Summary

The proposed new commercially-viable model for breeding of tea tree has distinct pre-breeding, breeding and propagation components. Here we outline the core breeding component for tea tree breeding program 2 (TTBP 2).
The proposed strategy builds on and secures the germplasm and knowledge base developed in TTBP 1, with two key components:
Data curation and integration underpin the new program, and will include adding value to existing TTBP 1 resources and data in a widely interpretable and convenient form.
Recovery, stabilisation and secure storage of seed resources to international standards of ex situ conservation.
A key change is the adoption of a two-tier breeding program, which includes controlled crossing in an elite population managed on a rolling front to maximise the rate of genetic gain.
This should allow for more frequent release of cultivars, more even expenditure and activity, and reduced operational risk, than was possible in TTBP 1.
Thus a sustainable pipeline of new cultivars can be released every other year commencing in Feb 2023.

Program

Tea Tree Oil

Research Organisation

Southern Cross University

Objective Summary

• Work with industry towards an agreed ideotype.
• Generate a sustainable pipeline of new cultivars released every second year, commencing in Feb 2023.
• Maximise genetic gains by releasing cultivars as clones or full sib families from testing and selection in an intensively managed elite population annually commencing from Feb 2023.
• Improve a broadly based main breeding population, in discrete generations by open pollination. This will act as a resource to enable progressive infusion of new genes (alleles) into the elite population, and also act as a potential backup resource for supplying a next generation of open pollinated seed cultivars.
• Secure, document and curate meta-data describing TTBP 1 physical resources. This will underpin management of the CropStoreDB for Tea Tree integrated database that will capture all relevant cumulative data and meta-data in common formats.
• Establish secure germplasm resource collections as duplicated seed repository and living collection(s), with potential for live duplication on Southern Cross University land in Lismore, and possible duplication on producers’ land holdings.
• Establish an open pollinated progeny trial, which if required may be converted to an orchard to supply a next generation open pollinated seedling cultivar in 2023.
• Elite genotypes from TTBP 1 will be captured by cloning for use in a controlled pollination orchard, and archived in a clone bank.