Whole-genome sequences in ancient bean seeds: new insights into the domestication history of common bean (Phaseolus vulgaris) in South-America

M. LARI; A. LOB; E. BITOCCHI; LEMA V.; GIL A.; DE LORENZI M.; H. DE BOER; G. BERTORELLE; E. TRUCCHI; L. NANNI; A. BENAZZO; J. A. SCOTT; S. VAI; OLISZEWSKI, O; C. XU; MICHIELI T.; BABOT M.P; B. STAR; NEME, G; R. PAPA; D. CARAMELLI; S. BOESSENKOOL

Jena

Congreso; 8th International Symposium on Biomolecular Archaeology (ISBA); 2018

Investigating the domestication history of cultivated plants in different geographic areas is relevant to understanding humanhistory, human-induced changes in plant genomes, and local adaptations to new environments. Genomic analyses on moderncommon bean (P. vulgaris) accessions indicate that two major genetic pools can be associated to Mesoamerica and the Andes,supporting the hypothesis of two independent domestication events that occurred approximately 8,000 years ago. Toinvestigate genomic change following domestication in the Andes, we collected ancient bean seeds from seven pre-Columbianarcheological sites in Northern Argentina spanning at least 1800 years. Preliminary analysis showed that DNA was extremelywell preserved in most of the seeds and we sequenced 19 genomes with coverage between 1 and 18X. All the seeds showed adomestication-associated phenotype. Comparing the genomes of these ancient seeds to a panel of modern genomes withwild and domesticated samples from Central and South America, we find that ancient seeds don"t have their closest relativesamong the modern varieties cultivated in the same region today. On the contrary, they show higher genetic similarity tomodern accessions commonly found in Chile, possibly as a consequence of ancient trades or ancestral traits sharing. Ancientseeds cluster in one genetic group indicating that these varieties were likely the product of a single domestication event andwere cultivated in that area without major transitions at least until the Spanish colonization of South America. By investigatingthe different levels of similarity and dissimilarity between modern (wild and domestic) and ancient seeds at different genes,we aim to study the genetic basis of the phenotypic changes that occurred following domestication.