Discovery of genetic resistance markers to Myrtle rust in Myrtaceae

Australian National University

  • Project code: PRJ-007524

  • Project stage: Closed

  • Project start date: Monday, September 19, 2011

  • Project completion date: Sunday, March 15, 2015

  • National Priority: NEPI-Industry building and connectivity


This project aims to discover the genetic basis of resistance to the plant pathogen myrtle rust (Puccinia psidii sensu lato) in four economically important species of Myrtaceae – Backhousia citriodora (lemon myrtle), Syzygium luehmannii (riberry), Syzygium anisatum (anise myrtle) and Melaleuca alternifolia (tea tree). A large number of genetically diverse individuals of each species will be screened for resistance to the pathogen. After identification of fully resistant and susceptible individuals, we will re-grow these plants in the absence of the pathogen. For each species, we will seek to identify at least one susceptible individual and one or more resistant individuals, because the resistance could be caused by different genetic markers. We will test the resistant individuals for the presence of the Eucalyptus Ppr loci via simple assays. This will be followed by a transcriptomics approach: young shoots will be sampled prior to inoculation with rust spores. Plants will be sampled again 4-6 days after inoculation. We will sequence the transcriptome for each sample using an in-house Illumina HiSeq 2000. In a bioinformatic-driven approach, we will identify which transcripts are up-regulated in resistant plants after inoculation. Genes or gene families that we can expect to discover are e.g. leucine-rich repeat (LRR) genes. The information we gain can be utilized by the industry to incorporate resistance markers into their breeding program. We aim to find multiple resistance markers and develop methods for identifying these quickly and cheaply in these four species so that growers can select robust resistant material. Further, we aim to identify the pattern of transcript changes induced by the systemic resistance activator Bion (acibenzolar-S-methyl) which we have shown in preliminary experiments to induce resistance in tea tree exposed to rust.


New and Emerging Plant Industries

Research Organisation

Australian National University

Objective Summary

The project aims to (i) identify resistant and susceptible plants in four economically important Australian plant species, (ii) identify markers of genetic resistance to myrtle rust and (iii) develop cheap and rapid methods to screen material for these markers and to make those methods available to Australian industry (iv) test the degree to which resistance can be induced in otherwise susceptible material via application of acibenzolar-S-methyl (“Bion”).