Journal article
The resistance of lemon myrtle (Backhousia citriodora) to myrtle rust (Austropuccinia psidii)
Australasian Plant Pathology, Vol.55(3), pp.1-17
2026
Abstract
Lemon myrtle (Backhousia citriodora, F. Muell.) is a native Australian myrtaceous species, highly valued for its unique, citral-rich essential oil. The development and success of this Australian industry has been in jeopardy since the detection of myrtle rust (Austropuccinia psidii) in Australia (April 2010). Since the initial invasion, it has spread across the major lemon myrtle growing regions in New South Wales and Queensland. The main commercial clones are highly susceptible to infection, with plantations experiencing up to 70% production losses. To identify resistance to A. psidii for industry use, disease assessments were conducted on germplasm originating from 13 Queensland provenances, established in two clonal field trials. Newly collected germplasm from the Ubobo provenance was also screened under controlled conditions. Infection caused symptoms ranging from small, restricted sori on a low percentage of leaves, to infection on up to 100% of leaves, with distorted shoots and severe dieback on infected stems. No fully resistant germplasm was identified, but significant differences in observed disease offer opportunities to select more resistant clones than those currently relied on by the industry. Germplasm from Eumundi, Noosa and Woondum (southern Queensland), and Silver Valley (northern Queensland), showed superior resistance to A. psidii across assessments and trial sites. Substantial variation in plant growth traits of importance to commercial production (e.g. canopy structure and foliage density) was observed among the provenances, families, and clones evaluated across the trials, suggesting the need to consider plant growth, biomass yield and essential oil properties when selecting industry-suitable germplasm. Implementing a breeding or hybridisation program should be a priority for the industry.
Details
- Title
- The resistance of lemon myrtle (Backhousia citriodora) to myrtle rust (Austropuccinia psidii)
- Authors
- Emily Kathryn Lancaster (Corresponding Author) - The University of QueenslandGeoffrey Samuel Pegg - Queensland Department of Primary Industries and FisheriesR. Andrew Hayes - University of the Sunshine CoastAndré Drenth - The University of QueenslandDavid John Lee - University of the Sunshine Coast
- Publication details
- Australasian Plant Pathology, Vol.55(3), pp.1-17
- Publisher
- Springer Dordrecht
- Date published
- 2026
- DOI
- 10.1007/s13313-026-01145-7
- ISSN
- 1448-6032
- Copyright note
- This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
- Data Availability
- The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
- Grant note
- This research was supported by the Plant Biosecurity Cooperative Research Centre.
- Organisation Unit
- Forest Industries Research Centre
- Language
- English
- Record Identifier
- 991225020602621
- Output Type
- Journal article
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