Combining Ability and Variability for Fiber Maturity among Diverse World Cotton Genotypes.

Increased U.S. export of cotton and global competition necessitates that plant breeders continue to improve fiber properties of upland cotton, Gossypium hirsutum (L.). TAM B182-33 ELS (Extra-Long Staple) (Smith, et al., 2009) germplasm line of upland cotton, and 'Tamcot CAMD-E' (Bird, 1979), a short-staple obsolete cultivar, were crossed with 12 cultivars from China, seven from northern Africa, 10 from southern Africa, and seven from the United States. Parents and 72 F1s were grown in College Station, TX, in a Line × Tester design during the summers of 2010 and 2011. Mature, unopened bolls were hand harvested, deburred and allowed to dry in limited light. Maturity ratio (MR) and ribbon width (RbWth) were determined on a Cottonscope at the Fiber and Biopolymer Research Institute (FBRI) in Lubbock, TX on the 38 parents and F1s, and general and specific combining abilities were determined. Genetic variation existed for MR and RbWth among the distinct germplasm pools utilized in this study. 'Allen 333-61 CB 4027' (northern Africa), 'Phytogen 72' (United States), 'UK 64' (southern Africa) and 'Lintsing Sze Tze 4B' (China) and their F1 progenies from crosses with TAM B182-33 ELS and Tamcot CAMD-E had enhanced maturity characteristics, particularly high MR values, indicating that their fibers are more mature than that from some of the other cultivars. Data suggest that MR could be improved through breeding and use of the Cottonscope. [ABSTRACT FROM AUTHOR]