黔中黄壤溶磷细菌溶磷特性及对土壤微生物碳循环基因的影响

Phosphorus Solubilizing Characteristics of Phosphorus Solubilizing Bacteria in Yellow Soil of Central Guizhou and Their Effects on Soil Microbial Carbon Cycling Genes

为探究黔中黄壤区溶磷细菌溶磷特性及其在土壤中的作用,以从贵州省安顺市农田土壤中筛选到的伯克霍尔德菌(Burkholderia sp.)QZW-3、假单胞菌(Pseudomonas sp.)QZY-5、中华根瘤菌(Sinorhizobium sp.)QZY-6共3株溶磷细菌为试验菌株,通过室内培养试验研究不同碳源、氮源条件下菌株的溶磷能力,通过盆栽试验研究菌株对土壤养分以及微生物碳循环基因的影响。结果表明,3株菌株对各种难溶态磷都具有较强的溶解能力;QZW-3、QZY-5、QZY-6均以葡萄糖为碳源时对磷酸三钙溶解能力最强,分别为603.13、645.82、672.21 mg/L;氮源对菌株溶磷能力的影响小于碳源。3株菌株组合处理油菜鲜质量显著高于其他处理,为37.89 g/盆;菌株各处理土壤pH值与基质处理(M处理)相比差异不显著,菌株各处理土壤有效磷、有机质含量均高于M处理。溶磷细菌各处理土壤微生物碳循环基因GHs相对丰度高于M处理,溶磷细菌各处理CEs、PLs、AAs基因相对丰度差异不显著。土壤pH值与AAs基因相对丰度呈极显著负相关关系,与PLs基因相对丰度呈极显著正相关关系;土壤有效磷含量与GHs基因相对丰度呈显著正相关关系,与PLs基因相对丰度呈极显著负相关关系;土壤有机质含量与微生物碳循环各类基因相关性不显著。

The purpose of this study was to explore the phosphorus solubilization characteristics of phosphorus solubilizing bacteria in yellow soil in central Guizhou Province.QZW‑3(Burkholderia sp.),QZY‑5(Pseudomonas sp.)and QZY‑6(Sinorhizobium sp.),which were screened from farmland soil in Anshun city of Guizhou Province,were used as the test strains.The phosphorus solubility of the strains under different carbon and nitrogen sources was studied by indoor culture experiment,and the influence of the strains on soil nutrients and microbial carbon cycling genes was studied by pot experiment.The results showed that the three strains had strong ability to dissolve all kinds of insoluble phosphorus.QZW‑3,QZY‑5 and QZY‑6 all took glucose as carbon source and had the highest soluble ability of tricalcium phosphate,which were 603.13,645.82 and 672.21 mg/L,respectively.Nitrogen source had less effect on phosphorus solubility than carbon source.The fresh weight of rape in the combination treatment of three strains was significantly higher than that of other treatments,which was 37.89 g/pot.There was no significant difference in soil pH between the treatments of phosphorus soluble bacteria and substrate.The contents of soil available phosphorus and organic matter in the treatments of phosphorus soluble bacteria were higher than those in the substrate treatment.The relative abundance of GHs genes of soil microbial carbon cycle in each treatment of phosphorus solubilizing bacteria was higher than that in the substrate treatment,while the relative abundance of CEs,PLs,AAs genes in each treatment of phosphorus solubilizing bacteria was not significantly different.Soil pH value was extremely significantly negatively correlated with AAs relative abundance,and extremely significantly positively correlated with PLs relative abundance.Soil available phosphorus was significantly positively correlated with GHs relative abundance and extremely significantly negatively correlated with PLs relative abundance.Soil organic matter was not significantly correlated with various genes of microbial carbon cycle.