Association mapping of resistance to common root rot and spot blotch in barley, and population genetics of Cochliobolus sativus

Cochliobolus sativus is an important fungal pathogen, which causes common root rot (CRR), spot blotch (SB) and black point/kernel blight in barley in North America. The genetics of resistance to CRR is poorly understood and information on virulence spectrum of C. sativus causing CRR is very limited. Therefore, the objectives of current studies are multifaceted. Association mapping of resistance to CRR and SB using single nucleotide polymorphisms (SNP) markers was applied to map QTL resistance to these diseases. Additionally, 289 single-spore isolates of C. sativus were analyzed for amplified fragment length polymorphism (AFLP) using three AFLP primer combinations. The screening of barley germplasm for resistance to CRR and SB indicates that only 0.9% and 0.5% of breeding lines showed resistance to CRR and SB during 2006-2008. None of the genotypes showed resistance to virulent isolates in greenhouse experiments. Hordeum jubatum sp. jubatum (Accession...