Upland Cotton (Gossypium hirsutum) is one of the most important worldwide crops it provides natural high-quality fiber for the industrial production and everyday use. Next-generation sequencing is a powerful method to identify single nucleotide polymorphism markers | Construction of a high-density genetic map by specific locus amplified fragment sequencing SLAF-seq and its application to Quantitative Trait Loci QTL analysis for boll weight in upland cotton Gossypium hirsutum.