QTL analysis is used to identify genetic factors underlying phenotypic variation in traits
in a wide variety of contexts. The Genstat QTL system comprises a set of menus and
commands to facilitate QTL analysis, bringing together a wide range of statistical
techniques.
You can find many more tutorials and practical assistance by reading the QTL guide (available as a downloadable PDF). Look for this in Genstat under Help | Genstat Guides | QTL Analysis.