Lindgren D
The Genetic Variation of Inter-Provenance Hybrids of Picea-Abies and Possible Breeding Consequences
Scandinavian Journal of Forest Research: 1992 7:15-26
The variance of general combining ability (GCA) and specific combining ability (SCA) for height and diameter growth were estimated from a 13 years old provenance hybridization study in Norway spruce. The GCA variance component for both height and diameter growth was significant, but there was no significant SCA variance. Hybrid progenies outperformed the progenies from strands, but this superiority was not intepreted as a provenance heterosis effect. Estimated family heritabilities for height and diameter growth were moderately high (0.40 for both traits). A consequence of the low SCA variance for Norway spruce may be that clonal testing should replace progeny testing for estimating GCA.