Abstract:Genetic mapping provides a powerful tool for quantitative trait loci (QTL) analysis at the molecular level. A simple sequence repeat (SSR) genetic map containing 590 markers and a BC1 population from two cultivated tetraploid cotton (Gossypium hirsutum L.) cultivars, namely TM-1 and Hai 7124 (G. barbadense L.), were used to map and analyze QTL using the composite interval mapping (CIM) method. Thirty one QTLs, 10 for lobe length, 13 for lobe width, six for lobe angle, and two for leaf chlorophyll content, were detected on 15 chromosomes or linkage groups at logarithm of odds (LOD) 2.0, of which 15 were found for leaf morphology at LOD≥3.0. The genetic effects of the QTL were estimated. These results are fundamental for marker-assisted selection (MAS) of these traits in tetraploid cotton breeding.