Population structure and phenotypic variation of a spring barley world collection set up for association studies

Abstract

With 3 figures and 4 tables Abstract Association mapping offers a tool to identify plant resources that carry important alleles for crop improvement and breeding. A necessary prerequisite for association mapping is a collection of genotypes representing a cross section of the examined germplasm. This study describes the genetic and phenotypic characterization of a collection of 224 spring barley ( Hordeum vulgare L.) accessions sampled from the IPK gene bank. The analysis of the genetic structure of the collection was based on 45 EST‐derived simple sequence repeat (SSR) markers and it revealed two major subgroups, mainly comprising two‐rowed and six‐rowed barleys, respectively. The phenotypic data were based on field trials performed at three locations in Germany in 2004 and 2005. Significant genotypic variation and genotype × environment interaction were observed for all traits under study (thousand‐grain weight, crude protein content, starch content, plant height, and flowering time). For all analysed traits entry mean‐based heritability estimates exceeded 0.9. After appropriately correcting for population structure and geographic origin significant associations between SSR markers and all traits under study were detected.