title: Phylogenetic Diversity of Ammopiptanthus Rhizobia and Distribution of Rhizobia Associated with Ammopiptanthus mongolicus in Diverse Regions of Northwest China.
abstract: Aiming to investigate the diversity and distribution of rhizobia associated with Ammopiptanthus, an endangered evergreen legume widely distributed in deserts, we characterized a total of 219 nodule isolates from nine sampling sites in Northwest China with different soil characteristics based upon restriction fragment length polymorphism (RFLP) analysis of 16S ribosomal RNA (rRNA) and symbiotic genes (nodC and nifH). Ten isolates representing different 16S rRNA-RFLP types were selected for further sequence analyses of 16S rRNA and four housekeeping genes. As results, nine genospecies belonging to the genera Ensifer, Neorhizobium, Agrobacterium, Pararhizobium, and Rhizobium could be defined among the isolates. The nodC and nifH phylogenies of 14 isolates representing different symbiotic-RFLP types revealed five lineages linked to Ensifer fredii, Ensifer meliloti, Rhizobium leguminosarum, Mesorhizobium amorphae, and Rhizobium gallicum, which demonstrated the various origins and lateral transfers of symbiotic genes between different genera and species. The rhizobial diversities of Ammopiptanthus mongolicus varied among regions, and the community compositions of rhizobia associated with A. mongolicus were significantly different in wild and cultured fields. Constrained correspondence analysis showed that the distribution of A. mongolicus rhizobia could be explained by available potassium content and that the assembly of symbiotic types was mainly affected by available phosphorus content and carbon-nitrogen ratio.
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Xinye
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Huo
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Guiji
authors.initials: G
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Dehui
authors.initials: D
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China. weigehong@nwsuaf.edu.cn.
authors.forename: Gehong
authors.initials: G
authors.lastname: Wei
mesh_terms: D044822:Biodiversity; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D007887:Fabaceae / Q000382:microbiology*; D005798:Genes, Bacterial; D014644:Genetic Variation; D059128:Mesorhizobium / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Ammopiptanthus; CCA; Community structure; Rhizobia; Symbiotic genes