c06-05-0336(8) Spooner.indd

The modern cultivated potato (Solanum tuberosum L.) was fi rst recorded in Europe in the Canary Islands in 1567, but its origin has long been in dispute. Two competing hypotheses have proposed an “Andean” area (somewhere from the Andean uplands from Venezuela to northern Argentina) or a lowland south-central “Chilean” area, but the Andean origin hypothesis is today generally accepted. The identity of extant Canary Island potato landraces as exclusively of upland Andean origin is one part of a multicomponent argument that the European potato originated from there, rather than from Chile. We reassess these two competing hypotheses with nuclear microsatellite and chloroplast DNA analyses of 19 Canary Island landraces, 14 Andean landraces, 11 Chilean landraces, and two wild potato species as outgroups, and with chloroplast DNA data of 150 landraces from South America. Our molecular results document a wide variation of Andeanand Chilean-type cultivars on the Canary Islands and possible hybrids of the two. Our new data, integrated with historical, molecular, agronomic, and crossing 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. D. Ríos, Centro de Conservación de la Biodiversidad Agrícola de Tenerife, Carretera Tacoronte-Tejina, 20 A. Tacoronte, 38.350, Tenerife, and Univ. of La Laguna, ETSIA, Carretera de Geneto 2, Campus de Anchieta, 38206, La Laguna, Tenerife; M. Ghislain, International Potato Center, P.O. Box 1558, La Molina, Lima 12, Peru; F. Rodríguez and D.M. Spooner, USDA-ARS, Dep. of Horticulture, Univ. of Wisconsin, 1575 Linden Dr., Madison, WI 53706-1590. Received 22 May 2006. *Corresponding author ([email protected]). Abbreviations: CIP, International Potato Center; NJ, neighbor-joining; PCR, polymerase chain reaction; PIC, polymorphic information content; SSR, simple sequence repeat or microsatellite. Published in Crop Sci. 47:1271–1280 (2007). doi: 10.2135/cropsci2006.05.0336 © Crop Science Society of America 677 S. Segoe Rd., Madison, WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. Published online May 31, 2007