生防荧光假单胞菌CPF-10对西瓜根围土壤真菌群落的影响

Effects of biocontrol agent Pseudomonas fluorescens CPF-10 on soil fungal community in watermelon rhizosphere

探讨了生防菌荧光假单胞菌Pseudomonas fluorescens CPF-10对西瓜根围土壤真菌群落结构的影响。采用传统分离培养法,结合变性梯度凝胶电泳(DGGE)分析,研究了施用CPF-10后不同生育期西瓜根围土壤真菌群落结构的变化。结果表明:施入生防菌CPF-10后2周,其对土壤真菌有一定的促进作用;第3～7周时,CPF-10对土壤真菌尤其是部分病原菌有较强的抑制作用;CPF-10对丛枝菌根真菌(AMF)有一定的促进作用,可维持3周左右;收获期后则检测不到CPF-10对土壤真菌群落的影响。生防菌CPF-10对西瓜根围土壤真菌群落产生的短暂影响不会对土壤生态系统构成长期威胁。对比土著真菌及丛枝菌根真菌的DGGE图谱和切胶条带测序结果,发现DGGE技术更适用于分析小范围特定菌属如丛枝菌根真菌的变化。

The influence of Pseudomonas fluorescens CPF-10 on soil fungal community in watermelon rhizosphere was studied.The traditional culturing method and denaturing gradient gel electrophoresis（DGGE） were used to assess the changes of fungal community at different growth stages of watermelon rhizosphere after application of P.fluorescens CPF-10.During the 1^st to 2^nd week post-inoculation,CPF-10 showed promoted effect on soil fungi,but it showed strong inhibitory effect on soil fungal community,especially for some pathogens during the 3^rd to 7^th week post-inoculation.Arbuscular mycorrhizal fungi（AMF） had been promoted to some extent and the effect lasted for 3 weeks.However,the effect of CPF-10 on fungal community was hardly detected during harvest period.The results suggested that the impact of CPF-10 on soil fungal community in the watermelon rhizosphere was short-term,which would not pose a long-term threat to soil ecosystem.Comparing the results of DGGE fingerprints and the sequencing of native fungi and arbuscular mycorrhizal fungi,it was found that DGGE technology was more suitable for analysis of the changes of small and specific community such as arbuscular mycorrhizal fungi.