Tracing back the history of pepper (Capsicum annuum L.) in the Iberian Peninsula

Abstract

Capsicum annuum was the first Capsicum introduced into Europe, likely trough Spain and Portugal, at the end of the XVth century. Therefore, the Iberian Peninsula constitutes a significant secondary diversification centre, where part of the original pepper genepool brought back from America might be preserved in the form of landraces. A previous work suggested that the diversification process of C. annuum in Spain may occur from an ancient population, still represented by some landraces with ancestral traits. The current work is focused on clarifying the origins and genetic relationships among the pepper landraces from the Iberian Peninsula. For that purpose, a larger number of Spanish peppers, a collection of Portuguese landraces and a panel of C. annuum resources from Mexico, including the wild relative C. annuum var. glabriusculum were genotyped with the DArTseq technology. Sequencing output consisted of 27,159 tags, of which 5,007 SNPs were selected for further analyses. Clustering and STRUCTURE approaches clearly differentiated wild and Mexican peppers from those originating in the Iberian Peninsula. Various Spanish and Portuguese accessions clustered within the Mexican group, while the others were primarily organized following a geographical pattern, although their genomic composition was not extremely different