between markers E14M2-320 and HAU2583- 310 (Fig. 5), in which a quantitative trait locus (QTL) for fiber strength (qFS-D8-1) (Shen et al. 2007) was previously identified in the (7235×TM-1) recombination inbreed lines (RIL) population. The phenotypic variation(PV) of this QTL was from 4.31 and 16.15% in four different environments, and co-localized with GhAOC in the overlapping intervals within 10 cM, implying an important role for GhAOC in cotton fiber development,