Quantitative trait loci (QTL) analysis is a research area in genetics that aims to identify and study the genetic regions or loci that are associated with quantitative traits, such as height, weight, and disease susceptibility. By mapping these QTLs, researchers can better understand the genetic basis of these traits and potentially identify genes or genetic markers that are linked to them. This information can be valuable for breeding programs in agriculture and livestock, as well as for understanding the genetic basis of complex diseases in humans. QTL analysis typically involves identifying associations between genetic markers and phenotypic traits through statistical analysis and genome mapping techniques.