Rocío Medina, Mario E. E. Franco, Laura C. Bartel, Cesar G. Lucentini, Silvina M. Y. López Diaz, Mario C. N. Saparrat, Pedro A. Balatti
Tomato grey leaf spot is a fungal disease that provokes losses in tomato yield. The aim of this work is to analyse genomic differences among three isolates of Stemphylium lycopersici that differ in virulence and sporulation. The bioinformatics analysis led us to predict the identity of putative effectors, pathogenesis and virulence factors. Like the genome of other necrotrophic pathogens, Stemphylium encodes a wide spectrum of effectors, including an ample and diverse array of carbohydrate-degrading enzymes. Interestingly, the number of predicted effectors was unrelated to virulence. Low virulence appeared to be associated with the presence of several double-stranded RNAs from viruses as well as cellular processes related to protein degradation, redox and detoxifying processes and monoterpenes production. This is the first identification of the potential effectors of tomato–S. lycopersici interaction; nonetheless functional studies should be done.
{"title":"Genome analysis of three isolates of Stemphylium lycopersici differ in their virulence and sporulation ability: Identification of effectors, pathogenesis and virulence factors","authors":"Rocío Medina, Mario E. E. Franco, Laura C. Bartel, Cesar G. Lucentini, Silvina M. Y. López Diaz, Mario C. N. Saparrat, Pedro A. Balatti","doi":"10.1111/ppa.13878","DOIUrl":"https://doi.org/10.1111/ppa.13878","url":null,"abstract":"Tomato grey leaf spot is a fungal disease that provokes losses in tomato yield. The aim of this work is to analyse genomic differences among three isolates of <i>Stemphylium lycopersici</i> that differ in virulence and sporulation. The bioinformatics analysis led us to predict the identity of putative effectors, pathogenesis and virulence factors. Like the genome of other necrotrophic pathogens, <i>Stemphylium</i> encodes a wide spectrum of effectors, including an ample and diverse array of carbohydrate-degrading enzymes. Interestingly, the number of predicted effectors was unrelated to virulence. Low virulence appeared to be associated with the presence of several double-stranded RNAs from viruses as well as cellular processes related to protein degradation, redox and detoxifying processes and monoterpenes production. This is the first identification of the potential effectors of tomato–<i>S</i>. <i>lycopersici</i> interaction; nonetheless functional studies should be done.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"75 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139917783","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}
Phrasia Mapfumo, Sikelela Buthelezi, Emma Archer, Dirk Z. H. Swanevelder, P. Markus Wilken, Nicky Creux
Sclerotinia head rot, caused by Sclerotinia sclerotiorum, is a major disease limiting sunflower production in tropical and subtropical agroecological zones. Sporadic outbreaks across South Africa have resulted in major losses, yet little is known about the in-field climatic factors driving this infection. Short-interval, staggered plantings have been proposed as a control method for Sclerotinia head rot, which help to limit the number of plants in a susceptible developmental stage during conducive environmental conditions. However, this complicates field management practices, especially if working at the fringes of a planting window due to delayed rains. This study aimed to investigate the effect of planting date on Sclerotinia head rot progression in monthly plantings across the summer period. Artificial mycelial plug inoculations were performed at the R5.9 flowering stage in an open field. Disease establishment, progression and severity were monitored at 3-day intervals for 30 days. We show that disease establishment was delayed by low relative humidity or extreme low temperatures in the January and March planting dates where the first lesions were only observed 6 days post-inoculation. Consistently high temperatures above 27°C also suppressed disease progression and produced low area under the disease progress curve (AUDPC) scores of 75.15 and 29.4 for the October and November planting dates, respectively. These findings suggest that regardless of season or location, selecting a planting date that ensures the sunflower bloom period aligns with the hottest, driest part of the season will probably suppress Sclerotinia head rot in regions with average summer highs above 27°C.
{"title":"In-field climatic factors driving Sclerotinia head rot progression across different sunflower planting dates","authors":"Phrasia Mapfumo, Sikelela Buthelezi, Emma Archer, Dirk Z. H. Swanevelder, P. Markus Wilken, Nicky Creux","doi":"10.1111/ppa.13873","DOIUrl":"https://doi.org/10.1111/ppa.13873","url":null,"abstract":"Sclerotinia head rot, caused by <i>Sclerotinia sclerotiorum</i>, is a major disease limiting sunflower production in tropical and subtropical agroecological zones. Sporadic outbreaks across South Africa have resulted in major losses, yet little is known about the in-field climatic factors driving this infection. Short-interval, staggered plantings have been proposed as a control method for Sclerotinia head rot, which help to limit the number of plants in a susceptible developmental stage during conducive environmental conditions. However, this complicates field management practices, especially if working at the fringes of a planting window due to delayed rains. This study aimed to investigate the effect of planting date on Sclerotinia head rot progression in monthly plantings across the summer period. Artificial mycelial plug inoculations were performed at the R5.9 flowering stage in an open field. Disease establishment, progression and severity were monitored at 3-day intervals for 30 days. We show that disease establishment was delayed by low relative humidity or extreme low temperatures in the January and March planting dates where the first lesions were only observed 6 days post-inoculation. Consistently high temperatures above 27°C also suppressed disease progression and produced low area under the disease progress curve (AUDPC) scores of 75.15 and 29.4 for the October and November planting dates, respectively. These findings suggest that regardless of season or location, selecting a planting date that ensures the sunflower bloom period aligns with the hottest, driest part of the season will probably suppress Sclerotinia head rot in regions with average summer highs above 27°C.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"40 1 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750608","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}
Matthew A. Back, Luís Bonifácio, Maria L. Inácio, Manuel Mota, Eric Boa
Pines are the most economically important trees in the world and, together with eucalyptus, they dominate commercial forests. But the success of a relatively small number of widely planted species, such as Pinus pinaster, the maritime pine, comes at a price. Pines are attractive to damaging pathogens and insect pests, including the pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). Originally described in Japan, PWD has caused widespread destruction to forests in countries such as China, Taiwan, Portugal, Spain and the United States. PWN causes irreparable damage to the vascular system of its pine hosts, leading to mortality within 3 months. Pine sawyer beetles (Monochamus spp.) are key vectors of PWD, introducing the PWN to healthy trees during feeding. Other organisms contribute to PWD spread and development, including bacteria, fungi and bark beetles. Control measures include tree felling to prevent vector transmission of PWN, insecticide treatments, trapping of Monochamus spp. and tree breeding for plant resistance. The PWN is a quarantine pathogen and subject to regular legislation and phytosanitary measures aimed at restricting movement and preventing introduction to new areas. Current research is investigating the use of biopesticides against PWN and Monochamus spp. This review examines the biology, epidemiology, impact and management of PWD through published research, grey literature and interviews with people directly involved in the management of the disease in Portugal.
{"title":"Pine wilt disease: A global threat to forestry","authors":"Matthew A. Back, Luís Bonifácio, Maria L. Inácio, Manuel Mota, Eric Boa","doi":"10.1111/ppa.13875","DOIUrl":"https://doi.org/10.1111/ppa.13875","url":null,"abstract":"Pines are the most economically important trees in the world and, together with eucalyptus, they dominate commercial forests. But the success of a relatively small number of widely planted species, such as <i>Pinus pinaster</i>, the maritime pine, comes at a price. Pines are attractive to damaging pathogens and insect pests, including the pinewood nematode (PWN), <i>Bursaphelenchus xylophilus</i>, the causal agent of pine wilt disease (PWD). Originally described in Japan, PWD has caused widespread destruction to forests in countries such as China, Taiwan, Portugal, Spain and the United States. PWN causes irreparable damage to the vascular system of its pine hosts, leading to mortality within 3 months. Pine sawyer beetles (<i>Monochamus</i> spp.) are key vectors of PWD, introducing the PWN to healthy trees during feeding. Other organisms contribute to PWD spread and development, including bacteria, fungi and bark beetles. Control measures include tree felling to prevent vector transmission of PWN, insecticide treatments, trapping of <i>Monochamus</i> spp. and tree breeding for plant resistance. The PWN is a quarantine pathogen and subject to regular legislation and phytosanitary measures aimed at restricting movement and preventing introduction to new areas. Current research is investigating the use of biopesticides against PWN and <i>Monochamus</i> spp. This review examines the biology, epidemiology, impact and management of PWD through published research, grey literature and interviews with people directly involved in the management of the disease in Portugal.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"198 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750600","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}
Nam Q. Pham, Hiroyuki Suzuki, Tuan A. Duong, Brenda D. Wingfield, Irene Barnes, Alvaro Durán, Michael J. Wingfield
Eucalyptus scab and shoot malformation is an emerging disease and a serious threat to the global plantation forestry industry. The disease appeared in North Sumatra (Indonesia) in the early 2010s and the causal agent was recently described as a novel species, Elsinoe necatrix. Nothing is known regarding its possible origin or why it emerged rapidly to cause a serious local epidemic. To investigate its population biology, we developed 15 polymorphic microsatellite markers as well as mating-type markers using genome sequences for two E. necatrix isolates. Isolates of the pathogen were collected from different host varieties at four locations in the Lake Toba region of North Sumatra and characterized using these markers. A high level of genotypic diversity was observed for all populations with little to no genetic differentiation between sampling areas. Discriminant analysis of principal components, genotype networks and analysis of molecular variance all showed a lack of population structure and a high level of gene flow among sampling regions. Mating-type ratios and linkage disequilibrium analyses suggest that sexual recombination is likely to be occurring, although a sexual state has not been found for the pathogen. The results of this study highlight the fact that new genotypes of E. necatrix, probably arising from cryptic sexual recombination, will challenge efforts to manage the disease, and that breeding and selection for tolerance will require substantial host genetic diversity.
桉树疮痂病和嫩枝畸形是一种新出现的病害，对全球人工林产业构成严重威胁。该病害于 2010 年代初出现在北苏门答腊（印度尼西亚），病原体最近被描述为一种新物种 Elsinoe necatrix。关于其可能的起源或为何迅速出现并在当地引起严重流行，目前尚无定论。为了研究其种群生物学特性，我们开发了 15 个多态性微卫星标记，并利用两个 E. necatrix 分离物的基因组序列开发了交配型标记。我们从北苏门答腊岛多巴湖地区四个地点的不同寄主品种中收集了病原体分离物，并利用这些标记对其进行了鉴定。所有种群的基因型多样性都很高，取样地区之间几乎没有遗传差异。主成分判别分析、基因型网络和分子方差分析都表明，采样区域之间缺乏种群结构，基因流动程度较高。交配型比率和连锁不平衡分析表明，虽然尚未发现病原体的有性状态，但有性重组可能正在发生。这项研究的结果突显了一个事实，即可能由隐性基因重组产生的新的 E. necatrix 基因型将对管理该疾病的工作提出挑战，而育种和选择耐受性将需要大量的宿主遗传多样性。
{"title":"Cryptic sexual reproduction in an emerging Eucalyptus shoot and foliar pathogen","authors":"Nam Q. Pham, Hiroyuki Suzuki, Tuan A. Duong, Brenda D. Wingfield, Irene Barnes, Alvaro Durán, Michael J. Wingfield","doi":"10.1111/ppa.13876","DOIUrl":"https://doi.org/10.1111/ppa.13876","url":null,"abstract":"Eucalyptus scab and shoot malformation is an emerging disease and a serious threat to the global plantation forestry industry. The disease appeared in North Sumatra (Indonesia) in the early 2010s and the causal agent was recently described as a novel species, <i>Elsinoe necatrix</i>. Nothing is known regarding its possible origin or why it emerged rapidly to cause a serious local epidemic. To investigate its population biology, we developed 15 polymorphic microsatellite markers as well as mating-type markers using genome sequences for two <i>E. necatrix</i> isolates. Isolates of the pathogen were collected from different host varieties at four locations in the Lake Toba region of North Sumatra and characterized using these markers. A high level of genotypic diversity was observed for all populations with little to no genetic differentiation between sampling areas. Discriminant analysis of principal components, genotype networks and analysis of molecular variance all showed a lack of population structure and a high level of gene flow among sampling regions. Mating-type ratios and linkage disequilibrium analyses suggest that sexual recombination is likely to be occurring, although a sexual state has not been found for the pathogen. The results of this study highlight the fact that new genotypes of <i>E. necatrix</i>, probably arising from cryptic sexual recombination, will challenge efforts to manage the disease, and that breeding and selection for tolerance will require substantial host genetic diversity.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"25 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750810","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}
Desmond Darko Asiedu, Félicien Akohoue, Sebastian Frank, Silvia Koch, Bärbel Lieberherr, Benedict Oyiga, Bettina Kessel, Thomas Presterl, Thomas Miedaner
Fusarium stalk rot (FSR) is among the most destructive maize diseases causing significant global yield losses. Resistance of 22 maize hybrids to FSR was tested using four inoculation methods in each of two locations in 2021 and 2022. The inoculation methods included needle injection (NI), toothpick method (TM), stick method (SM) and mycelium method (MM), and the inoculated fungi were Fusarium culmorum, F. graminearum and F. temperatum. NI displayed the highest FSR infection among maize hybrids followed by TM and SM. MM showed the least infection. From five stalk rot-related traits, full-length infection and internode proportion, that is, the percentage of visible infection summed up over internodes, captured most of the genetic variation. The latter was the trait with the highest heritability (0.90). No significant (p > 0.05) genotype × method and genotype × fungus interaction variances were observed for any traits. For F. graminearum inoculation, NI showed the highest internode proportion followed by TM and SM, with F. culmorum responding in a similar way. For F. temperatum, TM outranked all other methods. F. graminearum was the most aggressive fungal pathogen compared to F. culmorum and F. temperatum. For phenotyping maize lines with varying degrees of resistance to FSR, we recommend needle injection and internode proportion.
{"title":"Comparison of four inoculation methods and three Fusarium species for phenotyping stalk rot resistance among 22 maize hybrids (Zea mays)","authors":"Desmond Darko Asiedu, Félicien Akohoue, Sebastian Frank, Silvia Koch, Bärbel Lieberherr, Benedict Oyiga, Bettina Kessel, Thomas Presterl, Thomas Miedaner","doi":"10.1111/ppa.13874","DOIUrl":"https://doi.org/10.1111/ppa.13874","url":null,"abstract":"Fusarium stalk rot (FSR) is among the most destructive maize diseases causing significant global yield losses. Resistance of 22 maize hybrids to FSR was tested using four inoculation methods in each of two locations in 2021 and 2022. The inoculation methods included needle injection (NI), toothpick method (TM), stick method (SM) and mycelium method (MM), and the inoculated fungi were <i>Fusarium culmorum</i>, <i>F. graminearum</i> and <i>F</i>. <i>temperatum</i>. NI displayed the highest FSR infection among maize hybrids followed by TM and SM. MM showed the least infection. From five stalk rot-related traits, full-length infection and internode proportion, that is, the percentage of visible infection summed up over internodes, captured most of the genetic variation. The latter was the trait with the highest heritability (0.90). No significant (<i>p</i> > 0.05) genotype × method and genotype × fungus interaction variances were observed for any traits. For <i>F</i>. <i>graminearum</i> inoculation, NI showed the highest internode proportion followed by TM and SM, with <i>F</i>. <i>culmorum</i> responding in a similar way. For <i>F</i>. <i>temperatum</i>, TM outranked all other methods. <i>F</i>. <i>graminearum</i> was the most aggressive fungal pathogen compared to <i>F</i>. <i>culmorum</i> and <i>F</i>. <i>temperatum</i>. For phenotyping maize lines with varying degrees of resistance to FSR, we recommend needle injection and internode proportion.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"6 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139750606","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}
Cereals are some of the most important global crops that contribute directly and indirectly to the production of food for human consumption. Cereal aphids can cause significant damage to wheat, barley and oats, particularly via the transmission of plant viruses that cause devastating plant diseases, such as yellow dwarf disease. High levels of yellow dwarf disease can result in yield losses of around 20%, rising to 80% if infection is severe. Yellow dwarf disease is caused by multiple viruses, including viruses within the families Tombusviridae and Solemoviridae. These include yellow dwarf virus species within the genus Luteovirus (Barley yellow dwarf virus) and Polerovirus (Cereal yellow dwarf virus, Wheat yellow dwarf virus, Maize yellow dwarf virus). Some yellow dwarf virus species are primarily vectored by one aphid species whereas others can be transmitted by multiple vectors. Biological diversity within a given vector species (e.g., genotype, biotype) can influence virus transmission efficiency. However, it is unclear what biological factors drive this variation within a given vector species. Understanding how biological variation in vector populations influences virus transmission efficiency can help to identify biological traits that underpin successful transmission in competent vector populations. Here, the available literature on yellow dwarf virus transmission efficiency is synthesized and significant variation in yellow dwarf virus transmission efficiency is detected between different populations for several vector species. Three biological mechanisms that potentially underpin this variation are proposed.
{"title":"How does vector diversity influence the transmission efficiency of yellow dwarf virus? Perspectives from a review","authors":"Daniel J. Leybourne","doi":"10.1111/ppa.13871","DOIUrl":"https://doi.org/10.1111/ppa.13871","url":null,"abstract":"Cereals are some of the most important global crops that contribute directly and indirectly to the production of food for human consumption. Cereal aphids can cause significant damage to wheat, barley and oats, particularly via the transmission of plant viruses that cause devastating plant diseases, such as yellow dwarf disease. High levels of yellow dwarf disease can result in yield losses of around 20%, rising to 80% if infection is severe. Yellow dwarf disease is caused by multiple viruses, including viruses within the families <i>Tombusviridae</i> and <i>Solemoviridae</i>. These include yellow dwarf virus species within the genus <i>Luteovirus</i> (<i>Barley yellow dwarf virus</i>) and <i>Polerovirus</i> (<i>Cereal yellow dwarf virus</i>, <i>Wheat yellow dwarf virus</i>, <i>Maize yellow dwarf virus</i>). Some yellow dwarf virus species are primarily vectored by one aphid species whereas others can be transmitted by multiple vectors. Biological diversity within a given vector species (e.g., genotype, biotype) can influence virus transmission efficiency. However, it is unclear what biological factors drive this variation within a given vector species. Understanding how biological variation in vector populations influences virus transmission efficiency can help to identify biological traits that underpin successful transmission in competent vector populations. Here, the available literature on yellow dwarf virus transmission efficiency is synthesized and significant variation in yellow dwarf virus transmission efficiency is detected between different populations for several vector species. Three biological mechanisms that potentially underpin this variation are proposed.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"9 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139669258","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}
Ignacio A. Erreguerena, Peter N. Hoebe, Marcelo A. Carmona, Eduardo Guillín, Neil D. Havis
Ramularia collo-cygni (Rcc) is a major barley pathogen that causes yield and grain quality losses worldwide. The main sources of Rcc inoculum are the seed and asexual airborne spores. In Argentina, Rcc is considered to be an emerging threat to barley crops, especially as most varieties are susceptible to Rcc and have a European genetic background. Here, we describe the population genetic diversity and structure of the Argentinian Rcc population, based on 10 simple-sequence repeat (SSR) markers, in order to compare it with Rcc populations from the Czech Republic and Scotland. The Argentinian Rcc population showed lower genetic diversity, higher level of structuring and higher number of clonal isolates than European populations. Significant differentiation at population origin (country) and region (Europe and South America) level suggests the occurrence of a genetic bottleneck and/or a founder effect on Rcc entry to Argentina and that this population could still be in a state of establishment and emergence. Further research on Rcc genetic structure at local and global scale will be crucial for the understanding of Rcc population dynamics for disease management.
{"title":"Comparative analysis of Argentinian and European populations of Ramularia collo-cygni on barley","authors":"Ignacio A. Erreguerena, Peter N. Hoebe, Marcelo A. Carmona, Eduardo Guillín, Neil D. Havis","doi":"10.1111/ppa.13872","DOIUrl":"https://doi.org/10.1111/ppa.13872","url":null,"abstract":"<i>Ramularia collo-cygni</i> (Rcc) is a major barley pathogen that causes yield and grain quality losses worldwide. The main sources of Rcc inoculum are the seed and asexual airborne spores. In Argentina, Rcc is considered to be an emerging threat to barley crops, especially as most varieties are susceptible to Rcc and have a European genetic background. Here, we describe the population genetic diversity and structure of the Argentinian Rcc population, based on 10 simple-sequence repeat (SSR) markers, in order to compare it with Rcc populations from the Czech Republic and Scotland. The Argentinian Rcc population showed lower genetic diversity, higher level of structuring and higher number of clonal isolates than European populations. Significant differentiation at population origin (country) and region (Europe and South America) level suggests the occurrence of a genetic bottleneck and/or a founder effect on Rcc entry to Argentina and that this population could still be in a state of establishment and emergence. Further research on Rcc genetic structure at local and global scale will be crucial for the understanding of Rcc population dynamics for disease management.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"27 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139659010","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}
Juliana Ferreira de Mello, Ana Carla da Silva Santos, Amanda Cupertino de Queiroz Brito, José Vitorino da Silva Neto, Ana Elisa de Almeida Souza, Antônio Félix da Costa, André Angelo Medeiros Gomes, Cristina Maria de Souza-Motta, Ueder Pedro Lopes, Alexandre Reis Machado
The sweet potato is of great socioeconomic importance in Brazil and throughout the world. Among the fungal pathogens associated with root diseases of this crop, Fusarium is of particular importance due to the diversity of species, the pathogenic potential in their various hosts and their ability to survive inside plants as endophytes without apparently causing damage. The objective of this work was to identify fusarioid genera from stems and roots of symptomatic and asymptomatic plants. The identification of fungal species was based on multilocus phylogenetic analysis and morphology. A total of 51 isolates, distributed in the Fusarium incarnatum-equiseti species complex (FIESC), Fusarium fujikuroi species complex (FFSC), Fusarium oxysporum species complex (FOSC)—with a taxonomic novelty—and Neocosmospora were identified. The pathogenicity test on roots showed that 13 of the 14 tested isolates obtained from symptomatic roots and stems and from asymptomatic stems were capable of reproducing the rot symptoms observed in the field. The confirmation of the pathogenicity of isolates from asymptomatic stems corroborates the hypothesis that these fungi can live endophytically in asymptomatic tissue and are capable of causing damage to their hosts in stress situations. This is the first report of Fusarium agrestense, Fusarium annulatum, Fusarium caatingaense, Fusarium elaeidis, Fusarium pernambucanum, Fusarium pseudocircinatum, Neocosmospora falciformis and Neocosmospora suttoniana associated with root and stem rot of sweet potato.
{"title":"Species diversity of fusarioid genera associated with sweet potato in Brazil, including the description of a new species","authors":"Juliana Ferreira de Mello, Ana Carla da Silva Santos, Amanda Cupertino de Queiroz Brito, José Vitorino da Silva Neto, Ana Elisa de Almeida Souza, Antônio Félix da Costa, André Angelo Medeiros Gomes, Cristina Maria de Souza-Motta, Ueder Pedro Lopes, Alexandre Reis Machado","doi":"10.1111/ppa.13868","DOIUrl":"https://doi.org/10.1111/ppa.13868","url":null,"abstract":"The sweet potato is of great socioeconomic importance in Brazil and throughout the world. Among the fungal pathogens associated with root diseases of this crop, <i>Fusarium</i> is of particular importance due to the diversity of species, the pathogenic potential in their various hosts and their ability to survive inside plants as endophytes without apparently causing damage. The objective of this work was to identify fusarioid genera from stems and roots of symptomatic and asymptomatic plants. The identification of fungal species was based on multilocus phylogenetic analysis and morphology. A total of 51 isolates, distributed in the <i>Fusarium incarnatum-equiseti</i> species complex (FIESC), <i>Fusarium fujikuroi</i> species complex (FFSC), <i>Fusarium oxysporum</i> species complex (FOSC)—with a taxonomic novelty—and <i>Neocosmospora</i> were identified. The pathogenicity test on roots showed that 13 of the 14 tested isolates obtained from symptomatic roots and stems and from asymptomatic stems were capable of reproducing the rot symptoms observed in the field. The confirmation of the pathogenicity of isolates from asymptomatic stems corroborates the hypothesis that these fungi can live endophytically in asymptomatic tissue and are capable of causing damage to their hosts in stress situations. This is the first report of <i>Fusarium agrestense</i>, <i>Fusarium annulatum</i>, <i>Fusarium caatingaense</i>, <i>Fusarium elaeidis</i>, <i>Fusarium pernambucanum</i>, <i>Fusarium pseudocircinatum</i>, <i>Neocosmospora falciformis</i> and <i>Neocosmospora suttoniana</i> associated with root and stem rot of sweet potato.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"10 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139659313","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}
Zhaoxing Li, Kai Yang, Wei Ye, Jiaoyu Wang, Haiping Qiu, Hongkai Wang, Zhengguo Xu, Dejin Xie
Intelligent rice disease recognition methods based on deep neural networks can predict the degree of disease on the basis of, for example, the number of disease spots on an image, so that preventive measures can be taken. Currently, intelligent recognition methods for rice diseases suffer from the disadvantages of poor versatility and low accuracy. This paper uses eight common image classification networks to classify and identify four rice diseases. ResNet50 was selected as the feature extraction network and an enhanced feature fusion and target adaptive network (EFFTAN), referred to as EFFTAN, is proposed. The EFFTAN was used to detect four rice spot diseases in the rice leaf disease image samples dataset; the mean average precision of the final detection was 95.3%, and effective detection was also achieved for the dense spot features.
{"title":"Rice leaf disease detection based on enhanced feature fusion and target adaptation","authors":"Zhaoxing Li, Kai Yang, Wei Ye, Jiaoyu Wang, Haiping Qiu, Hongkai Wang, Zhengguo Xu, Dejin Xie","doi":"10.1111/ppa.13866","DOIUrl":"https://doi.org/10.1111/ppa.13866","url":null,"abstract":"Intelligent rice disease recognition methods based on deep neural networks can predict the degree of disease on the basis of, for example, the number of disease spots on an image, so that preventive measures can be taken. Currently, intelligent recognition methods for rice diseases suffer from the disadvantages of poor versatility and low accuracy. This paper uses eight common image classification networks to classify and identify four rice diseases. ResNet50 was selected as the feature extraction network and an enhanced feature fusion and target adaptive network (EFFTAN), referred to as EFFTAN, is proposed. The EFFTAN was used to detect four rice spot diseases in the rice leaf disease image samples dataset; the mean average precision of the final detection was 95.3%, and effective detection was also achieved for the dense spot features.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"227 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139588182","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}
Surender Singh Chandel, Dinesh Subhash Gaikwad, Rajeev Rathour, Vineet K. Dohru, Asmita Sirari, Uday Jha, Swarup Parida, Kamal Dev Sharma
Blight caused by Ascochyta rabiei is a major constraint in the productivity of chickpea (Cicer arietinum). The mechanisms governing resistance/susceptibility to blight in chickpea are poorly understood. We used a blight-resistant (HC1) and a blight-susceptible (GPF2) genotype of chickpea and genes of pathogenesis-related proteins (PRPs), phenylpropanoid pathway metabolites, abscisic acid (ABA), gibberellic acid (GA) and jasmonic acid (JA) to understand the role of these in A. rabiei resistance/susceptibility. The JA, ABA and GA biosynthesis genes of chickpea were retrieved, characterized and gene-specific primers were used for transcriptional studies. Gene expression revealed that chickpea activated its defences rather quickly and well before initiation of spore germination. In resistant HC1, the majority of the JA, GA and phenylpropanoid pathway genes had peak maxima at 2 h post-inoculation (hpi) whereas PRPs/defence genes had peak maxima at 24/36 hpi implying that defence to A. rabiei in chickpea is composed of a two-tier system separated by time: immediately after spore attachment and at or just prior to host penetration. Unlike HC1, susceptible GPF2 was late in activation of defence responses or did not activate them. Another striking difference between HC1 and GPF2 was up-regulation of ABA biosynthesis genes in inoculated GPF2 and down-regulation in HC1. This study revealed that phenylpropanoids, PRPs, JA, 8-(1R,2R)-3-oxo-2-(Z)-pent-2-enyl cyclopentyl octanoate, (15Z)-12-oxophyto-10,15-dienoic acid and methyl-jasmonate govern resistance to A. rabiei in chickpea whereas ABA governs susceptibility.
Ascochyta rabiei 引起的枯萎病是鹰嘴豆（Cicer arietinum）产量的主要限制因素。人们对鹰嘴豆抗/感枯萎病的机制知之甚少。我们利用鹰嘴豆的抗枯萎病基因型（HC1）和易感枯萎病基因型（GPF2）以及病原相关蛋白（PRPs）、苯丙酮途径代谢产物、脱落酸（ABA）、赤霉素（GA）和茉莉酸（JA）的基因来了解这些基因在 A. rabiei 抗性/易感性中的作用。对鹰嘴豆的 JA、ABA 和 GA 生物合成基因进行了检索和鉴定，并使用基因特异性引物进行转录研究。基因表达显示，鹰嘴豆在孢子萌发之前就迅速启动了防御机制。在抗性 HC1 中，大多数 JA、GA 和苯丙氨酸途径基因在接种后 2 小时（hpi）达到最大峰值，而 PRPs/防御基因在 24/36 小时（hpi）达到最大峰值，这意味着鹰嘴豆对 A. rabiei 的防御由两层系统组成，这两层系统在时间上是分开的：孢子附着后立即防御，在寄主穿透时或穿透前防御。与 HC1 不同，易感的 GPF2 在激活防御反应方面较晚，或者没有激活防御反应。HC1 和 GPF2 之间的另一个显著差异是，接种 GPF2 的 ABA 生物合成基因上调，而 HC1 则下调。这项研究表明，苯丙酮类、PRPs、JA、8-(1R,2R)-3-氧代-2-(Z)-戊-2-烯基环戊基辛酸酯、(15Z)-12-氧代-10,15-二烯酸和甲基-茉莉酮酸能调节鹰嘴豆对 A. rabiei 的抗性，而 ABA 能调节鹰嘴豆对 A. rabiei 的易感性。
{"title":"Differential expression of antimicrobial metabolites, phenylpropanoid and phytohormone metabolic pathway genes determines resistance or susceptibility to Ascochyta rabiei in chickpea","authors":"Surender Singh Chandel, Dinesh Subhash Gaikwad, Rajeev Rathour, Vineet K. Dohru, Asmita Sirari, Uday Jha, Swarup Parida, Kamal Dev Sharma","doi":"10.1111/ppa.13867","DOIUrl":"https://doi.org/10.1111/ppa.13867","url":null,"abstract":"Blight caused by <i>Ascochyta rabiei</i> is a major constraint in the productivity of chickpea (<i>Cicer arietinum</i>). The mechanisms governing resistance/susceptibility to blight in chickpea are poorly understood. We used a blight-resistant (HC1) and a blight-susceptible (GPF2) genotype of chickpea and genes of pathogenesis-related proteins (PRPs), phenylpropanoid pathway metabolites, abscisic acid (ABA), gibberellic acid (GA) and jasmonic acid (JA) to understand the role of these in <i>A. rabiei</i> resistance/susceptibility. The JA, ABA and GA biosynthesis genes of chickpea were retrieved, characterized and gene-specific primers were used for transcriptional studies. Gene expression revealed that chickpea activated its defences rather quickly and well before initiation of spore germination. In resistant HC1, the majority of the JA, GA and phenylpropanoid pathway genes had peak maxima at 2 h post-inoculation (hpi) whereas PRPs/defence genes had peak maxima at 24/36 hpi implying that defence to <i>A. rabiei</i> in chickpea is composed of a two-tier system separated by time: immediately after spore attachment and at or just prior to host penetration. Unlike HC1, susceptible GPF2 was late in activation of defence responses or did not activate them. Another striking difference between HC1 and GPF2 was up-regulation of ABA biosynthesis genes in inoculated GPF2 and down-regulation in HC1. This study revealed that phenylpropanoids, PRPs, JA, 8-(1<i>R</i>,2<i>R</i>)-3-oxo-2-(<i>Z</i>)-pent-2-enyl cyclopentyl octanoate, (15<i>Z</i>)-12-oxophyto-10,15-dienoic acid and methyl-jasmonate govern resistance to <i>A. rabiei</i> in chickpea whereas ABA governs susceptibility.","PeriodicalId":20075,"journal":{"name":"Plant Pathology","volume":"222 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139587825","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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