title: Nitrogen-metabolism related genes in barley - haplotype diversity, linkage mapping and associations with malting and kernel quality parameters.
abstract: BACKGROUND
  Several studies report about intra-specific trait variation of nitrogen-metabolism related traits, such as N(itrogen)-use efficiency, protein content, N-storage and remobilization in barley and related grass species. The goal of this study was to assess the intra-specific genetic diversity present in primary N-metabolism genes of barley and to investigate the associations of the detected haplotype diversity with malting and kernel quality related traits.
  
  
  RESULTS
  Partial sequences of five genes related to N-metabolism in barley (Hordeum vulgare L.) were obtained, i.e. nitrate reductase 1, glutamine synthetase 2, ferredoxin-dependent glutamate synthase, aspartate aminotransferase and asparaginase. Two to five haplotypes in each gene were discovered in a set of 190 various varieties. The development of 33 SNP markers allowed the genotyping of all these barley varieties consisting of spring and winter types. Furthermore, these markers could be mapped in several doubled haploid populations. Cluster analysis based on haplotypes revealed a more uniform pattern of the spring barleys as compared to the winter barleys. Based on linear model approaches associations to several malting and kernel quality traits including soluble N and protein were identified.
  
  
  CONCLUSIONS
  A study was conducted to investigate the presence of sequence variation of several genes related to the primary N-metabolism in barley. The detected diversity could be related to particular phenotypic traits. Specific differences between spring and winter barleys most likely reflect different breeding aims. The developed markers can be used as tool for further genetic studies and marker-assisted selection during breeding of barley.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Corrensstr, 3, 06466, Stadt Seeland, Germany. roder@ipk-gatersleben.de.
authors.forename: Inge E
authors.initials: IE
authors.lastname: Matthies
authors.forename: Stephan
authors.initials: S
authors.lastname: Weise
authors.forename: Jutta
authors.initials: J
authors.lastname: Förster
authors.forename: Viktor
authors.initials: V
authors.lastname: Korzun
authors.forename: Nils
authors.initials: N
authors.lastname: Stein
authors.forename: Marion S
authors.initials: MS
authors.lastname: Röder
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000235:genetics; D001215:Asparaginase / Q000235:genetics; D001219:Aspartate Aminotransferases / Q000235:genetics; D002874:Chromosome Mapping; D016000:Cluster Analysis; D017343:Genes, Plant; D014644:Genetic Variation; D005838:Genotype; D005974:Glutamate-Ammonia Ligase / Q000235:genetics; D006239:Haplotypes; D001467:Hordeum / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D015810:Linkage Disequilibrium; D050901:Nitrate Reductase / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D012621:Seasons; D012639:Seeds
chemical_list: D010940:Plant Proteins; D000594:Amino Acid Oxidoreductases; C042233:glutamate synthase (ferredoxin); D050901:Nitrate Reductase; D001219:Aspartate Aminotransferases; D001215:Asparaginase; C083818:glutamine synthetase 2; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen