Revealing the Introduction History and Phylogenetic Relationships of Passiflora foetida sensu lato in Australia.

Genomic analysis can be a valuable tool to assistmanagement of non-native invasive species, through determining source and number of introductions as well as clarifying phylogenetic relationships. Here, we used whole chloroplast sequencing to investigate the introduction history of Passiflora foetida sensu lato in Australia and clarify its relationship with other Passiflora species present. Phylogenetic analysis of chloroplast genome data identified three separate genetic lineages of P. foetida s. l. present in Australia, indicating multiple introductions. These lineages had affinities to samples from three separate areas within the native range in Central and South America that represented phylogenetically distinct lineages. These results provide a basis for a targeted search of the native range of P. foetida s. l. for candidate biological control agents that have co-evolved with this species and are thus better adapted to the lineages that are present in Australia. Results also indicated that the Passiflora species native to Australia are in a separate clade to that of P. foetida s. l. and other introduced Passiflora species cultivated in Australia. This knowledge is important to assess the likelihood of finding biological control agents for P. foetida s. l. that will be sufficiently host-specific for introduction in Australia. As P. foetida s. l. is a widespread non-native invasive species across many regions of the world, outcomes from this work highlight the importance of first evaluating the specific entities present in a country before the initiation of a biological control program.

Progress in Biological Control of Weeds with Plant Pathogens.

Plant pathogens have played an important role in weed biological control since the 1970s. So far, 36 fungal pathogens have been authorized for introduction across 18 countries for the classical biological control of weeds. Their safety record has been excellent, but questions continue to be asked about the risk that they could transfer to other plants. Quantitative data documenting their impact on the weed populations are still limited. Of the 15 bioherbicides based on living microorganisms that have ever been registered, only two were commercially available at the time of this review. The development and commercialization of bioherbicides in affluent countries are still plagued by technological hurdles and limited market potential. Not-for-profit small-scale production and distribution systems for bioherbicides in low-income countries may have potential as an inexpensive approach to controlling pervasive weeds. The types of research underpinning biological control approaches and challenges encountered are highlighted using specific examples.

Evaluation of the rust fungus Puccinia rapipes for biological control of Lycium ferocissimum (African boxthorn) in Australia: Life cycle, taxonomy and pathogenicity.

Fungal plant pathogens are increasingly recognised as being among the most effective and safe agents in classical weed biological control programs worldwide. Suitability of the rust fungus P. rapipes as a classical biological control agent for Lycium ferocissimum (African boxthorn) in Australia was assessed using a streamlined agent selection framework. Studies with P. rapipes were undertaken to elucidate its life cycle, confirm its taxonomic placement and determine its pathogenicity to L. ferocissimum and seven closely-related Solanaceae species that occur in Australia. Field surveys in the native range of South Africa, experiments in a containment facility in Australia and DNA sequencing confirmed that P. rapipes is macrocyclic and autoecious, producing all five spore stages on L. ferocissimum. The stages not previously encountered, spermogonia and aecia, are described. Sequencing also confirmed that P. rapipes is sister to Puccinia afra, in the 'Old World Lineage' of Puccinia species on Lycieae. Two purified isolates of the fungus, representing the Eastern and Western Cape distributions of P. rapipes in South Africa, were cultured in the containment facility for use in pathogenicity testing. L. ferocissimum and all of the Lycium species of Eurasian origin tested ‒ Lycium barbarum (goji berry), Lycium chinense (goji berry 'chinense') and Lycium ruthenicum (black goji berry) - were susceptible to both isolates of P. rapipes. The Australian native L. australe and three more distantly related species in different genera tested were resistant to both isolates. The isolate from the Western Cape was significantly more pathogenic on L. ferocissimum from Australia, than the Eastern Cape isolate. Our results indicate that P. rapipes may be sufficiently host specific to pursue as a biological control agent in an Australian context, should regulators be willing to accept damage to the Eurasian goji berries being grown, albeit to a limited extent, in Australia.

Quest to elucidate the life cycle of Puccinia psidii sensu lato.

There is controversy surrounding the described life cycle of the rust fungus Puccinia psidii sensu lato, which causes disease on several plant species in the family Myrtaceae. The objective of this study was to determine whether P. psidii s.l. is autoecious by performing basidiospore inoculations, and microscopically examining the fate of basidiospores on the leaf surface and nuclear condition at different stages of rust development. No spermogonia developed on leaves of Agonis flexuosa inoculated either with a teliospore suspension or basidiospores naturally discharged from telia. Uredinial sori that developed in all three inoculations with teliospore suspensions and in one of the five inoculations with naturally-discharged basidiospores from telia were most likely the result of urediniospore infections. Microsatellite analysis revealed that isolates made from these uredinial sori had the same multilocus genotype as that of the original isolate. No signs of penetration of plant cells by basidiospores were observed on A. flexuosa and Syzygium jambos. The nuclear condition of mycelia of uredinial sori, urediniospores, teliospores, and four-celled metabasidia was typical of that in many rust fungi. Our study could not provide unequivocal proof that P. psidii s.l. is autoecious. While it is possible that it could be heteroecious, with an unknown alternate aecial host, it is also possible that basidiospores have lost the ability to infect Myrtaceae or are infrequently operational.

Combining a climatic niche model of an invasive fungus with its host species distributions to identify risks to natural assets: Puccinia psidii Sensu Lato in Australia.

Puccinia psidii sensu lato (s.l.) is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets.

Can global weed assemblages be used to predict future weeds?

Predicting which plant taxa are more likely to become weeds in a region presents significant challenges to both researchers and government agencies. Often it is done in a qualitative or semi-quantitative way. In this study, we explored the potential of using the quantitative self-organising map (SOM) approach to analyse global weed assemblages and estimate likelihoods of plant taxa becoming weeds before and after they have been moved to a new region. The SOM approach examines plant taxa associations by analysing where a taxon is recorded as a weed and what other taxa are recorded as weeds in those regions. The dataset analysed was extracted from a pre-existing, extensive worldwide database of plant taxa recorded as weeds or other related status and, following reformatting, included 187 regions and 6690 plant taxa. To assess the value of the SOM approach we selected Australia as a case study. We found that the key and most important limitation in using such analytical approach lies with the dataset used. The classification of a taxon as a weed in the literature is not often based on actual data that document the economic, environmental and/or social impact of the taxon, but mostly based on human perceptions that the taxon is troublesome or simply not wanted in a particular situation. The adoption of consistent and objective criteria that incorporate a standardized approach for impact assessment of plant taxa will be necessary to develop a new global database suitable to make predictions regarding weediness using methods like SOM. It may however, be more realistic to opt for a classification system that focuses on the invasive characteristics of plant taxa without any inference to impacts, which to be defined would require some level of research to avoid bias from human perceptions and value systems.

Investigating the host-range of the rust fungus Puccinia psidii sensu lato across tribes of the family Myrtaceae present in Australia.

The exotic rust fungus Puccinia psidii sensu lato was first detected in Australia in April 2010. This study aimed to determine the host-range potential of this accession of the rust by testing its pathogenicity on plants of 122 taxa, representative of the 15 tribes of the subfamily Myrtoideae in the family Myrtaceae. Each taxon was tested in two separate trials (unless indicated otherwise) that comprised up to five replicates per taxon and six replicates of a positive control (Syzygium jambos). No visible symptoms were observed on the following four taxa in either trial: Eucalyptus grandis×camaldulensis, E. moluccana, Lophostemon confertus and Sannantha angusta. Only small chlorotic or necrotic flecks without any uredinia (rust fruiting bodies) were observed on inoculated leaves of seven other taxa (Acca sellowiana, Corymbia calophylla 'Rosea', Lophostemon suaveolens, Psidium cattleyanum, P. guajava 'Hawaiian' and 'Indian', Syzygium unipunctatum). Fully-developed uredinia were observed on all replicates across both trials of 28 taxa from 8 tribes belonging to the following 17 genera: Agonis, Austromyrtus, Beaufortia, Callistemon, Calothamnus, Chamelaucium, Darwinia, Eucalyptus, Gossia, Kunzea, Leptospermum, Melaleuca, Metrosideros, Syzygium, Thryptomene, Tristania, Verticordia. In contrast, the remaining 83 taxa inoculated, including the majority of Corymbia and Eucalyptus species, developed a broad range of symptoms, often across the full spectrum, from fully-developed uredinia to no visible symptoms. These results were encouraging as they indicate that some levels of genetic resistance to the rust possibly exist in these taxa. Overall, our results indicated no apparent association between the presence or absence of disease symptoms and the phylogenetic relatedness of taxa. It is most likely that the majority of the thousands of Myrtaceae species found in Australia have the potential to become infected to some degree by the rust, although this wide host range may not be fully realized in the field.

Have biopesticides come of age?

Biopesticides based on living microbes and their bioactive compounds have been researched and promoted as replacements for synthetic pesticides for many years. However, lack of efficacy, inconsistent field performance and high cost have generally relegated them to niche products. Recently, technological advances and major changes in the external environment have positively altered the outlook for biopesticides. Significant increases in market penetration have been made, but biopesticides still only make up a small percentage of pest control products. Progress in the areas of activity spectra, delivery options, persistence of effect and implementation have contributed to the increasing use of biopesticides, but technologies that are truly transformational and result in significant uptake are still lacking.

End-of-life planning in heart failure: it should be the end of the beginning.

Cardiovascular disease (CVD) is a chronic, progressive, incurable condition characterized by periods of apparent stability interspersed with acute exacerbations. Despite many important advances in its treatment, approximately one-third of deaths in Canada each year result from CVD. While this might lead one to assume that a comprehensive medical approach exists to the management of this inevitable outcome, the reality is much different. The current Canadian medical model emphasizes the management of acute exacerbations of CVD during which end-of-life issues figure frequently and prominently, although in a setting that is inappropriate to address the comprehensive needs of patients and their families.As a result, end-of-life care was made a theme of the recently reported Canadian Heart Health Strategy and Action Plan (www.chhs-scsc.ca). From this, several recommendations are made, central to which is the need to reframe CVD as a condition ideally suited to a chronic disease management approach. In addition, replacement of the term 'palliative care' with the term 'end-of-life planning and care' is proposed to foster earlier and more integrated comprehensive care, which, it is proposed, denotes the provision of advanced care planning, palliative care, hospice care and advanced directives, with a focus on decision making and planning. Finally, end-of-life planning and care should be a routine part of assessment of any patient with CVD, should be reassessed whenever important clinical changes occur and should be provided in a manner consistent with relevant CVD practice guidelines. Specifically, a Canadian strategy to improve end-of-life planning and care should focus on the following: * Integrated end-of-life planning and care across the health care system; * Facilitated communication and seamless care provision across all providers involved in end-of-life planning and care; * Adequate resources in the community for end-of-life planning and care; * Specialized training in sensitive communication and supportive care as part of core training for all members of the interdisciplinary care team; * Measurement of key performance indicators for end-of-life planning and care; and * Research into effective end-of-life planning and care.Heart failure is an advanced form of CVD with very high morbidity, mortality and burden of care, making it an ideal condition for implementation and testing of interventions to improve end-of-life planning and care.

Are the microcyclic rust species Puccinia melampodii and Puccinia xanthii conspecific?

The taxonomic relationship between two microcyclic rust species, Puccinia melampodii and Puccinia xanthii, recorded from a number of Asteraceae hosts, was explored by comparing teliospore morphology, host specificity and sequence data. Teliospore morphology varied between and within individual rust accessions but, in general, teliospores of P. xanthii were larger than those of P. melampodii. Field observations and cross-inoculation greenhouse studies showed that P. melampodii accessions were highly specific to their original host species and unable to establish compatible interactions with related Asteraceae species. Though small amounts of genetic variation were detected between P. melampodii and P. xanthii accessions, the ITS and TEF phylogenetic analyses comprising several other rust species grouped these accessions within a well supported clade. Our data indicate that despite differences between P. xanthii and P. melampodii accessions these rusts cannot readily be separated at the species level, supporting earlier taxonomic conclusions and the recent proposal to group them into a morphospecies. Based on host-specificity data, the name Puccinia xanthii var. parthenii-hysterophorae is proposed to accommodate all Mesoamerican records of P. melampodii associated with the host Parthenium hysterophorus.

Putative natural hybrid between Puccinia lagenophorae and an unknown rust fungus on Senecio madagascariensis in KwaZulu-Natal, South Africa.

Several specimens of an aecial rust fungus were collected on Senecio madagascariensis during a field survey carried out in KwaZulu-Natal, South Africa. As telia were not present in the specimens collected, DNA sequence analyses were undertaken to determine the identity of the rust species. ITS and beta-tub1 sequencing confirmed that one of the isolates recovered is Puccinia lagenophorae sensu lato. On the other hand, sequencing and RFLP analysis revealed the presence of two divergent copies of ITS and beta-tub1 in all the other six isolates investigated. In both phylogenetic trees, one copy of the gene region grouped within a well supported clade with sequences of P. lagenophorae accessions from different geographical origins and hosts, and the Australian rusts Puccinia saccardoi and Puccinia stylidii. The other copy of these gene regions grouped within a separate clade comprising European accessions of Puccinia dioicae (ITS) and Uromyces sommerfeltii (beta-tub1) that occur on Asteraceae hosts. Multiple copies of these gene regions were not observed in Australian isolates of P. lagenophorae. Our study provides some evidence that an interspecific hybrid rust fungus, with P. lagenophorae as one of its parents, may occur on S. madagascariensis in South Africa. The identity of the other parent remains unknown.

Genetic diversity in the blackberry rust pathogen, Phragmidium violaceum, in Europe and Australasia as revealed by analysis of SAMPL.

Indigenous to Europe, the blackberry rust fungus Phragmidium violaceum was introduced to Australia and subsequently appeared in New Zealand, with the most recent authorised introductions to Australia specifically for the biological control of European blackberry. Markers for 'selective amplification of microsatellite polymorphic loci' (SAMPL) were developed for studying the population genetics of P. violaceum. Modification of one of the two SAMPL primers with a HaeIII adapter (H) revealed significantly greater levels of genetic variation than primers used to generate AFLPs, the latter revealing little or no variation among 25 Australasian and 19 European isolates of P. violaceum. SAMPL was used to describe genetic variation among these 44 isolates of P. violaceum from 51 loci generated using primer pairs (GACA)4 +H-G and R1+H-G. The European isolates were more diverse than Australasian isolates, with 37 and 22 % polymorphic loci, respectively. Cluster analysis revealed geographic clades, with Australasian isolates forming one cluster separated from two clusters comprising the European isolates. However, low bootstrap support at these clades suggested that Australian isolates had not differentiated significantly from European isolates since the first record of P. violaceum in Australia in 1984. In general, the results support two hypotheses. First, that the population of P. violaceum in Australia was founded from a subset of individuals originating from Europe. Second, that P. violaceum in New Zealand originated from the Australian population of P. violaceum, probably by wind dispersal of urediniospores across the Tasman Sea. The application of SAMPL markers to the current biological control programme for European blackberry is discussed.