樱桃根际促生细菌的筛选与鉴定

Screening and identification of plant growth-promoting rhizobacteria from Cerasus pseudocerasus rhizosphere

摘要:

【目的】筛选樱桃[Cerasus pseudocerasus (Lindl.) G. Don]生物肥料中应用的优良菌株资源。【方法】通过保绿法和萝卜子叶增重法, 结合定量检测细菌分离物产植物激素的能力, 从樱桃根际土壤中筛选具有良好应用潜力的细菌分离物。利用盆栽试验, 验证其促生效果。对促生效果较好的细菌分离物, 进行形态学观察、生理生化测定、16S rRNA基因序列及系统发育树分析以确定其分类地位。【结果】筛选出4株具有良好应用潜力的细菌分离物, 盆栽试验结果表明: AI5、AI21、PII17、PI7, 尤其是PII17, 显著提高樱桃根系及地上部生物量, 对樱桃生长有明显的促进作用。分类鉴定结果显示: AI5、AI21为短小芽孢杆菌(Bacillus pumilus), PII17为假单胞菌属(Pseudomonas sp.), PI7为肠杆菌属(Enterobacter sp.)。【结论】AI5、AI21、PII17、PI7, 尤其是PII17, 对樱桃生长有明显的促进作用, 在生物肥料的生产中具有广阔的应用前景。

Abstract:

[Objective] The aim of the present study was to provide the excellent strain resources for the production of Cerasus pseudocerasus bio-fertilizer. [Methods] Bacterial isolates were isolated and screened from the rhizosphere soil of Cerasus pseudocerasus using the methods of remaining green and radish cotyledon bioassay. And then, plant hormones produced by the bacterial isolates were quantitatively detected. Additionally, a pot experiment was conducted to determine whether the use of the bacterial isolates benefits the growth of Cerasus pseudocerasus. At last, the bacterial isolates that exert beneficial effects were identified based on the results of morphologic characteristics, physiological biochemical properties and phylogenetic analysis of 16S rRNA genes. [Results] Four plant growth-promoting rhizobacteria (PGPR) with potential beneficial effects on Cerasus pseudocerasus growth were screened. According to the pot experiment results, AI5, AI21, PII17, and PI7, especially PII17 can significantly improve the root and aerial part biomass of Cerasus pseudocerasus, showing the beneficial effects on Cerasus pseudocerasus growth. AI5 and AI21 were identified as Bacillus pumilus. PII17 and PI7 were identified as Pseudomonas sp. and Enterobacter sp., respectively. [Conclusion] AI5, AI21, PII17, and PI7, especially PII17 that exert beneficial effects on Cerasus pseudocerasus growth exhibited broad application prospects in the bio-fertilizer production.