Fig 1 - uploaded by Alistair McTaggart
Content may be subject to copyright.
Thekopsora minima on Vaccinium corymbosum . a Abaxial and adaxial leaf symptoms; b Urediniospores. Scale A=1 cm; B=10 μ m
Source publication
The cause of blueberry rust in eastern Australia was determined by molecular and morphological analysis as Thekopsora minima.
Citations
... Pero, en el envés desarrollaron pústulas de color canela de forma circular (Figura 2) que se disponen de forma individual o en grupos (Figura Figura 2. Pústulas redondeadas de color canela en el envés de las hojas del cultivo de arándano. Mctaggart et al. (2013), informan que a medida que la enfermedad avanza como infecciones severas, las hojas se marchitan y caen, produciendo una defoliación de la planta. Estas observaciones concuerdan con lo descrito por Keith et al. (2008). ...
... Características morfológicas y biométricas. Se hicieron observaciones microscópicas con aumento del 10x y 40x, se observaron uredosporas subglobosas, elipsoidales a obovoides, pediceladas de color amarillo (Figura 4), con un tamaño de 22 µm -28 µm x 19 µm -22 µm, estas carac-terísticas también fueron reportados por Mctaggart et al. (2013). Además, formó teleutosporas de color marrón, que forman la estructura primaria de supervivencia del hongo entre las temporadas de cultivo, debido a que son resistentes a condiciones adversas (Latham et al., 2022). ...
The cultivation area of blueberries (Vaccinium corymbosum L.) has a significant growth worldwide due to its nutritional value, the growing global demand and its economic potential. In Peru, the production of this crop is mainly for export and one of the main producing areas is the province of Trujillo. The objective of the study was to characterize and describe the symptoms of pathogens causing fungal diseases in the blueberry crop. Samples were taken from plants showing necrotic streaks on the stem, leaves and fruit for microbiological analysis in the laboratory. Samples were processed by direct observation of symptoms and presence of signs, using a humid chamber to promote sporulation and PDA culture medium for fungal isolates. Pestalotia sp. causing leaf spot and stem blight, Thekopsora minima causing leaf rust, Botrytis cinerea causing gray mold on flowers and fruit, and Lasiodiplodia theobromae causing dieback were identified. To corroborate their identification, pathogenicity tests were performed. For the control of these diseases, it is recommended that an integrated management plan be implemented to reduce the conditions for pathogen development, thus avoiding short-, medium- and long-term economic losses in the blueberry crop.
... Urediniospores are ellipsoid to oblong, and covered evenly in small spines (echinulate) measuring 20-24 x 12-18 µm (Sato et al., 1993). Padamsee and McKenzie (2019) and McTaggart et al. (2013) provide good descriptions of uredinia on blueberry including colour images of urediniospores. Telia consist of 2-8 cells joined together laterally, and when examined in surface view, measure 20-35 x 18-32 µm, with germ pores of each cell clustering toward the centre of the junction of the cells (Sato et al., 1993). ...
... Early records include those from the northeastern states of the USA, southern-eastern states of Canada, and Japan (Sato et al., 1993). In more recent years the spread of P. minimum has grown to include records from Australia, New Zealand, Mexico, South Africa, Colombia, China, Belgium, Germany, Brazil, the Netherlands, Spain, Portugal, Peru, Sweden and Scotland (Mostert et al., 2010;Rebollar-Alviter et al., 2011;Salazar Yepes and BuriticáCéspedes, 2012;McTaggart et al., 2013;EPPO, 2016a, b;2017a, b;2021a, b;Zheng et al., 2017;Padamsee and McKenzie, 2019;Pazdiora et al., 2019;Huarhua et al., 2020;Wichura et al., 2020;Latham et al., 2022). ...
This datasheet on Pucciniastrum minimum covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Prevention/Control, Further Information.
... Argentina, USA, Canada, Mexico), Europe (e.g., Portugal, UK), Asia (e.g., China), Australia and New Zealand, have all reported the presence of rust leaf disease in blueberry plantation Rebollar-Alviter et al., 2011;McTaggart et al., 2013;Chicau, 2015;Babiker et al., 2018;Wichura et al., 2020). ...
Blueberry (Vaccinium corymbosum) is a perennial shrub, native to North America whose popularity has increasing due to its health benefits. In Portugal, this culture represents an important part of the country's economy, being cultivated in several regions. However, the fast growth of production has been accompanied by the appearance of pathogens, mainly fungi. Considering that studies carried out on pathogenic blueberry fungi in Portugal are still quite scarce, this study aimed to identify species of the genera Pestalotiopsis and Neopestalotiopsis, which are known pathogens severely affecting blueberry plantations worldwide. Therefore, a collection of 51 isolates was obtained from symptomatic blueberry plants collected in different cultivation orchards in Portugal. In order to assess the genetic diversity of our collection, all isolates were subjected to MSP-PCR fingerprinting. According to the analysis of the genetic profiles, 16 representative isolates were chosen for a molecular identification based on the sequencing and analysis of the ITS region, which allowed to identify 2 different genera: Pestalotiopsis and Neopestalotiopsis.To better discriminate the isolates at species level, a multi-locus sequence analysis was performed using, in addition to the ITS region, the protein
coding genes: translation elongation factor 1-alpha (tef1-α) and beta-tubulin 2 (tub2). A phylogenetic analysis of the ITS, tef1-α and tub2 regions revealed the presence of 4 known species, placed into distinct clades (Pestalotiopsis chamaeropis, P. biciliata, P. australis and Neopestalotiopsis rosae), and 3 putative new species. These were characterized in terms of morphology and ability to grow at different temperatures and the names N. baccae, N. scalabiensis and N. vaccinii proposed. Of all the identified
species, N. vaccinii and N. rosae were the most abundant. The pathogenicity tests carried out revealed that all tested species werepathogenic to blueberry plants (cultivar Duke). Among the species tested, P. biciliata and N. rosae were the most aggressive ones. Plants inoculated with isolates from these species exhibited more extensive branch necrosis
and, in some cases, death of the plant. To our knowledge, this represents the first study and the first report of species of Pestalotiopsis and Neopestalotiopsis in blueberries in Portugal. The diversity and distributionof these species, as well as their pathogenicpotential, need to be further explored in the future.
... In the USA, the pathogen was introduced to many western states from the presumed native source in the Northeast, and so far, the newest states with disease incidence reports of T. minima include Michigan, Oregon, and California (Schilder and Miles, 2011;Wiseman et al., 2016;Shands et al., 2018). In addition, blueberry production and trade on the global scale might also be the reason for the introduction of the pathogen to countries that are large geographical distances from the native sources such as Mexico, Colombia, Brazil, South Africa, Australia, and China (Rebollar-Alviter et al., 2011;Yepes and Céspedes, 2012;Pazdiora et al., 2019;Mostert et al., 2010;McTaggart et al., 2013;Zheng et al., 2017). The ability of rust spores to travel a far distance via strong wind or hurricanes might also explain the spread of the disease across neighboring countries in South America (Avila-Quezada et al., 2018). ...
Blueberry rust caused by Thekopsora minima is a common disease in wild blueberry (Vaccinium angustifolium) and other Vaccinium genera. Understanding the spore dispersal pattern and disease cycle of fungal pathogens in wild blueberry is crucial for the development of a more efficient disease management program. Molecular assays for rapid detection and quantification of Thekopsora minima were developed to be incorporated with a spore trap sampling method and weather data collection to examine spore dispersal pattern and production in three different fields: Blueberry Hill Farm in Jonesboro, East Machias, and Spring Pond in Deblois, Maine, in three years 2014, 2015 and 2017. A total of fifteen primer sets for PCR assays and one set of six Loop-mediated isothermal amplification assay (LAMP) primers developed from the internal transcribed spacer (ITS) regions of T. minima were tested for specificity and sensitivity towards T. minima DNA. There was one primer set (TMITS2F and TMITS2GR) that was specific to rust in both PCR and qPCR assay and could detect down to about 20 copies of DNA. Lower DNA level detection (about 2 copies) is possible but often nonreproducible. The LAMP assays results were found to be not reproducible. The qPCR with the two primers TMITS2F and TMITS2GR was used to quantify rust spores in the spore trap tape DNA extracted by a Phenol-Chloroform method. Weather factors including temperature and leaf wetness duration (LWD) were collected using weather stations and button loggers placed in the fields. Calculated weekly sums of LWD and optimal temperature (17oC to 22oC) hour for uredinia production (TH) and weekly averages of other weather factors were analyzed with the weekly spore count numbers using a linear mixed model with the random effects from weeks, fields and years. There was a significant correlation between spore counts using a compound microscope and the qPCR method. There was no clear pattern of temperature, TH and LWD effects on spore numbers quantified by qPCR or microscopy. A linear mixed model (LMM) for disease severity in 2017 testing the effects of log of spore number quantified by qPCR assays, average temperature, LWD, and the random effects of weeks and fields, found that both temperature and LWD had significant negative effects on the disease severity (pT. minima. This relationship could be due to the time required for spores to germinate and cause disease. The proposed preliminary models for disease severity and weather variables, as well as the relationship between the spore number and disease severity need to be tested with data from more years and fields to confirm the results. Nevertheless, the establishment of the molecular assay and predicting models for spore number in this study could be a useful tool for future research on disease management and development of a disease warning strategy for T. minima in wild blueberry.
... The incidence of the disease has been increasing in the United States, where the pathogen has been reported in several states, including Delaware, New York, Michigan, Oregon, Hawaii, California, and Georgia (Keith et al., 2008;Sato et al., 1993;Shands et al., 2018;Wiseman et al., 2016). In addition, leaf rust has been reported in many countries, including South Africa, Mexico, Spain, Argentina, Australia, and China (Barrau et al., 2002;Dal Bello and Perello, 1998;McTaggart et al., 2013;Mostert et al., 2010;Rebollar-Alviter et al., 2011;Zheng et al., 2017). T. minima is a heteroecious fungus requiring both primary and alternate host plants to complete its life cycle (Hiratsuka 1965). ...
... Urediniospores developed on the lower surface of older leaves as yellow-orange pustules within 10 to 14 d of infection and abundant sporulation across the lower leaf surface was observed. The disease symptoms displayed by these accessions were similar to the ones described in previous leaf rust reports (Barrau et al., 2002;Dal Bello and Perello, 1998;Keith et al., 2008;McTaggart et al., 2013;Mostert et al., 2010;Rebollar-Alviter et al., 2011;Shands et al., 2018;Wiseman et al., 2016;Zheng et al., 2017). ...
Blueberry leaf rust caused by Thekopsora minima is a serious threat to blueberry production. To investigate the host range and characterize new sources of resistance, 15 southern highbush accessions (Vaccinium corymbosum), two interspecific hybrids (V. elliottii X V. pallidum and V. corymbosum X V. pallidum), and accessions from five diploid Vaccinium species were inoculated with an isolate of T. minima. Of 15, only two southern highbush accessions displayed resistance, whereas both accessions of V. arboreum displayed immunity against T. minima. Accessions of V. darrowii exhibited necrosis but with limited sporulation, indicating a high level of resistance. Sporulating lesions and brown spots were observed in accessions of V. elliottii and V. tenellum. Brown lesions, large pustules, and abundant sporulation were observed on V. pallidum accessions and their interspecific hybrids. As the lesions expanded, defoliation was observed in V. pallidum accessions. When tested against rabbiteye (V. virgatum) and southern highbush blueberries, urediniospores of T. minima from overwintering leaves of V. pallidum were found to be virulent, suggesting that T. minima overwinters on V. pallidum. Based on symptoms and scanning electron microscopy (SEM) of uredinio- spores, we hypothesize that V. elliottii, V. tenellum, V. pallidum, and V. corymbosum exhibit no host specificity to T. minima. © 2018, American Society for Horticultural Science. All rights reserved.
... (Schilder and Miles, 2011). The pathogen was recorded in North America and Japan (Sato et al., 1993) and has been introduced on blueberries in other countries (e.g., in South Africa in 2006 [Mostert et al., 2010], Australia in 2012 [McTaggart et al., 2013], and Germany in 2015 [NPPO of Germany, 2016]). In 2012 in Tasmania all infected plants were eradicated (Tasmanian government, 2014). ...
... In 2012 in Tasmania all infected plants were eradicated (Tasmanian government, 2014). In Mexico the disease is listed as economically damaging (McTaggart et al., 2013;EPPO, 2016). The risk in Mexico is high because the market for berries is very important for the country's economy. ...
This review highlights the impact of emerging diseases; emerging diseases and pathogen dispersion; disease spread; and possible causes contributing to the emergence of pathogens. Some plant diseases are caused by potentially dangerous pathogens that have led changes in humanity. Despite our efforts in the fight against these dangerous pathogens; the influences of natural phenomena such as hurricanes or strong winds that disperse pathogens remain. However, some actions such as investment in research priorities that are focused on quarantined pathogens and official regulations can help in disease prevention. We discuss emerging diseases as a threat to crops, identify future research areas, and encourage the establishment of research networks focused on quarantine pathogens to address the problem and minimize risks.
... Hosts: Several Vaccinium spp., incl. V. corymbosum (Schilder and Miles, 2011;Rebollar-Alviter et al., 2011, Yepes andBuritica Cespedes, 2012;McTaggart et al., 2013 ), V. angustifolium var. laevifolium, V. erythrocarpon (Mostert et al., 2010), V. angustifolium , also others such as Azalea, Rhododendron, Gaylussacia, Lyonia . ...
... Distribution: Africa: South Africa (2006;Mostert et al., 2010); Asia: Japan ; North America: Canada, USA , Mexico (Rebollar-Alviter et al., 2011;first finding in 2007); South America: Colombia (Yepes and Buritica Cespedes, 2012); Oceania: Australia (New South Wales, Queensland, Victoria; and entered but did not establish in McTaggart et al., 2013;Biosecurity Tasmania, 2014a, b, c). T. minima was found recently on several new continents. ...
... There are several additional genera that have been reported from Australia: Atelocauda (Walker 2001), Bibulocystis (Walker et al. 2006), Cerotelium (Simmonds 1966), Coleosporium (Anon. 2014), Cystopsora (Sydow 1937b), Dasturella (Johnson 1985), Diabole (Burrows et al. 2012), Goplana (Langdon & Herbert 1944), Kernkampella (Walker et al. 2006), Maravalia (Tomley & Evans 2004), Masseeëlla (Liberato et al. 2014), Miyagia (Cooke & Dube 1989), Nyssopsora (Sydow 1938), Olivea (Daly et al. 2006), Phakopsora (Weinert et al. 2003), Prospodium (Thomas et al. 2006), Pucciniastrum (Shivas 1989), Ravenelia (Walker 1983), Sphaerophragmium (Alcorn & Walker 1996), Thekopsora (McTaggart et al. 2013), and Uredopeltis (Walker & Shivas 2004). The keys to the smut and rust fungi of Australia are the first online, taxonomically focused diagnostic tools created for the identification of Australian plant pathogenic fungi. ...
Interactive identification keys for Australian smut fungi (Ustilaginomycotina and Pucciniomycotina, Microbotryales) and rust fungi (Pucciniomycotina, Pucciniales) are available online at http://collections.daff.qld.gov.au. The keys were built using
Lucid software, and facilitate the identification of all known Australian smut fungi (317 species in 37 genera) and 100 rust fungi (from approximately 360 species in 37 genera). The smut and rust keys are illustrated with over 1,600 and 570 images respectively. The keys are designed to assist
a wide range of end-users including mycologists, plant health diagnosticians, biosecurity scientists, plant pathologists, and university students. The keys are dynamic and will be regularly updated to include taxonomic changes and incorporate new detections, taxa, distributions and images.
Researchers working with Australian smut and rust fungi are encouraged to participate in the ongoing development and improvement of these keys.
Two Cerrado rust fungi, Phakopsora rossmaniae and Aplopsora hennenii, described in 1993 and 1995 and originally assigned to families Phakopsoraceae and Ochropsoraceae, respectively, were subjected to molecular phylogenetic analyses using fragments of the nuc 28S and 18S rDNA and mitochondrial cytochrome c oxidase subunit 3 (CO3) gene. Although both taxa were morphologically well placed in their original genera, they were shown to belong in a strongly supported new lineage within the Raveneliineae distant from the Phakopsoraceae and Ochropsoraceae. Therefore, we properly treated this lineage as the new genus Cerradopsora now harboring C. rossmaniae (type species) and C. hennenii. However, this novel phakopsoroid genus remains in uncertain familial position without support to be included in any of the families that share space within the Raveneliineae.
