Disease Resistance of Eucalyptus Against Bacterial Wilt Caused by Ralstonia solanacearum and the Biocontrol Effect of Paenibacillus polymyxa

The disease resistance of the tissue culture seedlings of eucalypt against bacterial wilt caused by Ralstonia solanacearum was determined by the wounded roots dipped. The test results showed that the resistance ability of different clones of eucalyptus was significant difference. DH32-29 was susceptible clones; DH32-27 and H1 were highly susceptible clones. The biocontrol effect of Paenibacillus polymyxa was determined by the agar-well diffusion method in vitro and soaking root in greenhouse,and demonstrated that the average diameter of inhibition circle reached 10.3 mm at 30 ℃ for 48 h. Three clones of the tissue culture seedlings of eucalypt in pots were tested in greenhouse. The incidence rates were somewhat lower and the biocontrol effect was higher in resistant clones than in susceptible ones. In summary,P. polymyxa had obvious controlling effect on bacteria wilt of the tissue culture seedlings of eucalypt.