Genetic analysis of β-glucan content in diploid and hexaploid oat

Wild relatives of crop species are a rich source of valuable traits for crop improvement but the challenge is how to successfully access such genetic variation without negative effects on crop production. Diploid, tetraploid and hexaploid relatives of the cultivated oat (Avena sativa L.) have been shown to display resistance to a wide range of diseases and possess enhanced grain characteristics such as oil and β-glucan content.
A recombinant inbred line mapping population at the diploid level between two A-genome parents differing for a range of grain and agronomic characteristics including β-glucan content and the naked trait was used to develop a detailed genetic linkage map using both microsatellite and sequence based markers enabling comparisons with genetic maps of hexaploid oats and other Gramineae. The naked gene in this diploid population mapped as a single major recessive gene. Two regions of the genome were found to be associated with β-glucan content. In addition a high degree of clustering of QTL associated with domestication related traits was obtained in three genomic regions with clear separation from those QTL associated with agronomic traits. A comparison of the QTL obtained in this study with those obtained elsewhere and in hexaploid oats has been conducted. In addition, markers associated with β-glucan content have been used to identify combinations of beneficial alleles in progeny of crosses from both the winter and spring oat breeding programme at Aberystwyth. Progress toward developing higher β-glucan oats adapted to UK conditions will be described.