Monica A Kehoe

DPIRD

Five Australian potyviruses, passion fruit woodiness virus (PWV), passiflora mosaic virus (PaMV), passiflora virus Y, clitoria chlorosis virus (ClCV) and hardenbergia mosaic virus (HarMV), and two introduced potyviruses, bean common mosaic virus (BCMV) and cowpea aphid-borne mosaic virus (CAbMV), were detected in nine wild or cultivated Passiflora...

Next generation sequencing is quickly emerging as the go-to tool for plant virologists when sequencing whole virus genomes, and undertaking plant metagenomic studies for new virus discoveries. This study aims to compare the genomic and biological properties of Bean yellow mosaic virus (BYMV) (genus Potyvirus), isolates from Lupinus angustifolius pl...

Cassava is a major staple food for about 800 million people in the tropics and sub-tropical regions of the world. Production of cassava is significantly hampered by cassava brown streak disease (CBSD), caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). The disease is suppressing cassava yields in eastern Afr...

Disease outbreaks caused by turnip yellows virus (TuYV), a member of the genus Polerovirus, family Luteoviridae, regularly occur in canola and pulse crops throughout Australia. To understand the genetic diversity of TuYV for resistance breeding and management, genome sequences of 28 TuYV isolates from different hosts and locations were determined u...

This study examined the natural and experimental host range and aphid and graft transmission of the tentative polerovirus phasey bean mild yellows virus (PBMYV). Eleven complete coding sequences from PBMYV isolates were determined from a range of hosts and locations. We found two genetically distinct variants of PBMYV. PBMYV-1 was the originally de...

Sri Lankan cassava mosaic virus (SLCMV) is one of the viruses that cause cassava mosaic disease. Strong mosaic symptoms on a cassava plant in the Northern Territory tested positive in begomovirus specific PCR testing. The DNA sequence of the amplicon was 96.38% similar (over 528 bp) to SLCMV, a result confirmed by sequencing genomic DNA. This is th...

Austropuccinia psidii is the causal agent of myrtle rust in over 480 species within the family Myrtaceae. Lineages of A. psidii are structured by their hosts in the native range, and some have success in infecting newly encountered hosts. For example, the pandemic biotype has spread beyond South America, and proliferation of other lineages is an ad...

Soybean dwarf virus (SbDV; family Tombusviridae, genus Luteovirus, species Luteovirus glycinis) is an RNA plant virus that is transmitted solely by aphids in a persistent, circulative and non-propagative manner. SbDV causes significant losses in cultivated Fabaceae, especially in subterranean clover (Trifolium subterraneum) pastures of mainland Aus...

Sri Lankan cassava mosaic virus (SLCMV) is one of the viruses that cause cassava mosaic disease. Strong mosaic symptoms on a cassava plant in the Northern Territory tested positive in begomovirus specific PCR testing. The DNA sequence of the amplicon was 96.38% similar (over 528 bp) to SLCMV, a result confirmed by sequencing genomic DNA. This is th...

Pterocomma (Hemiptera: Aphidinae) are large aphids found across the northern hemisphere on various willow ( Salix ) and poplar ( Populus ) trees. We provide the first records of the Poplar Bark Aphid, Pterocomma populeum in Australia from Tasmania and New South Wales, a potential pest of poplar trees. Morphological character measurements and DNA (...

Gene- and genome-based approaches were used to determine whether Vigna little leaf (ViLL) phytoplasma, which occurs in northern Australia, is a distinct ‘ Candidatus Phytoplasma’ species. The ViLL 16S rRNA gene sequences exhibited the highest known similarity to species in the 16SrXXIX-A and 16SrIX-D subgroups, namely ‘ Candidatus Phytoplasma omane...

Modern diagnostic techniques based on DNA sequence similarity are currently the gold standard for the detection of existing and emerging pathogens. Whilst individual assays are inexpensive to use, assay development is costly and carries risks of not being sensitive or specific enough to capture an increasingly diverse range of targets. Sequencing c...

Xylella fastidiosa is a plant‐pathogenic bacterium that poses a serious threat to the production of economically important plant species including grapes, almonds, olives and a broad range of amenity plants, causing significant economic losses worldwide. While multiple molecular detection assays have been developed for X . fastidiosa , there is a l...

In this study, metagenomic sequence data was used to investigate the phytoplasma taxonomic diversity in vegetable-growing regions across Australia. Metagenomic sequencing was performed on 195 phytoplasma-positive samples, originating either from historic collections ( n =46) or during collection efforts between January 2015 and June 2022 ( n =149)....

High-quality complete genomes of five Xylella fastidiosa strains were assembled by combining Nanopore and Illumina sequencing data. Among these, International Collection of Micro-organisms from Plants (ICMP) 8731, ICMP 8742 and ICMP 8745 belong to subspecies fastidiosa while ICMP 8739 and ICMP 8740 were determined as subspecies multiplex . The stra...

Global trade and human movements outspread animal species, for example ants, from their native habitats to new areas. This causes biosecurity concerns because an exotic ant might have adverse impacts on agriculture, the environment, or health; thus, incurring economic losses. The browsing ant, Lepisiota frauenfeldi, was first detected in 2013 at th...

The detection of cucumber green mottle mosaic (CGMMV) in the Northern Territory (NT), Australia, in 2014 led to the introduction of strict quarantine measures for the importation of cucurbit seeds by the Australian federal government. Further detections in Queensland, Western Australia (WA), New South Wales and South Australia occurred in the perio...

Citrus exocortis viroid (CEVd), the causal agent of exocortis, is a pathogen that is thought to infect all citrus varieties, although it is asymptomatic in most. Symptoms of exocortis develop on susceptible rootstocks, resulting in stunting and yield reduction. To aid the detection and management of CEVd, a rapid near-field assay was developed usin...

The ability to swiftly respond to pathogen incursions relies heavily on fast and accurate diagnostics. Current published assays for citrus bacterial canker do not target Xanthomonas citri pv. citri, the causative agent, with high specificity when testing Australian samples. While the current diagnostics are useful in countries where canker is endem...

In 2014, cucumber green mottle mosaic virus (CGMMV) was detected for the first time in Australia infecting watermelon crops in the Northern Territory (NT). In July 2016, a leaf sample was collected from a cucumber plant with leaf mottle and distortion symptoms growing in a commercial plastic tunnel house at Geraldton, Western Australia (WA). Testin...

We report the discovery of the invasive aphid Aphis lugentis for the first time in Australia. This aphid specialises on Compositae, particularly on Senecio species. Aphids were tended by several ant species at a site on Kangaroo Island, South Australia, which is unlikely to be the location of the original introduction. We recommend the investigatio...

Forty-seven potato virus A (PVA) isolates from Europe, Australia, and South America’s Andean region were subjected to high-throughput sequencing, and 46 complete genomes from Europe (n = 9), Australia (n = 2), and the Andes (n = 35) obtained. These and 17 other genomes gave alignments of 63 open reading frames 9,180 nucleotides long; 9 were recombi...

Grapevine rupestris vein feathering virus (GRVFV; tentative genus Marafivirus; family Tymoviridae ) was first detected from a Greek grapevine (Vitis vinifera), with asteroid mosaic-like symptoms (El Beaino et al. 2001; Ghanem-Sabanadzovic et al. 2003) and was also infected with grapevine fleck virus. GRVFV has been detected in the United States, So...

Cassava is a staple food crop in sub-Saharan Africa; it is a rich source of carbohydrates and proteins which currently supports livelihoods of more than 800 million people worldwide. However, its continued production is at stake due to vector-transmitted diseases such as Cassava mosaic disease and Cassava brown streak disease. Currently, the manage...

The Ord River Irrigation Area (ORIA) produces annual crops during the dry season (April to October), and perennial crops all-year-round, and is located in tropical northwestern Australia. Sandalwood plantations cover 50% of the ORIA’s cropping area. Aphids cause major crop losses through transmission of viruses causing debilitating diseases and dir...

In the remote Ord River Irrigation Area (ORIA) in tropical northwest Australia, severe Zucchini yellow mosaic virus (ZYMV) epidemics threaten dry season (April-October) cucurbit crops. In 2016-2017, wet season (November-March) sampling studies found a low incidence ZYMV infection in wild Cucumis melo and Citrullus lanatus var. citroides plants, and...

A conspicuous leaf scorch of wheat associated with Didymellaceae family was observed on commercial wheat varieties in Western Australia during recent years. Two fungal species isolated from leaf lesions were identified based on morphological characteristics and DNA sequencing. Neoascochyta europaea was isolated from symptomatic leaf lesions on the...

In this case study we successfully teamed the PDQeX DNA purification technology developed by MicroGEM, New Zealand, with the MinION and MinIT mobile sequencing devices developed by Oxford Nanopore Technologies to produce an effective point-of-need field diagnostic system. The PDQeX extracts DNA using a cocktail of thermophilic proteinases and cell...

In this case study we successfully teamed the PDQeX DNA purification technology developed by MicroGEM, New Zealand, with the MinION and MinIT mobile sequencing devices developed by Oxford Nanopore Technologies to produce an effective point-of-need field diagnostic system. The PDQeX extracts DNA using a cocktail of thermophilic proteinases and cell...

Restricting Turnip yellows virus (TuYV) spread in canola (Brassica napus) crops often relies upon the application of systemic insecticides to protect young vulnerable plants from wide-scale green-peach aphid (GPA; Myzus persicae) colonization and subsequent virus infection. For these to be applied at the optimal time to ensure they prevent epidemic...

In Western Australia (WA) viruses belonging to the Luteoviridae have been identified infecting crops, including Barley yellow dwarf virus, Cereal yellow dwarf virus, Phasey bean mild yellows virus, Potato leaf roll virus, and Turnip yellows virus (TuYV). It is thought there are other viruses of the Luteoviridae in WA, however efforts to determine t...

Common bean (Phaseolus vulgaris L.) is the primary source of protein and nutrients in the majority of households in sub-Saharan Africa. However, pests and viral diseases are key drivers in the reduction of bean production. To date, the majority of viruses reported in beans have been RNA viruses. In this study, we carried out a viral metagenomic ana...

• In 2018, severe Turnip yellows virus (TuYV) epidemics in pre-flowering canola crops were caused by early green-peach aphid (GPA) incursions and infestation. Such epidemics are likely to become more frequent due to earlier sowing times, high susceptibility of current commercial varieties, and variable efficacy of neonicotinoid seed dressing. • Fo...

Plant viral diseases are one of the major limitations in legume production within sub-Saharan Africa (SSA), as they account for up to 100% in production losses within smallholder farms. In this study, field surveys were conducted in the western highlands of Kenya with viral symptomatic leaf samples collected. Subsequently, next-generation sequencin...

Cassava brown streak disease (CBSD) caused by Cassava brown streak virus (CBSV) and Uganda cassava brown streak virus (UCBSV) is a major constraint to cassava production in Mozambique. Full genome sequences of CBSD‐associated virus isolates contribute to the understanding of genetic diversity and the development of new diagnostic primers that can b...

Widespread Turnip yellows virus (TuYV) infection causes severe seed yield and quality losses in rapeseed (Brassica napus) crops grown in broadacre agricultural systems worldwide. Current TuYV detection protocols are expensive and time consuming, and can have poor specificity and sensitivity. Typically, they are used as a diagnostic tool to test alr...

Cassava brown streak disease (CBSD) caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) is the main constraint to cassava (Manihot esculenta Crantz) production in Mozambique. Using RT-PCR to amplify partial coat protein nucleotide sequences, we detected for the first time the occurrence of CBSV in two non-cass...

Viral symptomatic groundnut (Arachis hypogaea L.) leaf samples were collected in the heterogeneous agro-ecosystem of the western highlands of Kenya. High throughput RNA sequencing (RNA-Seq) was carried out on total plant RNA using the Illumina HiSeq platform. Subsequently, de novo assembly and sequence similarity searches identified the complete ge...

Sweet potato is a major food security crop within sub-Saharan Africa where 90% of Africa production occurs. One of the major limitations of sweet potato production are viral infections. In this study, we used a combination of whole genome sequences from a field isolate obtained from Kenya and those available in GenBank. Sequences of four sweet pota...

Crop losses due to viral diseases and pests are major constraints on food security and income for millions of households in sub-Saharan Africa (SSA). Such losses can be reduced if plant diseases and pests are correctly diagnosed and identified early. Currently, accurate diagnosis for definitive identification of plant viruses and their vectors in S...

The United Nations has listed Zero Hunger as one of the 17 global sustainable development goals to end extreme poverty by 2030. Plant viruses are a major constraint to crop production globally causing an estimated $30 billion in damage leaving millions of people food insecure. In Africa, agriculture employs up to 50% of the workforce, yet only cont...

Sweet potato is a major food security crop within sub-Saharan Africa where 90 % of Africa’s sweet potato production occurs. One of the major limitations of sweet potato production are viral infections. In this study, we used a combination of whole genome sequences from a field isolate from Kenya and those available in GenBank. Sequences of four swe...

Sweet potato is a major food security crop within sub-Saharan Africa where 90 % of Africa’s sweet potato production occurs. One of the major limitations of sweet potato production are viral infections. In this study, we used a combination of whole genome sequences from a field isolate from Kenya and those available in GenBank. Sequences of four swe...

Background:Endornavirus es are non-pathogenic viruses infecting multiple agricultural important crops including legumes, with global distribution. However, there is an absence on the complete genome of endornaviruses from legumes in particular with the sub-Saharan region. In this study, we report the first complete genomes of PvEV1 and PvEV2, and t...

Background:Endornavirus es are non-pathogenic viruses infecting multiple agricultural important crops including legumes, with global distribution. However, there is an absence on the complete genome of endornaviruses from legumes in particular with the sub-Saharan region. In this study, we report the first complete genomes of PvEV1 and PvEV2, and t...

Background: Bemisia tabaci species (B. tabaci), or whiteflies, are the world's most devastating insect pests. They cause billions of dollars (US) of damage each year, and are leaving farmers in the developing world food insecure. Currently, all publically available transcriptome data forB. tabaciare generated from pooled samples, which can lead to...

Plant viral diseases are one of the major limitations in legume production within sub Saharan Africa (SSA), as they account for up to 100 % in production losses within smallholder farms. In this study, field surveys were conducted in the western highlands of Kenya with viral symptomatic leaf samples collected. Subsequently, next-generation sequenci...

Cassava is the main staple food for over 800 million people globally. Its production in eastern Africa is being constrained by two devastating Ipomoviruses that cause cassava brown streak disease (CBSD); Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), with up to 100% yield loss for smallholder farmers in the region...

111 cassava brown streak virus sequences downloaded from GenBank all with the highly conserved DAG motif in the coat protein. (PDF)

Biological characteristics of 11 Potato virus S (PVS) isolates from three cultivated potato species (Solanum spp.) growing in five Andean countries and 1 from Scotland differed in virulence depending on isolate and host species. Nine isolates infected Chenopodium quinoa systemically but two others and the Scottish isolate remained restricted to ino...

Trialeurodes vaporariorum (Westwood, 1856) (Greenhouse whitefly) is an agricultural pest of global importance. It is associated with damage to plants during feeding and subsequent virus transmission. Yet, global phylogenetic relationships, population structure, and estimation of the rates of gene flow within this whitefly species remain largely une...

We present here the first complete genome sequence of the tobamovirus Cucumber green mottle mosaic virus (CGMMV) from Australia, obtained from an infected cucumber plant. Compared with other CGMMV genomes, its closest nucleotide identities were 99.6% to KP772568, 99.3% to KF155229, and 99.1% to DQ767631 from Canada, Israel, and India, respectively.

Zucchini yellow mosaic virus (ZYMV) isolates from cucurbit crops growing in northern Australia and East Timor were investigated to establish possible genetic connectivity between crop viruses in Australia and Southeast Asia. Leaves from symptomatic plants of pumpkin (Cucurbita moschata and C. maxima), melon (Cucumis melo), and zucchini (C. pepo) we...

Background Bemisia tabaci species (whiteflies) are the world’s most devastating insect pests within crops in the tropics. They cause billions of dollars (US) of damage each year and are leaving farmers in the developing world food insecure. Understanding the genetic and transcriptomic composition of these insect pests, the viruses they transmit and...

Cassava is a major staple food for about 800 million people in the tropics and subGtropical regions of the world. Production of cassava is significantly hampered by cassava brown streak disease (CBSD), which is caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). The disease is suppressing cassava yields in ea...

Genetic diversity within Trialeurodes vaporariorum (Westwood, 1856) remains largely unexplored, particularly within regions of Sub-Saharan Africa. In this study, T. vaporariorum samples were obtained from three locations in Kenya: Katumani, Kiambu and Kajiado counties. DNA extraction, PCR and Sanger sequencing were carried out on ~750 bp fragment o...

Current approaches used to name within-species, plant virus phylogenetic groups are often misleading and illogical. They involve names based on biological properties, sequence differences and geographical, country or place-association designations, or any combination of these. This type of nomenclature is becoming increasingly unsustainable as numb...

We present here the complete genome sequences of a novel polerovirus from Trifolium subterraneum (subterranean clover) and Cicer arietinum (chickpea) and compare these to a partial viral genome sequence obtained from Macroptilium lathyroides (phasey bean). We propose the name phasey bean mild yellows virus for this novel polerovirus.

Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa's most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families w...

Turnip mosaic virus (TuMV) causes crop losses worldwide. Seven Australian TuMV isolates originally obtained from five different species in two plant families were inoculated to 14 plant species belonging to four families to compare their host reactions. They differed considerably in virulence in Brassicaceae crop species and virus indicator hosts b...

Accurate identification of viruses is critical for resistance breeding and for development of management strategies. To this end, we are developing PCR diagnostics for the luteoviruses / poleroviruses that commonly affect chickpea and pulse crops in Australia. This is helping to overcome the shortfalls in virus identifications that often result fro...

Biological and whole genome properties were compared between eight historical European (1943-1984) and five Australian (2003-2012) Potato virus Y (PVY) isolates. Based on eliciting hypersensitivity genes Nc, Ny or Nz, the former belonged to biological strain groups PVYC (CT, CRM1), PVYO (CRN, KE, RS) or PVYZ (CM2, CRM2, DS). The latter were inocula...

Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa’s most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families w...

Pratylenchus quasitereoides n. sp. is described from Western Australia. It is characterized by 2 external incisures in the head cuticle, 4 lateral incisures at mid body, stylet length 17 µm to 19 µm, V greater than 75%, PUS less than 2 body diameters long and crenate tail terminus. Molecular data confirm the separation of the new species from morph...

Bean yellow mosaic virus (BYMV), genus Potyvirus, has an extensive natural host range encompassing both dicots and monocots. Its phylogenetic groups were considered to consist of an ancestral generalist group and six specialist groups derived from this generalist group during plant domestication. Recombination was suggested to be playing a role in...

In a region of Australia with a Mediterranean-type climate Wheat streak mosaic virus (WSMV) infection of wheat occurs in localised epidemics following extended periods when no grass or cereal hosts are present. To achieve a greater understanding of the epidemiology of WSMV in this environment, diverse components of the disease cycle were examined,...

Black pod syndrome (BPS) causes devastating losses in Lupinus angustifolius (narrow-leafed lupin) crops in Australia, and infection with Bean yellow mosaic virus (BYMV) was suggested as a possible cause. In 2011, an end-of-growing-season survey in which L. angustifolius plants with BPS were collected from six locations in southwestern Australia was...