Adaptation of Norway spruce to extreme climatic conditions is generally believed to develop in the course of many generations due to the interaction of several evolutionary processes (mostly selection). Recent results with Norway spruce have indicated that climatic adaptation can occur in only one generation in response to the climatic (temperature/photoperiod) conditions during the sexual reproduction. In order to establish the mechanisms underlying this short-term adaptation and to utilise the respective results for practical forestry purposes, several integrated investigations using the same progenies from controlled crosses in different environments are planned. Possible rapid selection processes during reproduction will be analysed by allonyms and DNA markers in female gametophytes and embryos of the different progenies. Possible gene regulations will be analysed by means of new innovative molecular genetic methods aiming at the detection of the mechanisms of potential differential gene expression in different progenies. Both main investigations will be supplemented by phonological and physiological studies on the same Norway spruce progenies.