Genetic analysis of archeological maize from the site of San Lorenzo (Azapa, Chile): A contribution to the prehispanic maize problem

We report the first genetic analysis of archeological maize specimens from the site of San Lorenzo (1,500-700 BP) (Azapa valley, Arica, Chile). Ancient DNA was successfully isolated from 11 archeological maize grains. The Alcohol dehydrogenase 2 (Adh2) gene was analyzed because it has a highly variable region due to the presence of a microsatellite region around -28 to -8, which consists of GA repeats that may be present in three types GA_n, GA_nTA and GA₁AA₁GA_n, which is used as an informative region of the routes of initial dispersion of maize. Five Adh2 alleles were obtained and the alignment of these sequences according to the variable region revealed the presence of the three types of GA repeated. Our results do not provide sufficient evidence to reject any maize spread model proposed. This is the first report focused on genetic analysis of maize associated with an archeological site in Chile.