Combining Ability in Winter Wheat

Knowledge of quantitative genetic parameters is crucial in allocating resources for different steps of multistage selection programs. The main objective of the present study was to investigate the magnitude of variance of general combining ability (GCA) and specifi c combining ability (SCA) effects and their interaction with environments in wheat (Triticum aestivum L.). We used four data sets (Exp. 1, 2, 3, and 4) generated in commercial hybrid winter wheat breeding programs with a total of 940 hybrids evaluated in multienvironment trials in 2010 and 2011 in France. In at least three out of four experiments, general combining ability variance for females (σGCA-F), specifi c combining ability variance (σSCA), general combining ability of females × environment interaction variance (σGCA-F×E), and general combining ability of males × times environment interaction variance (σGCA-M×E) were signifi cantly larger than zero but general combining ability variance for males (σGCA-M) was signifi cant only in Exp. 4. For Exp. 3, we found no signifi cant difference between the best performing hybrid and the best performing commercial variety. In contrast, 1.8% of hybrids in Exp. 2 and more than 21% of the hybrids in Exp. 1 and 4 signifi cantly (P < 0.05) outperformed the best commercial variety included in the respective experiment. This superiority was even apparent when projecting our fi ndings on line varieties of the same cycle of selection. In Exp. 2, 3, and 4, general combining ability variance (σGCA) was more pronounced compared to σ 2 SCA. Moreover, correlation between GCA predicted and observed hybrid performance was medium to high (rExp.1 = 0.50, P < 0.01; rExp.2 = 0.90, P < 0.01; rExp.3 = 0.59, P < 0.01; and rExp.4 = 0.92, P < 0.01). Consequently, selection based on GCA effects is promising in hybrid wheat breeding program. M. Gowda, C.F.H. Longin, and J.C. Reif, State Plant Breeding Institute, Univ. of Hohenheim, 70593 Stuttgart, Germany. V. Lein, Saaten Union Recherche SAS, 163 Avenue de Flandre, F-60190 Estrées-Saint-Denis, France. Received 19 Apr. 2012. *Corresponding author ( Jochen.Reif@ uni-hohenheim.de). Abbreviations: σe, residual variance confounded with specifi c combining ability × environment interaction variance; σGCA, general combining ability variance; σGCA×E, general combining ability × environment interaction variance; σGCA-F, general combining ability variance for females; σGCA-F×E, general combining ability of females × environment interaction variance; σGCA-M, general combining ability variance for males; σGCA-M×E, general combining ability of males × environment interaction variance; σSCA, specifi c combining ability variance; CH, commercial heterosis; CHA, chemical hybridizing agent; GCA, general combining ability; H2, broad-sense heritability; SCA, specifi c combining ability. Published in Crop Sci. 52:2494–2500 (2012). doi: 10.2135/cropsci2012.04.0245 © 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.