11氮磷增施对植物根际微生物群落和氮循环微生物群落之影响.pdf

World J Microbiol Biotechnol (2014) 30:99–107 DOI 10.1007/s11274-013-1427-9 ORIGINAL PAPER Effect of nitrogen and phosphorus fertilization on the composition of rhizobacterial communities of two Chilean Andisol pastures Milko A. Jorquera ? Oscar A. Mart?′nez ? Luis G. Marileo ? Jacquelinne J. Acun?a ? Surinder Saggar ? Mar?′a L. Mora Received: 7 April 2013 / Accepted: 3 July 2013 / Published online: 11 July 2013 ó Springer Science+Business Media Dordrecht 2013 Abstract The effect of nitrogen (N) and phosphorus Pha-1 year-1) and N–P application (270 kg N ha-1 (P) fertilization on composition of rhizobacterial commu- year-1 plus 240 kg P ha-1 year-1). In Site 2 (fertilized for nities of volcanic soils (Andisols) from southern Chile at 6 years with P; 400 kg P ha-1 year-1), PCR–DGGE tar- molecular level is poorly understood. This paper investi- geting rpoB, nifH, amoA and alkaline phosphatase genes gates the composition of rhizobacterial communities of two and MDS analysis showed changes in rhizobacterial com- Andisols under pasture after 1- and 6-year applications of munities only at the highest rate of N application N (urea) and P (triple superphosphate). Soil samples were (600 kg N ha-1 year-1). Quantitative PCR targeting 16S collected from two previously established sites and the rRNA genes also showed higher abundance of bacteria at composition of rhizobacterial communities was determined higher N application. In samples from both sites, the by denaturing gradient gel electrophoresis (PCR–DGGE). Shannon–Wiener index did not show signi?cant difference The difference in the composition and diversity between in the diversity of rhizobacterial communities. The changes rhizobacterial communities was assessed by nonmetric observed in rhizobacterial communities coincide in N fer- multidimensional scaling (MDS) analysis and the Shan- tilized pastures with lower soil pH and higher pasture non–Wiener index. In Site 1 (fertilized for 1 year), PCR– yields. Th