溶磷细菌筛选及在复垦土壤上对难溶态磷的活化作用

为研究溶磷细菌在复垦土壤上对难溶态磷的活化作用，通过PVK平板法从石灰性土壤中分离筛选出7株溶磷细菌，7株菌株的溶磷能力在296.5～563.5 mg/L之间，菌株的溶磷能力与溶磷圈直径（D）与菌落直径（d）的比值呈显著正相关（p<0.01）；16sRNA序列分析表明，W1、W6属于Enterobacter sp.，W2、W4属于Burkholderia sp.，W3、W5属于Rahnella sp.，W7属于Fluorescent pseudomonas。选择W3、W4、W7作为试验菌株，以磷酸三钙、磷矿粉为难溶态磷源，研究单菌株及组合菌株在配施难溶态磷酸盐条件下对复垦土壤有效磷、各形态无机磷含量及油菜产量的影响。结果表明，同一底物下溶磷细菌各处理复垦土壤有效磷含量和油菜产量显著高于基质处理（p<0.05），组合菌株处理优于单菌株处理，W3+W4+W7处理两项指标都最高；在溶磷细菌+磷酸三钙底物下，W3+W4+W7处理复垦土壤有效磷含量和油菜产量分别比单施溶磷细菌、溶磷细菌+磷矿粉两个底物下同一处理显著增加94.81%、40.25%和34.13%、9.43%；相同底物下溶磷细菌各处理复垦土壤Ca₂-P、Ca₈-P、Al-P、Fe-P含量都高于基质处理，Ca₁₀-P含量小于基质处理，O-P含量与基质处理差异不显著。这一结果可为溶磷细菌在复垦土壤上应用技术的研发提供理论基础。

Screening of Phosphate Solubilizing Bacteria and Activating of Insoluble Phosphorus in Reclaimed Soil

In order to study the activation effect of phosphate solubilizing bacteria on insoluble phosphorus in reclaimed soil, seven phosphate solubilizing bacteria were isolated from a calcareous soil by the PVK plate dilution method. The phosphorus solubilization abilities of 7 strains were between 296.5-563.5 mg/L and there was a significant positive correlation between the phosphate solubilizing capacity and the ratio of D/d (p<0.01). The 16sRNA sequence analysis showed that the strains, W1 and W6, belong to Enterobacter sp., W2 and W4 belong to Burkholderia sp., W3 and W5 belong to Rahnella sp., while W7 belongs to Fluorescent pseudomonas. The strains, W3, W4 and W7, were selected as the experimental strains. Tricalcium phosphate and phosphate rock powders were selected as insoluble phosphorus sources, the effects of single strain and strains combination on available phosphorus content, inorganic phosphorus content and rape yield in a reclaimed soil matched with the insoluble phosphates were studied. The results showed that with the same substrate, the available phosphorus content and the rapeseed yield in the reclaimed soils with different treatments of phosphorus soluble bacteria were significantly higher than the matrix treatment (p<0.05). The effects of strains combination treatments were better than those of the single strain treatments, the W3+W4+W7 treatment showed the most significant improvement on both available phosphorus content and rape yield. In the experiments of using tricalcium phosphate as the insoluble phosphorus source, the available phosphorus content and rapeseed yield of the W3 + W4 + W7 treatment were 94.81% and 40.25% higher than those of the single strain treatment, respectively, and were 34.13%, 9.43% higher than those of the treatment of single strain + phosphate rock powder, respectively. Under the same substate condition, the contents of Ca₂-P, Ca₈-P, Al-P and Fe-P in reclaimed soils with all strain treatments were higher than those in the matrix treatment, but the contents of Ca₁₀-P were lower and the contents of O-P were similar. This result can provide a theoretical basis for the research and development of application technology of using phosphate solubilizing bacteria in reclaimed soils.