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Publication in Annals of Forest Science

Publication in Annals of Forest Science – Molecular effects short-day treatment of spruce seedlings revealed

Together with Dalarna University (SE), Swedish University of Agricultural Sciences (SE) and Purdue University (US), NSure studied the effect of short day length on dormancy and freezing tolerance related genes in Norway spruce seedlings. This work has now been published in the peer-reviewed scientific journal ’’Annals of Forest Science’’ (

The quality of nursery seedlings play an important role in determining reforestation. One key attribute towards the end of nursery cultivation is the dormancy status. The dormancy cycle of many forest tree species is strongly affected by seasonal changes in day length and temperature. To prepare seedlings for autumn planting or frozen storage, nurseries across Canada and Scandinavia employ a short day treatment during summer. A short day treatment does not only inhibit plant growth and promote bud set, but also induce dormancy and eventually freezing tolerance.

Determination of plant growth and bud set is relatively straightforward, but the estimation of the level of dormancy and its relationship to subsequent freezing tolerance is more complex. Even though short day treatments have been used for several decades, up to now there was no practical way to assess dormancy progression.

Within this study, we clearly demonstrate that the expression of dormancy related genes can be used to monitor the level of dormancy. These genes could possibly be used in the future to develop a test for forest tree nurseries to determine when a short day treatment can be terminated. Furthermore, by using the existing ColdNSure test we were able to demonstrate that a short day treatment indeed stimulates the freezing tolerance, thereby speeding up the moment of storability.