Genetic control of wood colour, density and heartwood ellagitannin concentration in European oak (Quercus petraea and Q. robur)

Pressler cores of young clones of Quercus petraea and Q. robur were analysed from two sites in Germany. Variation of wood colour (defined by the CIELAB system), density and heartwood ellagitannins was examined between clones, species and sites. Similar studies were made of cores from another trial of 20 half-sib families of parent trees deriving from five German forests. The results from both the clonal and progeny trials indicate that heartwood ellagitannin content and wood density are under strong genetic control, while sapwood and heartwood colour are less so. A large proportion of between-clone variation in wood density and ellagitannin levels occurred between the two species, while these properties varied little among ramets of the same clone grown on two contrasting sites, despite a difference in growth rates. A large proportion of the total variation among progeny was attributed to forest origins and could not be attributed clearly to either genetic or environmental causes because of limitations of the sampling design