Session 10: Managing myrtle rust in Australia

biosecurity built on science

Managing myrtle rust in Australia

Dr Geoff PeggForest Health Team Leader

Forestry ScienceDAF Queensland

Plant Biosecurity Cooperative Research Centre

New South Wales

Queensland

South Australia

Western Australia

Northern Territory

Tasmania

Spread in Australia

Lord Howe Island October 2016


Screening methodologies for:- Selecting resistance to Puccinia psidii

within genera and species within breeding populations

- Examining resistance patterns, heritability and resistance mechanisms

Field assessment methodologies for:- Rating susceptibility of Myrtaceae to Puccinia psidii- Studying impact of Puccinia psidii on species and plant

communities

Myrtle rust research outputs


Interstate trade restrictions - loss of markets or increased treatment requirements

Species removed from production Forestry – minimal direct impact

- Restrictions on movement of germplasm for commercial development (e.g. Eucalyptus globulus)

Native foods- Significant reduction in productivity- Loss of organic status and related markets- Relocation of industry

Impact on plant industries


Host list and susceptibility rating identifying:- Resistant/tolerant species for future commercial development - Highly/extremely susceptible species from an environmental perspective

Full host list on-line and susceptibility ratings published- >350 species from 57 genera

Giblin FR & Carnegie AJ (2014) Puccinia psidii (myrtle rust) - Australian host list. http://www.anpc.asn.au/myrtle-rust

Pegg GS, Giblin FR, McTaggart AR, Guymer GP, Taylor H, Ireland KB, Shivas RG, Perry S (2014) Puccinia psidii in Queensland, Australia: disease symptoms, distribution and impact. Plant Pathology 63, 1005–102

- Proposed industry publications Publication in Horticulture journal and industry magazine articles - April 2017

Myrtle rust research outcomes – Plant industries


Simple field rating system- 180 species assessed

50 Species HS/ES Variability in some species

Predicting impact- All trees rated as HS/ES are in

severe decline

Assessment system to be adopted for all new host species reports

Tolerant Moderate Susceptibility

High Susceptibility

Extreme Susceptibility


Identification of resistance for implementation into current and future breeding programs - Eucalypt species

Pegg, G. S., Brawner, J. T., and Lee, D. J. 2014. Screening Corymbia populations for resistance to Puccinia psidii Plant Pathology 63: 425-436. Lee, David, Brawner, Jeremy, and Pegg, Geoff 2014. Screening Eucalyptus cloeziana and E. argophloia populations for resistance to Puccinia psidii.

Plant Disease 99, 71-79. Butler J. B., Freeman J. S., Vaillancourt R. E., Potts B. M., Glen M., Lee D. J., Pegg G. S. 2016. Evidence for different QTL underlying the immune and

hypersensitive responses of Eucalyptus globulus to the rust pathogen Puccinia psidii Tree Genetics & Genomes 12(3).

- Lemon myrtle RIRDC project – 392 clones screened

- D. Lee, J. Doran, G. Pegg, D. Lea, P. Macdonell and F. Giblin 2015. Myrtle Rust Screening in Lemon Myrtle Provenance Plantings. RIRDC Publication

PhD student (Emily Lancaster - QAFFI) Examining disease epidemiology, field tolerance and management options

- Broad leaved Melaleuca species

Myrtle rust research outcomes – plant industries


Melaleuca quinquenervia provenance susceptibility



Melaleuca leucadendra provenance susceptibility


Melaleuca viridiflora provenance susceptibility


Susceptibility and impact levels recorded for 180 species Detailed assessments on impact for 21 species

- Impact across host natural distribution- Impact on regeneration- Impact on plant communities

Myrtle rust research outcomes - Environment


Impact on widespread species

• Myrtle rust impact• Most populations consist entirely of

dead or dying trees

• Regenerating seedlings/suckers also infected & killed

• Rhodomyrtus psidioides • Native guava

• Conservation status• Least Concern

• Fast growing • Important successional role in

rainforest regeneration

Carnegie AJ, Kathuria A, Pegg GS, Entwistle P, Nagel M, Giblin FR, 2015. Environmental impact of the invasive rust Puccinia psidii on Australian native Myrtaceae. Biological Invasions DOI 10.1007/s10530-015-0996-y


Rhodomyrtus psidioides 2014


Rhodomyrtus psidioides 2016


Widespread species – Rhodamnia rubescens

2014

2016


Impact on plant communities – Wet sclerophyll with rainforest understory

Mid-storey species and compositionTree species % tree canopy healthyAcmena smithii 78.5 ±13.124 a

Archirhodomyrtus beckleri 7.66 ±3.063 bDecaspermum humile 0 ± 0 b

Gossia hillii 4.348 ±4.348 b

Impact of Puccinia psidii infection – mid-storey

66%

13%

12%

6%3%

Regenerating seedlings - species composition

Acmena smithii

Archirhodomyrtus beckleri

Rhodamnia maideniana

Decaspermum humile

Gossia hillii

41%

25%

15%

11%

2%2% 2%

1% 1%

Midstorey species and composition

Archirhodomyrtus beckleri

Gossia hillii

Decaspermum humile

Acmena smithii

Rhodamnia rubescens

Rhodomyrtus psidioides

Syzygium hodgkinsonii

Pilidiostigma glabrum

Syzygium oleosum


Tallebudgera Valley 2014

Decaspermum humile

Syzygium corynanthum

Acmena smithii


Tallebudgera Valley 2016

Decaspermum humile

Syzygium corynanthum

Acmena smithii


Impact on plant communities

Acmena smithiiAcmena smithii

Decaspermum humile

Acmena smithii

Rhodamnia rubescens


Impact on plant communities


Publication:- Angus J. Carnegie, Amrit Kathuria, Geoff S. Pegg, Peter Entwistle, Matthew Nagel, Fiona Giblin, 2015.

Environmental impact of the invasive rust Puccinia psidii on Australian native Myrtaceae. Biological Invasions DOI 10.1007/s10530-015-0996-y –

Proposed publications - 2017- Impact of Puccinia psidii on regeneration of Melaleuca quinquenervia and interaction with native insect pests - Impact of Puccinia psidii on Myrtaceous rich plant communities in wet sclerophyll environments in south-

east Queensland- Impact of Puccinia psidii on regeneration of Myrtaceae in coastal heath following wildfires

Workshop Brisbane April 2016 - Aimed at raising the awareness of myrtle rust within the various environment departments

Federal and State Environment Departments, PHA, PBCRC etc. NZ and USA representatives National Environmental Science Program (NESP)

Myrtle rust research outcomes - Environment


Legislative outcomes- Myrtle rust declared as a Threatening Process in NSW and applications submitted for national listing- Application for Rhodomyrtus psidioides and Rhodamnia rubescens to be listed as Critically Endangered submitted

Myrtle Rust Environmental Impacts Working Group

Briefing of Federal Department of Environment Division Heads and Head of Australian Environment Agencies- Recommended that issue be taken to a future COAG meeting

Project development- Prioritising species for conservation based on susceptibility/impact data and risk modelling – NSW Department of

Environment- Myrtle rust identified as a priority for National Environmental Science Program

PhD project funding looking at conservation of species identified from this project as being under threat

Myrtle rust research impacts


Thankyou- Dr Angus Carnegie, Dr Suzy Perry- Dr Fiona Giblin, Dr David Lee, John Huth, Peter Entwistle, Dr Kylie Ireland- Dr Gordon Guymer, Bob Makinson

The PBCRC for the support for this research

For more information, please email [[email protected]]