Population genetics of the Four Corners potato (Solanum jamesii)

<p>The domestication of wild plant species can begin with gathering and transport of propagules by Indigenous peoples. The effect on genomic composition, especially in clonal, self-incompatible perennials would be instantaneous and drastic with respect to new, anthropogenic populations subsequently established. Populations of the Four Corners potato, <em>Solanum jamesii</em> Torr., associated with archaeological sites in Utah and northern Arizona are unable to produce seeds and fruits unless crossed with non-archaeological populations. Presumably, founder events reduced genetic diversity and mating capability when tubers were transported and established in ancient gardens. Herein genetic sequencing (GBS) data is used to further examine the hypothesis of domestication in this culturally significant species by sampling 25 archaeological and non-archaeological populations. Archaeological populations from Utah, Colorado, and northern Arizona have lower levels of polymorphic loci, unique alleles, and heterozygosity than non-archaeological populations from the Mogollon Region of central Arizona and New Mexico. Principle components analysis, Fst values, and structure analysis revealed that genetic relationships among archaeological populations did not correspond to geographic proximity. Populations near Escalante, Utah were either derived from those found on the Mogollon Rim (400 km south) or related to those in Bears Ears (178 km east). Populations in Chaco Canyon are also similar to Escalante, but those in Mesa Verde, Chimney Rock, and El Morro have affinities to southern New Mexico and Texas. Movement of tubers from the Mogollon Region may have occurred many times and in multiple directions during the past, resulting in the complex genetic patterns seen in these populations from across the Four Corners Region.</p>