347 bacteria strains were isolated from rhizosphere of Chinese cabbage, 11.5% of them were screened for secreting quorum sensing signal substance N-acyl-homoserine lactone (AHL).

• 自大白菜的根际土壤中分离得到347个细菌分离株；有40个分离株能产生群体密度信号(quorumsens ing；QS)分子；占总分离株的11.；5%25。