大白菜根际细菌及其抗病原真菌的作用

Isolation and biocontrol effects of bacterial strains from rhizosphere of Chinese cabbage

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%。PDA培养基平板颉抗实验发现,有6个产生信号分子的分离株(C11、C26、C27、C33、C34和C41)具有颉抗作用,对油菜菌核病菌、立枯丝核菌、禾谷镰刀菌、尖孢镰刀菌、瓜果腐霉菌等6种病原真菌分别具有不同程度的抑制作用。分离株C33和C11在田间实验中对油菜菌核病菌具有与成团肠杆菌IC1270相同或更强的生防效果。

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). On PDA medium, 6 of the AHL producing bacteria strains C11,C26,C27,C33,C34 and C41 were found to suppress 6 pathogenic fungi, including Sclerotinia sclerotiorum, Rhizoctonia solani, Pythium aphanidermatum and Fusarium graminearum, Fusarium oxysporum, Fusarium sambveinum. Biocontrol assay were proceeded with C11 and C33 in the field path, C11 was found expressing better antagonistic ability to Sclerotinia sclerotiorum than Enterobacter agglomerans IC1270.