Frost hardiness of Finnish plus tree progenies of Scots pine from seed orchards in Finland and Ukraine

Abstract To avoid the surrounding pollination, seed orchards of Finnish plus trees have been established in Ukraine, i.e., far from their natural distribution. However, it is unknown whether pollination site affects frost hardiness (FH) progenies and thus use forest regeneration Finland. Using whole-plant freezing tests, we examined FH tree orchard Finland with three lots seeds each orchard, twice during cold acclimation controlled conditions. The needles, as assessed immediately after was higher than Ukrainian progenies. variation needles high among progenies, ranging − 44 to 79 °C by relative electrolyte leakage (REL), 29 46 chlorophyll fluorescence (CF). when based on growth shoots roots greenhouse weeks, differences between disappeared. then 10 15 shoot growth, 6 12 root 8 16 number new tips. results imply an epigenetic effect but no progeny or roots. In summary, seems be possible produced southern Ukraine practical reforestation actions