油松菌根际高效解磷钾细菌筛选与鉴定

Screening and Identification of Phosphate and Potassium Dissolving Bacteria from Mycorrhizosphere of Pinus tabulaeformis

本研究筛选出油松-褐环乳牛肝菌菌根根际土中高效解磷钾细菌并对其进行种类鉴定。采用平板稀释法自菌根际土中筛选解磷钾细菌,并用钼蓝比色法和原子吸收法分别对其液体培养5 d后的菌株进行解磷能力和解钾能力测定,筛选出高效的解磷钾细菌。同时,对筛选出的菌株进行显微观察、生物学鉴定和16Sr DNA序列分析。通过筛选得出解有机磷细菌P6和解无机磷细菌P15能力较强,其培养液中有效磷浓度分别为283 mg/L和898.5 mg/L,经鉴定P6属于节杆菌属(Arthrobacter sp.),P15为荧光假单胞菌(Pseudomonas fluorescens),以及2株能力较强的解钾细菌K1和K12,其培养液中有效钾浓度分别为21.6 mg/L,19.3 mg/L,经鉴定K1为壤霉菌属(Agromyces cerinus),K12为中华根瘤菌属(Sinorhizobium sp.)。由此可见,油松-褐环乳牛肝菌菌根根际存在高效解磷钾细菌,褐环乳牛肝菌可以通过影响根际解磷钾细菌的种类及能力来改善油松幼苗的根际磷钾营养状况。

This study screened out phosphate and silicate dissolving bacteria from mycorrhizal soil ofSuillus luteus in Pinus tabulaeformis and identified their species. The phosphate and silicate dissolving bacteria were isolated by the plate dilution method from the mycorrhizosphere ofP. tabulaeformis and the molybdenum blue method and atomic absorption were used to detect the ability of bacterial strain which was cultured for 5 days in the solution containing phosphate and silicate dissolving bacteria to dissolve phosphorus potassium. Meanwhile, the selected strains were identified by microscopic observations, biological identification and 16S rDNA sequence analysis. The results of screening showed that the ability of organic phosphate solubilizing bacteria P6 and inorganic phosphate solubilizing bacteria P 15 was stronger, and the available P concentration in their nutrient solutions were 283 mg/L and 898.5 mg/L, respectively. After identification, P6 was Arthrobacter sp., PI5 was Pseudomonas fluorescens. The effective potassium concentrations of two potassium solubilizing bacteria strains （K1, K12） were 21.6 mg/L and 19.3 mg/L, and K1 and K12 were identified as Agromyces cerinus and Sinorhizobium sp., respectively. Thus, there were lots of efficient phosphate and silicate dissolving bacteria under the mycorrhizosphere of P. tab ulaeforrnis P and K nutrition of P tab ulaeformis seedlings were improved by the effect of S. lute us on the species and the ability of phosphate and silicate dissolving bacteria in rhizosphere.