荧光假单胞菌Tn5转座诱变及对青枯病生防特性

目的：利用Tn5转座诱变荧光假单胞菌PF20001,研究所获得的突变株对青枯病的生防效果。方法：利用三亲本杂交方式,将带有转座子Tn5的Tn5-102（含luxAB）的质粒pTR102成功地转入PF20001,利用平板相互拮抗法分析突变株对青枯病致病菌的拮抗作用。结果：通过诱导Tn5转座,得到荧光假单胞菌PF20001的Tn5插入突变库。经平板相互拮抗实验发现,菌株PF20001-lux-48拮抗圈明显大于野生型（半径达0.35cm）。用Tn5-lux特异引物进行PCR扩增,结果显示只有以该突变株的DNA为模板才能得到300bp的扩增产物,证实该菌株基因组中有Tn5插入。结论：Tn5的插入使菌株PF20001对青枯病生物防治能力增强。

Mutagenesis on Resistant Efficacy of Pseudomonas flurosecens PF20001 to Ralstonia solanacearum by Tn5 Transposon

Objective: By Tn5 transposon mutagenesis, this study was aimed to analyse the biocontrol effect of mutant strains of Pseudomonas flurosecens PF20001. Method: By triparental mating, plasmid pTR102 containing the transposon Tn5 was transfered into the Pseudomonas flurosecens PF20001, and then biocontrol effect of mutant strains to Ralstonia solanacearum were determined, using plate mutual antagonization. Result: After transposition, mutant library by Tn5 insertion was generated. 100 transformants were selected for plate mutual antagonization, in which PF20001-lux-48 strain with higher ability (resistant radius 0.35 cm) on resistant efficacy to Ralstonia solanacearum than the wild strain. The 300 bp PCR result using specific primers of Tn5 proved that Tn5 was inserted into the genome of Pseudomonas flurosecens PF20001. So the PE20001-lux-48 strain can be regarded as the mutant of resistant efficacy to Ralstonia solanacearum. Conclusion: The higher ability of resistant efficacy is caused by the insertion of Tn5.