PROPAGATION

The key goal of NZDFI’s tree breeding work continues to be producing improved planting stock for growers. Millions more improved seedlings will be needed for planting if we are to achieve the vision of planting 60,000 hectares of naturally durable eucalypts by 2030 and developing a sustainable durable hardwood industry in New Zealand.

NZDFI has benefitted from innovative research by Proseed NZ into the development of rapid eucalypt propagation techniques, including clonal propagation.

Research programme and methods

Proseed NZ is Australasia's largest supplier of tree seed, and is a foundation partner of NZDFI. Its contribution to NZDFI’s work includes:

  1. seed collection – from phenotypically superior trees in both New Zealand and Australia, to begin the NZDFI breeding programme
  2. seed orchards - Proseed have established clonal seed orchards of E. globoidea and E. bosistoana to upscale and manage the production of improved seed
  3. seed handling - using state-of-the-art technology to dry, sort and store seed
  4. propagation – the team at Proseed continue to work on developing propagation techniques to multiply up selected parent stock.

Traditionally, tree breeding cycles are slow and expensive. To speed things up, NZDFI's approach is to identify trees with desirable growth and wood quality traits at as young an age as possible, using techniques being developed by School of Forestry wood technology researchers.

At the same time, Proseed NZ has made good progress on developing novel propagation techniques. This enables rapid multiplication of offspring from selected trees.

Developing clonal propagation

Testing and deployment of genotypes can be undertaken with seedlings, clones or a combination of both. Producing planting stock by vegetative propagation (clones) of outstanding individual genotypes identified in progeny tests maximises the selection gains.

The timeframe between seedling progeny testing and clonal deployment could be shortened if selections in progeny trials could be felled and the coppice harvested for cutting production. In our first attempt at producing E.bosistoana cuttings for clonal plantings, the coppice from young seedlings was used. With the support of a Te Uru Rakau 1BT partnership grant, we were able to undertake extensive testing of 33 E.bosistoana and 41 E.quadrangulata clones.

Some of the advanced propagation techniques with eucalypts have not been used before in New Zealand, and Proseed staff travelled to Australia to learn from expertise over there. In 2016, the company invested in a new state-of-the-art propagataion facility at their Amberley base.

Work to date has included:

  • establishment of a clonal seed orchards of bosistoana, E globoidea and E quadrangulata. Scions from ‘plus trees’ (best individual trees from top-ranked families in NZDFI breeding trials) have been grafted onto rootstock and then planted out into what will become a seed orchard, with first improved seed anticipated within 2-3 years
  • taking cuttings from coppice stools for rooting using a hydroponic system in Proseed's new high-tech propagation facility.

 

Young cuttings taken from coppice.

E.bosistoana cuttings growing well.

 

Grafting eucalypts for our clonal seed orchard.

Stools in a custom crop cover greenhouse.

E bosistoana and E quadrangulata stools growing in a hydroponic system.

Tissue culture: early advances

Under NZDFI’s One Billion Trees partnership project Proseed worked with Dr David Leung at University of Canterbury School of Biology to accelerate multiplication of E. bosistoana material using laboratory-based tissue culture techniques.

Dr Leung made good progress in attempts to reproduce E. bosistoana using tissue culture technique. Root formation was achieved, a critical step in producing new plantlets. This work is on hold for now, but provides a positive result for the future.

More information about Dr Leung's tissue culture work

More information

Check out our Resources, especially our six-monthly Project Updates, to read about propagation research. Details of some of the work we undertook under our One Billion Trees project are here:

You may also be interested in this article, which puts some of NZDFI's propagation work in context:

Propagation: a bottleneck in tree-breeding programmes

Key researchers

Paul Schroeder is Proseed’s Propagation Manager. Paul and his colleagues at Proseed work with Ruth McConnochie (NZDFI Tree Breeding Specialist), and members of the NZDFI Science Team.