Evaluation of a Simple Method to Screen Soybean Genotypes for Salt Tolerance

Excessive salt can reduce soybean yield [Glycine max (L.) Merr.] in grower fi elds. Salttolerant cultivars are needed to prevent fi eld yield losses where excess salt is a problem. Soybean genotypes have primarily been evaluated for reaction to salt in the greenhouse using a labor-intensive and costly hydroponics method. A reliable, inexpensive method to screen soybean lines for salt tolerance would be useful in breeding programs. A simple, inexpensive method of exposing V2 to V3 plants growing in a sandy soil in plastic cone-tainers (PC method) was compared to the hydroponics method to evaluate soybean genotypes for salt tolerance in the greenhouse. Fourteen soybean genotypes including checks ‘Hutcheson’ (sensitive), and ‘S-100’ and ‘Forrest’ (tolerant) were exposed to 100 mM salt solution at the V2 to V3 growth stage. Genotypes responded similarly to the screening methods except leaf scorch, an indicator of salt damage, appeared up to 4 d sooner in the PC method. The PC method was highly correlated with the hydroponics method for leaf scorch score and chloride content in soybean leaves among the 14 genotypes evaluated. Exposure of roots at the V2 to V3 growth stage to salt solution using the PC method was less labor intensive, consumed less time, was less costly, and gave similar results compared with the hydroponics method. Thus, the PC method is an easy, reliable method to screen soybean genotypes for salt tolerance. J.-D. Lee, S.L. Smothers, D. Dunn, and J.G. Shannon, Univ. of Missouri-Delta Center, P.O. Box 160, 147 State Highway T, Portageville, MO 63873; M. Villagarcia, and T.E. Carter, Jr., USDA-ARS, North Carolina State Univ., 3127 Ligon St., Raleigh, NC 27607; C.R. Shumway, College of Agriculture, Arkansas State Univ., State University, AR 72467. Received 11 Feb. 2008. *Corresponding author ([email protected]). Abbreviations: EC, electrical conductivity; ISE, ion selective electrode; PC, plastic cone-tainers; SSR, simple sequence repeat. Published in Crop Sci. 48:2194–2200 (2008). doi: 10.2135/cropsci2008.02.0090 © 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.