Author
BEDOYA, C. - International Maize & Wheat Improvement Center (CIMMYT) | |
DREISIGACKER, S. - International Maize & Wheat Improvement Center (CIMMYT) | |
HEARNE, S. - International Institute Of Tropical Agriculture (IITA) | |
FRANCO, J. - Universidad Del La Republica | |
MIR, C. - Centre National De La Recherche Scientifique | |
PRASANNA, B. - International Maize & Wheat Improvement Center (CIMMYT) | |
TABA, S. - International Maize & Wheat Improvement Center (CIMMYT) | |
CHARCOSSET, A. - Centre National De La Recherche Scientifique | |
Warburton, Marilyn |
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/21/2017 Publication Date: 4/12/2017 Citation: Bedoya, C., Dreisigacker, S., Hearne, S., Franco, J., Mir, C., Prasanna, B.M., Taba, S., Charcosset, A., Warburton, M.L. 2017. Linking modern maize populations to pre-Columbian cultures using microsatellite markers and archeological evidence. PLoS ONE. 12(4). Article: e0173488. Interpretive Summary: Corn (maize) was domesticated in central Mexico and was moved towards the Caribbean and South America during early human and subsequent post-Columbian human migration and trade. The current study used molecular genetic markers to measure how 194 maize populations from 23 countries of Latin America and the Caribbean are related to each other, and how much genetic diversity they contain. The populations represent 131 farmer’s maize varieties, or landraces, which are the varieties that farmers created and maintained over many generations of selection of the seeds representing the seeds they find the best for yield, disease, insect, and environmental stress tolerance, as well as flavor, color, and other nutritive and useful qualities. The relationships between Mexican landraces were tested first, because known patterns of relationships and diversity from past studies are available to confirm our analysis and characterization techniques. Following confirmation of past studies, all Latin American maize was analyzed, and our study is the first to look at many of the landraces in relation to each other. Characterization indicates that we can trace historical or archaeological events with the marker diversity. Three main groups of maize landraces were identified with the genetic markers. The first, the Mexico and Southern Andes group, highlights the Pre-Columbian and modern exchange of germplasm between North and South America. The second group, Mesoamerica lowland, shows that humans migrated (with their maize landraces) two different times to the Caribbean. The third, the Andean group, displayed very early introduction of maize into the Andes, and these landraces were not moved out of this region, nor mixed very much with any other populations, highlighting the geographic and trade isolation of this region with other parts of Latin America. Thus, the history of maize migration and introductions in Latin America can be associated with specific human migrations and activities, which played an important role in the creation and maintenance of the existing landraces of maize in Latin America. Technical Abstract: Maize was spread from its point of domestication in Mesoamerica towards the Caribbean and South America during early human and subsequent post-Columbian human migration and trade. This study describes the genetic diversity and population structure of 194 native maize populations from 23 countries of Latin America and the Caribbean. The germplasm, which represented 131 distinct landraces, was genetically characterized using 28 SSR markers on bulked DNA samples. Mexican populations were first characterized alone, because they are associated with very good historical and anthropological data which can be used to validate the conclusions drawn from the SSR data. Following confirmation of the technique, all Latin American populations were analyzed jointly to identify relationships between all accessions. Results reveal that historical or archaeological events can be associated with cultivated maize diversity. Three main groups of maize germplasm were identified with the SSR markers. The first, the Mexico and Southern Andes group, highlights the Pre-Columbian and modern exchange of germplasm between North and South America. The second group, Mesoamerica lowland, supports the hypothesis that two separate human migration events could have contributed to Caribbean germplasm. The third, the Andean group, displayed very early introduction of maize into the Andes, with little mixing since then, other than a regional interchange zone active in the past. Thus, the history of maize migration and introductions in Latin America can be associated with specific human migrations and activities, which played an important role in the creation and maintenance of the existing races of maize in Latin America. |