HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Condón, F. Articles by Smith, K. P. PubMed Articles by Condón, F. Articles by Smith, K. P. Agricola Articles by Condón, F. Articles by Smith, K. P. Related Collections Crop Genetics Other Grain Crops

Effect of Advanced Cycle Breeding on Genetic Diversity in Barley Breeding Germplasm

Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, St. Paul, MN 55108; present address for F. Condón: INIA La Estanzuela, Rta 50 km 11, CC 39173, Colonia, Uruguay

^* Corresponding author (smith376{at}umn.edu).

Plant breeding that emphasizes crosses among elite parents in a closed population (advanced cycle breeding) is presumed to decrease genetic diversity. To assess the effect of plant breeding on allelic diversity, we evaluated regional ancestors, parental lines, and cultivar candidates from the University of Minnesota six-rowed barley (Hordeum vulgare L.) breeding program between 1958 and 1998 using pedigree information, 70 simple sequence repeat (SSR) markers, and a gene specific marker. Pedigree and SSR allelic diversity indices revealed a decrease in genetic diversity, from an average of 5.89 alleles per locus in the ancestors group to 2.34 alleles per locus in the fourth decade of breeding. A correspondence analysis showed differentiation in the germplasm with time. At specific loci, we detected both reductions and no change in the number of alleles over time. Several marker loci that demonstrated a reduction in number of alleles were associated with major loci for disease resistance or malting quality and were presumably under selection during breeding. Assessment of locus-specific allelic variation across the genome in breeding germplasm should identify both the regions of the genome that should be conserved and the regions of the genome where there are opportunities to introgress new allelic diversity without disrupting desirable gene complexes.

Abbreviations: A-GD, average of genetic diversity • NSGC, National Small Grains Collection • PCR, Polymerase chain reaction • P-GD, Pair-wise pedigree genetic diversity • SM-GD, simple matching coefficient

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.

Received for publication November 26, 2007.