Effect of PEG stress on plantlets of Chrysanthemum morifolium induced by endophytic Botrytis sp. (C1) and Chaetomium globosum(C4)

Abstract

The effect of the endophytic fungi Botrytis sp. (C1) or Chaetomium globosum (C4) on the drought resistance of Chrysanthemum morifolium was studied. Ch. morifolium plantlets were inoculated with C1, C4 and cultured in the pots for 60 days, then the plantlets were stressed by 0%, 10%, 20%, 30%, 40% PEG6000 respectively in order to simulate different drought conditions. Biomass, the activities of SOD, POD, PAL, the contents of MDA and soluble protein of each group were determined. The results showed that endophytic fungi groups grew better than the control (without inoculation endophytic fungi). With the increasing of the concentration of PEG6000, the biomass of Ch. morifolium of each groups decreased, while the biomass of fungi groups was significantly higher than that of control, moreover C4 group higher than C1 group. With the concentration of PEG increasing, the content of MDA of each group increased too, while POD activity and soluble protein content of all treatments increased at first and then decreased. SOD activity and PAL activity of the control were increased with the increase of PEG concentration, but SOD activity of the two fungi groups were stable. After been stressed by different concentrations of PEG, MDA content of two fungi groups were always lower than the control, while SOD activity, POD activity, PAL activity and soluble protein content were higher. In conclusion, endophytic fungi can increase the drought resistance of Ch. morifolium.