Abstract:

To value the effect of grafting on Fusarium solani and Ralstonia solanacearum and effect of root exudates on disease incidence and yield，we anlysized the chemical element of pepper root exudates by Gas Chromatography–Mass Spectrometer（GC–MS），the results indicated remarkable differences of root exudates component among the rootstocks，grafted and own-root pepper. Compared to own-root pepper，the root exudates in grafted pepper and stock could inhibit the growth of pathogens like Fusarium solani and Ralstonia solanacearum. This indicates that the variation of root exudates component in grafted plants which prevented germs growth and reproduction，therefore increased the disease resistance. Based on the GC–MS results，it is supposed that the prevention may be related to 1,2-benzenedicarboxylic acid，diisooctyl ester and dibenzofuran. Further clarified the grafting capsicum can reduce the occurrence of soil-borne disease and continuous cropping obstacle. The function identification proves that 1,2-benzenedicarboxylic acid，diisooctyl ester and dibenzofuran do decrease the disease incidence of pepper and increase the yields by 31.7% and 38.3% respectively compared to the control. The optimum concentration of 1,2-benzenedicarboxylic acid，diisooctyl ester and dibenzofuran for the foliar-spraying is 0.2 mL · L^-1 and 0.1 g · L^-1.

Key words: grafted, pepper, root exudate, Fusarium solani, Ralstonia solanacearum