Myrtle Rust screening in lemon myrtle provenance plantings (Pt 2)

University of the Sunshine Coast

  • Project code: PRJ-008883

  • Project stage: Closed

  • Project start date: Thursday, May 30, 2013

  • Project completion date: Monday, November 30, 2015

  • National Priority: NEPI-Industry building and connectivity

Summary

Expected outcomes of this project are the establishment of new breeding populations and screening trials that will form the basis for further studies of rust tolerance and productivity of this species. These sites will be the prime source of rust-tolerant cultivars for the Australian Native Food, Essential Oil and Horticultural industries using B. citriodora. The new breeding populations will also facilitate on-going breeding of the species to enhance yields and rust tolerance of commercial cultivars. Myrtle rust screening trials undertaken during this project using isolates of the pathogen from across its current host range, will inform researchers and industry of the efficacy of the selection process, if the disease is mutating and highlight the need for on-going screening and selection of germplasm.

Program

New and Emerging Plant Industries

Research Organisation

University of the Sunshine Coast

Objective Summary

The principal aim of the project (a) is to capture and relocate clonally the majority of the existing ex-situ conservation/breeding population of Backhousia citriodora at Beerburrum Nursery (61 families from 11 provenances) to secure sites (government and industry) in Queensland and New South Wales. This will ensure that this valuable array of germplasm will not be lost to efforts to conserve the species and develop the best possible myrtle-rust tolerant clones as a basis for the lemon myrtle and essential oil industries.
Secondary aims are:
(b) To screen for rust resistance at a commercial lemon myrtle industry site the most rust resistant individuals observed in the ex-situ conservation/breeding population of B. citriodora at Beerburrum. This work has the objective of identifying rust tolerant clones for immediate deployment by industry in the place of the rust susceptible clones currently in use.
(c) To expand the genebank by introducing new families of B. citriodora (seedlots) from Woondum and Ubobo. In assessment of the planting at Beerburrum, the Woondum provenance had the most myrtle rust tolerant individuals of the provenances evaluated and it is considered important that this provenance be more widely sampled. The Ubobo provenance is poorly represented in the Beerburrum planting, so it was not included in the analysis of growth and rust scores but again it warrants further sampling.
(d) To test the rooted clones against different isolates of myrtle rust (Dr Fiona Giblin and student) to validate the field observations of plant susceptibility and tolerance.