Integration of somatic embryogenesis in a tree breeding programme: a case study with Picea abies

Potential for integration of somatic embryogenesis in a breeding programme of Norway spruce (Picea abies (L) Karat.), and its limitations, were invest igated in a case study with an ordinary breeding population. A standard pro tocol was used for initiation, proliferation, and cryopreservation of embry ogenic cultures; maturation of somatic embryos; and plant regeneration. Thi s is a practical necessity when dealing with a large number of genotypes. P roliferation and maturation were identified as major constraints. Clear dif ferences among families were seen for proliferation and for maturation. For plant regeneration, differences among cell lines within families were cons iderable while no significant differences were found among families. Signif icant differences among male parents were obtained for proliferation and ma turation. Our calculations show that by using an improved standard protocol , at least one third of the genotypes can be propagated via somatic embryog enesis. No clear relationship was found between embryogenic characters of s elected parents based on progenies and corresponding parental breeding valu es for growth and phenology characters. Three years can be gained by using somatic embryogenesis instead of cuttings in a breeding programme. Maintain ed propagation ability by including cryopreservation in the breeding progra mme will provide a very useful link between breeding and mass propagation. The results are encouraging, but further improvement of the standard protoc ol is necessary.