QTL analysis – did it deliver the goods?

Abstract

QTL analysis was first discussed in 1993 Australian Plant Breeding Conference and since then it has been widely used to develop genetic models for the control of complex traits. In barley, Australian researchers in various groups including the National Barley Molecular Marker Program (NBMMP), have now developed 16 populations which are in various stages of map construction, phenotyping and QTL analysis. In this paper, we will discuss the strengths and weaknesses of QTL analysis and future directions for the development of marker - trait associations. Specifically, the discussion will centre on five main issues - understanding the genetic control of complex traits, "dissecting" complex traits, understanding genotype x environment interactions, characterising response to selection at a genotypic level and the development of markers for applied breeding.