Submitted to: Botanical Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2006
Publication Date: 8/5/2006
Citation: Spooner, D.M., Rios, D., Rodriguez, F., Ghislain, M. 2006. Nuclear and chloroplast DNA reassessment of the origin of the first European introductions of cultivated potatoes from the Canary Islands [abstract]. Botanical Society of America Abstracts. p. 749. Interpretive Summary:
Technical Abstract: The modern cultivated potato was first recorded in Europe in the Canary Islands 1567, but its origin has long been in dispute. Two competing hypotheses have proposed an "Andean" area (somewhere from upland Venezuela to northern Argentina) or a lowland south central "Chilean" area. Potato landraces from these two areas can be distinguished, although sometimes with difficulty, by 1) cytoplasmic sterility factors, 2) morphological traits, 3) day length adaptation, 4) microsatellite markers, and 5) co-evolved chloroplast and mitochondria DNA. The Chilean introduction hypothesis originally was proposed because of similarities of Chilean landraces to modern "European" cultivars regarding traits 2 and 3. Alternatively, the Andean introduction hypothesis suggested that 1) traits 2 and 3 of European potato evolved rapidly, in parallel, from Andean landraces through selection after import to Europe to a Chilean type, and 2) the worldwide late blight epidemics beginning in 1845 in the United Kingdom displaced most existing European cultivars and the potato was subsequently improved by importations of Chilean landraces. An additional argument supporting the Andean introduction hypothesis was the identification of landraces from the Canary Islands, the first recorded site of introduction outside of South America, as Andean in origin. We reassess these two competing hypotheses with nuclear microsatellite and chloroplast DNA analyses of 19 Canary Island cultivars, 14 Andean landraces, 11 Chilean landraces, and two wild potato species as outgroups. Our molecular results document a wide variation of "Andean" and "Chilean"-type cultivars, and possible hybrids of the two. These data, in concert with newly presented historical and other data, support a hypothesis that there were multiple introductions of Andean and Chilean germplasm to the Canary Islands and that the early European potato was selected from Chilean introductions long before the late blight epiphytotics of the 1840s.