Table 2 - uploaded by Angus Carnegie
Content may be subject to copyright.
Current known hosts of Puccinia psidii sensu lato in Australia based on surveys in NSW a and Queensland b and host testing reported here. Plant names according to Govaerts et al. (2011)
Source publication
A rust affecting Myrtaceae was recently detected in New South Wales, Australia. Based on urediniospore morphology and host range, it was identified as Uredo rangelii, a taxon regarded as a member of the eucalyptus/guava rust (Puccinia psidii sensu lato) complex, although confusion currently surrounds its taxonomy. The exotic rust was given the comm...
Contexts in source publication
Context 1
... for P. psidii s.l. in NSW Repeat surveys of IPs in July revealed three new hosts for P. psidii s.l. in NSW (Table 2). On 19 July we observed rust on Tristania neriifolia at IP2. Symptoms on T. neriifolia included purple spots with old grey pustules on mature leaves to freshly (golden yellow) sporulating pustules on growing shoots (Fig. 3a). ...
Context 2
... G. inophloia, which appears to be a highly susceptible species, symptoms included large old pustules interspersed within multiple small, fresh pustules on expanded leaves, to severe and fresh infection on expanding foliage (Fig. 3e). All collections from surveys were confirmed as P. psidii s.l. and have been lodged at DAR. Surveys since mid-August have revealed many more infected premises and added more than 95 hosts (Table 2); this increasing host list was a trigger to stand down the emergency response (Carnegie and Cooper 2011). These surveys identified the first record of P. psidii s.l. on M. quinquenervia, S. glomulifera and Eucalyptus species in the native environment in Australia, previously identified only in trees/plants under cultivation or in host testing. ...
Context 3
... S. australe (J.C.Wendl. ex Link) B.Hyland S. bamagense B.Hyland S. canicortex B.Hyland (Table 2), as well as two hybrids. Seventy-eight species, four tribes and 16 genera are new records for the eucalyptus/guava rust complex, culminating in a total for the eucalyptus/guava rust complex worldwide of 207 host species. ...
Similar publications
This paper elaborated the epidermis properties, transverse sections of leaves, petioles and stems of five cultivated spe-cies belong to five genera of Myrtaceae. They are Callistemon viminalis (Sol. ex Gaertn.) G. Don, Eucalyptus camaldu-lensis Dehnh., Myrtus communis L., Psidium guajava L. and Syzygium aromaticum (L.) Merr. It was clear that certa...
The study area (Tuban) is a district of Lahej governorate, Republic of Yemen. Lahej governorate is located at the southwestern part of Yemen at latitudes between 1 2° 30' to 1 4° 00' N and longitudes between 43° 30' to 45° 30' E. This investigation was carried out during in 201 3. Syzygium jambos (L.) Alston (Myrtaceae), originally native to tropic...
Myrtle rust (Austropuccinia psidii (G. Winter) Beenken) was detected on the New Zealand mainland in May 2017. Myrtle rust was first described in Brazil in 1998, and since then has spread throughout the Americas, to Asia, Africa, the Pacific islands, and most recently to Australia, causing a global pandemic. A. psidii is a pathogen of the Myrtaceae...
Exotic fungal pathogens can substantially affect individuals and populations of susceptible native plant species, potentially resulting in changes in community structure and composition. Austropuccinia psidii (myrtle rust) is a pathogenic fungus native to South America that affects species in the plant family Myrtaceae. The pathogen was introduced...
Taxonomy and traditional medicinal plant species of the family Myrtaceae growing throughout the Rajshahi district, Bangladesh was carried out during August 2013 to July 2014. A total of 8 species under 3 genera belonging to the family Myrtaceae were collected and identified. Out of the total number of species Callistemon citrinus (Curtis) Skeels.,...
Citations
... Austropuccinia psidii, formerly Puccinia psidii (Beenken 2017), is a rust fungus and the causal agent of the disease myrtle rust that impacts species within the family Myrtaceae. Originating in South America, the first detection of the pathogen in Australia was in 2010 and it has since spread to all states and territories except South Australia (Carnegie et al. 2010;Carnegie and Lidbetter 2012;Westaway 2016; Department of Natural Resources and Environment Tasmania 2020; Agriculture Victoria 2022; The Department of Primary Industries and Regional Development 2022a). The most recent new detection within Australia was in the Kimberley region of Western Australia (WA), where infection was observed on two Melaleuca species near the Northern Territory border (The Department of Primary Industries and Regional Development 2022b). ...
... Although well adapted, changing conditions as a result of climate change are contributing to the decline of Melaleuca species in Australia (Saintilan et al. 2019). An increased threat is placed on these species by A. psidii, with several Melaleuca species found to be highly susceptible to the pathogen under field conditions and in controlled inoculations (Carnegie and Lidbetter 2012;Morin et al. 2012;Pegg et al. 2014Pegg et al. , 2018Berthon et al. 2019;Martino et al. 2022). Modelling predicts changes in the geographic range suiting the pathogen as a consequence of climate change, with increased suitability in areas of NSW, TAS, VIC, and WA (Berthon et al. 2018). ...
Austropuccinia psidii causes rust disease on species within the family Myrtaceae. It was first detected in Australia in 2010, with the first detection in Western Australia in 2022. While species within the genus Melaleuca from eastern Australia show variable responses to the pathogen, little is known of the response of species from Western Australia. This study established that 13 previously unscreened species of Melaleuca , including Threatened and Priority listed species that were grown from seeds sourced from Western Australian populations, were susceptible four months post-germination to the pandemic strain of the pathogen. The proportion of highly susceptible plants within a single species ranged from 2 to 94%, with several species displaying highly variable levels of resistance to A. psidii . These results highlight the importance of disease screening and may direct conservation efforts.
... Austropuccinia psidii, the causal agent of myrtle rust, is a pathogen native to central and South America, specific to hosts from the Myrtaceae (Carnegie & Lidbetter, 2012). Myrtle rust affects new growth, resulting in shoot dieback, stunted growth, and following repeat infections and defoliation, it can cause the death of trees (Carnegie et al., 2016). ...
Corymbia calophylla (marri), an endemic keystone tree species in southwest Western Australia, is increasingly impacted by the introduced basidiomycete smut Quambalaria pitereka. The basidiomycete rust Austropuccinia psidii (myrtle rust), an invasive pathogen recently introduced to Eastern Australia, is expected to spread to the southwest of Western Australia eventually. Austropuccinia psidii has similar epidemiology to Q. pitereka, and there is concern that C. calophylla may be susceptible. Preliminary pathogenicity tests showed significant differences in aggressiveness between twelve Q. pitereka isolates, and there was evidence of interactions between isolates and C. calophylla provenances. Seedlings from 59 open‐pollinated families from 11 provenances covering the natural range of marri were screened for resistance to Q. pitereka and A. psidii under controlled glasshouse conditions. Resistance of seedlings within provenances to Q. pitereka and A. psidii differed significantly. There was no significant correlation between resistance to Q. pitereka and resistance to A. psidii. Seedlings of provenances from wetter regions were more resistant to both pathogens, but the correlation coefficients were insignificant. Seedlings of four families in three provenances (Serpentine, Chidlow, and Kingston) showed 100% resistance to Q. pitereka. Narrow‐sense heritability estimates were 0.07 for quambalaria shoot blight resistance and 0.34 for myrtle rust resistance. The results indicate the potential to use selected families/individuals resistant to Q. pitereka and A. psidii for tree improvement programs and adaptive management strategies.
... Austropuccinia psidii, formerly Puccinia psidii (Beenken 2017), is the causal agent of myrtle rust and has been present in Australia since 2010 (Carnegie et al. 2010). Causing disease on species within the family Myrtaceae, it is present in New South Wales and Queensland ( Since the incursion into Australia, A. psidii has already caused the decline of keystone Myrtaceae including Melaleuca quinquenervia and several rainforest understory species such as Rhodamnia rubescens and Rhodomyrtus psidioides (Carnegie et al. 2010;Carnegie and Lidbetter 2012;Pegg et al. 2014 Seeds were sown into perforated trays containing a mix of 2:1:1 peat, coconut coir, and perlite supplemented with Osmocote® Native Controlled Release Fertiliser then covered with a fine coating of vermiculite. Perforated trays were placed into solid trays filled with and always maintaining 1 cm of water. ...
Austropuccinia psidii, the fungus causing myrtle rust, was detected in Western Australia for the first time in June 2022. Few Western Australian plant species have been screened for response to the pathogen. Melaleuca thyoides, Melaleuca marginata and Melaleuca leucadendra grown from seeds sourced from Western Australian populations were all highly susceptible to an isolate of the pathogen from eastern Australia.
... Initial spread of the disease was linked to infected nursery stock and human-assisted movement, as it appeared in major human population centres sooner than it could have arrived via proliferation through natural bushland (Pegg et al. 2014b). There is a high degree of variability in myrtle rust susceptibility amongst and within Australian Myrtaceae species (Carnegie and Lidbetter 2012;Berthon et al. 2019). Inoculation studies and field observations have demonstrated c. 378 Australian species are susceptible to myrtle rust (Fernandez Winzer et al. 2020). ...
Globalisation has resulted in the spread of infectious plant diseases to new regions and host species and the novel disease caused by myrtle rust poses a global threat to naïve hosts in the Myrtaceae family of plants. This study uses a focal species, Tristaniopsis exiliflora, to explore the climatic and microclimatic preference of the myrtle rust disease (Austropuccinia psidii). Populations of T. exiliflora were sampled across the species distribution in Far North Queensland, Australia, modelling A. psidii severity as a function of macro- and micro-environmental variables. Disease severity was found to increase with annual precipitation and foliage projective cover, and decrease with maximum temperature and valley confinement. A subsampled population found that individuals with lower canopy heights experienced more severe disease. Our results suggest that, in tropical environments with seasonal rainfall, A. psidii virulence is reduced when mean annual rainfall is less than 1500 mm and virulence is substantially reduced when maximum temperatures exceed 32 °C. The climatic drivers identified in this study align with optimal in vitro conditions for A. psidii germination and development. This suggests that climatic conditions are regulating myrtle rust in natural ecosystems at a broader scale, and that increased conservation efforts should focus on species with narrow climatic distributions and highly susceptible regions such as the Wet Tropics World Heritage Area.
... The biotrophic myrtle rust pathogen (Austropuccinia psidii), first reported in Brazil (Chardón and Toro 1934;Kern et al. 1933;Lindquist 1982), has spread to many countries including Japan (Kawanishi et al. 2009), Australia (Carnegie et al. 2010) and New Caledonia (Giblin 2013), USA (Rayachhetry et al. 1997), Jamaica (MacLachlan 1938), South Africa (Roux et al. 2013), Indonesia (McTaggart et al. 2016), and Singapore (Du Plessis et al. 2017), and is also widespread throughout South and Central America (Coutinho et al. 1998;Ross-Davis et al. 2013). Members of the plant family Myrtaceae are predominantly infected by A. psidii (Carnegie et al. 2010;Carnegie and Lidbetter 2012) with infections often leading to deformation of the leaves, leaf dieback and subsequent defoliation leading to tree death (Coutinho et al. 1998;Glen et al. 2007;Uchida et al. 2006). ...
Myrtle rust is a serious fungal disease caused by Austropuccinia psidii affecting a number of Myrtaceae species in New Zealand and elsewhere. Control with fungicides or biologicals provides a mechanism to reduce the build-up of inoculum in the short-term while other strategies are being developed or deployed for long-term management. This study evaluated the efficacy of fungicides for control of myrtle rust under controlled conditions and identified adjuvants that would promote spreading of fungicidal active ingredients across the leaf surface. The spread of fungicide on detached M. excelsa leaves was assessed by applying three different adjuvants in combination with seven fungicides. Subsequently, M. excelsa plants were treated with three fungicides/mixes, (azoxystrobin + epoxiconazole, triademinol or a natural tea-extract) at a single rate followed by inoculation with A. psidii urediniospores on day 0, 7, 14 or 21 days after spraying. The response to infection in M. excelsa plants based on different inoculation timings at days 0, 7 and 21 significantly differed among fungicide treatments. The fungicide azoxystrobin + epoxiconazole was the most effective with infections significantly lower on the adaxial leaf surface than abaxial, despite good surface coverage of fungicide being achieved on both leaf surfaces. There were significant differences among fungicides based on the proportion of infected leaves on M. excelsa plants. Day 21 post-spray inoculation indicated a significant interaction between inoculation time and fungicide on leaf disease ratings. However, this was not the case at either 28 or 35 days post-inoculation. This research contributes to fungicide options for myrtle rust control in New Zealand.
... It is believed to be of South American origin but gained international notoriety by causing severe damage to commercially grown allspice (Pimenta dioica (L.) Merr.) in Jamaica and Florida, as well as guava plantations in Brazil and exotic Eucalyptus species in several south American countries (Carnegie et al. 2010;Simpson et al. 2006). Austropuccinia psidii has a wide host range within the Myrtaceae (Carnegie and Lidbetter 2012;Morin et al. 2012), enabling it, over the past decades, to spread rapidly across different continents from south to north America, Asia, Africa, and Oceania, including Hawaii, New Caledonia, Australia, and New Zealand Soewarto et al. 2018). ...
... Only one strain/biotype of A. psidii has been reported to be present in Australia to date, which is the pandemic biotype (Carnegie and Cooper 2011;Sandhu et al. 2016;Stewart et al. 2018). Over 360 Australian native Myrtaceae species been identified as susceptible hosts (Giblin and Carnegie 2014), approximately 50% of which have been confirmed with field infections (Carnegie and Lidbetter 2012;Morin et al. 2012;Pegg et al. 2014), with the numbers expanding as the pathogen becomes established in new geographical regions ) and more species are tested . While large-scale tree mortality has not yet been attributed to A. psidii infections in Australia, the pathogen is severely affecting key species, including the rainforest understory species Rhodamnia rubescens (Benth.) ...
... Eucalypts are the mainstay of the native forest industry and the hardwood plantation industries in Australia (Downham and Gavran 2018;Florence 1996). Eucalyptus-dependent forest industries overseas have been impacted by various biotypes of myrtle rust (Roux et al. 2016;Stewart et al. 2018), but to date, native forests and plantations in Australia have been little affected (Carnegie 2015;Carnegie and Pegg 2018) despite seedlings of numerous species being recorded as susceptible in inoculation tests (Carnegie and Lidbetter 2012;Lee et al. 2015;Potts et al. 2016;Xavier et al. 2007). While species of Eucalyptus tend to be less susceptible than those from other Australian Myrtaceae genera Morin et al. 2012), their global and national importance coupled with potential pathogen range shifts due to climate change (Alvares et al. 2017;Beresford et al. 2018;Kriticos et al. 2013;Narouei-Khandan et al. 2020) Susceptibility differences between the eucalypt subgenera have been reported, with species from subgenus Eucalyptus reported to be more susceptible than those from subgenus Symphyomyrtus Yong et al. 2019). ...
Myrtle rust (caused by Austropuccinia psidii Beenken) is exotic to Australia, yet specific resistance is present in a range of naïve myrtaceous host plants. Resistance to myrtle rust is primarily quantitative in nature and controlled by multiple interacting loci. We undertook a genome-wide association study (GWAS) to discover relationships between nuclear genomic sequence variation and multiple aspects of resistance to A. psidii in Eucalyptus obliqua, a representative species from subgenus Eucalyptus. Sequence variation was assessed with respect to numeric severity, binary symptomatic, hypersensitive, and pustulation responses to inoculation of seedlings with A. psidii. A total of 1.13 million, single-nucleotide polymorphisms (SNPs) were tested for association with the rust resistance responses of 637 phenotyped E. obliqua seedlings, each from different, single mother tree seedlots. Thirty-three highly significant SNP-trait associations were detected, of which 26 associated with the binary symptomatic/asymptomatic response to A. psidii. Comparison of the genomic position of these SNPs with rust resistance loci (Ppr1-5), previously reported in species from subgenus Symphyomyrtus, suggested that several were positioned near the major Ppr1 locus and other Ppr loci. This study provides the first integrated genomic view of A. psidii resistance across the Eucalyptus subgenera and provides the foundation for discovering key resistance genes for use in marker-based resistance breeding.
... Because U. rangelii is considered to be a less serious pathogen, quarantine procedures were discontinued in Australia shortly after it was first detected. Later, however, teliospores with the morphological characteristics resembling those of P. psidii were observed (Carnegie and Cooper 2011), and the fungus was then referred to as P. psidii sensu lato (Carnegie and Lidbetter 2012) after which it was formally transferred to the new genus Austropuccinia (Beenken 2017). The unfortunate misidentification of this important quarantine pathogen delayed strategies to potentially contain its spread in Australia where it now threatens highly susceptible native Myrtaceae species with extinction (Carnegie et al. 2016). ...
Forest pathogens are a major cause of forest disturbances and they have a significant economic impact on commercial forestry. Genomics is an important technology now available for studies concerning tree health, enabling researchers to better understand pathosystems and potentially to prevent future epidemics from occurring. Comparative genomics at the species level makes possible the identification of unique genomic regions and/or genes that influence the development of pathogens and their ability to cause disease. In addition, population genomics can reveal processes involved in the evolution of pathogens potentially showing how selection and/or environmental adaptation could have driven their emergence. Using these tools, important mechanisms involved in the evolution of pathogens and their hosts can be determined. Practical applications of such knowledge include the formulation of strategies for pathogen detection and surveillance, as well as breeding disease-resistant trees. These new and evolving technologies are set to ensure the long-term sustainability of plantation forestry in the Southern Hemisphere.
... Managing Myrtle Rust-susceptible collections is especially challenging with a huge number of species and subspecies known to be affected. To date (2020) can extend from the usual 2 weeks to 5-6 weeks under cooler conditions (Makinson 2018a, p41;Carnegie and Lidbetter 2012) and the pathogen's latent period (active but asymptomatic infection) can extend to overwintering in some hosts and conditions (Beresford et al. 2020). Quarantine and treatment of incoming plant material, diligent monitoring, appropriate cultural methods and sound hygiene practices are all vital to maintaining healthy potted and in-ground collections. ...
... This pathogen has now been introduced into Australia, which threatens a wide range of native Myrtaceae spp. (Carnegie and Lidbetter 2012). Novel host species can also emerge as plant species are moved across the world. ...
This article is part of the Top 10 Unanswered Questions in MPMI invited review series.
Nonhost resistance is typically considered the ability of a plant species to repel all attempts of a pathogen species to colonize it and reproduce on it. Based on this common definition, nonhost resistance is presumed to be very durable and, thus, of great interest for its potential use in agriculture. Despite considerable research efforts, the molecular basis of this type of plant immunity remains nebulous. We here stress the fact that “nonhost resistance” is a phenomenological rather than a mechanistic concept that comprises more facets than typically considered. We further argue that nonhost resistance essentially relies on the very same genes and pathways as other types of plant immunity, of which some may act as bottlenecks for particular pathogens on a given plant species or under certain conditions. Thus, in our view, the frequently used term “nonhost genes” is misleading and should be avoided. Depending on the plant–pathogen combination, nonhost resistance may involve the recognition of pathogen effectors by host immune sensor proteins, which might give rise to host shifts or host range expansions due to evolutionary-conditioned gains and losses in respective armories. Thus, the extent of nonhost resistance also defines pathogen host ranges. In some instances, immune-related genes can be transferred across plant species to boost defense, resulting in augmented disease resistance. We discuss future routes for deepening our understanding of nonhost resistance and argue that the confusing term “nonhost resistance” should be used more cautiously in the light of a holistic view of plant immunity.
... Although plant pathogens in the introduced range generally attack species which are closely related to the primary host in the natural range (Gilbert and Webb, 2007;De Vienne et al., 2009;Gilbert et al., 2015), in some cases drastic host changes are observed. For example, the rust fungus Puccinia psidii Winter considerably expanded its host range when introduced to Australia ( Carnegie and Lidbetter, 2012). The bark pathogen Chrysoporthe cubensis Bruner Gryzenhout causes severe damage on introduced Eucalyptus spp. ...
... For example, Tooley and Kyde (2007) tested the susceptibility to Phytophthora ramorum Werres, De Cock, Man of different potential new host species in the eastern United States. Similarly, Carnegie and Lidbetter (2012), assessed the pathogenicity of an invasive rust species in Australia by inoculating a selection of potential host trees. ...
Invasions by non-native pathogens represent a major threat to managed and natural ecosystems worldwide. Although necessary for adopting preventive strategies, the identification of invasive species before they are introduced is particularly difficult. Indeed, most pathogenic species that have become established in the last decades were first described only after they became invasive. To prevent further biological invasions, not only the early identification of potential new invasive plant pathogens is crucial, but also the assessment of their potential host range. In this study, we determined the pathogenicity and the saprotrophic ability of three Cryphonectria species toward three potential hosts in the family Fagaceae. For this, seedlings and dormant stems of European chestnut (Castanea sativa), pedunculate oak (Quercus robur) and European beech (Fagus sylvatica) were inoculated with different genotypes of C. parasitica (Asian species, invasive in Europe), C. naterciae (European species), and C. japonica (Asian species, not present in Europe). Lesion growth was measured and mortality assessed for 4 months. The highest damage was caused by C. parasitica on European chestnut, while C. japonica and C. naterciae induced significantly smaller lesions on this host species. All three Cryphonectria species did not grow saprophytically on F. sylvatica and Q. robur, but successfully colonized dormant stems of C. sativa. In the context of biological invasions, our study shows that the Asian C. japonica most likely represents a much less severe threat than C. parasitica for the tested European host species. Nonetheless, the ability of C. naterciae and C. japonica to saprotrophically colonize fresh chestnut wood may suggest that they could become established in chestnut forests and eventually infect weakened chestnut trees or other hosts not tested in this study.
