Identifi cation of Chromosome Locations of Genes Aff ecting Preharvest Sprouting and Seed Dormancy Using Chromosome Substitution Lines in Tetraploid Wheat (Triticum turgidum L.)

Seed dormancy, the main factor contributing to preharvest sprouting (PHS) resistance, is a complex trait and is strongly infl uenced by environmental growth conditions. In this study, three sets of single chromosome substitution lines, including 36 genotypes, in a durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] background with donor chromosomes originating from three wild emmer [T. turgidum L. ssp. dicoccoides (Körn. ex Asch. and Graebn.) Thell.] accessions were grown in nine fi eld environments and evaluated for seed dormancy and PHS resistance. The substitution lines involving chromosome 3A were among the most dormant genotypes. Germination tests indicated that fi ve chromosomes contained genes infl uencing seed dormancy at a level comparable to 3A. Results from PHS tests showed that PHS was affected by at least eight T. dicoccoides chromosomes including 3A. The chromosomes harboring genes for seed dormancy did not fully correspond with those for PHS resistance. The weak correlations between PHS and dormancy observed in this study indicate that different genes are affecting these traits and they may be differentially infl uenced by the environment. Nonetheless, our results revealed that genes present on fi ve chromosomes, 2A, 2B, 3A, 4A, and 7B, were found to affect both PHS resistance and seed dormancy. These genotypes thus provide useful resources for further studies on genetic interactions that contribute to the overall phenotypic variation and on genetic dissection of quantitative trait loci underlying PHS resistance. S. Chao, USDA-ARS Biosciences Research Lab., 1605 Albrecht Blvd., Fargo, ND 58105; S.S. Xu and J.D. Faris, USDA-ARS Northern Crop Science Lab., 1307 18th St. N., Fargo, ND 58105; E.M. Elias, Dep. of Plant Sciences, North Dakota State Univ., Fargo, ND 58105; M.E. Sorrells, Dep. of Plant Breeding and Genetics, Cornell Univ., 240 Emerson Hall, Ithaca, NY 14853. Received 9 Oct. 2009. *Corresponding author ([email protected]). Abbreviations: 521, PI 481521; 742, PI 478742; FN, falling number; GI, germination index; GR, percent germination rate; ISA, Israel A; LDN, Langdon; LMA, late maturity α-amylase; PHS, preharvest sprouting; QTL, quantitative trait locus. Published in Crop Sci. 50:1180–1187 (2010). doi: 10.2135/cropsci2009.10.0589 Published online 20 Apr. 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.