Development of SCAR Marker Linked to a Major QTL for High Fiber Strength and Its Usage in Molecular‐Marker Assisted Selection in Upland Cotton

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. On the basis of genetic analysis and molecular mapping, a major quantitative trait locus (QTL) for fiber strength was identified in 7235, an Upland cotton (Gossypium hirsutum L.) germplasm line in our institute, which possesses super quality fiber properties. Eight molecular markers, two simple sequence repeat (SSRs) and six random amplified polymorphic DNA (RAPDs) markers, were linked to the QTL. The objective of this study was to develop rapid and reliable sequence characterized amplified region (SCAR) markers linked to the QTL for marker‐assisted selection (MAS). Two RAPD markers, UBC4311920 and UBC7571365, were converted to SCAR markers after sequencing the two ends of the two polymorphic DNA fragments. Only SCAR4311920 marker detected polymorphism between TM‐1 and 7235, whereas SCAR7571365 showed monomorphism. SCAR4311920 marker was explored to determine its stability in (7235 × TM‐1) F2 with UBC4311920 marker as a control and to screen the major fiber strength QTL of (7235 × Simian 3) BC1F4 population for transferring good fiber quality. The result showed that the specific SCAR4311920 marker could be applied to large‐scale screening for the presence or absence of the major fiber strength QTL in breeding populations.