title: Multiple origins of the determinate growth habit in domesticated common bean (Phaseolus vulgaris).
abstract: OBJECTIVE
  The actual number of domestications of a crop is one of the key questions in domestication studies. Answers to this question have generally been based on relationships between wild progenitors and domesticated descendants determined with anonymous molecular markers. In this study, this question was investigated by determining the number of instances a domestication phenotype had been selected in a crop species. One of the traits that appeared during domestication of common bean (Phaseolus vulgaris) is determinacy, in which stems end with a terminal inflorescence. It has been shown earlier that a homologue of the arabidopsis TFL1 gene - PvTFL1y - controls determinacy in a naturally occurring variation of common bean.
  
  
  METHODS
  Sequence variation was analysed for PvTFL1y in a sample of 46 wild and domesticated accessions that included determinate and indeterminate accessions.
  
  
  RESULTS
  Indeterminate types - wild and domesticated - showed only synonymous nucleotide substitutions. Determinate types - observed only among domesticated accessions - showed, in addition to synonymous substitutions, non-synonymous substitutions, indels, a putative intron-splicing failure, a retrotransposon insertion and a deletion of the entire locus. The retrotransposon insertion was observed in 70 % of determinate cultivars, in the Americas and elsewhere. Other determinate mutants had a more restricted distribution in the Americas only, either in the Andean or in the Mesoamerican gene pool of common bean.
  
  
  CONCLUSIONS
  Although each of the determinacy haplotypes probably does not represent distinct domestication events, they are consistent with the multiple (seven) domestication pattern in the genus Phaseolus. The predominance of determinacy in the Andean gene pool may reflect domestication of common bean prior to maize introduction in the Andes.
authors.affiliation: Department of Plant Sciences/MS1, Section of Crop and Ecosystem Sciences, University of California, Davis, 95616-8780, USA.
authors.forename: Myounghai
authors.initials: M
authors.lastname: Kwak
authors.forename: Orlando
authors.initials: O
authors.lastname: Toro
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Debouck
authors.forename: Paul
authors.initials: P
authors.lastname: Gepts
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D005788:Gene Pool; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006239:Haplotypes; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000235:genetics* / Q000254:growth & development*; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; C102864:TFL1 protein, Arabidopsis