不同施肥模式对设施菜地细菌群落结构及丰度的影响

【目的】研究设施菜地不同施肥处理下细菌群落结构和丰度的变化。【方法】利用16S rRNA基因的末端限制性片段多态性分析（T-RFLP）技术与实时荧光定量（Real-time）PCR 相结合的方法，研究了不施肥（CK）、1/2量氮磷钾化肥+1/2量有机肥（1/2 MNPK）、氮磷钾化肥+有机肥（MNPK）、有机肥（M）、氮磷钾化肥（NPK）5种不同施肥处理对土壤中细菌群落结构和丰度的影响。【结果】147个阳性质粒测序结果显示设施菜地土壤中细菌主要包括厚壁菌门、变形菌门、绿弯菌门、酸杆菌门、拟杆菌门、放线菌门、疣微菌门、蓝藻门、硝化螺旋菌门及浮霉菌门10个门。其中变形细菌（26.53%）、拟杆菌（14.97%）和放线细菌（10.88%）是优势菌，共52.38%。Shannon-Wiener、Simpson’s diversity、Margalef指数均是在1/2 MNPK 处理下0—20 cm表层土壤中达到最高，分别为3.14、0.945、4.31，Evenness指数则以NPK处理0—20 cm土层最高，为0.941。不同施肥处理细菌的主要类群种类及丰度明显不同。RDA分析显示pH（P=0.002）和有机质含量（P=0.006）是造成群落结构差异的主要原因。定量PCR结果显示1/2 MNPK 处理下0—20 cm和20—40 cm土层中细菌的16S rRNA基因丰度最高达5.26×109和4.96×109拷贝数/g，比CK处理增加90.8%和197.5%。【结论】施用有机肥处理的土壤中细菌的优势种群明显不同于单施化肥和不施肥，适量化肥和有机肥配合施用（1/2 MNPK）可以显著增加土壤中细菌的丰度。

Effects of Different Fertilization Regimes on Abundance and Composition of the Bacterial Community in Greenhouse Vegetable Soils

【Objective】 The impacts of different fertilization regimes on the structure and abundance of soil microbial community were studied.【Method】The influence of fertilization regimes including CK, 1/2MNPK, MNPK, M and NPK on the structure community and abundance of the 16S rRNA gene were analyzed by terminal restriction fragment length polymorphism (T-RFLP) and real-time quantitative PCR.【Result】The sequences from 147 positive clones implied that there were ten phylums bacteria in the soil. They were Firmiutes, Proteobacteria, Chloroflexi, Acidobacteria, Bacteroridetes, Actinobacteria, Verrucomicrobia, Cyanbacteria, Nitrospira, and Planctomycetes. Proteobacteria (relative abundance 26.53%), Bacteroridetes (relative abundance 14.97%) and Actinobacteria (relative abundance 10.88%) were dominated diversities in the soil accounted for relative abundance 52.38%. The highest abundance of Shannon, Simpson’s diversity and Margalef Index were all showed in 0-20 cm soil layer of 1/2MNPK treatment with 3.14, 0.945 and 4.31, respectively. The highest Evenness Index was showed in 0-20 cm layer soil of NPK treatment with 0.941. There were pronounced differences in the primary bacterial community composition and abundance in the different fertilization regimes. RDA results indicated that pH (P=0.002) and soil organic matter (SOM, P=0.006) had the greatest influence on the bacterial community composition. The highest abundance of bacterial both in 0-20 cm and 20-40 cm soil layers were detected in 1/2MNPK treatment. The 16S rRNA gene copy numbers in 1/2MNPK regime with 5.26×109 and 4.96×109 copies/g soil for 0-20 cm and 20-40 cm layers soils respectively, which increased by 90.8% and 197.5% compared to the unfertilized regime.【Conclusion】The dominant populations of bacteria in the soil fertilized with organic manure were significantly different from the chemical fertilizer and unfertilized regime. The rational proportion of chemical fertilizer and organic manure (1/2MNPK) can significantly increase the abundance of 16S rRNA gene in the soil.