1. Inst. of Dendrology, Polish Academy of Sciences Parkowa 5 62‐035 Kórnik Poland
2. Dept of Botany, Univ. of Life Sciences Wojska Polskiego 71c PL‐60‐625 Poznań Poland
3. Laboratory of Molecular Biology and Cytometry, UTP Univ. of Science and Technology Bydgoszcz Poland
4. Inst. for Alpine Environment, European Academy of Bozen/Bolzano, Eurac Research Bolzano/Bozen Italy