Genetic Expression for Monoterpenes in Clones of Pinus sylvestris Grown on Different Sites

The terpenic profile for 8 major monoterpenes determined on ten grafted clones of Scots pine grown on three different sites in Sweden. As graft effects could not be detected, oleoresin, samples from primary and secondary grafts were used to study genetic variation. In three quite different environmental conditions, a strong broad sense heritability was demonstrated for 3-carene, myrcene, limonene and beta-phellandrene. Pinenes and sabinene seem to be much more dependent on environmental factors. Both site and clone x site interaction have a small effect on overall phenotypic variation. There is a strong positive correlation between concentrations of 3-carene and terpinolene, which supports a possible pleiotropic effect of the same major gene on the two monoterpenes. The results show that there is no risk of an important bias when the comparison is made between genotypes sampled on very different sites (stands or comparative trials). The relative concentration of monoterpenes is to a great extent independent of environmental conditions.