The Yd2 gene and enhanced resistance to barley yellow dwarf virus (BYDV) in winter barley

A breeding programme was developed to obtain barley yellow dwarf virus (BYDV)-resistant winter genotypes using the Yd2 gene. The aim was to incorporate the Yd2 allele into the new high-yielding genotypes to release cultivars that allow barley cultivation in areas where BYDV is endemic. The resistant lines were developed using pedigree selection. An ICARDA resistant line (83RCBB130) carrying the Yd2 gene was crossed with three susceptible, high-yielding winter varieties and their F-1 lines were either selfed or backcrossed to the matching susceptible parent. The best lines selected from subsequent selfing generations were evaluated in replicated trials in the presence or absence of BYDV, starting from F-6 and BC1F5 to F-8 and BC1F7 generations. Four genotypes with superior agronomic traits and BYDV resistance were selected.