Biological control of bacterial wilt-root knot disease complex by Bacillus sp.
芽孢杆菌对青枯病菌-根结线虫复合侵染病害的生物防治

Forty-six bacterial strains were isolated from root-knot nematode infected tomato roots, 13 of which could inhibit the growth of Ralstonia solanacearum in vitro with the inhibition zone diameter ranging from 7.1 mm to 26.3 mm on NA plate. In the greenhouse tests, tomato bacterial wilt caused by Ralstonia solanacearum was controlled effectively by the isolates EN5, EN15, EN01 and EN16 with the average control efficacy of 70.82%,89.54%,85.38% and 78.81%, respectively. Root-knot disease caused by Meloidogyne incognita was reduced 49% by EN5, SW1 and SB2. They were also tested for their ability to control the complex disease caused by two pathogens, likewise, the isolates EN5, SW1 and SB2 significantly reduced the infection percentage compared with non-treated control, among which, SW1 showed best effects on reduction of incidence of bacterial wilt disease by 56.66 and root galling index by 5.21. Based on their physiological and biochemical characteristics and 16S rDNA sequences, EN5, SW1 and SB2 were identified as Bacillus subtilis.