Germplasm Potential for Continuing Improvement of Fiber Quality in Upland Cotton: Combining Ability for Lint Yield and Fiber Quality

Exotic germplasm, that is, germplasm without commercial applicability, can broaden the genetic base in upland cotton (Gossypium hirsutum L.). The objectives of this study were to determine combining ability and identify parents from exotic germplasm for breeding. Twelve regionally adapted exotic germplasm lines were crossed with one cultivar and three elite germplasm lines in a North Carolina Design II scheme. The 48 F2 hybrids were evaluated at two locations with 4 and 3 replicates each in 2008 and 2009, respectively. General combining ability (GCA) effects were signifi cant (p ≤ 0.001) for lint yield and all fi ber properties. General combining ability effects were more important than specifi c combining ability (SCA) effects for most traits. Signifi cant (p ≤ 0.05) favorable GCA effects were detected in all exotic germplasm parents for different fi ber properties. Positive GCA effects for lint yield and favorable GCA effects for at least one fi ber property were detected in some exotic parents: SP156 and SP224 for lint yield and strength; SP192, SP205, and JC65 for lint yield, micronaire, and elongation; and SP192 and SP224 for lint yield and short fi ber content and fi neness, respectively. Signifi cant high parent heterosis (HPH) for lint yield was detected in F2 hybrids of FM832 × SP205 (14%) and MD15 × SP205 (26%). These results provide evidence for the potential of these germplasm lines in breeding for continuing improvement of lint yield and fi ber quality. USDA-ARS, Crop Genetics Research Unit, Delta Research Center, Stoneville, MS 38776. Mention of trade names or commercial products in this article is solely for the purpose of providing specifi c information and does not imply recommendation by the USDA. Received 14 July 2010. *Corresponding author ([email protected]). Abbreviations: GCA, general combining ability; HPH, high parent heterosis; JC, John Cotton; SCA, specifi c combining ability; SP, Species Polycross. Published in Crop Sci. 51:60–68 (2011). doi: 10.2135/cropsci2010.07.0413 Published online 15 Nov. 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.