Identification of three large full-sib families of Quercus rubra for genetic mapping in an isolated planting outside the species’ range in Germany

Forest tree breeding faces challenges due to long generation times and high costs. To address these issues, the concept of “breeding without breeding” (BwB) offers the opportunity to accelerate breeding cycles by using naturally generated half- sib and full-sib families. An isolated population of trees may provide an ideal environment to identify full-sib families for genetic mapping without the need for controlled pollination. In this study, paternity analysis based on genotyping of 16 SSR markers in 1232 seedlings identified three large full-sib families of Quercus rubra (Qr_N - Qr_W with 576 siblings, Qr_N - Qr_S with 175 siblings and 124 siblings in the family Qr_P - Qr_11). Paternity assignments were effectively corroborated by segregation analysis, resulting in large F₁ full-sib families for further experiments such as Quantitative Trait Locus (QTL) mapping.