title: Genetic diversity of indigenous soybean-nodulating rhizobia in response to locally-based long term fertilization in a Mollisol of Northeast China.
abstract: The influences of five different fertilizer treatments on diversity of rhizobia in soybean nodule were investigated in a long-term experiment with with four replicates: (1) control (without fertilization), (2) balanced NPK fertilizer (NPK), and (3-5) unbalanced chemical fertilizers without one of the major elements (NP, PK, and NK) in Mollisol in Northeast China. The highest soybean yield was observed in the NPK treatment. Total of 200 isolates were isolated and grouped into four Bradyrhizobium genospecies corresponding to B. japonicum, B. diazoefficiens, B. ottawaense and Bradyrhizobium sp. I, based upon the multilocus sequence analysis of 6 housekeeping genes. The Bradyrhizobium sp. I was extensively distributed throughout the study site and was recorded as the dominant soybean rhizobia (82.5-87.5%). Except the NK treatment, the other fertilizer treatments had no effect on rhizobial species composition. Compared with the CK treatment, all the fertilizer treatments decreased species richness, diversity and evenness. The soil organic carbon contents, available N content and pH were the key soil factors to rhizobial community structure. Results suggest that long-term fertilization can decrease rhizobial species diversity, while balanced fertilization with NPK is the most suitable fertilization regime if taking both soybean yields and rhizobial diversity into account.
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China. yanjun985625@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Yan
authors.affiliation: State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
authors.forename: WenFeng
authors.initials: W
authors.lastname: Chen
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: XiaoZeng
authors.initials: X
authors.lastname: Han
authors.affiliation: Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340, México D.F., Mexico.
authors.forename: EnTao
authors.initials: E
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: WenXiu
authors.initials: W
authors.lastname: Zou
authors.affiliation: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China.
authors.forename: ZhiMing
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D044822:Biodiversity; D020369:Bradyrhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D005308:Fertilizers / Q000032:analysis*; D005798:Genes, Bacterial; D020043:Genes, Essential; D014644:Genetic Variation; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012231:Rhizobium / Q000235:genetics*; D053204:Root Nodules, Plant / Q000235:genetics / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D013025:Glycine max / Q000254:growth & development* / Q000382:microbiology
chemical_list: D005308:Fertilizers; D012987:Soil
keywords: Balanced fertilization; Bradyrhizobium; Genetic diversity; Unbalanced fertilization