Selection for Drought Tolerance in Dry Bean Derived from the Mesoamerican Gene Pool in Western Nebraska

Dry bean (Phaseolus vulgaris L.) is highly susceptible to drought stress, and drought affects 60% of global bean production. We evaluated elite exotic dry bean germplasm derived from the Mesoamerican gene pool for drought tolerance, yield, and adaptation to western Nebraska during 2006 and 2007 at three research sites. Seven tropical lines were evaluated with two great northern cultivars (Matterhorn and BerylR) and one pinto cultivar (Bill-Z) serving as checks. Adjacent nonstressed (NS) and droughtstressed (DS) blocks were evaluated. Within each block, the selected lines were assigned to experimental units using a randomized complete block design with four replications at each location. On average, yield was 60% less, 100-seed weight was 19.2% lower, and maturity occurred 4 d earlier under DS than under NS conditions. Beryl-R, SER 22, and Matterhorn had the greatest average yield under both NS (3564, 3347, and 3440 kg ha–1, respectively) and DS (1701, 1773, and 1584 kg ha–1, respectively). These genotypes were also the most drought tolerant based on the drought susceptibility index (0.9, 0.8, and 0.9, respectively) and geometric mean (2462, 2436, and 2335, respectively). Based on these results, Matterhorn, Beryl-R, and SER 22 show the most promise for use in breeding for drought tolerance. Univ. of Nebraska, Panhandle Research & Extension Center, 4502 Ave. I, Scottsbluff , NE 69361. Received 8 Dec. 2008. *Corresponding author ([email protected]). Abbreviations: DII, drought intensity index; DS, drought-stressed; DSI, drought susceptibility index; GM, geometric mean; NS, nonstressed. Published in Crop Sci. 49:2005–2010 (2009). doi: 10.2135/cropsci2008.12.0694 © 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 November, 2009