Characteristics of cotton ‘fiber’ (single-celled, epidermal trichomes) vary greatly in the wild diploids, as well as within and among the four independently domesticated cultivated cottons; the latter, which includes the two A-genome species G. herbaceum (A1) and G. arboreum (A2) and the two allopolyploids G. hirsutum (AD1, Upland cotton) and G. barbadense (AD2, Pima cotton), all produce spinnable fibers, whereas some species such as G. rotundifolium (K2) and G. sturtianum (C1) lack fiber or have sparse short fiber13. Comparative population genomic and genetic analyses have unraveled the complex population history of domestication14–16, in addition to some of the genetic components associated with fiber yield and quality in cultivated cotton17. Notwithstanding these and other advances enabled through comparative genome sequencing and functional studies, pan-genome or regulome resources remain to be developed for the Gossypium genus.