Landscape genetics, adaptive diversity and population structure in Phaseolus vulgaris

Here we studied the organization of genetic variation of the common bean (Phaseolus
vulgaris) in its centres of domestication.
We used 131 single nucleotide polymorphisms to investigate 417 wild common bean accessions
and a representative sample of 160 domesticated genotypes, including Mesoamerican
and Andean genotypes, for a total of 577 accessions.
By analysing the genetic spatial patterns of the wild common bean, we documented the
existence of several genetic groups and the occurrence of variable degrees of diversity in
Mesoamerica and the Andes. Moreover, using a landscape genetics approach, we demonstrated
that both demographic processes and selection for adaptation were responsible for
the observed genetic structure.
We showed that the study of correlations between markers and ecological variables at a
continental scale can help in identifying local adaptation genes. We also located putative areas
of common bean domestication in Mesoamerica, in the Oaxaca Valley, and the Andes, in
southern Bolivia-northern Argentina. These observations are of paramount importance for the
conservation and exploitation of the genetic diversity preserved within this species and other
plant genetic resources.