Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/2/2001
Publication Date: 2/2/2002
Citation: Guo, W.Z., Zhang, T.Z., Sheng, X.L., Yu, J., Kohel, R.J. 2003. Development of scar marker linked to a major QTL for high fiber strength and its molecular marker assisted selection in upland cotton. Crop Science. 43:2252-2256. Interpretive Summary: Molecular markers developed from DNA sequence characterized amplified region (SCAR) are very useful in genetic mapping of agronomic genes such as those controlling cotton fiber strength. They are also used for selecting desirable individual cotton plants in the breeding programs. A previous genetic mapping study identified a major gene for fiber strength in 7235, a germplasm line in Upland cotton with super quality fiber. The present study developed SCAR markers to assist in selecting the fiber strength gene. A large-scale screening for the presence or absence of the major fiber strength gene in breeding populations is made possible with one specific SCAR marker.
Technical Abstract: Cotton fiber is a basic raw material in the textile industry. All the changes in spinning technology require unique and often greater cotton fiber quality, especially strength, for processing. Based on a genetic analysis and molecular mapping, a major QTL for fiber strength was identified in 7235, a germplasm line in Upland cotton with super quality fiber properties in our institute. Eight molecular markers, 2SSRs and 6 RAPDs, were linked to the QTL. The objective of the present study was to develop fast and reliable sequence characterized amplified region (SCAR) markers linked to the QTL for MAS. Two random applification polymorphic DNA markers (RAPD markers), UBC431 sub1920 and UBC757 sub1365, were converted to SCAR markers after sequencing the two ends of the two polymorphic DNA fragments. Only SCAR431 sub1920 marker detected polymorphism between TM-1 and 7235, whereas SCAR757 sub 1365 showed monomorphism. SCAR431 sub1920 marker was explored to detect its stability in (7235 x TM-1)F2 with UBC431 sub1920 marker as control and to screen the major fiber strength QTL of (7235 x Simian 3)BC1F4 population for transferring good fiber quality. The result showed the specific SCAR431 sub1920 marker could be applied to large-scale screening for the presence or absence of the major fiber strength QTL in breeding populations.