ABSTRACT
Principles of genetic sampling and conservation in perennial species are considered and, as an application, arctic bramble (Rubus arcticus L.) is discussed. This is a subarctic wild berry species now in the process of domestication. Possible ways of conserving its genetic variation in the Nordic Genebank are considered.
Vegetative propagation of clones, both naturally and with the aid of mist techniques, is common practice with the arctic bramble although it is rather expensive. In the near future arctic bramble clones may be stored as meristem cultures under refrigeration, and later on may also be deep frozen.
Intercrossing of arctic bramble clones by hand is too resource-consuming and does not offer essential advantages taking into consideration the total strategy of conservation.
Selfing is practically ruled out in the arctic bramble, due to the strong self-incompatibility and inbreeding depression. Instead, bulk-pollinating will probably prove to be both easy and cheap and will still maintain the most fundamental genetic structures.
Thus a dual strategy is proposed for the arctic bramble — both clone collections and bulk populations should be established.
Clone collections should be established during the first stage.
As a basis for classifying the collection localities in the northern countries, a subdivision into five natural geographic zones, characterised by vegetation and soil types, should be used.
It is anticipated that these zones will influence the formation of genetic co-adaptation.
In clone collections of R. arcticus, accessions from a particular zone should be planted together to secure the conservation of co-adapted genes.
Different zones in a clone collection should be isolated by a surrounding zone of a triploid clone which flowers abundantly but is incapable of fertilisation, either as a male or as a female parent.
