Abstract:

The effects of salicylic acid (SA) on a pathogen (Pestalotiopsis guepinii) of Camellia were investigated by glass germination method. The result showed that the SA of 0~5 mmol·L^-1 did not inhibit growth of the pathogen. The induced resistance of camellia could last 10~15 days, and the optimum induced time was interval 3 days. The MDA, lignin, soluble protein had different responses to the disease resistance of camellia induced by spraying SA. MDA content in leaves decreased in certain period of time, suggesting that the membrane lipids peroxidation was decreased, but the effects of SA gradually were weakened with time. The responses were different with different SA concentrations. The experiment of induction and challenge inoculation showed that the MDA concentrations were lower than that in the control at initial stage, and then increased slowly at later stage. The treatment of induction and challenge inoculation brought about the same change trend of lignin content as the induction treatment. High SA concentrations were more effective than the low concentration. The contents of soluble proteins in the treatment of induction and challenge inoculation exhibited the same change trend as that in induction treatment, but were higher than that in the latter and the control. The correlation analysis of biochemical reaction and disease index showed there were significant (P<0.05) correlations between the contents of MDA, lignin and disease index.

Key words: induced factor, resistance, Pestalotiopsis guepinii, Camellia pitardii