苹果根际解磷菌的分离筛选及解磷能力

Isolation and screening of phosphorus-solubilizing bacteria in apple rhizosphere

关键词:  苹果  根际土壤  筛选鉴定  解磷细菌  磷酸酶活性

Key words:  apple  rhizosphere soil  screening and identification  phosphate-solubilizing bacteria  phosphatase activity

摘要:

为实现果园化肥减施计划，开发高效微生物解磷肥，利用蒙金娜有机磷固体培养基从苹果根际土壤中筛选具有矿化有机磷能力的细菌，经分离、纯化培养后鉴定其矿化植酸钙的效率。同时测定培养液的pH和磷酸酶的活性，运用16S rDNA测序分析进行菌株的分类信息鉴定，最后将其回接入有机磷培养基中，观察其对拟南芥生长的影响。结果表明:从苹果根际土壤中分离纯化得到10株解磷能力存在一定差异的解磷菌，其溶磷量在14.82~104.13 mg/mL，磷酸酶活性为12.61~44.24 μg/(mL·h)。经鉴定10株解磷菌分别属于Acinetobacter、Enterobacterer和Pseudomonas 3个属，综合生理特性和进化树分析，最终筛选出PsbM4，为较优候选苹果根际解磷菌，其可有效矿化培养基中有机磷，并刺激拟南芥植株泌氢以更好应对低磷胁迫。

Abstract:

In order to realize the plan of reducing the application of orchard chemical fertilizer, a high-efficiency microbial phosphate fertilizer was developed. In this study, organophosphorus mineralized bacteria were screened from apple rhizosphere soil by Monggina organophosphorus solid medium. The efficiency of mineralized calcium phytate was identified after isolation and purification. Meanwhile, the pH and phosphatase activity of the culture medium were measured, and 16S rDNA sequencing analysis was used to identify the strain classification information. Finally, it was transplanted to organophosphorus medium to observe its effect on Arabidopsis thaliana growth. The results showed that: A total of 10 strains of phosphorus-extracting bacteria from rhizosphere soil of apple were isolated and purified, which had different phosphorus extracting abilities. Their phosphorus dissolving capacity ranged from 14. 82-104. 13 mg/mL, and phosphatase activity varied from 12. 61-44. 24 μg/(mL·h). According to the identification, the 10 strains belong to three genera of Acinetobacter, Enterobacterer and Pseudomonas, respectively. Based on the analysis of physiological characteristics and evolutionary tree, PsbM4 was finally screened out as a better candidate for phosphorus dephosphorization bacteria in apple rhizosphere. And it could promote the growth of A. thaliana. l fertilizer to improve the plant's ability to absorb phosphorus provides a scientific basis.