Abstract
In the Triticeae crops wheat and barley, only genetic information is available for many genes underlying agronomically important traits, as well as for natural or induced mutants. Therefore, map-based (positional) cloning is the most promising approach for the molecular isolation of genes causing these traits or mutant phenotypes. A growing number of genes (currently 19) have been isolated from wheat and barley based on genetic information only, and a lot has been learnt oil the most suitable approaches for such challenging projects in the large and complex genomes of Triticeae. With the ongoing or starting projects oil the generation of high-resolution physical maps in barley and wheat. map-based cloning will become simpler and faster In the near future. In order to fully exploit these new resources, there is an increasing need for high-resolution mapping populations. In addition, new and efficient tools have to be developed for the validation of the candidate genes identified in positional cloning. Here, we review the state of the art of positional gene cloning in the Triticeae crops and discuss the challenges in this field of research in the next years.