title: Biogeography of Sinorhizobium meliloti nodulating alfalfa in different Croatian regions.
abstract: Sinorhizobium meliloti is a nitrogen-fixing rhizobium symbiont of legumes, widespread in many temperate environments the high genetic diversity of which enables it to thrive as a symbiont of host legumes and free-living in soil. Soil type, together with geographic differences and host plant genotype, seem to be prominent factors in shaping rhizobial genetic diversity. While a large body of research supports the idea that the genetic structure of free-living microbial taxa exhibits a clear biogeographic pattern, few investigations have been performed on the biogeographic pattern of S. meliloti genotypes in a restricted geographic range. In the present study, a collection of 128 S. meliloti isolates from three different regions in Croatia was investigated to analyze the relationship between genetic diversity, geographic distribution, soil features and isolate phenotypes by using amplified fragment length polymorphism (AFLP) as a genome-wide scanning method. Results obtained led to the conclusion that the genotypes of isolates cluster according to the region of origin and that the differentiation of S. meliloti populations can be mainly ascribed to geographic isolation following an isolation-by-distance model, with a strong distance-decay relationship of genetic similarity with distance, in which local soil conditions are not the major component influencing the isolate phenotypes or their genomic differentiation.
authors: Institute of Plant Genetics, National Research Council (IGV-CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy.
authors: Francesca
authors: F
authors: Donnarumma
authors: Department of Biology, University of Firenze, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy. Electronic address: marco.bazzicalupo@unifi.it.
authors: Marco
authors: M
authors: Bazzicalupo
authors: Department of Microbiology (AGR), University of Zagreb, Grad Zagreb, Croatia.
authors: Mihaela
authors: M
authors: Blažinkov
authors: Department of Biology, University of Firenze, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy.
authors: Alessio
authors: A
authors: Mengoni
authors: Department of Microbiology (AGR), University of Zagreb, Grad Zagreb, Croatia.
authors: Sanjia
authors: S
authors: Sikora
authors: Department of Microbiology (AGR), University of Zagreb, Grad Zagreb, Croatia.
authors: Katarina Huić
authors: KH
authors: Babić
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D017523:Croatia; D004269:DNA, Bacterial / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D000455:Medicago sativa / Q000382:microbiology*; D058974:Phylogeography; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000382:microbiology; D016962:Sinorhizobium meliloti / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial
keywords: Alfalfa; Biogeography; Croatia; Genomic differentiation; Sinorhizobium meliloti