Abstract: Systemic resistance to gray mould ( Bot rytis ci nerea) in tomato leaves was induced by antagonistic bacteria Paenibacillus polymyxa W3 , Y2 and Bacillus licheniformis W10 and their metabolites. Induced resistance effect s were from 23. 4 % to 64. 5 % as expressed by reduced lesion area. 　
Among 3 antagonistic bacteria , W3 was the best for the induction. After tomato leaves were t reated by W3 and it s metabolites , induced resistance reached the maximum at the fifth day , and lasted over twelve days. Induced resistance was gradually enhanced along with the increase in bacterial concentration , and reached peak at the concentration of 108cfu/ ml. There were no significant differences in in duced resistance effects among the leaves above the treated leaf .