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Background:Genetic improvement in fiber quality is one of the main challenges for cotton breeders. Quantitative trait loci (QTL) mapping provides a powerful approach to dissect the molecular mechanism in fiber quality traits. In present study, F14 recombinant inbred line (RIL) population was backcrossed to patal parent for a patal backcross (BC/P) population, deriving from one upland cotton hybrid. Three repetitive BC/P field trials and one matal backcross (BC/M) field trial were performed including both two BC populations and the original RIL population.Results:In total, 24 novel QTLs are detected for fiber quality traits and among which 13 QTLs validated previous results. Thirty-five QTLs in BC/P populations explain 5.01%-22.09%of phenotype variation (PV). Among the 35 QTLs, 23 QTLs are detected in BC/P population alone. Present study provides novel alleles of male parent for fiber quality traits with positive genetic effects. Particularly, qFS-Chr3–1 explains 22.09%of PV in BC/P population, which increaseds 0.48 cN·tex?1 for fiber strength. A total of 7, 2, 8, 2 and 6 QTLs explain over 10.00%of PV for fiber length, fiber uniformity, fiber strength, fiber elongation and fiber micronaire, respectively. In RIL population, six common QTLs are detected in more than one environment:qFL-Chr1–2, qFS-Chr5–1, qFS-Chr9–1, qFS-Chr21–1, qFM-Chr9–1 and qFM-Chr9–2. Two common QTLs of qFE-Chr2–2 (TMB2386-SWU12343) and qFM-Chr9–1 (NAU2873-CGR6771) explain 22.42%and 21.91%of PV. The region between NAU4034 and TMB1296 harbor 30 genes (379 kb) in A05 and 42 genes (49 kb) in D05 for fiber length along the QTL qFL-Chr5–1 in BC/P population, respectively. In addition, a total of 142 and 46 epistatic QTLs and QTL × environments (E-QTLs and QQEs) are identified in recombinant inbred lines in patal backcross (RIL-P) and patal backcross (BC/P) populations, respectively.Conclusions:The present studies provide informative basis for improving cotton fiber quality in different populations.