF-11, 27, 40, 41 had the same effects; but EF-15, 38 were mild, showing that under different experiment conditions, the growth rate of fungi may affect the relationship of fungus-host.EF-17, 18, 32, 60 grew very slowly in agar medium, they had no effects on seedlings of S. involucrate at first ;but in vermiculite medium, they grew very fast and killed the seedlings soon. EF-M had no effect on seedlings of S. involucrate in agar medium, but inoculation of EF-M increased host shoot biomass in vermiculite medium. Only EF-37 had positive effects on seedlings of S. involucrate in agar or vermiculite medium: effect of EF-37 on leaves and petiole elongation, root system extension and dry weight of seedlings were significant in the inoculated seedlings in comparison with the controls.Phylogenetic analysis of EF-37 ,EF-M and EF-15 placed them within the Mycocentrospora ,Leptodontidium and Glomerella. The most closely related organism to EF-M was Leptodontidium orchidicola.