Genetic mapping of quantitative trait loci for fiber quality and yield trait by RIL approach in Upland cotton Xinlian Shen Æ Wangzhen Guo Æ Qiongxian Lu Æ Xiefei Zhu Æ Youlu Yuan Æ Tianzhen Zhang Received: 5 July 2006 / Accepted: 6 December 2006 / Published online: 30 December 2006 Ó Springer Science+Business Media B.V. 2006 Abstract The improvement of cotton fiber qual- ity has become more important because of changes in spinning technology. Stable quantitative trait loci (QTLs) for fiber quality will enable molecular marker-assisted selection to improve fiber quality of future cotton cultivars. A simple sequence repeat (SSR) genetic linkage map consisting of 156 loci covering 1,024.4 cM was constructed using a series of recombinant inbred lines (RIL) devel- oped from an F 2 population of an Upland cotton (Gossypium hirsutum L.) cross 7235 · TM-1. Phenotypic data were collected at Nanjing and Guanyun County in 2002 and 2003 for 5 fiber quality and 6 yield traits. We found 25 major QTLs (LOD ‡3.0) and 28 putative QTLs (2.0 < LOD < 3.0) for fiber quality and yield components in two or four environments independently. Among the 25 QTLs with LOD ‡ 3, we found 4 QTLs with large effects on fiber quality and 7 QTLs with large effects on yield components. The most important chromosome D8 in the present study was densely populated with markers and QTLs, in which 36 SSR loci within a chromosomal region of 72.7 cM and 9 QTLs for 8 traits were detected. Keywords Gossypium hirsutum Á RIL Á QTL Á Fiber quality Á Yield Á Molecular mapping Introduction The demand for higher cotton fiber quality has risen with the advent of more open-end, air-jet and vortex spinning. The negative genetic cor- relation between fiber quality and lint yield has been a major problem in cotton breeding for a long time. Both backcrossing and intermating have been used to break linkages among these traits and to generate desired recombinants (Meredith and Bridge 1971). However, success has been limited because of difficulties in the identification of desirable recombinants. Quan- titative trait loci (QTL) conferring fiber quality traits have been identified and mapped using molecular markers in interspecific populations from crosses between Gossypium hirsutum and G. barbadense (Jiang et al. 1998; Kohel et al. 2001; Paterson et al. 2003; Mei et al. 2004; Chee et al. 2005a, b; Draye et al. 2005; Park et al. 2005) and in intraspecific G. hirsutum popula- tions (Shappley et al. 1998; Ulloa and Meredith 2000; Zhang et al. 2003; Shen et al. 2005; Ulloa et al. 2005). Mapping the QTLs for fiber quality and yield will facilitate application of marker- assisted selection (MAS) in simultaneous improvement of yield and fiber quality. X. Shen Á W. Guo Á Q. Lu Á X. Zhu Á Y. Yuan Á T. Zhang (&) National Key Laboratory of Crop Genetics & Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, P.R. China e-mail: cotton@njau.edu.cn 123 Euphytica (2007) 155:371–380 DOI 10.1007/s10681-006-9338-6