用PCR-DGGE研究菌肥对西藏青稞土壤微生物群落多样性的影响

A PCR-DGGE-Based Study of the Effects of Microorganism Agents on Soil Microbial Community Diversity in Tibetan Barley-Planting Soil

为探讨微生物菌肥对西藏青稞土壤根际微生态的影响,利用传统纯培养与PCR-DGGE(聚合酶链式反应-变性梯度凝胶电泳)技术相结合的方法,研究了谷特微生物菌肥不同施用方式和施肥浓度对西藏青稞根区土壤微生物量和细菌群落结构的影响.结果表明,与对照相比,施肥处理显著降低了土壤真菌数量(p<0.05),土壤放线菌数量和微生物量氮含量显著上升(p<0.05).DGGE分析表明,菌肥处理土壤与未施菌肥土壤的细菌群落结构存在明显差异,土壤微生物区系结构发生了改变;DGGE所反映的土壤细菌多样性可以用来判断菌肥发挥作用的程度,合理指导菌肥的施用.本研究中,菌肥的施入促进了土著细菌Acidobacteria、Actinobacteria和Bacillus的生长,抑制了土壤中Blastomonas、Uncultured Rhizobium和Cyanobacterium的生长.两种施肥方式,根施对青稞根区土壤中细菌、真菌和放线菌数量的影响较叶面喷施大,根施对土壤微生物区系的改变较叶面喷施高,根施最佳菌肥施用量为20.0mL/hm2,叶面喷施最佳菌肥施用量为26.7mL/hm2.本研究为准确预测和评价微生物菌肥的施用效果提供了技术参考.

In order to investigate the effects microorganism agents （MA） on soil micro-ecological character istics in Tibetan barley, a field plot experiment with different managements and different volume of micro bial fertilizer was carried out to monitor the soil fertility, soil microbial biomass nitrogen and soil microbial community diversity by the denaturing gradient gelelectrophoresis （DGGE） method after MA application. Compared with the control, fertilization treatment significantly reduced the number of soil fungi （p 0.05）, while the soil actinomycetes and microbial DGGE profile revealed that microorganism agents a b ff iomass nitrogen increased significantly （p ~ 0.05）. ected the structure of bacterial community, and so it can be used to determine the extent of fertilizer and guide fertilizer application. MA application promoted the growth of indigenous bacteria Acidobacteria, Actinobacteria and Bacillus, hut inhibited the growth of Blastomonas, uncultured Rhizobium and Cyanobacterium in the soil. Of the two fertilization methods used, root-application showed a greater influence on soil bacteria, fungi and actinomycetes than foliar spray. The optimum rate of MA application was 20. 0 mL/ha for root application and 26.7 mL/ha for foliar spray.