Bulbosum to Go: A Toolbox to Utilize Hordeum vulgare/bulbosum Introgressions for Breeding and Beyond.

Hordeum bulbosum L., a wild relative of barley (Hordeum vulgare L.), has been considered as a valuable source of genetic diversity for barley improvement. Since the 1990s, a considerable number of barley/H. bulbosum introgression lines (IL)s has been generated, with segments introgressed from H. bulbosum harboring a diverse set of desirable traits. However, the efficient utilization of these ILs has been hampered, largely due to the lack of suitable molecular tools for their genetic characterization and highly reduced interspecific recombination frequencies in the region of the introgression. In the present study, we utilized genotyping-by-sequencing for the detailed molecular characterization of 145 ILs. Genotypic information allows the genetic diversity within the set of ILs to be determined and a strategy was outlined to tackle the obstacle of reduced recombination frequencies. Furthermore, we compiled exome capture re-sequencing information of barley and H. bulbosum and designed an integrated barley/H. bulbosum sequence resource with polymorphism information on interspecific and intraspecific sequence variations of both species. The integrated sequence will be valuable for marker development in barley/H. bulbosum ILs derived from any barley and H. bulbosum donors. This study provides the tools for the widespread utilization of barley/H. bulbosum ILs in applied barley breeding and academic research.