Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2004
Publication Date: 1/31/2005
Citation: Shen, X., Guo, W., Zhu, X., Yu, J., Kohel, R.J., Zhang, T. 2005. Molecular mapping of QTLs for fiber qualities in three diverse lines of upland cotton using SSR markers. Molecular Breeding. 15:169-181. Interpretive Summary: Changes in textile machinery operations require stronger, longer, and finer cotton fibers. One of the most effective approaches to the improvement of fiber quality is to identify stable genes that control these traits. Biotechnology provides powerful tools to enhance the genetic improvement. By use of specific DNA markers that are associated to the fiber quality traits, 38 genetic factors were identified in three high-quality fiber cottons, 7235, HS427-10, and PD6992. Among them, 10 genes are responsible for fiber strength, 11 for fiber length, 9 for fiber fineness, and 8 for fiber elongation. Some of these genes are consistently present in different generations and environments. The DNA markers associated to these genes are useful in assisting genetic improvement of fiber quality in cotton breeding programs.
Technical Abstract: The improvement of cotton fiber quality is extremely important because of changes in spinning technology. The identification of the stable QTLs affecting fiber traits across different generations will be greatly helpful to be used effectively in molecular marker-assisted selection to improve fiber quality of cotton cultivars in the future. Using three elite fiber lines of Upland cotton (Gossypium hirsutum L.) as parents, three linkage maps were constructed to tag QTLs for fiber qualities using SSR markers. There were 38 QTLs, detected by composite interval mapping for fiber traits, in which 11 QTLs were for fiber length, 10 for fiber strength, 9 for micronaire, and 8 for fiber elongation. Among them, 15 stable QTLs (39.47%) could be found in both F2 and F2:3 segregating populations. At least 3 identical QTLs could be identified in two populations. These identical QTLs detected in different populations suggested that there existed elite fiber genes and possibly of the same origin. In addition, we found three pairs of putative homoeologous QTLs, qFL-7-1c and qFL-16-1c, qFS-D03-1a and qFS-A02-1b, qFS-A02-1c, and qFE'D03-1a and qFE-A02-1c. Our results provided a better understanding of the genetic factors of fiber traits in AD tetraploid cottons. Both stable and identical QTLs have a great potential for molecular-assisted selection in improving fiber quality.