Clonal Forestry

Abstract

Thulin (Breeding Pinus radiata through seed improvement and clonal afforestation. Second World Consultation on Forest Tree Breeding, Washington, 7–12 Aug. 1969) dreamed of a clonal forestry programme based on the 588 ‘268’ clones. He hoped that the cuttings taken from these 12–17-year-old selections would root and form the basis of a large clonal forestry programme. Only about 30 of them rooted sufficiently to plant a clonal test, and these later showed strong maturation effects. Other attempts were made to start clonal forestry, and successful clonal tests were planted and grew well, but cuttings from their archive hedges neither rooted nor performed like their ramets in the clonal tests. These early efforts at clonal forestry failed in their objective. Mike Carson examined Libby and Rauter’s paper supporting clonal forestry and found little advantage for radiata. Shelbourne looked at the use of cloning of the breeding population and found superior gain from selecting clones (versus seedlings) for the future breeding population. Beauregard, in a sawing study on 26-year-old clones, showed highly superior random-width board grades for long internode, large-diameter clones. However, as reported by Mike Carson et al., a successful ‘varietal’ programme based on embryogenesis-propagated clones is fully operational and successful (for ‘varietal’ for this chapter, read ‘clonal’). Interestingly, the somatic clones, cold-stored in liquid nitrogen, when rooted in nursery beds still show slight evidence of maturation or ‘c’ effects.