|
|
||||||||
a Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, St. Paul, MN 55108
b International Maize and Wheat Improvement Center (CIMMYT), Apdo Postal 6-641, 06600, Mexico D.F., Mexico
c USDA-ARS, Cereal Disease Laboratory, St. Paul, MN 55108
d Campo Experimental Valle de Mexico, INIFAP, Apdo. Postal 10, Chapingo, 56230 Edo de Mexico, Mexico
* Corresponding author (ander319{at}umn.edu).
The CIMMYT spring wheat Weebill 1 has near-immune levels of adult plant resistance (APR) to leaf rust caused by Puccinia triticina Eriks. To determine the genetic basis of resistance in seedlings and adult plants Weebill 1 was crossed with two susceptible parents Jupateco 73S and Thatcher. Advanced F4:5, F4:6, and F5:7 recombinant inbred lines (RIL) populations from Jupateco 73S/Weebill 1 and BC1F2 populations from Thatcher/Weebill 1 were derived. The F5:7 RILs and BC1F2 families were tested as seedlings with five races of P. triticina. The F1 and F4:5, F4:6, and F5:7 RILs of Jupateco 73S/Weebill 1 were evaluated in plots in Mexico and St. Paul. The Jupateco 73S/Weebill 1 RILs and Thatcher*2/Weebill 1 F2 families segregated for Lr14b, an unknown seedling leaf rust resistance gene derived from Weebill 1 in both crosses, and Lr17a derived from Jupateco 73S in the RIL population. Lr17a was mapped to the distal end of chromosome 2AS and was linked to microsatellite maker Xgwm636 at a distance of 4.0 cM. The seedling genes did not condition effective resistance in the field plots with races used in the field trials. The segregation ratio in the RILs and F2 families indicated the presence of three to four APR genes in Weebill 1. One of the APR genes was linked to the seedling gene Lr14b on chromosome 7BL and reduced leaf rust by 47% in St. Paul and 31% in Mexico. Based on the haplotypes of DNA markers, we do not believe that any of the APR genes is Lr34.
Abbreviations: APR, adult plant resistance IT, infection types PCR, polymerase chain reaction QTL, quantitative trait loci RIL, recombinant inbred lines
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 December 17, 2007.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Vadose Zone Journal | |||
| Journal of Plant Registrations | Soil Science Society of America Journal | ||||
| Journal of Natural Resources and Life Sciences Education |
Journal of Environmental Quality |
||||