A Dominant Gene for Resistance to Wheat Streak Mosaic Virus in Winter Wheat Line CO960293-2

Wheat streak mosaic (WSM), caused by Wheat streak mosaic virus (WSMV), is a devastating disease in wheat (Triticum aestivum L.) in the Great Plains of North America. Use of resistance is an effective and environmentally sound method to control the disease. In this study, six wheat genotypes were compared for their responses to WSMV infection under growth chamber conditions. The three resistant genotypes, KS96HW10-3 (Wsm1), Mace (Wsm1), and CO960293-2, had disease scores signifi cantly lower than the remaining three genotypes without major resistance. Disease in TAM 111 and TAM 112 was consistently less severe than Karl 92. A population consisting of 188 F2:3 families derived from the cross CO960293-2 × TAM 111 was used for determining inheritance of the WSMV resistance and for molecular mapping of the resistance in CO960293-2. Data on segregation of resistance indicated that the resistance in CO960293-2 is conditioned by a single dominant gene, which was named Wsm2. Transgressive segregation toward susceptibility occurred in the population suggesting a minor gene in the moderately susceptible parent TAM 111, which was not allelic to Wsm2. Wsm2 was mapped to the short arm of chromosome 3B with two fl anking simple sequence repeat markers. The single dominant gene inheritance for WSMV resistance in CO960293-2 has been consistent with the observations that the resistance can be readily transferred to adapted cultivars. Texas AgriLife Research and Extension Center at Amarillo, 6500 Amarillo Blvd. West, Amarillo, TX 79106. Received 26 Jan. 2010. *Corresponding author ( [email protected]). Abbreviations: ANOVA, analysis of variance; ELISA, enzymelinked immunosorbent assay; LSD, least signifi cant diff erence; MAS, marker-assisted selection; PCR, polymerase chain reaction; SSR, simple sequence repeat; WSM, wheat streak mosaic; WSMV, Wheat streak mosaic virus. Published in Crop Sci. 51:5–12 (2011). doi: 10.2135/cropsci2010.01.0038 Published online 18 Oct. 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.