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Formation of chlamydospores on PDA medium under dark conditions by Wilsonomyces carpophilus : (A) Single, terminal and intercalary chlamydospores (bar 1⁄4 50 m m); (B) Chain chlamydospores (bar 1⁄4 50 m m).
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Shot hole disease is one of the most important diseases of stone fruit trees in Iran. The disease is wide spread among orchards of Prunus spp. During spring and summer of 2007, 80 monoconidial isolates of the pathogen were recovered from infected leaves, fruits and twigs of different Prunus spp. in West Azerbaijan, Tehran, Ghazvin and Razavi Khoras...
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Bacterial canker, caused by Pseudomonas syringae pv. syringae and pv. morsprunorum, is one of the most important diseases of stone fruit trees (Prunus spp.). The pathogen infects buds, flowers, fruitlets, leaves and shoots, from which the disease spreads to the branches, boughs and trunks, causing necrosis and cankers. The efficacy of different che...
Citations
... The fungi conidia germination in chamber and field conditions was more than 90% after 4 h at 20 °C (Shaw et al. 1990). Ahmadpour et al. (2012) determined an optimal temperature range of 15-22 °C with no growth below 5 °C or above 30 °C. Rainfall is an important component in the shot-hole disease cycle. ...
... It infects stone fruit trees of Prunus, mainly apricot, peach, nectarine, and cherry. However, the first three are the most commonly affected hosts [4], [5]. It damages twigs, buds, blossoms, fruits, and leaves. ...
... Lesions can be circular to slightly ellipsoid; their tissues can become raised and scurfy and will tear along the lesion margins and may hang on at one attached point. It often dries up and falls away, giving the shot hole; as if someone fired a shotgun at the leaf [5]. ...
Bacterial and Fungal diseases may affect the yield of
stone fruit and cause damage to the Chlorophyll synthesis process, which is crucial for tree growth and fruiting. However, due to their similar visual shot-hole symptoms, novice agriculturalists and ordinary farmers usually cannot identify and differentiate these two diseases. This work investigates and evaluates the use of machine learning for diagnosing these two diseases. It aims at paving the way toward creating a generic deep learning-based model that can be embedded in a mobile phone application or in a web service to provide a fast, reliable, and cheap diagnosis for plant diseases which help reduce the excessive, unnecessary, or improper use of pesticides, which can harm public health and the environment. The dataset consists of hundreds of samples collected from stone fruit farms in the north of Jordan under normal field conditions. The image features were extracted using a CNN algorithm that was pre-trained with millions of images, and the diseases were identified using three machine learning classification algorithms: (1) K-nearest neighbour (KNN); (2) Stochastic Gradient Descent (SGD); and (3) Random Forests (RF). The resulting models were evaluated using 10-fold crossvalidation, with CNN-KNN achieving the best AUC performance with a score of 98.5%. On the other hand, the CNN-SGD model performed best in Classification Accuracy (CA) with a score of 93.7%. The results shown in the Confusion Matrix, ROC, Lift, and Calibration curves also confirmed the validity and robustness of the constructed models.
... Symptoms of SHD occur on the leaves, shoots and fruits of most cultivated stone fruit species [6]. In the case of plum, the leaf symptom of SHD is the most common symptom type [7][8][9][10]. Leaf symptoms appear as tiny light spots that gradually turn brown. ...
... The authors declare no conflict of interest. J. Fungi 2022, 8, 580 ...
Shot hole disease (SHD) can cause severe epidemics in plum orchards, depending on cultivar susceptibility and training system; however, the combined effect on the progress of temporal disease and on the possible reduction in SHD in the disease management was not investigated. The aim of this 3-year study was (i) to monitor and analyze the temporal dynamics of SHD progress under four training systems (4 × 1.5, 4 × 2, 5 × 2.5 and 6 × 3 m) and on four plum cultivars (‘Čačanska lepotica’, ‘Bluefre’, ‘Stanley’ and ‘President’) in an integrated plum orchard; (ii) to identify those time periods when training system and cultivar combinations can reduce the disease development. Both SHD incidences and the area under the disease progress curves (AUDPC) were significantly affected by the training system, cultivar and year. Plum cultivars with high or mid–high susceptibility to SHD showed continuous SHD development from May to November, while cultivars with low susceptibility to SHD showed no symptoms until mid-summer and then progressed slowly until November. High (4 × 1.5 m) vs. low (6 × 3 m) density training systems reduced SHD incidence and AUDPC consistently for three cultivars (‘Čačanska lepotica’, ‘Stanley’ and ‘President’) in September, October and November, compared to the high-density training system. Only cv. ‘Bluefre’ showed no effect either on disease incidence or AUDPC, due to very high disease incidences in all training systems from September to November. In conclusions, combinations of training system and cultivar can significantly reduce SHD incidence, which may be successfully used as a part of the integrated pest management approach during the establishment new plantations.
... Symptoms of W. carpophilus include narrow circular purple lesions with pale center that gradually became larger and necrotic in the centre until the centre fell out, imitating a shot hole and on fruits sunken necrotic lesions are formed (Ye et al., 2020). Although the studies have been conducted on W. carpophilus morphology (Adaskaveg, 1995;Ahmadpour et al., 2009a), host inoculation and varietal response (Ahmadpour et al., 2012a), disease epidemiology (Adaskaveg, 1990b), disease control and genetic diversity (Ahmadpour et al., 2012b;Nabi et al., 2018), no information is available on its genetic structure. Recently, phylogentic analysis using large subunit (LSU) nuclear ribosomal RNA, internal transcribed spacer (ITS), and translation elongation factor 1-alpha (tef1) sequences identi ed Wilsonomyces as a separate genus and it has been placed in the Dothidotthiaceae family (Marin-Felix et al., 2017). ...
Background
Shot hole caused by Wilsonomyces carpophilus is one of the major fungal diseases of stone fruits. The population structure of this fungus has not been studied in detail. The objective of this work was to study the population differentiation of W.carpophilus associated with peach, plum, apricot and almond in three geographical regions using inter simple sequence repeats (ISSR) markers and DNA sequence of internal transcribed spacer (ITS1-5.8S-ITS2) region from fungal isolates. ResultsThe geographical as well as host populations were homogenous with highest genetic diversity within the populations than among populations. Furthermore, the W.carpophilus population on plum host revealed minimal but considerable genetic difference from peach, apricot, and almond populations, suggesting that this pathogen may have speciated on plum host. Conclusion
Gene flow is the main evolutionary process shaping the genetic structure of W.carpophilus in Kashmir. In addition, W.carpophilus population on plum host showed low but significant genetic differentiation with peach, apricot and almond population implicating the possibility of speciation of this pathogen on plum host.
... Several authors have used Random Amplified Polymorphic DNA (RAPD) analysis to characterize fungal pathogens (Abe et al. 2010;Shalini-Devi et al. 2012;Singha et al. 2016). RAPD is simple, flexible and economical (Gryganskyi et al. 2010) relative to other molecular tools hence it is frequently used in molecular characterization of plant pathogenic fungi (Abe et al. 2003;Ahmadpour et al. 2012;Hartanti et al. 2020).This study was conducted to identify and characterize Rhizopus isolates using internal transcribed spacer (ITS) region and determine relatedness among the Rhizopus isolates. ...
Rhizopus species are important pathogens associated with vegetables, fruits and root crops. They are ubiquitous and have been implicated in soft rot disease of sweetpotato roots, which accounts for huge economic losses. However, there is paucity of information on accurate identification of Rhizopus spp. infecting sweetpotato in Nigeria using modern tools. In this study, characterization and pathogenicity of Rhizopus isolates were investigated. Diseased tuber samples were collected during the dry season in 2019 from potato fields in Oyo Sate, Nigeria. Isolation, purification of fungal cultures and pathogenicity of selected, representative isolates were conducted. Morphological identification of Rhizopus isolates was carried out using sporangia fruiting bodies and hyphal structures, while molecular identification and characterization were accomplished through amplification of the internal transcribed spacer (ITS) region of ribosomal DNA. ITS sequences of rDNA 18S, ITS, and 28S D1/D2 of all Rhizopus species were analyzed and compared with standard database for identification to species level. All the 20 isolates were morphologically similar and identified as Rhizopus oryzae and R. stolonifer. Molecular analysis, however, confirmed 16 of the 20 isolates as R. oryzae, two as Aspergillus brasiliensis and the remaining two as Lasiodipodia pseudotheobromae. Phylogenetic analysis distinguished all the 20 isolates into three major clades and intraspecies variation among isolates and reference strains was minimal. All Rhizopus isolates were pathogenic on re-inoculation with lesions identical to field symptoms. This study provides an invaluable information for effective breeding for resistance to soft rot disease in sweetpotato.
... Different W. carpophilus isolates have been previously reported to have high intraspecific genetic diversity. Ahmadpour et al. showed high genetic diversity in 28 isolates of W. carpophilus from different regions in Iran using DNA fingerprinting by random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) and four random primers [64]. A high level of polymorphism in different isolates of W. carpophilus in Kashmir using seven ISSR (inter-simple sequence repeat) markers also indicated that these markers were suitable for studying the genetic diversity in shot-hole pathogens [61]. ...
Prunus divaricata and Prunus armeniaca are important wild fruit trees that grow in part of the Western Tianshan Mountains in Central Asia, and they have been listed as endangered species in China. Shot-hole disease of stone fruits has become a major threat in the wild-fruit forest of the Western Tianshan Mountains. Twenty-five isolates were selected from diseased P. divaricata and P. armeniaca. According to the morphological characteristics of the culture, the 25 isolates were divided into eight morphological groups. Conidia were spindle-shaped, with ovate apical cells and truncated basal cells, with the majority of conidia comprising 3–4 septa, and the conidia had the same shape and color in morphological groups. Based on morphological and cultural characteristics and multilocus analysis using the internal transcribed spacer (ITS) region, partial large subunit (LSU) nuclear ribosomal RNA (nrRNA) gene, and the translation elongation factor 1-alpha (tef1) gene, the fungus was identified as Wilsonomyces carpophilus. The 25 W. carpophilus isolates had high genetic diversity in phylogenetic analysis, and the morphological groups did not correspond to phylogenetic groups. The pathogenicity of all W. carpophilus isolates was confirmed by inoculating healthy P. divaricata and P. armeniaca leaves and fruits. The pathogen was re-isolated from all inoculated tissues, thereby fulfilling Koch's postulates. There were no significant differences in the pathogenicity of different isolates inoculated on P. armeniaca and P. divaricata leaves (p > 0.05). On fruit, G053 7m3 and G052 5m2 showed significant differences in inoculation on P. armeniaca, and G010 5m2 showed extremely significant differences with G004 7m2 and G004 5m2 on P. divaricata (p < 0.05). This is the first report on shot-hole disease of P. armeniaca (wild apricot) leaves and P. divaricata induced by W. carpophilus in China.
... Being an economically important disease, dearth of information is available on resistance, pathogenicity mechanism, and the molecular dialogue that happens between stone fruit hosts and the pathogen. Most of the stud ies conducted in T. carpophilum refer to identification, molecular and morphological characterization of pathogen (Ahmadpour et al., 2012;Ashour and Allam, 1954;Leveille, 1843;Munjal and Kulshreshta, 1968;Nabi et al., 2018). Lack of information in the pathosystem hampers biotechnological disease management interventions that needs due attention. ...
Thyrostroma carpophilum, a causal agent of shot hole disease of stone fruits, cause severe loss in economically important fruit crops of Kashmir. Understanding its pathogenesis at molecular level will aid in devising a better management strategy. In this study, we optimized Agrobacterium tumefaciens mediated transformation (ATMT) conditions for T. carpophilum using PBIF2-EGFP construct. Using this protocol, we obtained 328 positive trans-formants per 10 4 spores and subsequent sub-culturing of transformants on selective and non-selective media resulted in stable T-DNA integration. Southern blot analysis revealed that most of the transformants embodied single T-DNA integration. Using this method, we obtained a small-scale transformant library (2050 transformants). Among this pool, we tested 1005 transformants for their pathogenicity; out of which 185 showed complete path-ogenicity loss, 35 displayed reduced virulence and 785 were pathogenically similar to wild type. Out of this experimental stock, three transformants from each category were randomly selected to dissect the infection assay. The findings deciphered that transformants with complete pathogenicity loss failed to penetrate the host tissue and a few transformants failed to sporulate in laboratory. Transformants from reduced category could not form appressorium and occasionally sporulated. Transformants similar to wild type were morphologically and patho-genically similar to wild type because of un-alteration in their modus operandi. Our work provides a new platform to understand the pathogenicity mechanism of T. carpophilum. The optimized ATMT protocol will help in developing large transformant library that can help to identify the virulence arsenals necessary for the pathogen to cause disease.
... ahari, 2015; Damm Crous, & Fourie, 2007; Damm, Fourie, & Crous, 2010;Damm, Mostert, Crous, & Fourie, 2008;Gramaje et al., 2012;Hausner, Eyjólfsdóttir, Reid, & Klassen, 1992;Hawksworth, Gibson, & Gams, 1976;Inderbitzin, Bostock, Trouillas, & Michailides, 2010;Mostert, Groenewald, Summerbell, Gams, & Crous, 2006;Réblová, Mostert, Gams, & Crous, 2004;Rumbos, 1986;Trouillas et al., 2012). Another important pathogen of Prunus spp. is Wilsonomyces carpophilus, which causes a disease known as shot hole disease on the host leaves and produces cankers on branches, necrotic spots on the twigs and necrotic lesions on fruit (Ahmadpour, Ghosta, Javan-Nikkhah, Ghazanfari, & Fatahi, 2012;Ivanová, Kalocaiová, & Bolvansky, 2012;Marin-Felix et al., 2017;Nabi, Shah, Padder, Dar, & Ahmad, 2018;Tovar-Pedraza, Ayala-Escobar, & Segura-León, 2013). ...
... These results are consistent with the results obtained by other researchers who tested the pathogenicity of this fungus on Prunus spp. hosts (apricot, almond, peach, nectarine, plum, sweet cherry and sour cherry) and found it as a pathogen on the twigs, leaves, buds and shoots (Ahmadpour et al., 2012;Tovar-Pedraza et al., 2013). Moderate temperature and longer periods of high humidity are the most important factors favouring development and spread of the pathogen (Grove, 2002;Văcăroiu, Zală, Cristea, & Oprea, 2009). ...
... Th. cornicola and C. paarla were isolated from these cankers.According to our knowledge, this is the first report of this pathogen in wild almond. Previous studies revealed that W. carpophilus is highly variable based on morpho-cultural, pathological and molecular characterizations(Ahmadpour et al., 2012;Nabi et al., 2018). The bestknown disease caused by W. carpophilus is shot hole disease on host leaves(Marin-Felix et al., 2017;Nabi et al., 2018). ...
Wild almond (Amygdalus scoparia) is a dominant shrub species in mountain forests of the Irano‐Turanian region. Dieback and decline symptoms of wild almond shrubs were first observed in Harat protected forest (Yazd, Iran) in the autumn of 2014. Since then, the incidence and severity of the disease have increased. To study the aetiology and estimate losses from the disease, field studies were conducted in 2016 and 2017. For this purpose, eight stands were selected, in which 24%–99% of the trees were wild almond in their species composition. In total, 50 cankers and 50 infected twigs of wild almond shrubs were collected. Fungal isolates were identified based on morphological and cultural characteristics, as well as sequence data of ITS1 + 5.8S + ITS2 rDNA. Pathogenicity of fungi was checked on detached shoots and evaluated after 40 days by measuring the discoloured lesion length at the inoculation site. Among 681 wild almond shrubs checked, 84.44% showed decline symptoms with different severities; only 15.56% did not show observable disease symptoms. The most frequent colonizers of infected tissues taken from cankers were Wilsonomyces carpophilus (56%), Thyrostroma cornicola (40%) and Collophorina paarla (30%). Infected twigs were extensively colonized by W. carpophilus (36%), Th. cornicola (24%) and Ulocladium consortiale (24%). Other species, such as Endoconidioma populi, Microsphaeropsis olivacea, Trichoderma asperellum, Paecilomyces formosus, Saccothecium rubi, Preussia sp. and Chaetomium globosum, had lower isolation frequencies. W. carpophilus, Th. cornicola, C. paarla and U. consortiale were found as pathogens on detached wild almond shoots. Based on the frequency of the isolates and the pathogenicity tests, four fungi, such as W. carpophilus, Th. cornicola, C. paarla and U. consortiale, are considered serious contributing agents playing a significant role in the dieback and decline of wild almond. All isolated species are reported for the first time on the wild almond shrubs of the world.
... ahari, 2015; Damm Crous, & Fourie, 2007; Damm, Fourie, & Crous, 2010;Damm, Mostert, Crous, & Fourie, 2008;Gramaje et al., 2012;Hausner, Eyjólfsdóttir, Reid, & Klassen, 1992;Hawksworth, Gibson, & Gams, 1976;Inderbitzin, Bostock, Trouillas, & Michailides, 2010;Mostert, Groenewald, Summerbell, Gams, & Crous, 2006;Réblová, Mostert, Gams, & Crous, 2004;Rumbos, 1986;Trouillas et al., 2012). Another important pathogen of Prunus spp. is Wilsonomyces carpophilus, which causes a disease known as shot hole disease on the host leaves and produces cankers on branches, necrotic spots on the twigs and necrotic lesions on fruit (Ahmadpour, Ghosta, Javan-Nikkhah, Ghazanfari, & Fatahi, 2012;Ivanová, Kalocaiová, & Bolvansky, 2012;Marin-Felix et al., 2017;Nabi, Shah, Padder, Dar, & Ahmad, 2018;Tovar-Pedraza, Ayala-Escobar, & Segura-León, 2013). ...
... These results are consistent with the results obtained by other researchers who tested the pathogenicity of this fungus on Prunus spp. hosts (apricot, almond, peach, nectarine, plum, sweet cherry and sour cherry) and found it as a pathogen on the twigs, leaves, buds and shoots (Ahmadpour et al., 2012;Tovar-Pedraza et al., 2013). Moderate temperature and longer periods of high humidity are the most important factors favouring development and spread of the pathogen (Grove, 2002;Văcăroiu, Zală, Cristea, & Oprea, 2009). ...
... Th. cornicola and C. paarla were isolated from these cankers.According to our knowledge, this is the first report of this pathogen in wild almond. Previous studies revealed that W. carpophilus is highly variable based on morpho-cultural, pathological and molecular characterizations(Ahmadpour et al., 2012;Nabi et al., 2018). The bestknown disease caused by W. carpophilus is shot hole disease on host leaves(Marin-Felix et al., 2017;Nabi et al., 2018). ...
Recently the use of medicinal plants potential in the production of nanoparticles has received serious attention. Here, the main component of Camellia sinensis L. (green tea) extract was detected by spectroscopy and the optimal conditions were determined for their performance in green synthesis of silver nanoparticles at room temperature. Epigallocatechin gallate was identified as the dominant component in the extract as determined by spectroscopy, and it was established that its oxidation was a function of the solution pH. Transmission electron microscopy, dynamic light scattering, and visible absorption spectroscopy (UV-Vis) confirmed the reduction in silver ions to silver nanoparticles (Ag NPs). Controlling over Ag NPs shape and narrow size distribution was achieved with 10 ml green tea leaf extract solution and in different reaction pH. Spherical colloidal Ag NPs with well-defined hydrodynamic diameters (with average hydrodynamic size of 27.9-50.2 nm) were produced. Silver nitrate concentrations used in this study were lower than that of reported in similar works, and synthesis efficiency was also higher. Nanoparticles were perfectly spherical and their uniformity, compared to similar studies, was much higher. These NPs showed higher degree of stability and were aqueously stable for >10 months in dark glasses at 4°C. © 2019 Institution of Engineering and Technology. All rights reserved.
As an online university textbook for the students of SUA in Nitra.
