Field performance of 17-year-old micropropagated hybrid aspen clones and aspen seedlings at three sites in Germany

Micropropagated clones from thirteen hybrid aspen (Populus tremula L. x P. tremuloides Michx.), two P. tremula clones, and seedlings of three open pollinated P. tremula families were field-tested up to the age of 17 years on three sites in northwestern Germany. Twelve of these clones have earlier been approved under the category “Tested Material” in the multiclonal variety ‘Grosshansdorf’. Growth and development of the tissue culture derived clones and the seedlings were monitored in a long-term field trial. Survival, growth potential, and trunk as well branching habit were studied. The field evaluations have shown no negative effects of micropropagation on the growth potential, or tree morphology of hybrid aspen clones. On more favorable sites the hybrid aspen clones demonstrated their distinct superiority as compared to P. tremula trees. Our data indicates that miropropagated hybrid aspen clones offer new opportunities as a choice material for their better performance, especially on more favorable sites.