1932 WWW.CROPS.ORG CROP SCIENCE, VOL. 50, SEPTEMBER– OCTOBER 2010 RESEARCH T wo main gene pools have been described for common bean (Phaseolus vulgaris L.). One center of domestication is located in Mesoamerica and the other in the Andes (Becerra-Velásquez and Gepts, 1994; Thome et al., 1996). In addition to these two major gene pools, wild beans may contain another center of diver- sity in Colombia and the region between Ecuador and the north- ern part of Peru (Tohme et al., 1995; Beebe et al., 1997; Islam et al., 2001). The Mesoamerican gene pool can be divided into four domesticated races: Mesoamerica, Guatemala, Durango, and Jalisco, with these last two overlapping in genetic diversity (Beebe et al., 2000; Díaz and Blair, 2006). Meanwhile, the Andean gene pool can be divided into three races: Nueva Granada, Peru, and Chile (Singh et al., 1991; Blair et al., 2006, 2007). Landraces per- taining to Andean gene pool are remarkably diverse in plant and grain morphology as well as agro-ecological adaptation (Beebe et al., 2001). This situation presents challenges for researchers to adequately characterize the variable germplasm and for plant breeders to utilize this germplasm to improve the productivity of Microsatellite Marker Characterization of Chilean Common Bean ( Phaseolus vulgaris L.) Germplasm Viviana Becerra V.,* Mario Paredes C., Carmen Rojo M., Lucy M. Díaz, and Matthew W. Blair* ABSTRACT The Chilean national common bean germplasm collection consists of 1200 accessions, most of which have not been characterized or used in breeding programs. As part of the characteriza- tion of this germplasm we have formed a core collection of 246 accessions that represent 21% of the whole collection and that consists of many race Chile representatives as well as varieties from other races that are traditionally grown in the country. The specifc objectives of this work were to use microsatellites to evaluate the level of polymorphism in the Chilean core collection and to determine the genetic variability of race Chile and its relationships with other races. The results indicate that the level of polymorphism detected with microsatellites was higher than that obtained with previous molecular or bio- chemical markers. The number of microsatellite alleles varied from 2 to 14 and the polymor- phism information content (PIC) values were 0.08 to 0.84. Heterozygosity ranged from 0 to 0.052 for each of the markers. Euclidean genetic distance ranged from 0.12% between race Chile and race Nueva Granada to 0.71% between race Chile and race Mesoamerica. Multiple cor- respondence analysis (MCA) showed clustering of the accessions into the two main genepools, with race Chile genotypes grouping mainly with race Nueva Granada genotypes. V. Becerra, M. Paredes, C. Rojo, Instituto de Investigaciones Agro- pecuarias (INIA), Centro Regional de Investigación, INIA Quilamapu, Casilla de Correos 426, Chillán, Chile; L.M. Díaz, M.W. Blair, Centro Internacional de Agricultura Tropical (CIAT) Apartado Aéreo 6713, Cali, Colombia. Received 12 Aug. 2009. *Corresponding coauthors (vbecerra@inia.cl, m.blair@cgiar.org). Abbreviations: K, population structure; MCA, multiple correspondence analysis; PCR, polymerase chain reaction; PIC, polymorphism informa- tion content; RAPD, randomly amplifed polymorphic DNA; RFLP, restriction fragment length polymorphism; SSR, simple sequence repeat; UPGMA, unweighted pair-group method using arithmetic average. Published in Crop Sci. 50:1932–1941 (2010). doi: 10.2135/cropsci2009.08.0442 Published online 23 July 2010. © Crop Science Society of America | 5585 Guilford 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 September, 2010