Plant Pathology最新文献

{"title":"Resistance of pistachio grafted on different Pistacia rootstocks against Verticillium wilt under field conditions","authors":"Begoña I. Antón‐Domínguez, Octavio Arquero, María Lovera, Antonio Trapero, Carlos Agustí‐Brisach, Carlos Trapero","doi":"10.1111/ppa.13978","DOIUrl":"https://doi.org/10.1111/ppa.13978","url":null,"abstract":"Verticillium wilt of pistachio (<jats:italic>Pistacia vera</jats:italic>), caused by <jats:italic>Verticillium dahliae</jats:italic>, is one of the most important diseases in this crop. The most effective and economical control measure is the use of resistant rootstocks. The main objective of this work was to evaluate the resistance of five rootstocks commonly used in pistachio against the disease under field conditions. Pistachio plants (cv. Kerman) grafted on the rootstocks <jats:italic>Pistacia atlantica</jats:italic>, <jats:italic>Pistacia integerrima</jats:italic>, <jats:italic>Pistacia terebinthus</jats:italic> and cv. Platinum and UCBI hybrids, were planted in a field with high inoculum density of <jats:italic>V</jats:italic>. <jats:italic>dahliae</jats:italic> in the soil. Plants grafted on <jats:italic>P</jats:italic>. <jats:italic>terebinthus</jats:italic>, followed by <jats:italic>P</jats:italic>. <jats:italic>integerrima</jats:italic>, showed significantly higher disease severity values than the rest of the rootstocks almost 53 months after planting; also, plants grafted on <jats:italic>P</jats:italic>. <jats:italic>atlantica</jats:italic> were more resistant than those grafted on <jats:italic>P</jats:italic>. <jats:italic>integerrima</jats:italic>. These results highlighted the intraspecific variability in resistance to the disease. In addition, the disease was monitored in pistachios grafted onto <jats:italic>P</jats:italic>. <jats:italic>terebinthus</jats:italic> or UCBI in an established commercial field with three different zones of <jats:italic>V</jats:italic>. <jats:italic>dahliae</jats:italic> inoculum density in the soil (none, low or high). In the high‐density zone, the percentage of diseased plants was significantly lower for plants grafted on UCBI than for those grafted on <jats:italic>P</jats:italic>. <jats:italic>terebinthus</jats:italic>. The results indicate the importance of rootstock species and specific genotype or seed population used, concentration of <jats:italic>V</jats:italic>. <jats:italic>dahliae</jats:italic> inoculum in the soil, and previous history of crops on the plot, on the development of the disease under natural conditions.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"103 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141940498","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}

{"title":"Histological characterization of downy mildew infection in wild rocket (Diplotaxis tenuifolia)","authors":"Ana L. Pereira, Paula Scotti‐Campos, Paula S. Coelho","doi":"10.1111/ppa.13979","DOIUrl":"https://doi.org/10.1111/ppa.13979","url":null,"abstract":"Wild rocket downy mildew (DM), caused by oomycete <jats:italic>Hyaloperonospora</jats:italic> sp., is a widely spread disease reducing crop production and quality. New productive wild rocket varieties resistant to DM are crucial to control disease and ensure high quality leaves. A histological characterization of <jats:italic>Hyaloperonospora</jats:italic> sp. infection was performed in 11 wild rocket (<jats:italic>Diplotaxis tenuifolia</jats:italic>) accessions with contrasting DM responses (R, resistant; PR, partially resistant; S, susceptible). Samples of infected cotyledons, first and second leaves of 14‐day‐old seedlings were collected at 3, 6, 9, 21 and 24 h post‐inoculation (hpi) and 7 days post‐inoculation (dpi) and stained for appressoria and haustoria observation and tissue necrosis evaluation. Occurrence of appressoria on host surfaces was higher in leaves compared with cotyledons but unrelated with DM resistance response. Haustoria growth in mycelium was delayed in R accessions from 3 hpi, and signs of cell hypersensitivity reaction were observed at 9 hpi. At 24 hpi, necrotic spots limited pathogen growth in resistant accessions, whilst mycelium invaded larger mesophyll areas and produced more haustoria in susceptible ones. At 7 dpi, sporulation was heavy in S, restricted to droplet deposition sites in PR, and did not occur in R hosts. A rapid response of R accessions resulted in slower mycelium growth and longer infection periods. These traits have important agronomic value and should be considered in germplasm selection for breeding programmes aimed at crop protection. A better understanding of the host response to DM infection will allow selection of more suitable wild rocket accessions in future breeding programmes.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"79 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881136","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}

{"title":"Yellow rust infection of wheat: How the quantity of light received by wheat seedlings before inoculation affects infection efficiency","authors":"Camila M. Zanella, Ruth MacCormack, John Caulfield, Anna Gordon, Huw Jones, Amelia Hubbard, Lesley A. Boyd","doi":"10.1111/ppa.13977","DOIUrl":"https://doi.org/10.1111/ppa.13977","url":null,"abstract":"Many factors are known to influence infection by cereal rusts, including environmental variables such at light, humidity and temperature, the topography of the leaf surface, as well as plant volatiles. However, few studies have aimed to link these factors. Previously, the quantity of light received by wheat seedlings prior to inoculation with <jats:italic>Puccinia striiformis</jats:italic> f. sp. <jats:italic>tritici</jats:italic> (Pst) urediniospores was shown to influence yellow rust infection efficiency. In this study we show that germination and the ability of germlings (germinated urediniospores) to enter stomata is enhanced on wheat seedlings subjected to high quantities of light pre‐inoculation with Pst urediniospores, while on seedlings exposed to a long dark period germination and infection were compromised. Using headspace collections and gas chromatography–mass spectrometry (GC–MS) analysis thereof, we link this effect of high light quantity to quantitative changes in the profile of volatile organic compounds (VOCs). We show that the VOCs within headspace collections from wheat seedlings exposed to high quantities of light were able to support greater levels of Pst urediniospore germination than the headspace collections from wheat seedlings exposed to a period of dark. In vitro analysis of individual VOCs identified compounds that enhanced Pst urediniospore germination. These VOCs included the sesquiterpene caryophyllene, the monoterpene α‐pinene, the fatty acid α‐linolenic acid, the organic alcohols 1‐hexanol, 3‐hexen‐1‐ol and 5‐hexen‐1‐ol, the aldehyde <jats:italic>cis</jats:italic>‐3‐hexenal and the ester hexyl acetate.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"37 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141881139","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}

{"title":"Populations of Bemisia tabaci Mediterranean in São Paulo state are inefficient vectors of Brazilian begomoviruses","authors":"Angélica Maria Nogueira, Cíntia Sabino de Oliveira, Vinicius Henrique Bello, Gabriel Madoglio Favara, Eduardo Vicentin, Julio Massaharu Marubayashi, Caroline da Cruz Martines, Luis Fernando Maranho Watanabe, Tarsiane Mara Carneiro Barbosa, Daniel de Lima Alvarez, Regiane Cristina de Oliveira, Francisco Murilo Zerbini, Jorge Alberto Marques Rezende, Renate Krause‐Sakate","doi":"10.1111/ppa.13970","DOIUrl":"https://doi.org/10.1111/ppa.13970","url":null,"abstract":"Begomoviruses cause losses in several crops around the world. Whiteflies of the <jats:italic>Bemisia tabaci</jats:italic> cryptic species MEAM1 and MED are efficient vectors of begomoviruses. MEAM1 has been the predominant species in Brazil since the mid‐1990s. MED was detected in Brazil in 2014, and since then, high insect infestations have been reported, mainly in greenhouse production of solanaceous crops. In this study, we compared the transmission efficiency of the begomoviruses tomato severe rugose virus (ToSRV) and tomato rugose mosaic virus (ToRMV) to tomato (<jats:italic>Solanum lycopersicum</jats:italic>) and bean golden mosaic virus (BGMV) to common bean (<jats:italic>Phaseolus vulgaris</jats:italic>) by a population of MEAM1 and four populations of MED. <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MEAM1 efficiently transmitted ToSRV and ToRMV to tomato and BGMV to common bean. <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MED populations did not transmit ToSRV and ToRMV to tomato. Only one population of <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MED transmitted BGMV with an efficiency of 3%. PCR analysis indicated that <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MED can acquire ToSRV, ToRMV and BGMV after a 24 h acquisition access period. Furthermore, some greenhouse tomato plantings from São Paulo state were surveyed for the presence of viruses and whiteflies, and <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MED were predominant, whereas begomoviruses were absent. Our results demonstrate that populations of MED from São Paulo state are inefficient vectors of begomoviruses, being able to acquire the virus but not transmit it to plants. Understanding this interaction is important and suggests that the spread of <jats:italic>B</jats:italic>. <jats:italic>tabaci</jats:italic> MED could change the epidemiological scenario of begomoviruses in areas where this insect predominates.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"50 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871079","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}

{"title":"Exploring the role of cultivar, year and plot age in the incidence of esca and Eutypa dieback: Insights from 20 years of regional surveys in France","authors":"Lucas Etienne, Frédéric Fabre, Davide Martinetti, Elise Frank, Lucie Michel, Valérie Bonnardot, Lucia Guérin‐Dubrana, Chloé E. L. Delmas","doi":"10.1111/ppa.13975","DOIUrl":"https://doi.org/10.1111/ppa.13975","url":null,"abstract":"Grapevine trunk diseases cause yield losses and vine mortality in vineyards worldwide. However, there have been few quantitative studies evaluating grapevine dieback on a large spatial and temporal scale. Here, we consolidated and standardized databases from the 13 main wine regions of France, compiling records of leaf symptoms associated with esca and Eutypa dieback from 2082 plots and 36 cultivars over a 20‐year period. This large dataset was used (a) for quantitative analysis of the prevalence (number of plots with at least one symptomatic plant) and incidence (percentage of symptomatic plants) of esca and Eutypa dieback; and (b) to decipher the effects of cultivar, year and plot age on both the prevalence and incidence of esca leaf symptoms by temporal Bayesian modelling. Esca was present on a mean of 74 ± 2% plots annually, with an incidence of 3.1 ± 0.1%. Eutypa dieback occurred in 41 ± 3% of the plots, with an incidence of 1.4 ± 0.1%. Our modelling approach revealed that the cultivar had a significant impact on the prevalence of esca, but not on its incidence when prevalence is greater than zero. Esca prevalence remained stable, whereas esca incidence was higher than the mean value in six of the years after 2012. We also found a significant non‐linear effect of plot age, with 10‐ to 30‐year‐old plots significantly more susceptible, depending on the cultivar. This study clearly illustrates the importance of considering extensive and continuous monitoring to improve our understanding of the impact and evolution of crop diseases.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"49 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871102","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}

{"title":"Multistress‐tolerant Pseudomonas aeruginosa SSVP3 uses multiple strategies to control Meloidogyne incognita in tomato","authors":"Vikram Poria, Prakriti Jhilta, K. P. Adhuna, Vishal S. Somvanshi, Anuj Rana, Surender Singh","doi":"10.1111/ppa.13974","DOIUrl":"https://doi.org/10.1111/ppa.13974","url":null,"abstract":"Tomato is the most important horticultural crop, and India is its second largest producer; however, the plant‐pathogenic nematode <jats:italic>Meloidogyne incognita</jats:italic> is a serious pest of tomato, causing detrimental losses in its production. This study is focused on the use of multistress‐tolerant <jats:italic>Pseudomonas aeruginosa</jats:italic> SSVP3 to control this devastating nematode and attempts to decipher the roles of its metabolites and volatile organic compounds (VOCs) during this interaction. The supernatant of <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> SSVP3 caused 58% mortality in <jats:italic>M</jats:italic>. <jats:italic>incognita</jats:italic> J2 juveniles. The major nematicidal metabolites, identified using liquid chromatography‐mass spectrometry, were pyocyanin, pyoluteorin, pyochelin, benthocyanin and phenazines. The VOCs secreted by <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> SSVP3, which were identified via gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) in a mixture, caused 98% mortality in <jats:italic>M</jats:italic>. <jats:italic>incognita</jats:italic> J2 juveniles. In a pot experiment, seedling root treatment with <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> SSVP3 activated the induced systemic response in tomato plants to <jats:italic>M</jats:italic>. <jats:italic>incognita</jats:italic> by increasing the activity of defence and antioxidant enzymes as well as the proline and phenolic contents. The malondialdehyde content in <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> SSVP3‐treated plants decreased as compared to those in the other treatment groups. The number of galls formed and the number of endoparasitic stages of <jats:italic>M</jats:italic>. <jats:italic>incognita</jats:italic> in the untreated nematode control plants were much greater (19 and 35) than those in the <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> SSVP3‐treated (0.33 and 1) and chemically treated groups (0.67 and 1.33). These results indicate that <jats:italic>P</jats:italic>. <jats:italic>aeruginosa</jats:italic> and its secreted metabolites and VOCs have a high potential for controlling nematodes.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"77 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745585","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}

{"title":"Detection of tomato brown rugose fruit virus in environmental residues: The importance of contextualizing test results","authors":"Anne K. J. Giesbers, Elise Vogel, Anna Skelton, Zafeiro Zisi, Mandy Wildhagen, Yue Lin Loh, Lucas Ghijselings, Johanne Groothuismink, Marcel Westenberg, Jelle Matthijnssens, Annelien Roenhorst, Christine Vos, Adrian Fox, Marleen Botermans","doi":"10.1111/ppa.13968","DOIUrl":"https://doi.org/10.1111/ppa.13968","url":null,"abstract":"Tomato brown rugose fruit virus (ToBRFV) is regulated as a quarantine pest in many countries worldwide. To assess whether ToBRFV is present in cultivations, plants or seed lots, testing is required. The interpretation of test results, however, can be challenging. Reverse transcription‐quantitative (real‐time) PCR results, even though considered “positive”, may not always signify plant infection or indicate the presence of infectious virus, but could be due to the presence of viral residues in the environment. Here, case studies from the Netherlands, Belgium, and the United Kingdom address questions regarding the detection of ToBRFV in various settings, and the infectiousness of ToBRFV‐positive samples. These exploratory analyses demonstrate widespread detection of ToBRFV in diverse samples and environments. ToBRFV was detected inside and around greenhouses with no prior history of ToBRFV infection, and on different materials and surfaces, including those that were untouched by individuals, plants or objects. This suggested the dispersal of viral residues through aerosols. ToBRFV or its residues were more often detected in regions with nearby tomato production, yet were also found in a wider environment extending beyond infected crops. ToBRFV originating from environmental contamination may or may not be infectious, adding complexity to decision‐making in response to positive test results. Contextual information, such as the origin of the sample and the likelihood of residues from prior cultivations and/or the broader environment, is important for interpreting test results. A nuanced approach is crucial to correctly interpret ToBRFV test results, necessitating further research to support risk assessment.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"872 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141720169","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}

{"title":"Investigating weather variables driving boxwood blight epidemics: Insights from field trials with Buxus sempervirens ‘Suffruticosa’ in northern Germany between 2006 and 2020","authors":"Ihsanul Khaliq, Thomas Brand, Margery Daughtrey, Ping Kong, Chuanxue Hong","doi":"10.1111/ppa.13969","DOIUrl":"https://doi.org/10.1111/ppa.13969","url":null,"abstract":"Boxwood blight is a highly invasive disease, but studies on host–pathogen–environment interactions are rare because the initial research emphasis has been on developing resistant cultivars and chemical control of the disease. We used generalized additive models to investigate weather variables driving boxwood blight epidemics in field trials conducted between 2006 and 2020. Briefly, three or four replicate rows with 10 boxwood plants per row were planted in 0.75 m<jats:sup>2</jats:sup> plots. Plants were artificially inoculated in 2006, while those in subsequent years were naturally infected with inoculum left over from previous trials. Disease severity was assessed by estimating the percentage of leaves blighted, including fallen leaves. There was a significant positive main effect of mean rainfall per rainy day, daily minimum temperatures and daily minimum relative humidity on disease severity observed over individual field trial periods. There was a significant negative interaction effect of mean rainfall per rainy day and daily maximum wind speed, and daily minimum relative humidity and daily minimum temperature on disease severity. Higher disease severity was associated with higher mean rainfall per rainy day and lower daily maximum wind speed. Likewise, an increase in daily minimum relative humidity at lower daily minimum temperatures was associated with a greater increase in disease severity than at higher temperatures, suggesting that higher temperatures resulted in lower humidity that led, in turn, to less disease severity. The implications of our findings for forecasting models and conservation of boxwood are discussed.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"34 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141614072","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}

{"title":"Glycine tabacina, native to Australia, is an alternate host of Erysiphe diffusa causing powdery mildew on soybean","authors":"Lisa A. Kelly, Aftab Ahmad, Buddhika A. Dahanayaka, John D. W. Dearnaley, Niloofar Vaghefi, Levente Kiss","doi":"10.1111/ppa.13971","DOIUrl":"https://doi.org/10.1111/ppa.13971","url":null,"abstract":"Powdery mildew, caused by <jats:italic>Erysiphe diffusa</jats:italic>, is an emerging pathogen in Australian soybean crops. Since its initial detection in 2012, the disease has been observed every season in soybean paddocks throughout Australia. It is not known how <jats:italic>E</jats:italic>. <jats:italic>diffusa</jats:italic> survives between soybean cropping seasons in the Australian environment. This study identified the native <jats:italic>Glycine</jats:italic> species, <jats:italic>G. tabacina</jats:italic>, as an alternate host for <jats:italic>E</jats:italic>. <jats:italic>diffusa</jats:italic> in Australia. <jats:italic>G. tabacina</jats:italic> specimens naturally infected with powdery mildew were collected and the pathogen was identified based on morphological characters and nrDNA ITS and <jats:italic>MCM7</jats:italic> sequences. Cross‐inoculation experiments demonstrated that the <jats:italic>E</jats:italic>. <jats:italic>diffusa</jats:italic> isolates infecting <jats:italic>G. tabacina</jats:italic> in the field were pathogenic to soybean. This study is the first to report <jats:italic>E</jats:italic>. <jats:italic>diffusa</jats:italic> on <jats:italic>G. tabacina</jats:italic> in Australia. As a perennial native often found in the vicinity of the annual soybean crops, <jats:italic>G. tabacina</jats:italic> can easily serve as an alternate host for <jats:italic>E</jats:italic>. <jats:italic>diffusa</jats:italic> and could be an example of a host range expansion in this powdery mildew species. Weed control in soybean crops, with special attention to the removal of the native <jats:italic>Glycine</jats:italic> species, may be an option for powdery mildew management for Australian soybean growers.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"17 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141614842","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}

{"title":"Frequency of avirulence genes and race structure in a Leptosphaeria maculans population in Tunisia","authors":"Essia Maghrebi, Birger Koopmann, Julius Sander, Hanene Chaabane, Bochra Amina Bahri","doi":"10.1111/ppa.13958","DOIUrl":"https://doi.org/10.1111/ppa.13958","url":null,"abstract":"Blackleg, caused by <jats:italic>Leptosphaeria maculans</jats:italic>, is a major oilseed rape disease present in many traditional growing regions worldwide and is also becoming increasingly important in Tunisia. Cultivation of oilseed rape varieties harbouring major blackleg resistance genes (R‐genes) in an integrated approach represents the most effective means of controlling this fungal threat; knowledge of the pathogen population structure is a prerequisite for its efficient use. <jats:italic>Leptosphaeria</jats:italic> spp. isolates (145) were collected and characterized during 2018–2020 from oilseed rape stubble originating from seven northern Tunisian regions. As in most other growing areas, <jats:italic>L</jats:italic>. <jats:italic>maculans</jats:italic> and <jats:italic>L</jats:italic>. <jats:italic>biglobosa</jats:italic> occurred together on diseased plants. Most isolates (78.6%, <jats:italic>n</jats:italic> = 114) were <jats:italic>L</jats:italic>. <jats:italic>maculans</jats:italic>. For those, a combination of differential set phenotyping and PCR‐based avirulence gene analyses was used to perform race typing. Overall, 30 races were identified, carrying at least two and up to eight of the 11 avirulence genes tested. The most predominant race (14.9%) carried <jats:italic>AvrLm7</jats:italic>, <jats:italic>AvrLepR1</jats:italic> and <jats:italic>AvrLepR2</jats:italic> and was detected each year and in six out of the seven regions sampled, indicating the effectiveness of major R‐genes <jats:italic>Rlm7</jats:italic> and <jats:italic>LepR1</jats:italic> in Tunisia. <jats:italic>Rlm2</jats:italic> was overcome by all Tunisian <jats:italic>L</jats:italic>. <jats:italic>maculans</jats:italic> isolates, but most were avirulent on <jats:italic>Rlm6</jats:italic> and <jats:italic>LepR2</jats:italic> (&gt;50%), suggesting that using these R‐genes would provide protection in Tunisia. Both mating types were identified, with MAT1‐2 being twice as frequent as MAT1‐1. These results endorse the need for regular race surveillance of the local pathogen population at temporal and regional scales to develop appropriate blackleg management strategies.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"70 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141571537","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}