Wanissa Mellikeche, G. Casini, A. Ricelli, G. Colelli, M. Gallo, A. D’ONGHIA
Postharvest losses, which occur between harvest and consumption of agricultural commodities, are major causes of food waste. Minimizing food loss helps provide nutritious food for animals and humans, and alleviate adverse environmental effects on food production. These losses are often related to the presence of postharvest pathogens, including fungi and bacteria, which typically start by infecting crops in the field as well as during postharvest chain. Control of these pathogens relies on development of tools that ensure their early and accurate detection. Among these is loop-mediated isothermal amplification (LAMP), a molecular method for pathogen detection. LAMP characteristics of rapidity, specificity and simplicity have encouraged development of a number of LAMP assays for detection of postharvest pathogens. Each LAMP assay allows to detect a specific genetic region of the target microorganism, which can be directly related to mycotoxin production, fungicide resistance and phytotoxicity. The LAMP amplicons are rapidly visualized, either at a specific timepoint, or in real-time by taking measurements throughout reaction, thereby necessitating less sophisticated facilities than those needed for PCR assays. In addition, many studies have developed simple protocols for the direct detection of pathogens on fresh produce. This paper explains the LAMP reaction, and its importance for postharvest detection of fungi and bacteria. Previous studies that have developed LAMP assays are also discussed.
{"title":"Detection of post-harvest pathogens by loop-mediated isothermal amplification: a review","authors":"Wanissa Mellikeche, G. Casini, A. Ricelli, G. Colelli, M. Gallo, A. D’ONGHIA","doi":"10.36253/phyto-14093","DOIUrl":"https://doi.org/10.36253/phyto-14093","url":null,"abstract":"Postharvest losses, which occur between harvest and consumption of agricultural commodities, are major causes of food waste. Minimizing food loss helps provide nutritious food for animals and humans, and alleviate adverse environmental effects on food production. These losses are often related to the presence of postharvest pathogens, including fungi and bacteria, which typically start by infecting crops in the field as well as during postharvest chain. Control of these pathogens relies on development of tools that ensure their early and accurate detection. Among these is loop-mediated isothermal amplification (LAMP), a molecular method for pathogen detection. LAMP characteristics of rapidity, specificity and simplicity have encouraged development of a number of LAMP assays for detection of postharvest pathogens. Each LAMP assay allows to detect a specific genetic region of the target microorganism, which can be directly related to mycotoxin production, fungicide resistance and phytotoxicity. The LAMP amplicons are rapidly visualized, either at a specific timepoint, or in real-time by taking measurements throughout reaction, thereby necessitating less sophisticated facilities than those needed for PCR assays. In addition, many studies have developed simple protocols for the direct detection of pathogens on fresh produce. This paper explains the LAMP reaction, and its importance for postharvest detection of fungi and bacteria. Previous studies that have developed LAMP assays are also discussed.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48124116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Tizzani, A. Gentili, A. Taglienti, S. Bertin, V. Ilardi
In Europe and the Mediterranean region, ‘Candidatus Liberibacter solanacearum’ (Lso) is associated with emerging diseases of Apiaceae crops, mainly carrot. Emergency measures for import of carrot seed were set, requiring seed to be heat-treated at 50°C or tested as Lso-negative by PCR. The germination response to heat treatment was assessed for 24 carrot cultivar and hybrid seed lots. Ten parsley, five fennel, and two celery seed lots were also analysed. Of these 41 seed lots, 21 were Lso-infected. Water heat treatment significantly decreased germinability compared to dry heat treatment, indicating that dry heat treatment is a cheaper and less detrimental procedure. However, the dry heat treatment significantly decreased seed germination compared to untreated controls in four of 24 seed lots of carrot, four of ten parsley seed lots, three of five fennel seed lots, and one of two celery seed lots. For parsley, the heat treatment reduced germinability to a lesser extent in Lso-infected than Lso-free seed lots. These data show that heat treatment can affect the germination of Apiaceae seeds to varying degrees, depending on species or variety, the type of heat treatment, and the sanitary status of the seeds.
{"title":"Response of carrot seed germination to heat treatment, the emergency measure to reduce the risk of ‘Candidatus Liberibacter solanacearum’ seed transmission","authors":"L. Tizzani, A. Gentili, A. Taglienti, S. Bertin, V. Ilardi","doi":"10.36253/phyto-13958","DOIUrl":"https://doi.org/10.36253/phyto-13958","url":null,"abstract":"In Europe and the Mediterranean region, ‘Candidatus Liberibacter solanacearum’ (Lso) is associated with emerging diseases of Apiaceae crops, mainly carrot. Emergency measures for import of carrot seed were set, requiring seed to be heat-treated at 50°C or tested as Lso-negative by PCR. The germination response to heat treatment was assessed for 24 carrot cultivar and hybrid seed lots. Ten parsley, five fennel, and two celery seed lots were also analysed. Of these 41 seed lots, 21 were Lso-infected. Water heat treatment significantly decreased germinability compared to dry heat treatment, indicating that dry heat treatment is a cheaper and less detrimental procedure. However, the dry heat treatment significantly decreased seed germination compared to untreated controls in four of 24 seed lots of carrot, four of ten parsley seed lots, three of five fennel seed lots, and one of two celery seed lots. For parsley, the heat treatment reduced germinability to a lesser extent in Lso-infected than Lso-free seed lots. These data show that heat treatment can affect the germination of Apiaceae seeds to varying degrees, depending on species or variety, the type of heat treatment, and the sanitary status of the seeds.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44236497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. P. Velasco-Amo, A. Vicent, P. Zarco-Tejada, J. A. Navas‐Cortés, B. Landa
Xylella fastidiosa is a major transboundary plant pest, causing severe socioeconomic impacts. Development of preventive strategies and methods for surveillance, early detection, monitoring, and accurate diagnosis of X. fastidiosa and its vectors, are keys to preventing the effects of this plant pathogen, and assist timely eradication or optimisation of containment measures. This review focuses on approaches for early detection of X. fastidiosa in the Mediterranean Basin, including development of climatic suitability risk maps to determine areas of potential establishment, and epidemiological models to assist in outbreak management through optimized surveillance and targeted responses. The usefulness of airborne hyperspectral and thermal images from remote sensing to discriminate X. fastidiosa infections from other biotic- and abiotic-induced spectral signatures is also discussed. The most commonly used methods for identifying X. fastidiosa in infected plants and vectors, and the molecular approaches available to genetically characterize X. fastidiosa strains, are described. Each of these approaches has trade-offs, but stepwise or simultaneous combinations of these methods may help to contain X. fastidiosa epidemics in the Mediterranean Basin.
{"title":"Recent research accomplishments on early detection of Xylella fastidiosa outbreaks in the Mediterranean Basin","authors":"M. P. Velasco-Amo, A. Vicent, P. Zarco-Tejada, J. A. Navas‐Cortés, B. Landa","doi":"10.36253/phyto-14171","DOIUrl":"https://doi.org/10.36253/phyto-14171","url":null,"abstract":"Xylella fastidiosa is a major transboundary plant pest, causing severe socioeconomic impacts. Development of preventive strategies and methods for surveillance, early detection, monitoring, and accurate diagnosis of X. fastidiosa and its vectors, are keys to preventing the effects of this plant pathogen, and assist timely eradication or optimisation of containment measures. This review focuses on approaches for early detection of X. fastidiosa in the Mediterranean Basin, including development of climatic suitability risk maps to determine areas of potential establishment, and epidemiological models to assist in outbreak management through optimized surveillance and targeted responses. The usefulness of airborne hyperspectral and thermal images from remote sensing to discriminate X. fastidiosa infections from other biotic- and abiotic-induced spectral signatures is also discussed. The most commonly used methods for identifying X. fastidiosa in infected plants and vectors, and the molecular approaches available to genetically characterize X. fastidiosa strains, are described. Each of these approaches has trade-offs, but stepwise or simultaneous combinations of these methods may help to contain X. fastidiosa epidemics in the Mediterranean Basin.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":"160 1-2","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41308609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Passera, Valentina Grosso, N. Miotti, M. Rossato, F. Gaffuri, P. Casati, M. Delledonne, P. Bianco
Xylella fastidiosa is a fastidious Gram-negative bacterium that is associated with several important plant diseases, and is regulated as a quarantine pest in many countries where strategies are implemented to prevent its introduction and spread. To enact efficient quarantine measures, effective and early detection of the pathogen are essential, especially because global trade of goods increases the risks of introduction of alien pathogens. this study aimed to adapt two qPCR-based diagnostic methods (SYBR Green and Probe based qPCR), already in use to detect X. fastidiosa, for use with a nanoplate based digital PCR assay. Detection of the pathogen using the two digital PCR assays (EvaGreen- and Probe-based) was similar to standard qPCR, giving 100% sensitivity, specificity, and accuracy, while providing accurate absolute quantification of the pathogen when using experimental samples that had low concentrations of host DNA. Using undiluted plant DNA added with low concentrations of X. fastidiosa, only the TaqMan method maintained satisfactory performance and quantification, and is therefore preferred. These results are a first step demonstrating the usefulness of nanoplate-based digital PCR for detection of plant pathogens, which allows greater throughput than qPCR, reducing the time and cost of diagnostic assays.
苛养木杆菌是一种挑剔的革兰氏阴性菌，与几种重要的植物疾病有关，在许多实施了防止其传入和传播战略的国家，它被作为检疫性有害生物加以管制。为了制定有效的检疫措施，有效和早期发现病原体至关重要，特别是因为全球货物贸易增加了引入外来病原体的风险。本研究旨在将两种基于qPCR的诊断方法(SYBR Green和Probe based qPCR)应用于基于纳米板的数字PCR检测。使用两种数字PCR方法(基于evgreen和基于probe的)检测病原体与标准qPCR相似，具有100%的灵敏度、特异性和准确性，同时在使用具有低浓度宿主DNA的实验样品时提供准确的病原体绝对定量。在未稀释的植物DNA中加入低浓度的苛养X.，只有TaqMan法保持了令人满意的性能和定量，因此是首选方法。这些结果是证明基于纳米板的数字PCR检测植物病原体有用性的第一步，它比qPCR具有更高的通量，减少了诊断分析的时间和成本。
{"title":"Nanoplate digital PCR assays for detection and quantification of Xylella fastidiosa","authors":"A. Passera, Valentina Grosso, N. Miotti, M. Rossato, F. Gaffuri, P. Casati, M. Delledonne, P. Bianco","doi":"10.36253/phyto-13803","DOIUrl":"https://doi.org/10.36253/phyto-13803","url":null,"abstract":"Xylella fastidiosa is a fastidious Gram-negative bacterium that is associated with several important plant diseases, and is regulated as a quarantine pest in many countries where strategies are implemented to prevent its introduction and spread. To enact efficient quarantine measures, effective and early detection of the pathogen are essential, especially because global trade of goods increases the risks of introduction of alien pathogens. this study aimed to adapt two qPCR-based diagnostic methods (SYBR Green and Probe based qPCR), already in use to detect X. fastidiosa, for use with a nanoplate based digital PCR assay. Detection of the pathogen using the two digital PCR assays (EvaGreen- and Probe-based) was similar to standard qPCR, giving 100% sensitivity, specificity, and accuracy, while providing accurate absolute quantification of the pathogen when using experimental samples that had low concentrations of host DNA. Using undiluted plant DNA added with low concentrations of X. fastidiosa, only the TaqMan method maintained satisfactory performance and quantification, and is therefore preferred. These results are a first step demonstrating the usefulness of nanoplate-based digital PCR for detection of plant pathogens, which allows greater throughput than qPCR, reducing the time and cost of diagnostic assays.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49044270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kassemeyer, Fabian Kluge, Evi Bieler, Markus Ulrich, J. Grüner, Sigfried Fink, M. Dürrenberger, René Fuchs
Wood colonizing fungi are specialists that exploit the lignocellulose of cell wall components in host wood cylinders as a carbon sources. Some of these specialized fungi, including Fomitiporia mediterranea (Fmed) and Phaeomoniella chlamydospora (Pch), cause the disease Esca of grapevine. This disease complex includes grapevine leaf stripe disease (GLSD) of canopies and white rot and black wood streaking in trunks. The present study gained insights into the activity of Esca pathogens in host xylem of the trunk tissues at an anatomical level. Lesions with white rot and brown wood streaking were microscopically analyzed, and the structures of affected tissues were compared with intact xylem. In trunks with white rot, demarcation zones separated intact tissues from the lesions. Immediately adjacent to the demarcation zones, cell wall decomposition initiated in the xylem. At this initial stage, cavities appeared in the secondary cell walls of libriform fibres, which expanded and closely resembled the degradation pattern of soft rot. In the advanced stage, the fibre cell walls were completely decomposed, and the vessels were attacked with a degradation pattern similar to white rot. Only remnants of the xylem elements remained, forming amorphous matrices. These decomposition patterns occurred in field samples and in wood cores artificially infected with Fmed. The obvious compartmentalization of the tissue affected by Fmed indicated a defense reaction in the xylem, according to the CODIT model. In contrast, brown wood streaking affected only small groups of vessels, adjacent libriform fibres and parenchyma. Dark inclusions in cells and tyloses in vessels indicate a defense reaction against the pathogens causing brown wood streaking. Artificial inoculation of sterile wood cores with Pch confirmed the contribution of this pathogen to brown wood streaking. This research provides insights into the structural and functional anatomy of intact and infected tissues of grapevines, which clarify the etiology of Esca, and provide new knowledge for developing new approaches to control of this disease complex.
{"title":"Trunk anatomy of asymptomatic and symptomatic grapevines provides insights into degradation patterns of wood tissues caused by Esca-associated pathogens","authors":"H. Kassemeyer, Fabian Kluge, Evi Bieler, Markus Ulrich, J. Grüner, Sigfried Fink, M. Dürrenberger, René Fuchs","doi":"10.36253/phyto-13154","DOIUrl":"https://doi.org/10.36253/phyto-13154","url":null,"abstract":"Wood colonizing fungi are specialists that exploit the lignocellulose of cell wall components in host wood cylinders as a carbon sources. Some of these specialized fungi, including Fomitiporia mediterranea (Fmed) and Phaeomoniella chlamydospora (Pch), cause the disease Esca of grapevine. This disease complex includes grapevine leaf stripe disease (GLSD) of canopies and white rot and black wood streaking in trunks. The present study gained insights into the activity of Esca pathogens in host xylem of the trunk tissues at an anatomical level. Lesions with white rot and brown wood streaking were microscopically analyzed, and the structures of affected tissues were compared with intact xylem. In trunks with white rot, demarcation zones separated intact tissues from the lesions. Immediately adjacent to the demarcation zones, cell wall decomposition initiated in the xylem. At this initial stage, cavities appeared in the secondary cell walls of libriform fibres, which expanded and closely resembled the degradation pattern of soft rot. In the advanced stage, the fibre cell walls were completely decomposed, and the vessels were attacked with a degradation pattern similar to white rot. Only remnants of the xylem elements remained, forming amorphous matrices. These decomposition patterns occurred in field samples and in wood cores artificially infected with Fmed. The obvious compartmentalization of the tissue affected by Fmed indicated a defense reaction in the xylem, according to the CODIT model. In contrast, brown wood streaking affected only small groups of vessels, adjacent libriform fibres and parenchyma. Dark inclusions in cells and tyloses in vessels indicate a defense reaction against the pathogens causing brown wood streaking. Artificial inoculation of sterile wood cores with Pch confirmed the contribution of this pathogen to brown wood streaking. This research provides insights into the structural and functional anatomy of intact and infected tissues of grapevines, which clarify the etiology of Esca, and provide new knowledge for developing new approaches to control of this disease complex.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44651894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Curvularia americana and C. tropicalis are described as causes of leaf and crown necroses on Bermuda grass (Cynodon dactylon x Cynodon transvaalensis) in Veneto, Northern Italy. These pathogens were characterized using morphological characters, and a multilocus molecular phylogenetic analysis based on the nuclear ribosomal internal transcribed spacer (ITS) region, the partial glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor-1α (tef1-α) genes. Pathogenicity tests and the fulfilment of Koch’s postulates confirmed C. americana and C. tropicalis as foliar pathogens of Bermuda grass. This is the first report of C. americana and C. tropicalis as pathogens of Bermuda grass, and the first record these two fungi in Europe.
{"title":"Curvularia americana and Curvularia tropicalis cause leaf and crown necrosis on Bermuda grass in Italy","authors":"G. Gilardi, M. Mocioni, M. Gullino, V. Guarnaccia","doi":"10.36253/phyto-13825","DOIUrl":"https://doi.org/10.36253/phyto-13825","url":null,"abstract":"Curvularia americana and C. tropicalis are described as causes of leaf and crown necroses on Bermuda grass (Cynodon dactylon x Cynodon transvaalensis) in Veneto, Northern Italy. These pathogens were characterized using morphological characters, and a multilocus molecular phylogenetic analysis based on the nuclear ribosomal internal transcribed spacer (ITS) region, the partial glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor-1α (tef1-α) genes. Pathogenicity tests and the fulfilment of Koch’s postulates confirmed C. americana and C. tropicalis as foliar pathogens of Bermuda grass. This is the first report of C. americana and C. tropicalis as pathogens of Bermuda grass, and the first record these two fungi in Europe.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44693102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Lecomte, Céline Cholet, E. Bruez, Tommaso Martignon, M. Giudici, M. Simonit, Adeline Alonso Ugaglia, D. Forget, Jérôme Miramon, M. Arroyo, D. Dubourdieu, L. GENY-DENIS, P. Rey
Grapevine curettage was re-introduced in France in the early 2000s, and is important for facilitating recovery of plants from esca disease. This surgical practice involves removal of deadwood of vines with leaf symptoms, focusing on white rot generally observed at the centres of grapevine trunks. Assessment of the efficacy of this practice was initiated in the Bordeaux region in 2014. One ‘Sauvignon Blanc’ vineyard severely affected by esca was initially surveyed in the summer of 2014, to identify and treat vines with esca foliar symptoms. Annually thereafter, from 2014 to 2018, selected vine stocks were curetted. Two other ‘Sauvignon Blanc’ vineyards also displaying high levels of esca damage were added to the study in 2015 and 2016. Curettage treatments ceased in 2018, resulting in 11 trials (vineyard × year combinations). In total, 856 vines (422 curetted and 434 control vines) were then surveyed annually up to 2021, for assessments and comparisons of esca development. At each site, plants with esca symptoms recovered well after curettage: on average 85% of all curetted vines became asymptomatic the year immediately after the treatment. Six years after treatment, for curettage campaigns carried out in 2014 and 2015, more than half of the curetted vines were symptom-free, whereas <12% of the control vines were asymptomatic, and gradual loss of efficacy was observed at each site. The mean annual proportion of efficacy erosion was approx. 8% per year. This study highlights the possible short- and mid-term benefits of trunk surgery to enable recovery of esca-affected vines, and for them to recover and remain leaf-asymptomatic for several years.
{"title":"Recovery after curettage of grapevines with esca leaf symptoms","authors":"P. Lecomte, Céline Cholet, E. Bruez, Tommaso Martignon, M. Giudici, M. Simonit, Adeline Alonso Ugaglia, D. Forget, Jérôme Miramon, M. Arroyo, D. Dubourdieu, L. GENY-DENIS, P. Rey","doi":"10.36253/phyto-13357","DOIUrl":"https://doi.org/10.36253/phyto-13357","url":null,"abstract":"Grapevine curettage was re-introduced in France in the early 2000s, and is important for facilitating recovery of plants from esca disease. This surgical practice involves removal of deadwood of vines with leaf symptoms, focusing on white rot generally observed at the centres of grapevine trunks. Assessment of the efficacy of this practice was initiated in the Bordeaux region in 2014. One ‘Sauvignon Blanc’ vineyard severely affected by esca was initially surveyed in the summer of 2014, to identify and treat vines with esca foliar symptoms. Annually thereafter, from 2014 to 2018, selected vine stocks were curetted. Two other ‘Sauvignon Blanc’ vineyards also displaying high levels of esca damage were added to the study in 2015 and 2016. Curettage treatments ceased in 2018, resulting in 11 trials (vineyard × year combinations). In total, 856 vines (422 curetted and 434 control vines) were then surveyed annually up to 2021, for assessments and comparisons of esca development. At each site, plants with esca symptoms recovered well after curettage: on average 85% of all curetted vines became asymptomatic the year immediately after the treatment. Six years after treatment, for curettage campaigns carried out in 2014 and 2015, more than half of the curetted vines were symptom-free, whereas <12% of the control vines were asymptomatic, and gradual loss of efficacy was observed at each site. The mean annual proportion of efficacy erosion was approx. 8% per year. This study highlights the possible short- and mid-term benefits of trunk surgery to enable recovery of esca-affected vines, and for them to recover and remain leaf-asymptomatic for several years.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45835052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. D’ONGHIA, F. Santoro, S. Minutillo, D. Frasheri, M. Gallo, S. Gualano, G. Cavallo, F. Valentini
Early detection of Xylella fastidiosa outbreaks in Apulian olive groves is crucial, especially in buffer zones and pathogen-free areas where olive trees are asymptomatic. Three studies were conducted. Two were on the spatial and temporal progression of X. fastidiosa infections in tree canopies of asymptomatic or mildly symptomatic olive trees of tolerant (‘Leccino’) and susceptible (‘Cellina di Nardò’ and ‘Ogliarola salentina’) cultivars. Despite different trends in pathogen infection rates and concentrations between ‘Leccino’ and susceptible olive cultivars over the study period, results showed that sampling was most effective in the mid-upper part of tree canopies throughout the year, excluding the warmest and coldest periods. Stem xylem tissues were the most appropriate for detecting the pathogen compared to lower parts of mature leaves with petioles, using serological and molecular assays. Based on these results, a third study was conducted to compare molecular and serological tests (qPCR, real-time LAMP, DAS-ELISA, DTBIA) for detection of X. fastidiosa in the mid-upper part of asymptomatic branches of infected ‘Leccino’ trees that were sampled in an appropriate collection time, using stem xylem tissue as the most appropriate matrix for testing. The molecular methods showed the greatest sensitivity, with no undetermined results, while among the serological assays, DTBIA was more sensitive than DAS-ELISA. An improved protocol for monitoring asymptomatic olive trees is recommended.
{"title":"Optimisation of sampling and testing for asymptomatic olive trees infected by Xylella fastidiosa in Apulia region, Italy","authors":"A. D’ONGHIA, F. Santoro, S. Minutillo, D. Frasheri, M. Gallo, S. Gualano, G. Cavallo, F. Valentini","doi":"10.36253/phyto-13732","DOIUrl":"https://doi.org/10.36253/phyto-13732","url":null,"abstract":"Early detection of Xylella fastidiosa outbreaks in Apulian olive groves is crucial, especially in buffer zones and pathogen-free areas where olive trees are asymptomatic. Three studies were conducted. Two were on the spatial and temporal progression of X. fastidiosa infections in tree canopies of asymptomatic or mildly symptomatic olive trees of tolerant (‘Leccino’) and susceptible (‘Cellina di Nardò’ and ‘Ogliarola salentina’) cultivars. Despite different trends in pathogen infection rates and concentrations between ‘Leccino’ and susceptible olive cultivars over the study period, results showed that sampling was most effective in the mid-upper part of tree canopies throughout the year, excluding the warmest and coldest periods. Stem xylem tissues were the most appropriate for detecting the pathogen compared to lower parts of mature leaves with petioles, using serological and molecular assays. Based on these results, a third study was conducted to compare molecular and serological tests (qPCR, real-time LAMP, DAS-ELISA, DTBIA) for detection of X. fastidiosa in the mid-upper part of asymptomatic branches of infected ‘Leccino’ trees that were sampled in an appropriate collection time, using stem xylem tissue as the most appropriate matrix for testing. The molecular methods showed the greatest sensitivity, with no undetermined results, while among the serological assays, DTBIA was more sensitive than DAS-ELISA. An improved protocol for monitoring asymptomatic olive trees is recommended.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43021873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jun Wang, Shi Feng, B. Lu, Lina NA YANG, Xue Wang, Yanjing Zhang, Jie Ying Gao
Panax ginseng is a valuable medicinal plant which is affected by many diseases during its long cultivation period. Ginseng root rot, caused by Fusarium oxysporum, has become severe in China. This soilborne pathogen comprises many formae speciales based on host specificity. Ten representative isolates from diseased ginseng rot root showed pathogenicity on ginseng. To identify the forma specialis of the F. oxysporum strains, host range tests of three representative isolates were carried out on nine plant species. All three isolates caused severe symptoms only on ginseng, but only slight or no visual symptoms on the other eight hosts, indicating that the strains were host-specific to ginseng. Phylogenetic trees were constructed based on sequences of the translation elongation factor 1-α (EF-1α) gene, two endopolygalacturonase genes (Pg1, Pg5) and two exopolygalacturonase genes (Pgx1 and Pgx4). The ten F. oxysporum isolates from ginseng clustered into a unique group clearly separated from other formae speciales already described. Based on the host range tests and phylogenetic analyses, the isolates of F. oxysporum derived from ginseng have been identified as a new forma specialis, designated Fusarium oxysporum f. sp. ginseng. This is the first report of forma specialis of F. oxysporum on ginseng.
人参是一种珍贵的药用植物，在长期栽培过程中受到多种病害的侵袭。人参根腐病是由尖孢镰刀菌引起的一种严重病害。这种土传病原体根据宿主的特异性包括许多不同的形式。10株有代表性的人参腐根病原菌对人参具有致病性。为了鉴定尖孢镰刀菌菌株的特殊形态，对9种植物进行了3株代表性菌株的寄主范围试验。所有三株菌株仅在人参上引起严重症状，但在其他8个宿主上仅引起轻微或没有视觉症状，表明菌株对人参具有宿主特异性。以翻译延伸因子1-α (EF-1α)基因、2个内聚半乳糖醛酸酶基因(Pg1、Pg5)和2个外聚半乳糖醛酸酶基因(Pgx1、Pgx4)序列为基础构建系统发育树。从人参中分离出的10株尖孢镰刀菌聚集成一个独特的类群，与前面所述的其他特殊类群明显分开。通过寄主范围测定和系统发育分析，确定了人参尖孢镰刀菌(Fusarium oxysporum F. sp. ginseng)为一种新的特殊菌种。本文首次报道了人参上尖孢霉的特殊形式。
{"title":"Fusarium oxysporum f. sp. ginseng, a new forma specialis causing Fusarium root rot of Panax ginseng","authors":"Jun Wang, Shi Feng, B. Lu, Lina NA YANG, Xue Wang, Yanjing Zhang, Jie Ying Gao","doi":"10.36253/phyto-13723","DOIUrl":"https://doi.org/10.36253/phyto-13723","url":null,"abstract":"Panax ginseng is a valuable medicinal plant which is affected by many diseases during its long cultivation period. Ginseng root rot, caused by Fusarium oxysporum, has become severe in China. This soilborne pathogen comprises many formae speciales based on host specificity. Ten representative isolates from diseased ginseng rot root showed pathogenicity on ginseng. To identify the forma specialis of the F. oxysporum strains, host range tests of three representative isolates were carried out on nine plant species. All three isolates caused severe symptoms only on ginseng, but only slight or no visual symptoms on the other eight hosts, indicating that the strains were host-specific to ginseng. Phylogenetic trees were constructed based on sequences of the translation elongation factor 1-α (EF-1α) gene, two endopolygalacturonase genes (Pg1, Pg5) and two exopolygalacturonase genes (Pgx1 and Pgx4). The ten F. oxysporum isolates from ginseng clustered into a unique group clearly separated from other formae speciales already described. Based on the host range tests and phylogenetic analyses, the isolates of F. oxysporum derived from ginseng have been identified as a new forma specialis, designated Fusarium oxysporum f. sp. ginseng. This is the first report of forma specialis of F. oxysporum on ginseng.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":"1 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41669665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sweet cherries (Prunus avium L.) are important as fruit crops, and can be affected by numerous viruses. An investigation on the occurrence of the three most common viruses of sweet cherry was carried out in commercially managed orchards in South Tyrol (Italy). The incidence of apple chlorotic leaf spot virus (ACLSV), Prunus necrotic ringspot virus (PNRSV) and prune dwarf virus (PDV) was investigated using enzyme-linked immunosorbent assays (ELISA) and the reverse transcriptase-polymerase chain reaction technique (RT-PCR) in spring 2018 and 2020, and during the summer and autumn of 2020. All three viruses were detected in the surveyed orchards. Comparative analyses showed that detection was more effective with RT-PCR than with ELISA, especially for detecting PNRSV and PDV. Mixed infections were detected in all the surveyed orchards. The results also showed clear differences between and during host growth periods, likely due to a variable virus concentration in the host trees.
{"title":"Occurrence of cherry viruses in South Tyrol (Italy) by comparing growth periods in two consecutive years","authors":"Evi Deltedesco, Magdalena Niedrist, S. Oettl","doi":"10.36253/phyto-12807","DOIUrl":"https://doi.org/10.36253/phyto-12807","url":null,"abstract":"Sweet cherries (Prunus avium L.) are important as fruit crops, and can be affected by numerous viruses. An investigation on the occurrence of the three most common viruses of sweet cherry was carried out in commercially managed orchards in South Tyrol (Italy). The incidence of apple chlorotic leaf spot virus (ACLSV), Prunus necrotic ringspot virus (PNRSV) and prune dwarf virus (PDV) was investigated using enzyme-linked immunosorbent assays (ELISA) and the reverse transcriptase-polymerase chain reaction technique (RT-PCR) in spring 2018 and 2020, and during the summer and autumn of 2020. All three viruses were detected in the surveyed orchards. Comparative analyses showed that detection was more effective with RT-PCR than with ELISA, especially for detecting PNRSV and PDV. Mixed infections were detected in all the surveyed orchards. The results also showed clear differences between and during host growth periods, likely due to a variable virus concentration in the host trees.","PeriodicalId":20165,"journal":{"name":"Phytopathologia Mediterranea","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48775764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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