Genetic Improvement of the Pee Dee Cotton Germplasm Collection following Seventy Years of Plant Breeding

One of the most signifi cant, long-term public U.S. Upland cotton (Gossypium hirsutum L.) germplasm enhancement programs is known as the Pee Dee germplasm program. The unique, genetic foundation of the Pee Dee germplasm was created using germplasm from Upland, Sea Island (Gossypium barbadense L.), and primitive diploid cottons. Since the program’s inception in 1935, the Pee Dee germplasm program has released >80 improved germplasm lines and cultivars. In this study, the agronomic and fi ber quality performance of Pee Dee germplasm was evaluated across southeastern U.S. environments to estimate genetic improvement within the Pee Dee germplasm program. Results suggest that the Pee Dee germplasm enhancement program has (i) maintained usable genetic variation and (ii) maintained high fi ber quality potential while concomitantly improving agronomic performance. Although the results highlight the need to continue improving lint percent, lint yield, and bolls m−2, there is also evidence to suggest that Pee Dee germplasm can continue being utilized to develop the next generation of high-fi berquality and high-yielding cotton cultivars. B.T. Campbell, USDA-ARS Coastal Plains Soil, Water, and Plant Research Center, 2611 W. Lucas St., Florence, SC 29501; P.W. Chee and E. Lubbers, Univ. of Georgia, Molecular Cotton Breeding Lab., Tifton, GA 31794; D.T. Bowman, North Carolina State Univ., Dep. of Crop Science, Box 7620, Raleigh, NC 27695; W.R. Meredith, Jr., USDA-ARS, 141 Experiment Station Rd., Stoneville, MS 38776; J. Johnson, Dow Agrosciences, 3790 Old Hwy. 61, Leland, MS 38756; D.E. Fraser, Monsanto Company, 1401 4th St., Hartsville, SC 29550. Received 23 Sept. 2010. *Corresponding author (todd.campbell@ars. usda.gov). Abbreviations: G × E, genotype × environment; HVI, high-volume instrument; SSR, simple sequence repeat. Published in Crop Sci. 51:955–968 (2011). doi: 10.2135/cropsci2010.09.0545 Published online 16 Mar. 2011. © 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.