Achievements in forest tree genetic improvement in Australia and New Zealand 10: Pinus radiata in New Zealand

Pinus radiata is the subject of much the largest and longest-running tree breeding program in New Zealand. Very intensive plus-tree selection began in the early 1950s, the first seed orchard planting was in 1958, and the first orchard seed was collected in 1968. By 1985 seed Orchards Could meet the national planting needs, which helped prompt an innovative seed certification scheme. Selection began in local, 'land-race' stands. That proved appropriate, but better knowledge led to research oil material from the species' entire natural range and then to further seed importations from natural stands, mainly for future genetic resources. Initial plus-tree selection largely addressed poor tree form in the central North Island. This led to selecting a 'short-internode' ('multinodal') branching ideotype, with great improvements in general tree form and Substantial gains in growth rate. A distinctive portfolio of several breeds, representing different breeding goals, has since been developed for the diverse planting sites and the various end products. By contrast, the original regionalisation of seed orchards proved largely unjustified. Despite early research indicating good heritabilities, wood properties have figured significantly in breeding goals only since growers Substantially reduced harvest ages, but they are now intensively researched. The breeding program was greatly expanded from 1968 to meet the needs of multi-generation breeding. This was one or the program's contributions to developing breeding strategy as a discipline, various of which were reflected in the 1986 Development Plan. Industry uptake of tree breeding has since posed challenges in maintaining genetic variability for a secure, long-term underpinning of the program. Special genetic-gain trials were first planted in 1978, to demonstrate and quantify genetic improvement, and to help update forest out-turn predictions. The gains achieved in tree form helped induce New South Wales State to affiliate with the New Zealand program, following significant earlier contributions of breeding material to Australian breeding programs. Improved technologies for seed Orchards and vegetative propagation have facilitated development of the breed portfolio and more specific customisation of seedlots. Becoming able to deliver genetic gain through controlled pollination has allowed changes in the Structure of the breeding Population. Further changes are resulting from an increasing capability to reconstruct pedigrees after open pollination. Developments towards full clonal forestry have faced obstacles, but offer greater genetic gains and a more precise customisation, and clonal forestry is now being vigorously commercialised. Having a single, large Forest Service until 1987 undoubtedly favoured the development of a very strong tree improvement program. Since then, continuing institutional changes, which are reviewed, have posed numerous challenges.