title: Influence of nitrogen fertilization on diazotrophic communities in the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.).
abstract: Diazotrophs in the soil may be influenced by plant factors as well as nitrogen (N) fertilization. In this study, we investigated potential diazotrophic communities in the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.) supplied with differing amounts of N. The community structure of N(2)-fixing bacteria was profiled using the length heterogeneity polymerase chain reaction (LH-PCR) and terminal restriction fragment length polymorphism (T-RFLP) based on a variation in the nifH gene. Higher numbers of diazotrophs were detected by T-RFLP compared to LH-PCR. The lowest number of N(2)-fixing bacteria was observed in the rhizosphere soil with high N fertilization. T-RFLP was a better method than LH-PCR for profiling microbial diversity of diazotrophs using multidimensional scaling (MDS) and analysis of similarity (ANOSIM) of fingerprints as well as diversity measures. The supply of N fertilizer appeared to negatively influence the abundance of diazotrophs in the rhizophere of the Jerusalem artichoke.
authors.affiliation: Key Laboratory of Marine Biology, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. lxh108@yahoo.com.cn
authors.forename: Xianfa
authors.initials: X
authors.lastname: Meng
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Long
authors.forename: Zhaopu
authors.initials: Z
authors.lastname: Liu
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Zhang
authors.forename: Rengel
authors.initials: R
authors.lastname: Zed
mesh_terms: D058448:Biota; D005308:Fertilizers; D006368:Helianthus / Q000382:microbiology*; D054892:Metagenome; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000235:genetics; D018517:Plant Roots / Q000382:microbiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D058441:Rhizosphere
chemical_list: D005308:Fertilizers; D010088:Oxidoreductases; C029130:nitrogenase reductase; D009584:Nitrogen