Candidate Genes within Tissue Culture Regeneration QTL Revisited with a Linkage Map Based on Transcript-Derived Markers

Green plant regeneration from tissue culture is under the genetic control of multiple genes. Candidate genes for regeneration have been identifi ed in multiple species using quantitative trait loci (QTL) and microarray analyses, and some of these genes have been verifi ed as improving regeneration through transformation. Multiple studies have located QTL for regeneration from barley (Hordeum vulgare L.) tissue cultures, but these studies have been based on restriction fragment length polymorphism markers that do not provide information on candidate genes. A recent transcript-derived marker barley map based on expressed sequence tags was used to locate QTL for barley green plant regeneration and identify candidate genes. Quantitative trait loci analysis identifi ed four signifi cant regions, on chromosomes 2H, 3H, 6H, and 7H, in places where QTL were previously identifi ed. An additional four regions were suggestive for green and/or albino plant regeneration on chromosomes 1H, 3H, 4H, and 5H. Examination of transcript-derived markers at the QTL peaks showed that many genes identifi ed as important for regeneration in other species were located in these QTL peaks, including a gene for ferredoxin-nitrate reductase and genes involved in hormone response and synthesis, cell division and the cell cycle, chloroplast development, and transcription factors. Identifying these genes allows manipulation to better understand the processes involved in regeneration from barley tissue cultures. N. Tyagi, Dep. of Plant Sciences, North Dakota State Univ., Fargo, ND 58105; L.S. Dahleen, USDA-ARS, Red River Valley Agricultural Research Center, 1307 18th St. N., Fargo, ND 58102-2765; P. Bregitzer, USDA-ARS, National Small Grains Germplasm Research Facility, Aberdeen, ID 83210. Received 26 Oct. 2009. *Corresponding author ([email protected]). Abbreviations: ACC, l-aminocyclopropane-l-carboxylic acid; CIM, composite interval mapping; DH, doubled haploid; e-QTL, expression-QTL; EST, expressed sequence tag; KNG, ‘Kanto Nakate Gold’; LRS, likelihood ratio statistic; NIR, ferredoxin-nitrite reductase; QTL, quantitative trait loci; RFLP, restriction fragment length polymorphism; TDM, transcript-derived marker. Published in Crop Sci. 50:1697–1707 (2010). doi: 10.2135/cropsci2009.10.0624 Published online 1 July 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.