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A conidiophore of Oidium lycopersici collected in South Australia in 1980 and rehydrated in lactic acid from a herbarium specimen (DAR 35763). Bar = 20 μm.
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A previous morphological study of Oidium anamorphs responsible for the recent tomato (Lycopersicon esculentum) powdery mildew outbreaks worldwide suggested that, despite controversial data in the literature, the North American epidemics were caused solely by a newly erected species, O. neolycopersici. We report here the first molecular evidence tha...
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... studies. All the pow- dery mildew fungi obtained from North America, Europe, and Japan produced conidia singly (Fig. 1), and their morpho- logical features corresponded to those of O. neolycopersici. They were clearly dif- ferent from the three Australian specimens of O. lycopersici included in this study, which produced conidia in chains (Fig. 2). The morphological differences between O. neolycopersici and O. lycopersici have been discussed previously ...
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... Others are forest pathogens (Marçais and Desprez-Loustau, 2014). Some powdery mildews have become invasive in different parts of the world (Kiss, 2005;Desprez-Loustau et al., 2010), posing plant health biosecurity risks (Jones and Baker, 2007;Brasier, 2008;Biosecurity Australia, 2010;Desprez-Loustau et al., 2010). Two species, Blumeria graminis infecting cereals, and Erysiphe necator infecting grapevine, have become model species in plant pathology research (Gadoury et al., 2012;Bindschedler et al., 2016), while the interactions between Podosphaera plantaginis and its host Plantago lanceolata have long been in focus in the study of wild plant pathosystems (Susi et al., 2015). ...
... Neither O. ixodiae nor N. kerribeeensis have been reported outside Australia. Curiously, another powdery mildew species known only from Australia is Golovinomyces lycopersici on tomato, a vegetable introduced from overseas ( Kiss et al., 2001Kiss et al., , 2005Braun et al., 2019). This tomato pathogen is closely related to the Australian O. ixodiae (Cunnington et al., 2005a), and also to G. longipes that causes epidemics on solanaceous vegetables and ornamentals in Europe and the USA Kovács et al., 2011). ...
... Golovinomyces ixodiae ( Golovinomyces ixodiae is sister to the clade containing G. longipes, G. lycopersici and Euoidium sp. on Solanum melongena and Nicotiana alata with identical ITS sequences (Cunnington et al., 2005b) (Figure 10). Amongst these taxa, G. lycopersici on tomato has never been recorded outside Australia (Kiss et al., 2005;Braun et al., 2019), although tomato is a crop introduced from overseas. In Australia, G. lycopersici has been reported since 1980 (Kiss et al., 2001), including in this study ( Table 2). ...
In contrast to Eurasia and North America, powdery mildews (Ascomycota, Erysiphales) are understudied in Australia. There are over 900 species known globally, with fewer than currently 60 recorded from Australia. Some of the Australian records are doubtful as the identifications were presumptive, being based on host plant-pathogen lists from overseas. The goal of this study was to provide the first comprehensive catalog of all powdery mildew species present in Australia. The project resulted in (i) an up-to-date list of all the taxa that have been identified in Australia based on published DNA barcode sequences prior to this study; (ii) the precise identification of 117 specimens freshly collected from across the country; and (iii) the precise identification of 30 herbarium specimens collected between 1975 and 2013. This study confirmed 42 species representing 10 genera, including two genera and 13 species recorded for the first time in Australia. In Eurasia and North America, the number of powdery mildew species is much higher. Phylogenetic analyses of powdery mildews collected from Acalypha spp. resulted in the transfer of Erysiphe acalyphae to Salmonomyces, a resurrected genus. Salmonomyces acalyphae comb. nov. represents a newly discovered lineage of the Erysiphales. Another taxonomic change is the transfer of Oidium ixodiae to Golovinomyces. Powdery mildew infections have been confirmed on 13 native Australian plant species in the genera Acacia, Acalypha, Cephalotus, Convolvulus, Eucalyptus, Hardenbergia, Ixodia, Jagera, Senecio, and Trema. Most of the causal agents were polyphagous species that infect many other host plants both overseas and in Australia. All powdery mildews infecting native plants in Australia were phylogenetically closely related to species known overseas. The data indicate that Australia is a continent without native powdery mildews, and most, if not all, species have been introduced since the European colonization of the continent.
... No: MF991288) (Fig. 2). Kiss et al. (2005) confirmed the identity of causal agent of tomato powdery mildew as O. neolycopersici by using ITS-1 and ITS-2 primers. Attanayake et al. (2009) used Erysiphe specific primers, i.e., EryF and EryR to identify the Erysiphe trifolii causing powdery mildew of lentil. ...
The morphological and molecular characterization using primers EryF and EryR confirmed the associated pathogen with collected samples of tomato powdery mildew as Oidium neolycopersici. Incubation and latent period of the pathogen under in vitro was 4 and 5 days, respectively, however it was 5 days for both under in vivo. Effect of weather variables on the disease development in March 30th and August 30th transplanted crop showed that low temperature and high relative humidity were most favourable factors for disease development. The studies on colonization behavior of the pathogen showed that tissue colonization was directly proportional to the disease severity.
... No: MF991288) (Fig. 2). Kiss et al. (2005) confirmed the identity of causal agent of tomato powdery mildew as O. neolycopersici by using ITS-1 and ITS-2 primers. Attanayake et al. (2009) used Erysiphe specific primers, i.e., EryF and EryR to identify the Erysiphe trifolii causing powdery mildew of lentil. ...
... Powdery mildew is a common disease observed in many horticultural crops, caused by the fungal pathogen Oidium lycopersici and Oidium neolycopersici. Isolates from North America belong to O. neolycopersici (Kiss et al., 2005). The disease poses a has high risk to in greenhouse production, and can develop in the field. ...
... Global trade, plantings of exotic plants and global environmental changes over the past years were major driving forces of invasions of phytopathogenic fungi to new environments, continents, and countries (Kreisel and Scholler 1994;Desprez-Loustau et al. 2010;Mułenko et al. 2010;Wingfield et al. 2010), including such remarkable fungal invasions of recent years as Hymenoscyphus fraxineus (Timmermann et al. 2011), Puccinia lagenophorae (Scholler at al. 2011), Puccinia psidii (Machado et al. 2015), Peronospora belbahrii (Thines et al. 2009;Voglmayr and Piątek 2009;Wyenandt et al. 2015), or powdery mildews (Ale- Agha et al. 2004;Bolay et al. 2005;Kiss et al. 2005). Considering smut fungi, several important introductions and subsequent invasions were already noticed in Europe in the past such as those caused by Entyloma calendulae since the 19th century, Entyloma gaillardianum, and Thecaphora oxalidis in the 20th century, or the model species Ustilago maydis dating Klenke and Scholler (2015) reported also Cosmos sulphureus, but the occurrence of E. cosmi on this host plant is dubious; the report should be reconsidered b Vánky (2012) erroneously reported also Cosmos bipinnatus Eur J Plant Pathol back to at least 18th century (Kreisel and Scholler 1994). ...
The white leaf smut is one of the recently reported and apparently spreading diseases of the garden cosmos (Cosmos bipinnatus) causing necrosis and wilting of the leaves and leading to reduction of its ornamental value. The occurrence of this fungal disease was first observed in Japan (Hokkaido Island) in 1996, and later in Germany (Saxony-Anhalt) in 2002, and the causative agent was described as new species, Entyloma cosmi, in 2005. This smut was subsequently reported from Canada, Switzerland, and Korea. Here it is reported for the first time from Austria, France, Italy, Poland, and Slovenia. This indicates the rapid spread of Entyloma cosmi on Cosmus bipinnatus in temperate climate gardens. The phylogenetic position of Entyloma cosmi is analyzed using ITS rDNA sequences, the phenotypic characters are critically re-evaluated, and the species is characterized using the Consolidated Species Concept, including morphology, ecology (host plant), and rDNA sequences (ITS and LSU). Selected ITS sequences and one LSU sequence generated in this work are deposited on the BarCode of Life website in GenBank (www. ncbi. nlm. nih. gov/ genbank/ barcode/ ) and Fungal Barcoding Database (www. fungalbarcoding. org), and could serve as DNA barcodes to facilitate rapid identification of this economically important species. The ITS sequence from the holotype of Entyloma cosmi, sequenced here, is recommended to be deposited in the RefSeq Targeted Loci database.
... Powdery mildew infections caused by Oidium neolycopersici L. Kiss have become a problem in tomato (Solanum lycopersicum L.) production from the late 1980s in many parts of the world (Kiss et al., 2001;Lebeda et al., 2014). Early after the appearance and rapid spread of the disease in Europe and North America (Kiss et al., 2005), breeding programs have been started because all the commercial tomato cultivars were susceptible to O. neolycopersici at that time (Lebeda et al., 2014;Seifi et al., 2014). Wild relatives of tomato were used as valuable sources of resistance (e.g., Lebeda et al., 2014) and the cytological and molecular background of powdery mildew resistance was also deciphered in Solanum spp. ...
... Two samples of O. neolycopersici were collected and microscopically examined. Based on morphological features (shape and size of conidia, arrangement of conidia, conidiophores size, size and appearance of hyphal appressoria) they corresponded with those of O. neolycopersici previously described by Kiss et al. (2001Kiss et al. ( , 2005 and Braun and Cook (2012) (Table 1). Their main shared characters are size and shape of conidia (mainly ellipsoid-ovoid, sometimes subcylindrical-doliiform), formation of conidia singly (Pseudoidium type) and size and appearance of hyphal appressoria (Fig. 2). ...
Oidium neolycopersici has a world-wide distribution causing severe epidemics mainly on greenhouse tomatoes. Currently, only Leveillula taurica has been reported on tomato from South Africa. However, another powdery mildew species on tomato was found recently. Based on morphological comparison and molecular analysis, its identity was confirmed as O. neolycopersici. The possible means of introduction and other aspects of this finding are discussed.
... O. lycopersici was initially assumed to be the cause for this epidemic, however, later studies discovered that the causal agent is O. neolycopersici (Jones et al. 2000Jones et al. , 2001 Kiss et al. 2001). Now it is believed that O. neolycopersici is present worldwide, except in Australia where O. lycopersici is the causal agent for PM disease in tomato (Kiss et al. 2001Kiss et al. , 2005). Although there is not a consensus on the host range of O. neolycopersici (Jones et al. 2001; Lebeda et al. 2013), there is some evidence suggesting that this pathogen is adapted to plant species from 13 plant families (Whipps et al. 1998; Jankovics et al. 2008). ...
Abstract
Powdery mildews (PMs) cause disease in a wide range of plant species including important crops. Taking tomato as an example, here we review findings on the genetic basis and mechanisms of plant resistance
to PMs. First, we present a summary of our research on tomato resistance to two PM species, with the focus on Oidium neolycopersici. We discuss the genetics of resistance to this pathogen in tomato. Then, we
compare different forms of resistance mediated by different resistance genes based on molecular and
cytological data. Also, we provide a comparison between these resistance genes in tomato with those
in barley, Arabidopsis and wheat, in order to present a model for the genetic basis of resistance to PMs in
plants. We try to accommodate these resistance mechanisms in the current model of plant innate
immunity. At the end we discuss possibilities to translate these findings to practical approaches in
breeding for resistance to PMs in crops
... Erysiphe). Then, Kiss et al. (2005) confirmed the identity of Oidium neolycopersici isolates originated from the North America as O. neolycopersici on the basis of molecular and morphological data. ...
Tomato powdery mildew (Oidium neolycopersici) is one of the most devastating diseases of cultivated tomatoes worldwide. Although the first epidemics were recorded more than 25 years ago many aspects of this host-pathogen interaction are still not well understood. Detailed morphological and molecular studies of the anamorphs confirmed that O. neolycopersici is phylogeneticaly close to Erysiphe aquilegiae var. ranunculi. Host range is rather broad, apart from Solanaceae hosts were found in the families Apocynaceae, Campanulaceae, Crassulaceae, Cistaceae, Cucurbitaceae, Linaceae, Malvaceae, Papaveraceae, Pedialiaceae, Scrophulariaceae, Valerianaceae a Violaceae. Non-host resistance within these families is not based on inhibition of formation of primary haustorium, however, on post-haustorial hypersensitive reponse and another type of non-hypersensitive resistance. Screening of wild Solanum species (previous Lycopersicon spp.) germplasm revealed valuable sources of resistance (S. habrochaites, S. pennellii, S. cheesmaniae, S. chilense, S. peruvianum). The main resistance mechanism was found to be a hypersensitive response (HR), in some cases followed by limited development of the pathogen. However, there is a broad variation in resistance response on the histological and cytological level. Interaction between many wild Solanum spp. and O. neolycopersici is race-specific, at least three races were differentiated. In some interspecific crosses (S. lycopersicum x S. habrochaites) adult plant resistance was observed. Biochemical studies focusing on production of reactive oxygen species (ROS) and peroxidase activity during infection of O. neolycopersici showed that production of ROS and activity of corresponding enzymes is related to activation of defence responses in genotypes of wild Solanum sect. Lycopersicon. The significance of nitric oxide (NO) in O. neolycopersici pathogenesis was supported by experiments with NO donors and scavengers. In moderately resistant genotype S. chmielewskii, treatment by heat stress caused slight deceleration of pathogen development, increased production of jasmonic acid (JA) and abscisic acid (ABA) and increased peroxidase activity in infected plants. The different degree of tomato resistance/susceptibility did not markedly change the rate and extent of photosynthetic response to O. neolycopersici; only minimal impairment of photosynthesis was found in both susceptible and moderately resistant genotypes during the first 9 days after inoculation. The accumulated evidence confirm a crucial role of localised increased production of ROS and reactive nitrogen species (RNS) in response to pathogen penetration into plant tissue and its involvement in the plant resistance responses including the initiation and progression of plant cell death in host wild Solanum species. Crucial points of further research are discussed.
... Golovinomyces orontii is common to many host plants in both temperate and tropical regions and is the only ectophytotic fungus on tomato that produces conidia in long chains (Noordeloos and Loerakker, 1989;Kiss et al., 2005). In the late 1970s, a new powdery mildew disease was reported on tomatoes in Japan, Australia, and later from many parts of Europe and North America and has spread rapidly around the world (Price, 1981;Marois et al., 2001;Kiss et al., 2005). ...
... Golovinomyces orontii is common to many host plants in both temperate and tropical regions and is the only ectophytotic fungus on tomato that produces conidia in long chains (Noordeloos and Loerakker, 1989;Kiss et al., 2005). In the late 1970s, a new powdery mildew disease was reported on tomatoes in Japan, Australia, and later from many parts of Europe and North America and has spread rapidly around the world (Price, 1981;Marois et al., 2001;Kiss et al., 2005). While others described another oidium anamorph on tomato that produced conidia in chains (Kiss, 1996;Neshev, 1993;Wics andClare, 1981, Smith, et al. 1997;Whipps, et al., 1998). ...
Powdery mildew is one of the most important disease concerns of tomato production in different regions of the world, which is caused by different species of Erysiphales. The most important causal agents of which are Leveillula taurica and Oidium neolycopersici. In the present study tomato farms in Qazvin were surveyed and tomato leaves with powdery mildew symptoms were collected. After morphological studies in laboratory and using reliable resources, the causal agent of tomato powdery mildew was identified as Leveillula taurica. The host range was determined by inoculation of Leveillula taurica from tomato on nine species of plants belonging to four different plant families. All cultivars of tomato, eggplant, pepper and cucumber used in this study, showed disease symptoms on their leaf surfaces. Other plant species including potato, alfalfa, sunflower, clover and sainfoin did not get infected by the pathogen. The nucleotide divergence for the rDNA nternal transcribed spacers region between tomato and other 21 Leveillula taurica isolates ranged from 0.00 to 0.031 %. The sequence of ITS region of Leveillula taurica from tomato was identical to eight isolates from different plant species.
... Oidium neolycopersici is the causal agent of tomato powdery mildew; it causes powdery white lesions on the leaf surface, petioles and the calyx. Severe infections lead to marked reduction in fruit size and quality and to leaf wilt (Kiss et al., 2005). Change in temperatures may allow either more severe disease or reduction in disease severity. ...
