The orthotospovirus, capscium chlorosis virus (CaCV) was shown to be common and widespread in the weed host Ageratum conyzoides in eastern coastal regions of Queensland, Australia with up to 92% of plants infected. This is the first report of A. conyzoides being an important host of CaCV in Australia. CaCV was also found as natural infections of Arachis hypogaea (peanut), Ananas comosus (pineapple), Sonchus oleraceus, Tagetes minuta and Emilia sonchifolia. This is the first report of CaCV infecting pineapple and being associated with severe disease symptoms. Thrips palmi, Frankliniella schultzei and Microcephalothrips abdominalis were shown to transmit CaCV while no transmission was achieved using F. occidentalis.

In 2004, a vein yellowing disease of soil-grown greenhouse capsicum was observed in southern Australia (Fig. 1). Symptoms were similar to those of pepper yellow vein disease, a suspected viral disease of capsicum transmitted by soilborne Olpidium species (Fletcher et al., 1). Disease symptoms were apparent on young plants and faded as the plant matured. In 2008, the disease was again detected in this region and was graft-transmitted to four capsicum plants which developed vein-yellowing symptoms. This isolate (2155) and a sample lyophilised in 2004 (isolate 1631) were tested by RT-PCR using the OP1 and OP2 primers specific for RNA-1 of the genus Ophiovirus (Varia et al., 4). RT-PCR amplicons of the expected size (136 bp) were obtained from the suspected virus-infected samples but not from healthy capsicum. A larger amplicon was amplified using the OP2 primer and a newly designed degenerate genus-specific primer OP3 (5‘-TCDCAAACHCAAGTACAAATGGAAG-3‘) in RT-PCR. The product was amplified from isolate 1631 and the amplicons cloned. Four clones were sequenced, and all were identical (GenBank Accesssion No. MN128532). This sequence was 97.5% identical to that of Ranunculus white mottle virus (RWMV, AF335429) using a pairwise nucleotide sequence alignment. ICTV criteria for classifying Ophiovirus species are based on coat protein sequence (http://www.ictv.global/report/aspiviridae; Garcia et al., 2; 3), however, there are no RWMV coat protein sequences available for comparison. Based on available sequence, the virus is identified as RWMV. Specific primers, RWMVF1 (5'-CGAACATTCCATCTACGCCT-3') and RWMVR1 (5'-GATAGACAATGCCGCAACAA-3') were developed and used in RT-PCR to screen field samples. The expected 383 bp amplicons were obtained from the original two symptomatic field samples collected from southern Australian and samples from the four graft-transmitted plants. In 2018, disease symptoms were seen on capsicum plants in seven greenhouse crops inspected in geographically separated areas of the growing region. The disease incidence was between 1-5% and infection by RWMV was confirmed using the specific RT-PCR in samples collected from these greenhouses. No incidence data is available for the earlier detections. In Italy, RWMV was reported to infect ranunculus (Ranunculus asiaticus hybrids) (Vaira et al., 5) and anemone (Anemone coronaria) (Vaira et al., 6) and was mechanically transmitted from Nicotiana benthamiana to both N. clevelandii and N. megalosiphon where it elicited systemic infection (Vaira et al., 5). There is no evidence that RWMV causes significant economic loss in capsicum crops, but symptoms can be confused with those caused by the more damaging Tomato spotted wilt virus which can lead to inappropriate management choices. This is the first report of RWMV in Australia, and of the virus infecting capsicum. It is, however, likely that RWMV is the cause of the earlier reports of pepper yellow vein disease in this host (Fletcher et al., 1). We thank growers for access to plants and Hort Innovation Australia, the Australian vegetable industry and Australian Federal Government for funding.

The Global Strategy for the Conservation and Use of Musa Genetic Resources (hereafter referred to as the ‘Global Strategy’) has been expanded in 2016 by Musa genetic resources and breeding experts within the framework of the Global Musa Genetic Resources Network, MusaNet. MusaNet’s mandate is to oversee the further development and monitoring of the implementation of the Global Strategy. The updated Global Strategy aims to provide a clear framework and roadmap to be used by the Musa community for the efficient and effective conservation of the globally important collections of Musa and to strengthen the utilization of the genetic resources toward an increased use of available diversity. It includes recommendations and priorities indicated in several consultation processes following the 2006 Global Musa Strategy and particularly the expertise and key groups represented, including the Regional Research Networks (BAPNET, BARNESA, Innovate Plantain and MusaLAC) and global networks such as ProMusa. The Global Strategy covers numerous topics dealing with Musa genetic resources, with the 12 chapters divided into four main parts: Diversity, Identity, Management and Use. Each chapter contains the sections titled Where we are now, Where do we want to go and How will we get there. For Musa researchers, including taxonomists and breeders, but also end users such as farmers, decisions on the management of banana diversity are often made with limited information. With this in mind, the Global Strategy is a core reference on the taxonomy, characterization, evaluation and genetic improvement of cultivars, leading to actions such as the selection of new and improved cultivars. The use of a more diverse genepool can lead to higher production while at the same time promote ecosystem services such as resilience to pest and disease and the effects of climate change.

In June 2103, “Candidatus Liberibacter solanacearum” (CLso) (haplotype A) was detected in tomato plants (Solanum lycopersicon) with yellowing symptoms growing on Norfolk Island, non-self-governing external Australian Territory in the western Pacific Ocean. This appears to be only the second record, after New Zealand, of CLso haplotype A outside North America.

HomePlant DiseaseVol. 102, No. 2First Report of Fusarium oxysporum f. sp. cubense Tropical Race 4 (VCG 01213/16) Associated with Cavendish Bananas in Laos PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Fusarium oxysporum f. sp. cubense Tropical Race 4 (VCG 01213/16) Associated with Cavendish Bananas in LaosK. Chittarath, D. Mostert, K. S. Crew, A. Viljoen, G. Kong, A. B. Molina, and J. E. ThomasK. Chittarath, D. Mostert†Corresponding author: D. Mostert; E-mail: E-mail Address: diane@sun.ac.za, K. S. Crew, A. Viljoen, G. Kong, A. B. Molina, and J. E. ThomasAffiliationsAuthors and Affiliations K. Chittarath , Plant Protection Centre, Department of Agriculture, Vientiane Capital, Lao PDR D. Mostert † , Department of Plant Pathology, Stellenbosch University, Stellenbosch, South Africa K. S. Crew , Department of Agriculture and Fisheries, Brisbane, QLD, Australia A. Viljoen , Department of Plant Pathology, Stellenbosch University, Stellenbosch, South Africa G. Kong , Redclaw Ink PTY LTD, Eumundi, QLD, Australia A. B. Molina , Bioversity International, IIRI Campus, Los Baños, Philippines J. E. Thomas , The University of Queensland, Brisbane, QLD, Australia. Published Online:6 Dec 2017https://doi.org/10.1094/PDIS-08-17-1197-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat The popular Cavendish banana (Musa spp., AAA) constitutes about 45% of all bananas grown worldwide (Lescot 2015). Mainland China is one of the leading producers of Cavendish bananas, and to satisfy local demand for the fruit, commercial production is expanding into neighboring countries such as Laos, Myanmar, and Vietnam. In Laos, local banana varieties such as "kuay nam" (Silk, AAB), "kuay hom" (local Cavendish, AAA), and "kuay klai" (Horn Plantain, AAB) are preferentially grown for food and income generation. The expansion of Cavendish production from China into Laos, therefore, presents significant risks to these varieties, such as the introduction of Fusarium oxysporum f. sp. cubense (Foc) tropical race 4 (TR4; vegetative compatibility group [VCG] 01213/16), a soil-borne fungus that causes severe epidemics and crop losses in Cavendish plantations in southern Chinese provinces. In November 2016, Laos Department of Agriculture staff reported wilting plants from Luang Namtha and Borkeo provinces. In February 2017, yellow leaf symptoms typical of banana Fusarium wilt were observed in commercial Cavendish plantations in Luang Namtha and Vientiane provinces of Laos. When plants were cut open, the pseudostems displayed a dark-red to brown discoloration of the vascular tissue, and the inner rhizome revealed a ring of yellow-brown staining. Infected vascular strands were collected from five plants (three from Luang Namtha province and two from Vientiane province) for morphological, molecular, and VCG identification. Infected vascular strands were plated out onto potato dextrose agar containing 0.04 g/liter of streptomycin. The fungal cultures were single-spored and identified as F. oxysporum based on cultural characteristics and spore morphology (Nelson et al. 1983). Total DNA was extracted from each fungal culture for molecular identification. Amplicons of the expected sizes for Foc TR4-specific primers (Dita et al. 2010) and Foc race 4-specific primers (Lin et al. 2009) were obtained for all five samples. VCG testing (Puhalla 1985) established that the fungal isolates were all compatible with VCG 01213/16. For two isolates collected from Luang Namtha, pathogenicity testing was performed by adding a 30-ml spore suspension (108 conidia/ml) onto the potting soil in which 4-month-old "kuay hom" plants were grown. Each isolate was inoculated onto three plants, and the control plants were treated with sterile distilled water. The infected plants were then incubated in a screened shade house under ambient temperature conditions. After 8 weeks, the Foc TR4-inoculated plants produced typical wilting and internal discoloration symptoms of Fusarium wilt. Fusarium spp. were reisolated from the inoculated plants and identified as Foc TR4/VCG 01213/16 by PCR (Dita et al. 2010), thereby completing Koch's postulates. Many large- and small-scale Cavendish plantations of less than 5 years old are affected by Fusarium wilt in Luang Namtha and Vientiane provinces, sometimes at a high incidence. The incursion of Foc TR4 in Laos threatens not only the rapidly expanding Chinese Cavendish banana production but also susceptible popular varieties grown by small farmers for local markets in Laos.References:Dita, M. A., et al. 2010. Plant Pathol. 59:348. Crossref, ISI, Google ScholarLescot, T. 2015. Fruitrop 231:98. Google ScholarLin, Y. H., et al. 2009. Eur. J. Plant Pathol. 123:353. Crossref, ISI, Google ScholarNelson, P. E., et al. 1983. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University, State College. Google ScholarPuhalla, J. E. 1985. Can. J. Bot. 63:179. Crossref, ISI, Google ScholarDetailsFiguresLiterature CitedRelated Vol. 102, No. 2 February 2018SubscribeISSN:0191-2917e-ISSN:1943-7692 Metrics Article History Issue Date: 19 Jan 2018Published: 6 Dec 2017First Look: 17 Oct 2017Accepted: 16 Oct 2017 Page: 449 Information© 2018 The American Phytopathological SocietyCited byFusarium Species Associated with Diseases of Major Tropical Fruit Crops1 March 2023 | Horticulturae, Vol. 9, No. 3Genome Sequence Data Reveal at Least Two Distinct Incursions of the Tropical Race 4 Variant of Fusarium Wilt into South AmericaPaula H. Reyes-Herrera, Eliana Torres-Bedoya, Diana Lopez-Alvarez, Diana Burbano-David, Sandra L. Carmona, Daniel P. Bebber, David J. Studholme, Monica Betancourt, and Mauricio Soto-Suarez14 December 2022 | Phytopathology®, Vol. 113, No. 1Efficacy of Disinfectants Against Tropical Race 4 Causing Fusarium Wilt in Cavendish BananasMaricar Salacinas, Harold J. G. Meijer, Samuel Herbert Mamora, Benny Corcolon, Amir Mirzadi Gohari, Bikal Ghimire, and Gerrit H. J. Kema6 March 2022 | Plant Disease, Vol. 106, No. 3Fusarium oxysporum f.sp. cubense (Panama disease of banana)CABI Compendium, Vol. CABI CompendiumFusarium oxysporum f.sp. cubense tropical race 4 (Foc TR4)CABI Compendium, Vol. CABI CompendiumIn Vitro Based Mass-Screening Technique for Early Selection of Banana Mutants Resistant to Fusarium Wilt1 June 2022Geographical Distribution and Genetic Diversity of the Banana Fusarium Wilt Fungus in Laos and Vietnam2 January 2022 | Journal of Fungi, Vol. 8, No. 1Development of PCR-Based Race-Specific Markers for Differentiation of Indian Fusarium oxysporum f. sp. cubense, the Causal Agent of Fusarium Wilt in Banana5 January 2022 | Journal of Fungi, Vol. 8, No. 1Pest categorisation of Fusarium oxysporum f. sp. cubense Tropical Race 4EFSA Journal, Vol. 20, No. 1Taxonomic Revision of the Banana Fusarium Wilt TR4 Pathogen Is PrematureEliana Torres Bedoya, Daniel P. Bebber, and David J. Studholme2 December 2021 | Phytopathology®, Vol. 111, No. 12The effect of a consortium of Penicillium sp. and Bacillus spp. in suppressing banana fungal diseases caused by Fusarium sp. and Alternaria sp.23 March 2021 | Journal of Applied Microbiology, Vol. 131, No. 4Gone Bananas? Current and Future Impact of Fusarium Wilt on Production23 May 2021Marker Development for Differentiation of Fusarium oxysporum f. sp. Niveum Race 3 from Races 1 and 215 January 2021 | International Journal of Molecular Sciences, Vol. 22, No. 2Western Alternative Development and Chinese Development30 September 2021Genetic mapping of Fusarium wilt resistance in a wild banana Musa acuminata ssp. malaccensis accession12 September 2020 | Theoretical and Applied Genetics, Vol. 133, No. 12Draft Genome Sequences of Three Fusarium oxysporum f. sp. niveum Isolates Used in Designing Markers for Race DifferentiationMicrobiology Resource Announcements, Vol. 9, No. 42Fusarium Wilt in Banana: Epidemics and Management Strategies5 February 2020A loop‐mediated isothermal amplification (LAMP) assay based on unique markers derived from genotyping by sequencing data for rapid in planta diagnosis of Panama disease caused by Tropical Race 4 in banana20 October 2019 | Plant Pathology, Vol. 68, No. 9First detection of Fusarium oxysporum f. sp. cubense tropical race 4 (TR4) on Cavendish banana in India5 March 2019 | European Journal of Plant Pathology, Vol. 154, No. 3Fusarium Wilt of Banana: Current Knowledge on Epidemiology and Research Needs Toward Sustainable Disease Management19 October 2018 | Frontiers in Plant Science, Vol. 9New Geographical Insights of the Latest Expansion of Fusarium oxysporum f.sp. cubense Tropical Race 4 Into the Greater Mekong Subregion9 April 2018 | Frontiers in Plant Science, Vol. 9

Strong statistical evidence was found for differences in tolerance to natural infections of Tobacco streak virus (TSV) in sunflower hybrids. Data from 470 plots involving 23 different sunflower hybrids tested in multiple trials over 5 years in Australia were analysed. Using a Bayesian Hierarchical Logistic Regression (BHLR) model for analysis provided: (a) a rigorous method for investigating the relative effects of hybrid, seasonal rainfall and proximity to inoculum source on the incidence of severe TSV disease; (b) a natural method for estimating the probability distributions of disease incidence in different hybrids under historical rainfall conditions; and (c) a method for undertaking all pairwise comparisons of disease incidence between hybrids while controlling the familywise error rate without any drastic reduction in statistical power. The tolerance identified in field trials was effective against the main TSV strain associated with disease outbreaks, TSV-parthenium. Glasshouse tests indicate this tolerance to also be effective against the other TSV strain found in central Queensland, TSV-crownbeard. The use of tolerant germplasm is critical to minimise the risk of TSV epidemics in sunflower in this region. We found strong statistical evidence that rainfall during the early growing months of March and April had a negative effect on the incidence of severe infection with greatly reduced disease incidence in years that had high rainfall during this period.

Diseases caused by Tobacco streak virus (TSV) have resulted in significant crop losses in sunflower and mung bean crops in Australia. Two genetically distinct strains from central Queensland, TSV-parthenium and TSV-crownbeard, have been previously described. They share only 81% total-genome nucleotide sequence identity and have distinct major alternative hosts, Parthenium hysterophorus (parthenium) and Verbesina encelioides (crownbeard). We developed and used strain-specific multiplex Polymerase chain reactions (PCRs) for the three RNA segments of TSV-parthenium and TSV-crownbeard to accurately characterise the strains naturally infecting 41 hosts species. Hosts included species from 11 plant families, including 12 species endemic to Australia. Results from field surveys and inoculation tests indicate that parthenium is a poor host of TSV-crownbeard. By contrast, crownbeard was both a natural host of, and experimentally infected by TSV-parthenium but this infection combination resulted in non-viable seed. These differences appear to be an effective biological barrier that largely restricts these two TSV strains to their respective major alternative hosts. TSV-crownbeard was seed transmitted from naturally infected crownbeard at a rate of between 5% and 50% and was closely associated with the geographical distribution of crownbeard in central Queensland. TSV-parthenium and TSV-crownbeard were also seed transmitted in experimentally infected ageratum (Ageratum houstonianum) at rates of up to 40% and 27%, respectively. The related subgroup 1 ilarvirus, Ageratum latent virus, was also seed transmitted at a rate of 18% in ageratum which is its major alternative host. Thrips species Frankliniella schultzei and Microcephalothrips abdominalis were commonly found in flowers of TSV-affected crops and nearby weed hosts. Both species readily transmitted TSV-parthenium and TSV-crownbeard. The results are discussed in terms of how two genetically and biologically distinct TSV strains have similar life cycle strategies in the same environment.

Following the open comment period for MusaNet and ProMusa members in September 2015, the ''BSV Position Paper'' was finalized and is now available here. The purpose of the position paper was to propose a strategy for the distribution of germplasm containing infective endogenous BSV in the B genome, while minimising any risk associated with the distribution of BSV to the recipient country. Comments on the paper were well received and addressed by the taskforce. Please click here for a summary of the comments and responses. The next step is for the International Transit Centre (ITC) to develop an official procedure for the distribution of eBSV infected germplasm based on the position paper. This will be discussed in the MusaNet Expert Committee and reviewed by the taskforce (pictured below) that developed the position paper. The strategy will be implemented after all of the ITC accessions containing the B genome are screened and cleaned if necessary. This is currently being carried out by CIRAD and the University of Liege, Gembloux Agro-Biotech, and is expected to be completed by the end of 2016. If you have any questions or comments, please contact Rachel Chase at r.chase@cgiar.org. (Resume d'auteur)

This greenhouse study investigated the efficacy of acibenzolar-S-methyl (Bion®) treatment of lower leaves of passionfruit, (Passiflora edulis f. sp. flavicarpa), on Passionfruit woodiness disease and activities of two pathogenesis-related proteins, chitinase and β-1,3-glucanase after inoculation with passionfruit woodiness virus (PWV). All Bion® concentrations reduced disease symptoms, but the concentration of 0.025 g active ingredient (a.i.)/l was the most effective, reducing disease severity in systemic leaves by 23, 29 and 30 % compared with water-treated controls at 30, 40 and 50 days post inoculation (dpi) with PWV, respectively. Correspondingly, relative virus concentration as determined by DAS-ELISA in the upper, untreated leaves (new growth) above the site of inoculation at 50 dpi was reduced by 17 and 22 % in plants treated with 0.025 and 0.05 g a.i./l, respectively. Bion® treatment and subsequent inoculation with PWV increased chitinase and β-1,3-glucanase activities in the new leaves above the site of inoculation at 30 dpi with PWV. It was concluded that optimal protective Bion® treatment concentrations were 0.025 and 0.05 g a.i./l.

In 2011, an outbreak of the quarantine-regulated pathogen Potato spindle tuber viroid (PSTVd) occurred in a commercial glasshouse-grown tomato crop in Queensland, Australia. Phylogenetic studies showed that the genotype of this isolate grouped in a cluster of PSTVd genotypes from tomato and Physalis peruviana , and exhibited an interesting mutation (U 257 →A) that has previously been linked to lethal symptom expression in tomato. Transmission studies showed that the viroid could be mechanically transmitted from crushed fruit sap, but not from undamaged fruits. A low rate of asymptomatic infection was determined for plants in the affected glasshouse, demonstrating the efficacy of using symptoms to detect PSTVd infections in tomato. No PSTVd infections were detected in solanaceous weeds located outside of the infected glasshouse, excluding them from playing a role in the viroid epidemiology. Monitoring and subsequent testing of new tomato crops grown in the facility demonstrated successful eradication of the pathogen. A trace-back analysis linked the outbreak of PSTVd to an infected imported tomato seed-lot, indicating that PSTVd is transmitted internationally through contaminated seed.

This is the first report of the genetic diversity within ilarvirus subgroup 1 from eastern Australia. It supports the separation of tobacco streak virus (TSV) strains from parthenium (Parthenium hysterophorus) and crownbeard (Verbescina encelioides) based on serology and host specificity. It has confirmed one previously described strain of TSV as a member of the species Strawberry necrotic shock virus and another as a new subgroup 1 ilarvirus, ageratum latent virus (AgLV), from Ageratum houstonianum. A multiplex RT-PCR showed that the genetically distinct strains of TSV and AgLV were commonly found in symptomless infections in virus-specific alternative weed hosts growing over a wide geographical range in eastern Australia. TSV has been one of the most damaging viruses in Australian oilseed and pulse crops in recent years, and this study has provided the taxonomic knowledge essential for the development of control programs for these viruses.

A new approach for the simultaneous identification of the viruses and vectors responsible for tomato yellow leaf curl disease (TYLCD) epidemics is presented. A panel of quantitative multiplexed real‐time PCR assays was developed for the sensitive and reliable detection of Tomato yellow leaf curl virus‐Israel (TYLCV‐IL), Tomato leaf curl virus (ToLCV), Bemisia tabaci Middle East Asia Minor 1 species (MEAM1, B biotype) and B. tabaci Mediterranean species (MED, Q biotype) from either plant or whitefly samples. For quality‐assurance purposes, two internal control assays were included in the assay panel for the co‐amplification of solanaceous plant DNA or B. tabaci DNA. All assays were shown to be specific and reproducible. The multiplexed assays were able to reliably detect as few as 10 plasmid copies of TYLCV‐IL, 100 plasmid copies of ToLCV, 500 fg B. tabaci MEAM1 and 300 fg B. tabaci MED DNA. Evaluated methods for routine testing of field‐collected whiteflies are presented, including protocols for processing B. tabaci captured on yellow sticky traps and for bulking of multiple B. tabaci individuals prior to DNA extraction. This work assembles all of the essential features of a validated and quality‐assured diagnostic method for the identification and discrimination of tomato‐infecting begomovirus and B. tabaci vector species in Australia. This flexible panel of assays will facilitate improved quarantine, biosecurity and disease‐management programmes both in Australia and worldwide.

Banana streak virus is identified for the first time in Papua New Guinea and Irian Jaya, Indonesia.

A range of plant species that are either cultivated, naturalised or indigenous to sub-tropical eastern Australia and are also able to sustain feeding by Pentalonia nigronervosa , the vector of banana bunchy top virus (BBTV), were investigated as possible hosts of the virus. Alocasia brisbanensis, Alpinia arundelliana. Alpinia caerulea, Alpinia zerumbet, Canna indica, Colocasia esculenta, Hedychiumcoronarium and Heliconia psittacorum cv. Red Parakeet were aphidinoculated with BBTV and none became systemically infected. Furthermore, no BBTV was detected in surveys of field plants of Alocasia brisbanensis, Alpinia caerulea, Cannaindica, Canna × generalis, Canna × orchiodes,Colocasia esculenta and Strelitzia reginae found growing in or near banana plantations affected by BBTV. It is therefore concluded that hosts other than Musa spp. probably do not play a role as reservoirs of BBTV in Australia.

Two novel mastreviruses (genus Mastrevirus; family Geminiviridae), with proposed names chickpea chlorosis virus (CpCV) and chickpea redleaf virus, are described from chickpea (Cicer arietinum) from eastern Australia. The viruses have genomes of 2,582 and 2,605 nucleotides, respectively, and share similar features and organisation with typical dicot-infecting mastreviruses. Two distinct strains of CpCV were suggested by phylogenetic analysis. Additionally, a partial mastrevirus Rep sequence from turnip weed (Rapistrum rugosum) indicated the presence of a distinct strain of Tobacco yellow dwarf virus (TYDV). In phylogenetic analyses, isolates of Bean yellow dwarf virus, Chickpea chlorotic dwarf Pakistan virus and Chickpea chlorotic dwarf Sudan virus from southern and northern Africa and south-central and western Asia clustered separately from these three viruses from Australia. An Australian, eastern Asian, or south-eastern Asian origin for the novel mastreviruses and TYDV is discussed.

Natural infection by mastreviruses was investigated in chickpea ( Cicer arietinum ) and other dicotyledonous crops and weeds in grain production areas of Queensland and northern New South Wales, Australia, from 2000 to 2005. Altogether, 33 639 plants comprising 31 species and 10 dicot families were screened for infection by a tissue-blot immunoassay that did not distinguish between mastrevirus strains or species. Nine plant species in three families were identified as natural hosts. Chickpea was infected throughout the region although infection incidence did not exceed 5%. Infection was rare in faba bean ( Vicia faba ), canola ( Brassica napus ), and mustard ( B. juncea ) and not detected in field pea ( Pisum sativum ). Infection of chickpea and turnip weed ( Rapistrum rugosum ) was confirmed by immunocapture polymerase chain reaction (IC-PCR) with primers generic for dicot-infecting mastreviruses, and also immunosorbent electron microscopy and graft transmission in the case of chickpea. Individual mastreviruses were identified by comparing their IC-PCR amplicons by a combination of methods. Among 42 isolates from 41 chickpea plants, one was typical Tobacco yellow dwarf virus (TYDV) and the others were three recently distinguished strains including two proposed novel species: 34 Chickpea chlorosis virus strain A, six Chickpea chlorosis virus strain B, and one Chickpea redleaf virus. All of 10 isolates from 10 turnip weed plants were TYDV-B, a strain distinct from typical TYDV. The symptoms associated with mastrevirus infection in chickpea included foliar chlorosis or reddening, stunting, and usually phloem browning. The potential for losses in winter and summer grown field crops is discussed.

Introduction: The purpose of this in vitro study was to determine whether para-chloroaniline (PCA) is formed through the reaction of mixing sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Methods: Initially, commercially available samples of chlorhexidine acetate (CHXa) and PCA were analyzed with H-1 nuclear magnetic resonance (NMR) spectroscopy. Two solutions, NaOCl and CHXa, were warmed to 37 degrees C, and when mixed they produced a brown precipitate. This precipitate was separated in half, and pure PCA was added to 1 of the samples for comparison before they were each analyzed with H-1 NMR spectroscopy. Results: The peaks in the H-1 NMR spectra of CHXa and PCA were assigned to specific protons of the molecules, and the location of the aromatic peaks in the PCA spectrum defined the PCA doublet region. Although the spectrum of the precipitate alone resulted in a complex combination of peaks, on magnification there were no peaks in the PCA doublet region that were intense enough to be quantified. In the spectrum of the precipitate to which PCA was added, 2 peaks do appear in the PCA doublet region. Comparing this spectrum with that of precipitate alone, the peaks in the PCA doublet region are not visible before the addition of PCA. Conclusions: On the basis of this in vitro study, the reaction mixture of NaOCl and CHXa does not produce PCA at any measurable quantity, and further investigation is needed to determine the chemical composition of the brown precipitate. (J Endod 2010;36:315-317)