An assessment of family variation of Norway spruce (Picea abies (L.) Karst.) of the Kolonowskie provenance from a reconstitution seed orchard

Variation in spring bud break dates and growth traits was studied among 183 half-sib families developed from Norway spruce grafts on a reconstitution seed orchard. The grafts were derived from maternal trees (ortets), which were selected on the IUFRO 1964/68 experimental plots in 11 countries. All maternal trees belong to the same provenance Kolonowskie, which should be reconstituted as a population by a seed orchard because its exact location was not documented, and thus seed of this provenance was not available. Analyses of variance of the data collected in the first six years of the experiment revealed a very high variation between families in general and between families within clones. Differences between the clones were observed in some traits (plant height after the first growing season, spring flushing in the sixth growing season), but differences between families within clones proved to be more significant. A positive correlation was found between bud break dates of grafts in the seed orchard and their generative progeny on the family experimental plot. The correlation was significant both at the family (graft) level (p = 0.01) and at the clonal level (p = 0.05). The substantial variation between open pollinated families from the reconstitution seed orchard cannot entirely be interpreted but it indicates a high selective potential of Norway spruce at the family level.