Summary

This project has two streams, one for further wide hybridisation within the Chamelaucium alliance and the second to apply embryogenesis technology developed in Stage 1 of the Chamelaucium project to Corymbia.
1. Somatic fusion within the Chamelaucium alliance Stage 2
Results from the Stage 1 RIRDC project on fusion within the Chamelaucium alliance has shown that the development of fused hybrids in this plant group is only possible where one parent line can be propagated through embryogenesis. Somatic embryos are a type of tissue where an embryonic structure is formed by applying various hormone recipes. These structures are like a seed embryo in that both a shoot and root meristem is present however unlike seeds they are clonal. That is, all somatic embryos derived from a single source will be the same, similar to cutting derived plants.
Our latest research has shown that fusing an embryonic line with a line that will not form embryos gives the best outcomes for generating fused hybrids. Further, by applying metabolic inhibitors such as iodoacetic acid the metabolism in the embryonic cells is stopped, although the innate propensity to form embryos remains. When these treated cells are fused with a non embryonic line any cells that then form somatic embryos will very likely be fused hybrids. In this system, the non-embryogenic cells ‘rescue’ the metabolically inhibited embryogenic cells. This detailed research has resulted in somatic hybrids between a C. uncinatum hybrid with C. megalopetalum, and the red flowered Verticordia etheliana.
The second stage of this research project will use Chamelaucium hybrids that have been selected for their ability to develop somatic embryos and target a range of species from other genera within the Chamelaucium alliance that will provide desired attributes for enhancing the hybrids and varieties currently used for cutflowers.
Two C. uncinatum X C. megalopetalum hybrids that are high level producers of somatic embry

Program

New and Emerging Plant Industries

Research Organisation

Botanic Gardens and Parks Authority

Objective Summary

This research proposal aims to deliver tissue culture protocols for somatic embryogenesis of Corymbia ficifolia and hybrids, and species and hybrids within the Chamelaucium alliance. This will for the first time provide a reliable system for clonally propagating these economically important ornamental crops in commercial quantities at significantly reduced cost.
Further, the project will provide protocols for the somatic fusion for species and hybrids within the Chamelaucium alliance as a specialised breeding tool for producing wide hybrids and introducing novel colours into Australia’s primary export cutflower crop.
This research will enhance the Australian ornamental plant industry’s ability to select and commercialise superior high value forms of species and hybrids of the Australian flora for use as cutflowers, ornamental bud and foliage and in landscaping.
This project will result in the application and publication of contemporary methods of biotechnology to commercially successful crops. It will enhance the Australian industry’s capacity to better exploit the genetic diversity in the Australian flora and will position Australian industry and researchers as leaders in the international arena for developing elite plants for cutflowers.