Submitted to: Solanaceae International Congress Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 5/29/2006
Publication Date: 7/30/2006
Citation: Ramsay, G., Mclean, K., Waugh, R., Spooner, D.M., Bryan, G. 2006. On the domestication of potato: evidence from molecular studies [abstract]. Solanaceae International Congress Proceedings. p. 89. Interpretive Summary:
Technical Abstract: Molecular evidence using nuclear markers on a large set of accessions has recently shown that the direct ancestors of the cultivated potato lie amongst a morphologically similar group of species from the Northern Brevicaule complex from central and Southern Peru. Previous suggestions of a major involvement, such as a direct hybrid origin, of species from Bolivia and Argentina in the creation of tetraploid potato now appear untenable. Here we present further analysis of the AFLP data set, also drawing on published data on cytoplasmic markers to clarify the domestication of the potato and its early spread in South America. In multivariate analyses of the AFLP data, the Northern Brevicaule group of species form a cluster which overlaps with the cultivated group, and it is this association of the two groups which will be explored in more detail. Accessions in the study from the Northern Brevicaule group are currently held in their originating genebanks under the names of nine different but morphologically similar species, and some accessions of several of these species appear to be more similar to the cultivated group than others. Comparing the altitudinal and eco-geographic ranges of the accessions in this study together with their molecular similarity to the main group of cultivated accessions suggests that domestication may have occurred from sub-groups of these taxa which came from a relatively narrow altitudinal band within the range of these taxa. The taxa closest to the cultigens also appear to be more vigorous types, growing in the richer soils at these altitudes. A synthesis will be attempted, which will show a central point of domestication, migration of these early domesticates both altitudinally and laterally along the Andes, and subsequent introgression introducing some cytoplasmic diversity but retaining a main core of nuclear DNA diversity similar to the original wild progenitors.