有机种植对麦田土壤微生物群落影响

Influence of Organic Cultivation on Soil Microbial Community in Cornfield

以麦田土壤微生物为研究对象,利用平板计数、微平板法(BIOLOG-ECO)、聚合酶链式反应与变性梯度凝胶电泳联用技术(PCR-DGGE)探究有机种植方式对麦田土壤微生物群落的影响。平板计数结果表明,在各土层中细菌数量最多,约为1.1×107 CFU/g。BIOLOG-ECO测定结果表明,有机种植表层土样中微生物活性最高,其252h平均颜色变化率(AWCD)达0.68,有机种植较之常规种植能够显著增加土壤微生物群落多样性(P<0.05)。在麦田中施用有机肥初期可以提高表层土壤微生物利用碳源的能力。PCR-DGGE结果表明,有机种植的条带数明显多于常规种植,有机种植麦田中细菌种群更为丰富,有机种植可以增加土壤细菌多样性,且不同土层细菌多样性存在差异。对DGGE条带进行了测序分析,常规种植主要优势菌群归属为马赛菌属(Massiliasp.),有机种植中则是埃希氏杆菌属(Escherichiasp.)和志贺氏杆菌属(Shigellasp.)。综上,有机种植可丰富麦田土壤微生物群落,增加土壤微生物多样性。

Cornfield was taken as the research object in this study and plate counting,BIOLOG-ECO and PCR-DGGE methods were used to compare the impacts of organic and conventional cultivation on soil microbial community in cornfield.Plate counting indicated that the population of bacteria was the largest,about 1.1×10^7CFU/g in different soil layers.The BIOLOG-ECO method demonstrated that the microbial activity was the highest in the surface soil,and the AWCD went up to 0.68 at 252h.Comparing with conventional cultivation,organic cultivation could significantly increase the soil microbial community diversity（P0.05）.The ability of carbon utilization could be increased in the beginning stage of organic cultivation.The method of PCR-DGGE showed that there were more stripes and the species of bacteria were more abundant in organic cultivation,which illustrated that organic cultivation could increase the diversity of bacteria in soil,and there were differences between bacteria diversity in different soil layers.The Analysis of DGGE bands sequencing revealed that Massilia,Escherichia and Shigella were three dominant bacteria in soils.To sum up,organic cultivation can rich microbial community,as well as augment microbial diversity in cornfield.