NZDFI Tree Breeding Programme
A distinctive feature of the NZDFI tree breeding programme is the very early and intensive selection for roundwood. Therefore, large breeding populations are planned to capture a broad range of genetic diversity from which to select for the four key traits that the breeding programme
will initially focus on. These are fast growth, good form, early heartwood formation and ability to coppice.
The NZDFI have selected sites to cover a range of abiotic (cold, drought, soils etc) and biotic (pests, diseases) stress factors likely to be found in Marlborough and Canterbury drylands. This de-risks the project against the unknown relative contributions of genetic
and environmental effects on disease, growth and early heartwood formation and ensures that a broad-based elite selection is possible.
In addition, the breeding programme is planned to provide the potential to follow overseas initiatives in developing inter-specific hybrids. Thus the breeding strategy is based on establishing these species in pairs, because inter-species breeding is possible within sub-species.
Breeding Population Establishment
Breeding populations are planned for E. bosistoana and E argophloia; E. camaldulensis and E. quadrangulata; and E. macrorhyncha and E. globoidea. NZDFI is committed to this strategy so as to improve growth, form and productivity by capturing hybrid vigour and broaden the diversity
of sites durable species can be grown. It may also reduce the potential impact of diseases and pests while offering the prospect to greatly improve the aesthetics and properties of the timber.
On this basis over the next three years the NZDFI have funding to plant the first breeding populations with E. bosistoana and E. argophloia.
These two species are very closely related so their combination in our programme will broaden and diversify the pool of genetic material that is used to select for an elite breeding population.
The other four species, E. camaldulensis and E. quadrangulata, and E. macrorhyncha and E. globoidea, will be introduced as pairs into the programme once further industry and government funding has been secured.
The first three breeding populations will be planted on three South Marlborough sites in spring 2009.
These three sites will provide the foundation for a long term tree breeding and improvement programme for up to six class 1 and 2 durable species.
Seedlings for planting the first breeding populations are being grown by Morgans Road Nursery in Marlborough under contract to the Marlborough Research Centre. In spring 2009, 18,000 will be planted into three replicates of 6,000 trees at the three sites.
There are two stages planned for screening of genetic traits. Early screening at age 3-5 will be for growth, form and early onset of heartwood aimed at selecting trees to produce seed that will grow into uniform trees suited for use as durable posts. This will provide growers greater
certainty of crop value at 8 years. Our second screening (8-10 years hence) will be for traits critical to timber – colour, collapse, growth stresses, ease of drying, shrinkage and stability. Conceptually, the breeding programme could stop at stage one (durable poles) and still be successful.
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