Genetic analysis of a quantitative trait

Abstract

For several years, many studies have been undertaken in order to identify the genes which actually control the variability of quantitative traits. Mainly two strategies have been developed for this purpose. One relies on the genetic map knowledge and searches for the so-called QTL (quantitative trait loci). It gives rise to an early application to selection process by the use of markers associated to the trait ; it is also a first step towards the location of genes actually involved in part of the trait variability determinism. The other one is supported by the biological knowledge of the trait and focus on few genes -candidate genes – supposed to be responsible for part of the trait variability. At the moment the analysis of these methods and their results allow to make out their abilities and limits. Moreover, it brings to the fore their complementary nature in the genetic analysis of quantitative traits, and their similarities in part of the experimental designs.