Selection during backcrossing was mostly based on a single character , but many mutations act pleiotropically, affecting multiple aspects of barley plant morphology and development (e.g. Fig. 2, AP–AV). One task for the future will be a detailed and systematic comparative phenotypic analysis of the Bowman NILs at the whole plant level at different developmental stages. When the identity of many individual genes is determined, such a phenotypic data set may facilitate the interpretation of a gene’s action and interactions underlying related phenotypes.