The article introduces the concept of Advanced Backcross QTL analysis (ABQTL) as a method to integrate QTL analysis with variety development. This approach aims to discover and transfer valuable QTL alleles from unadapted donor inbred lines into elite breeding lines. By delaying QTL analysis until the BC2 or BC3 generation, negative selection is applied to reduce the frequency of deleterious donor alleles. Simulations suggest that ABQTL can effectively detect various types of QTLs, though with less power for epistatic or partially recessive QTLs. QTL-NILs (Quantitative Trait Loci Non-Inbred Lines) can be derived from advanced backcross populations and used to verify QTL activity, representing commercial inbreds improved for one or more quantitative traits. The process from QTL discovery to the construction and testing of improved QTL-NILs is minimal, typically taking 1-2 years. If successfully implemented, ABQTL can facilitate the exploitation of unadapted and exotic germplasm for the quantitative trait improvement of crop plants. The article highlights the need for integrating QTL discovery and variety development into a single process and the potential of using unadapted and wild germplasm to broaden the genetic base of crop species.The article introduces the concept of Advanced Backcross QTL analysis (ABQTL) as a method to integrate QTL analysis with variety development. This approach aims to discover and transfer valuable QTL alleles from unadapted donor inbred lines into elite breeding lines. By delaying QTL analysis until the BC2 or BC3 generation, negative selection is applied to reduce the frequency of deleterious donor alleles. Simulations suggest that ABQTL can effectively detect various types of QTLs, though with less power for epistatic or partially recessive QTLs. QTL-NILs (Quantitative Trait Loci Non-Inbred Lines) can be derived from advanced backcross populations and used to verify QTL activity, representing commercial inbreds improved for one or more quantitative traits. The process from QTL discovery to the construction and testing of improved QTL-NILs is minimal, typically taking 1-2 years. If successfully implemented, ABQTL can facilitate the exploitation of unadapted and exotic germplasm for the quantitative trait improvement of crop plants. The article highlights the need for integrating QTL discovery and variety development into a single process and the potential of using unadapted and wild germplasm to broaden the genetic base of crop species.