ABSTRACT
Quantitative trait loci (QTL) mapping research often represents an interface between “genetics” and “breeding.” The literature of QTL mapping is most closely allied with the experimental methods and statistical tests used in genetics — however, applications of QTL mapping frequently address traits of importance to breeders. The independence of QTL action has remained controversial. Intuitively, no gene can function completely independently of all other genes in the genome. Modified experimental designs may reconcile QTL mapping results with the importance attributed to epistasis in classical studies. One of the most important considerations in analysis and interpretation of QTL data is the threshold employed for inferring statistical significance. Because QTL mapping involves analysis of many independent markers throughout a genome, there are many opportunities for false-positive results. A frequent criticism of QTL mapping has been that the populations studied were not representative of the elite gene pools relevant to mainstream improvement of many crops.
