These are special seed lots (or in some cases plants) which have been supplied to the GB Forestry Commission (FC) and private nurseries since 1981. They have been used for commercial vegetative propagation and also for purely research applications.
They are either half-sibling (polycross) or full-sibling (specific cross) mixtures of seed from parents of proven superiority over direct import Queen Charlotte Islands, British Columbia, Canada (QCI) material for growth and quality traits. The seed has been produced using controlled pollination techniques between highly selected parents. Since 2013 such controlled pollinations have been carried out exclusively by the Conifer Breeding Cooperative.
Prior to the formation of the CBC a complete re-analysis of all original plus tree breeding values and performance of all full-sibling families was carried out by an independent body. This resulted in new ‘Predictions of Genetic Gain’ for existing parents of families available in the marketplace. The same data will be used to predict gains for new Parents of Families produced in the future. For details of the new predicted genetic gains, please visit:
http://www.coniferbreedingcoop.co.uk/species/sitka-spruce/new-gain-statistics/