Comparative QTL Map for White Mold Resistance in Common Bean, and Characterization of Partial Resistance in Dry Bean Lines VA19 and I9365-31

White mold caused by the necrotrophic fungus Sclerotinia sclerotiorum (Lib.) de Bary limits common bean (Phaseolus vulgaris L.) production in temperate climates. Disease resistance has been identifi ed, but breeding is hampered by a paucity of resistance sources and complex inheritance, as numerous quantitative trait loci (QTL) conditioning partial resistance have been found. Our objectives were to characterize the partial white mold resistance found in breeding lines I9365-31 and VA19 and to construct a comparative linkage map for all the white mold resistance QTL identifi ed to date. Recombinant inbred line (RIL) populations ‘Benton’/VA19 (BV) and ‘Raven’/I9365-31 (R31) consisting of 79 F6 and 105 F5 RILs, respectively, were evaluated for white mold (WM) reaction in multiple greenhouse and fi eld tests. Two QTL were found in BV, WM2.2 expressed in the greenhouse (R2 = 33%) and the fi eld (13%) and WM8.3 expressed in fi eld (11%) only, and seven were found in R31 (WM2.2, WM4.2, WM5.3, WM5.4, WM6.1, WM7.3, WM8.4), three expressed in greenhouse tests and four in the fi eld, ranging in phenotypic variance from 5 to 52%. These QTL were compared with 26 previously identifi ed QTL, resulting in a comparative linkage map of 35 QTL, which coalesced into 21 distinct regions across nine linkage groups. Four QTL found in R31 were novel. Sequence characterized amplifi ed region markers associated with WM2.2, WM8.3, and WM7.3 QTL were generated. The comparative linkage map provides a framework for integrating and interpreting future QTL studies concerning white mold resistance in common bean. M. Soule, L. Porter, and P.N. Miklas, USDA-ARS, Vegetable and Forage Crop Research Unit, 24106 N. Bunn Rd., Prosser, WA 99350; J. Medina, G.P. Santana, and M.W. Blair, CIAT, Apartado Aereo 6713, Cali, Columbia. Received 18 June 2010. *Corresponding author (phil. [email protected]). Abbreviations: BJ, BAT93/Jalo EEP558 mapping population; BV, Benton/VA19 mapping population; CIM, composite interval mapping; DAP, days after planting; DG, DOR364/G19833 mapping population; EST, expressed sequence tag; GN, great northern; LG, linkage group; MAS, marker-assisted selection; PDA, potato dextrose agar; QTL, quantitative trait locus or loci; R31, Raven/I9365-31 mapping population; RAPD, random amplifi ed polymorphic DNA; RIL, recombinant inbred line; RFLP, restriction fragment length polymorphism; SCAR, sequence characterized amplifi ed region; SRAP, sequence related amplifi ed polymorphism; SSR, simple sequence repeat (microsatellite); WM, white mold. Published in Crop Sci. 51:123–139 (2011). doi: 10.2135/cropsci2010.06.0356 Published online 22 Nov. 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.