Abstract: Map-based cloning is a classical and effective method to identify candidate genes for specific phenotypic variants. Map-based cloning of functional genes plays important roles in the innovative utilization of germplasm resources, molecular design breeding and improving breeding efficiency. In recent years, the whole-genome sequencing of Gossypium raimondii, Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense has been completed and improved. map-based cloning has entered into a crucial period. In 2016, the dominant glandless gene Gl₂^e (GoPGF) was the first map-based cloning gene in cotton. So far, 20 qualitative traits genes and 5 quantitative traits genes have been identified by map-based cloning technology. In this paper, research progress was systematically reviewed in fiber, gland, nectary, leaf type, plant architecture, plant color, and fertility in terms of gene symbols, names, chromosomal positioning, and candidate genes. Moreover, map-based cloning strategies were systematically review in mapping populations and bulked segregate analysis-sequencing (BSA-seq). With the reduction of sequencing cost and utilization of BSA-seq. In addition, transformation and genome editing have been successfully used to evaluate the function of the candidate gene in the target interval. It is believed that map-based cloning could provide a theoretical basis and genetic resources for molecular design breeding in cotton.

Key words: cotton, map-based cloning, molecular marker, mapping population, BSA-seq