Associations among Lint Yield, Yield Components, and Fiber Properties in an Introgressed Population of Cotton

Broadening the genetic base is essential for genetic improvement of lint yield and fi ber quality in upland cotton (Gossypium hirsutum L.). An exotic germplasm population derived from multiple crosses between G. barbadense L. and G. hirsutum was obtained from USDA-ARS at Las Cruces, NM. Experiments were designed to evaluate this germplasm for genotypic variation in lint yield and fi ber quality. Two hundred germplasm lines and fi ve cultivars were planted at two locations in 2006 and one location in 2007. Signifi cant (P ≤ 0.001) genotypic variation for yield and fi ber quality was identifi ed. In path coeffi cient analysis, bolls per square meter had the largest direct effect on lint yield, while boll weight and lint percentage had secondary direct effects on yield. Lint yield was negatively associated with fi ber quality. Lint per seed was favorably correlated with lint percentage, elongation, span lengths, and fi neness. Based on stepwise analysis, 50% length, short fi ber content, fi neness, maturity ratio, and 2.5% length contributed to strength, in decreasing order of signifi cance. Short fi ber content was negatively correlated with fi neness (r = –0.41). These results indicate that this germplasm is a useful genetic resource for genetic improvement of lint yield, fi ber quality, and analysis of interrelationships between lint yield and fi ber quality. USDA-ARS, Crop Genetics and Production Unit, Delta Research Center, Stoneville, MS 38776. Received 22 Sept. 2008. *Corresponding author ([email protected]). Abbreviations: 50% length, 50% span length; 2.5% length, 2.5% span length; AFIS, Advanced Fiber Information System; JC, ‘John Cotton’ germplasm; REML, restricted maximum likelihood; SP, species polycross. Published in Crop Sci. 49:1647–1654 (2009). doi: 10.2135/cropsci2008.09.0547 © Crop Science Society of America 677 S. Segoe 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.