3株芽孢杆菌的分离鉴定及其促生效果研究

Isolation,Identification and Growth Promoting Effect of Three Bacillus Strains

[目的]获得安全高效的微生物肥料备用菌种。[方法]分别从贵州石漠化土壤和广东水稻土中分离得到3株芽孢杆菌,对其进行16S rRNA序列分析鉴定种属,分析其形态学和其他生理生化特性,采用大豆盆栽试验进行促生功能研究。[结果]16S rRNA基因序列分析结果显示,菌株RL1和Y26与沙佛芽孢杆菌(Bacillus safensis)、P90与阿氏芽孢杆菌(Bacillus aryabhattai)的系统发育相似性最高。生理生化特征显示,3株芽孢杆菌均具有不同程度地解磷、泌氢以及产吲哚-3-乙酸的能力。其中,RL1的解磷能力和泌氢能力均显著高于其他2个菌株。在盆栽试验中接种这3株菌株均提高了大豆植株的生物量和磷含量。在正常磷条件下,促生效果RL1>P90>Y26。其中,与不接种处理相比,RL1处理条件下大豆地上部干重、根系干重、地上部磷含量和根系磷含量分别增加了68.32%、40.38%、48.29%和57.33%。钙磷处理条件下,促生效果P90>Y26>RL1。其中,与不接种处理相比,接种菌株P90条件下,大豆植株的地上部干重、根系干重、地上部磷含量和根系磷含量分别提高了64.2%、48.21%、39.77%和73.62%。[结论]该研究所分离的3株菌株在促进作物生长方面均具有一定的应用潜力,可为微生物肥料的研制提供优质的菌种资源。

[Objective]To obtain safe and efficient microbes for microbial fertilizers production.[Method]Three Bacillus strains,which isolated from rocky desert soil in Guizhou and paddy soil in Guangdong,were characterized at morphological,physiological,biochemical and molecular biological level.Their growth-promotion effects were investigated.[Result]The 16S rRNA sequence analysis showed that RL1 and Y26 belonged to Bacillus safensis,while P90 belonged to Bacillus aryabhattai.All the three Bacillus strains were able to remobilize sparingly soluble phosphorus,secrete H+,and produce indole-3-acetic acid.Among them,RL1 had the strongest capacity for phosphate remobilization and H+secretion.The pot experiment showed that inoculation of all the three strains could increase the biomass and phosphorus content of soybean plants.Moreover,the growth-promotion effect of RL1 on soybeans was the strongest under normal phosphorus condition.Compared to the non-inoculation control,inoculation of RL1 increased the soybean shoot dry weight,root dry weight,shoot phosphorus content and root phosphorus content by 68.32%,40.38%,48.29%and 57.33%,respectively.However,under tricalcium phosphorus condition,the growth-promotion effect of P90 was the strongest.Compared to the non-inoculation control,inoculation of P90 increased the shoot dry weight,root dry weight,shoot phosphorus content and root phosphorus content by 64.2%,48.21%,39.77%and 73.62%,respectively.[Conclusion]The three strains all had application potential in plant growth promotion and they could provide high-quality microbes resources for the development of microbial fertilizers.