Pub Date : 2022-08-31DOI: 10.1080/07060661.2022.2119603
K. Jayasena, A. van Burgel, J. Galloway, G. Thomas
Abstract Petal testing can be used to determine the presence of Sclerotinia sclerotiorum inoculum during canola flowering as an indicator of disease risk and the potential need for fungicide application. Traditionally, the culture plate method has been used to test petals, but this takes up to 7 days to obtain results, which is a drawback in terms of making timely fungicide use decisions. Therefore, the availability of a simple, faster detection technique for S. sclerotiorum infected canola petals would be an advantage. We have documented and compared a canola petal clearing and staining technique with the standard culture plate method to study sclerotinia ascospore infestation. The staining technique was found to be a rapid, simple and reliable method compared to the traditional culture plate system.
{"title":"Detection and quantification of Sclerotinia sclerotiorum infestation of canola petals using a clearing and staining technique","authors":"K. Jayasena, A. van Burgel, J. Galloway, G. Thomas","doi":"10.1080/07060661.2022.2119603","DOIUrl":"https://doi.org/10.1080/07060661.2022.2119603","url":null,"abstract":"Abstract Petal testing can be used to determine the presence of Sclerotinia sclerotiorum inoculum during canola flowering as an indicator of disease risk and the potential need for fungicide application. Traditionally, the culture plate method has been used to test petals, but this takes up to 7 days to obtain results, which is a drawback in terms of making timely fungicide use decisions. Therefore, the availability of a simple, faster detection technique for S. sclerotiorum infected canola petals would be an advantage. We have documented and compared a canola petal clearing and staining technique with the standard culture plate method to study sclerotinia ascospore infestation. The staining technique was found to be a rapid, simple and reliable method compared to the traditional culture plate system.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"173 2","pages":"70 - 75"},"PeriodicalIF":2.0,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41291182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-25DOI: 10.1080/07060661.2022.2091663
D. Soresi, Marina L Díaz, P. Bagnaresi, C. Gallo, A. Carrera
Abstract To identify the transcriptional mechanisms underpinning Fusarium head blight (FHB) resistance in durum wheat, an RNA-seq comparative transcriptome analysis was conducted on spikes 72 h after inoculation of a resistant line Langdon(Dic-3A)10 and a susceptible cultivar ‘Langdon’. Previously, 14 differentially expressed genes (DEGs) were mapped in the region of the quantitative trait locus Qfhs.ndsu-3AS, associated with type II resistance to FHB. Here, we focused on the global response of durum wheat to Fusarium graminearum (Fg) infection, identifying the molecular pathways in which DEGs are involved and lncRNAs with roles in transcriptional and post-transcriptional regulation of gene expression. A set of 921 DEGs was identified using the reference genome of the cultivar ‘Svevo’. Relative to the susceptible cultivar, the resistant line Langdon(Dic-3A)10 showed 452 up-regulated genes and 469 down-regulated genes. Upregulated genes in the resistant line included fungal cell-wall degrading enzymes, transcription factors, and genes involved in kinase signalling, phytohormone pathways, calcium signalling, secondary metabolite biosynthesis and toxin sensitivity. Differentially expressed lncRNAs showed different genome locations: 12 cis intergenic (6 up-regulated in Langdon(Dic-3A)10), 4 trans intergenic (one up-regulated in Langdon(Dic-3A)10), 4 intronic (two up-regulated in Langdon(Dic-3A)10) and 2 putative miRNAs precursors. Possible target genes were predicted for 14 lncRNAs, indicating potential regulative effects on wax and lignin synthesis and ankyrines in the resistant line. In a context where resistance sources against Fg are scarce in durum germplasm, the transcriptomic characterization of a valuable genotype contributes to the understanding of the genetic basis and regulatory network involved in the resistance conferred by Qfhs.ndsu-3AS.
{"title":"Gene and lncRNA expression patterns associated with Qfhs.ndsu-3AS Fusarium head blight resistance QTL in durum wheat","authors":"D. Soresi, Marina L Díaz, P. Bagnaresi, C. Gallo, A. Carrera","doi":"10.1080/07060661.2022.2091663","DOIUrl":"https://doi.org/10.1080/07060661.2022.2091663","url":null,"abstract":"Abstract To identify the transcriptional mechanisms underpinning Fusarium head blight (FHB) resistance in durum wheat, an RNA-seq comparative transcriptome analysis was conducted on spikes 72 h after inoculation of a resistant line Langdon(Dic-3A)10 and a susceptible cultivar ‘Langdon’. Previously, 14 differentially expressed genes (DEGs) were mapped in the region of the quantitative trait locus Qfhs.ndsu-3AS, associated with type II resistance to FHB. Here, we focused on the global response of durum wheat to Fusarium graminearum (Fg) infection, identifying the molecular pathways in which DEGs are involved and lncRNAs with roles in transcriptional and post-transcriptional regulation of gene expression. A set of 921 DEGs was identified using the reference genome of the cultivar ‘Svevo’. Relative to the susceptible cultivar, the resistant line Langdon(Dic-3A)10 showed 452 up-regulated genes and 469 down-regulated genes. Upregulated genes in the resistant line included fungal cell-wall degrading enzymes, transcription factors, and genes involved in kinase signalling, phytohormone pathways, calcium signalling, secondary metabolite biosynthesis and toxin sensitivity. Differentially expressed lncRNAs showed different genome locations: 12 cis intergenic (6 up-regulated in Langdon(Dic-3A)10), 4 trans intergenic (one up-regulated in Langdon(Dic-3A)10), 4 intronic (two up-regulated in Langdon(Dic-3A)10) and 2 putative miRNAs precursors. Possible target genes were predicted for 14 lncRNAs, indicating potential regulative effects on wax and lignin synthesis and ankyrines in the resistant line. In a context where resistance sources against Fg are scarce in durum germplasm, the transcriptomic characterization of a valuable genotype contributes to the understanding of the genetic basis and regulatory network involved in the resistance conferred by Qfhs.ndsu-3AS.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"41 - 56"},"PeriodicalIF":2.0,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42816780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-19DOI: 10.1080/07060661.2022.2103737
C. Pascouau, Corentin Chateau, F. Bastide, T. Le Moullec-Rieu, T. Guillemette, B. Hamon, Sophie Aligon, Agathe Cailleau, Daniel Sochard, J. Gombert, E. Morel, E. Laurent, I. Sérandat, R. Berruyer, P. Poupard
Abstract Since 2015, necrosis caused by Fusarium spp. has been regularly observed in carrot seed crops in France. A collection of 53 Fusarium isolates was gathered from lesions on carrot between 2016 and 2019. Morphological characterization at both the macroscopic and microscopic levels and molecular typing based on the ACL1, RPB2 and EF1-α partial gene sequences resulted in the identification of two main groups, corresponding to 22 F. avenaceum and 22 F. tricinctum isolates. In addition, three isolates of F. graminearum, two each of F. oxysporum and F. acuminatum, and one isolate of F. solani were also identified. Dual cultures of Trichoderma spp. (T. atroviride and T. harzianum) and Fusarium spp. (F. tricinctum isolate FT001 and F. avenaceum isolate FA002) did not indicate any antibiosis capabilities of Trichoderma. The in vitro sensitivity of isolates FT001 and FA002 to two fungicides and one natural product was similar, with an efficacy depending on the active ingredient. Prothioconazole + tebuconazole was more effective (mycelial growth reduced by 97% for FT001 and 99.8% for FA002) than fluopyram + trifloxystrobin (mycelial growth reduced by 58% and 56%, respectively). Allium extracts seemed to be a promising alternative to fungicides, since they were almost as efficient as prothioconazole + tebuconazole. Artificial inoculation of durum wheat using three isolates from carrot lesions (FT001, FA002 and F. graminearum FG001) induced plant necrosis. This result suggests that Fusarium pathogens of carrot seed crops may be transmitted to wheat, which is commonly used in rotation with carrot.
{"title":"Characterization and pathogenicity of Fusarium spp. isolates causing root and collar rot on carrot","authors":"C. Pascouau, Corentin Chateau, F. Bastide, T. Le Moullec-Rieu, T. Guillemette, B. Hamon, Sophie Aligon, Agathe Cailleau, Daniel Sochard, J. Gombert, E. Morel, E. Laurent, I. Sérandat, R. Berruyer, P. Poupard","doi":"10.1080/07060661.2022.2103737","DOIUrl":"https://doi.org/10.1080/07060661.2022.2103737","url":null,"abstract":"Abstract Since 2015, necrosis caused by Fusarium spp. has been regularly observed in carrot seed crops in France. A collection of 53 Fusarium isolates was gathered from lesions on carrot between 2016 and 2019. Morphological characterization at both the macroscopic and microscopic levels and molecular typing based on the ACL1, RPB2 and EF1-α partial gene sequences resulted in the identification of two main groups, corresponding to 22 F. avenaceum and 22 F. tricinctum isolates. In addition, three isolates of F. graminearum, two each of F. oxysporum and F. acuminatum, and one isolate of F. solani were also identified. Dual cultures of Trichoderma spp. (T. atroviride and T. harzianum) and Fusarium spp. (F. tricinctum isolate FT001 and F. avenaceum isolate FA002) did not indicate any antibiosis capabilities of Trichoderma. The in vitro sensitivity of isolates FT001 and FA002 to two fungicides and one natural product was similar, with an efficacy depending on the active ingredient. Prothioconazole + tebuconazole was more effective (mycelial growth reduced by 97% for FT001 and 99.8% for FA002) than fluopyram + trifloxystrobin (mycelial growth reduced by 58% and 56%, respectively). Allium extracts seemed to be a promising alternative to fungicides, since they were almost as efficient as prothioconazole + tebuconazole. Artificial inoculation of durum wheat using three isolates from carrot lesions (FT001, FA002 and F. graminearum FG001) induced plant necrosis. This result suggests that Fusarium pathogens of carrot seed crops may be transmitted to wheat, which is commonly used in rotation with carrot.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"76 - 91"},"PeriodicalIF":2.0,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47092872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-14DOI: 10.1080/07060661.2022.2097315
D. O'gorman, P. Haag, J. Boulé, Glen Healy, Jordan Fraser, M. Walker, J. R. ÚRBEZ-TORRES
Abstract A relatively new condition of sweet cherry (Prunus avium L.), cherry slip-skin-maceration disorder (cherry-SSMD), presumably associated with yeast species, required a detailed study looking at the microbial communities inhabiting the fruit and blossoms of commercial cherry trees. Cherry-SSMD affects the fruit quality of mainly late harvest sweet cherries and may lead to symptom development that is associated with one or more different, but typically non-pathogenic yeast species. These symptoms may be the result of significant shifts within the fruit’s normal microbiota, and may in turn be influenced by tree fruit phenology and/or environmental factors relating to variable harvest dates. Therefore, the main objective of this study was to conduct field surveys to investigate the microbial species composition on cherry blossoms and fruit. Results obtained from surveys conducted during the 2013 and 2014 growing seasons indicated that while fungal populations remained low, numbers of yeasts and bacteria continued to increase on the surface of developing fruit throughout the growing season. Species composition was also observed to be variable between years and throughout the growing seasons. However, despite general increases in microbial populations of bacteria and yeasts leading up to harvest, no specific pattern was observed to suggest a pathogenic profile that would link either microbial communities, or individual species to cherry-SSMD.
{"title":"Microbial communities of sweet cherry (Prunus avium L.) and assessment of their association with cherry slip-skin-maceration disorder","authors":"D. O'gorman, P. Haag, J. Boulé, Glen Healy, Jordan Fraser, M. Walker, J. R. ÚRBEZ-TORRES","doi":"10.1080/07060661.2022.2097315","DOIUrl":"https://doi.org/10.1080/07060661.2022.2097315","url":null,"abstract":"Abstract A relatively new condition of sweet cherry (Prunus avium L.), cherry slip-skin-maceration disorder (cherry-SSMD), presumably associated with yeast species, required a detailed study looking at the microbial communities inhabiting the fruit and blossoms of commercial cherry trees. Cherry-SSMD affects the fruit quality of mainly late harvest sweet cherries and may lead to symptom development that is associated with one or more different, but typically non-pathogenic yeast species. These symptoms may be the result of significant shifts within the fruit’s normal microbiota, and may in turn be influenced by tree fruit phenology and/or environmental factors relating to variable harvest dates. Therefore, the main objective of this study was to conduct field surveys to investigate the microbial species composition on cherry blossoms and fruit. Results obtained from surveys conducted during the 2013 and 2014 growing seasons indicated that while fungal populations remained low, numbers of yeasts and bacteria continued to increase on the surface of developing fruit throughout the growing season. Species composition was also observed to be variable between years and throughout the growing seasons. However, despite general increases in microbial populations of bacteria and yeasts leading up to harvest, no specific pattern was observed to suggest a pathogenic profile that would link either microbial communities, or individual species to cherry-SSMD.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"57 - 69"},"PeriodicalIF":2.0,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45728261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-01DOI: 10.1080/07060661.2022.2096697
T. Reshma, Smitha Balan, C. Dileep
Abstract Rice is one of the most important staple food crops, and bacterial diseases are among the major limitations to its productivity and yield. Kuttanad is a unique agro-climatic region in Kerala, India, where rice cultivation occurs below sea level. It is recognized as a Globally Important Agricultural Heritage System by the Food and Agriculture Organization of the United Nations. In July 2021, grain discolouration and leaf blight symptoms were noted on rice plants in the field. Leaves developed yellowish to brown lesions, which turned a pale white to straw colour as the disease progressed. Bacteria were isolated from symptomatic leaves and grains. The pathogenicity of a recovered bacterial strain was assessed by artificial inoculation and Koch’s postulates were met. Re-isolation of the pathogenic strain showed high similarity with the originally recovered strain. The 16S rRNA gene was sequenced (accession no. OK398432) and found to have 100% similarity with Pantoea ananatis, an emerging pathogen of rice. To our knowledge, this is the first report of P.ananatis from the Kuttanad region of India.
{"title":"First report of rice grain discolouration and leaf blight caused by Pantoea ananatis in the Kuttanad agro-ecosystem, Kerala, India","authors":"T. Reshma, Smitha Balan, C. Dileep","doi":"10.1080/07060661.2022.2096697","DOIUrl":"https://doi.org/10.1080/07060661.2022.2096697","url":null,"abstract":"Abstract Rice is one of the most important staple food crops, and bacterial diseases are among the major limitations to its productivity and yield. Kuttanad is a unique agro-climatic region in Kerala, India, where rice cultivation occurs below sea level. It is recognized as a Globally Important Agricultural Heritage System by the Food and Agriculture Organization of the United Nations. In July 2021, grain discolouration and leaf blight symptoms were noted on rice plants in the field. Leaves developed yellowish to brown lesions, which turned a pale white to straw colour as the disease progressed. Bacteria were isolated from symptomatic leaves and grains. The pathogenicity of a recovered bacterial strain was assessed by artificial inoculation and Koch’s postulates were met. Re-isolation of the pathogenic strain showed high similarity with the originally recovered strain. The 16S rRNA gene was sequenced (accession no. OK398432) and found to have 100% similarity with Pantoea ananatis, an emerging pathogen of rice. To our knowledge, this is the first report of P.ananatis from the Kuttanad region of India.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"30 - 34"},"PeriodicalIF":2.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44206231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-29DOI: 10.1080/07060661.2022.2086925
J. Tucker, A. Brûlé-Babel, C. Hiebert, R. Larios, W. Legge, A. Badea, W. Fernando
Abstract Fusarium head blight (FHB), primarily incited by Fusarium graminearum Schwabe, is the most devastating disease of barley (Hordeum vulgare L.) in Canada. Contaminated grains are unsuitable for use as livestock feed or by the malting industry, primarily due to contamination by mycotoxins such as deoxynivalenol (DON). Reducing DON content has been a long-term goal of barley breeders; however, the complex genetics of resistance and laborious testing required have made it difficult to develop resistant cultivars. An Illumina 50 K SNP beadchip was used to genotype a diverse collection (n = 400) of two-row barley genotypes, selected primarily from North American-breeding programs. This genomic panel was phenotyped in three environments in Manitoba, Canada, over two growing seasons. Genotypes were evaluated for heading date, height, FHB score, and DON content. A genome-wide association study (GWAS) was carried out using a mixed linear model (MLM: Q + K) accounting for population structure (Q) and kinship (K) as covariates. This study characterized the population structure of two-row barley germplasm important to North American-breeding programs. Significant marker-trait associations were identified on all chromosomes for FHB, and on all chromosomesexcept 1 H and 6 H for DON content. Individual marker effects were small, explaining only up to 5% of the phenotypic variation. Genes within genomic regions that were associated with FHB-related traits displayed multiple functions linked with disease resistance. While numerous minor, marker-trait associations were identified, phenotypic evaluations are still the best predictors of these traits, despite their time-consuming nature and dependenceon environmental conditions.
摘要镰刀菌头疫病(Fusarium head blight, FHB)是加拿大大麦(Hordeum vulgare L.)最具破坏性的病害，主要由镰刀菌(Fusarium graminearum Schwabe)引起。受污染的谷物不适合用作牲畜饲料或用于酿酒业，主要原因是受到脱氧雪腐镰牙菌素(DON)等真菌毒素的污染。降低DON含量一直是大麦育种者的长期目标;然而，复杂的抗性遗传和费力的测试使得培育抗性品种变得困难。使用Illumina 50 K SNP头芯片对主要来自北美育种项目的不同双排大麦基因型(n = 400)进行基因分型。该基因组组在加拿大马尼托巴省的三个环境中表型化，超过两个生长季节。对抽穗日期、高度、FHB评分和DON含量进行基因型评价。以种群结构(Q)和亲缘关系(K)为协变量，采用混合线性模型(MLM: Q + K)进行全基因组关联研究(GWAS)。本文研究了对北美育种计划具有重要意义的二列大麦种质资源的群体结构。在FHB的所有染色体上都发现了显著的标记-性状相关性，除了1 H和6 H的DON含量外，所有染色体上都发现了显著的标记-性状相关性。个体标记效应很小，只能解释高达5%的表型变异。基因组区域内与fhb相关性状相关的基因显示出与抗病相关的多种功能。虽然发现了许多次要的标记-性状关联，但表型评估仍然是这些性状的最佳预测指标，尽管它们耗时且依赖于环境条件。
{"title":"Genetic structure and genome-wide association study of a genomic panel of two-row, spring barley (Hordeum vulgare L.) with differential reaction to Fusarium head blight (Fusarium graminearum Schwabe) and deoxynivalenol production","authors":"J. Tucker, A. Brûlé-Babel, C. Hiebert, R. Larios, W. Legge, A. Badea, W. Fernando","doi":"10.1080/07060661.2022.2086925","DOIUrl":"https://doi.org/10.1080/07060661.2022.2086925","url":null,"abstract":"Abstract Fusarium head blight (FHB), primarily incited by Fusarium graminearum Schwabe, is the most devastating disease of barley (Hordeum vulgare L.) in Canada. Contaminated grains are unsuitable for use as livestock feed or by the malting industry, primarily due to contamination by mycotoxins such as deoxynivalenol (DON). Reducing DON content has been a long-term goal of barley breeders; however, the complex genetics of resistance and laborious testing required have made it difficult to develop resistant cultivars. An Illumina 50 K SNP beadchip was used to genotype a diverse collection (n = 400) of two-row barley genotypes, selected primarily from North American-breeding programs. This genomic panel was phenotyped in three environments in Manitoba, Canada, over two growing seasons. Genotypes were evaluated for heading date, height, FHB score, and DON content. A genome-wide association study (GWAS) was carried out using a mixed linear model (MLM: Q + K) accounting for population structure (Q) and kinship (K) as covariates. This study characterized the population structure of two-row barley germplasm important to North American-breeding programs. Significant marker-trait associations were identified on all chromosomes for FHB, and on all chromosomesexcept 1 H and 6 H for DON content. Individual marker effects were small, explaining only up to 5% of the phenotypic variation. Genes within genomic regions that were associated with FHB-related traits displayed multiple functions linked with disease resistance. While numerous minor, marker-trait associations were identified, phenotypic evaluations are still the best predictors of these traits, despite their time-consuming nature and dependenceon environmental conditions.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"44 1","pages":"874 - 891"},"PeriodicalIF":2.0,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46298127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-16DOI: 10.1080/07060661.2022.2091041
Stephen A. Wyka, And Kirk Broders
Abstract The fungal pathogen Claviceps purpurea can infect numerous grass species including important crops like barley, rye, and wheat, but the ecology of ergot disease is rarely studied in non-crop grass species. Recent outbreaks of ergot in barley production systems in the western U.S. have implicated nearby grass hosts as reservoirs for inoculum and spread of C. purpurea into the barley crop. We surveyed the prevalence of ergot infections among native, invasive, and weedy grass species near barley fields in the San Luis Valley of Colorado over three years. We found that barley fields with a history of ergot disease were surrounded by a grass community composed largely of smooth brome, that smooth brome was very susceptible to ergot infection and had the highest infection rates among grass species, and that disease severity among the grass community increased during the growing season. Over the study period there was a low incidence of barley infections and this precluded analysing the effects unmanaged grass composition and disease incidence had on within field disease incidence. Our findings indicate that smooth brome represents a significant source of C. purpurea inoculum and inoculum levels increase as the composition of brome grass in the grass community increases. There is sufficient inoculum present in the brome grass population in the San Luis Valley to cause sporadic disease in barley fields when environmental conditions are optimal for infection. Future disease management strategies should take into account the large pool of inoculum in the grass population near barley production fields.
{"title":"Brome grasses represent the primary source of Claviceps purpurea inoculum associated with barley fields in the San Luis Valley of Colorado","authors":"Stephen A. Wyka, And Kirk Broders","doi":"10.1080/07060661.2022.2091041","DOIUrl":"https://doi.org/10.1080/07060661.2022.2091041","url":null,"abstract":"Abstract The fungal pathogen Claviceps purpurea can infect numerous grass species including important crops like barley, rye, and wheat, but the ecology of ergot disease is rarely studied in non-crop grass species. Recent outbreaks of ergot in barley production systems in the western U.S. have implicated nearby grass hosts as reservoirs for inoculum and spread of C. purpurea into the barley crop. We surveyed the prevalence of ergot infections among native, invasive, and weedy grass species near barley fields in the San Luis Valley of Colorado over three years. We found that barley fields with a history of ergot disease were surrounded by a grass community composed largely of smooth brome, that smooth brome was very susceptible to ergot infection and had the highest infection rates among grass species, and that disease severity among the grass community increased during the growing season. Over the study period there was a low incidence of barley infections and this precluded analysing the effects unmanaged grass composition and disease incidence had on within field disease incidence. Our findings indicate that smooth brome represents a significant source of C. purpurea inoculum and inoculum levels increase as the composition of brome grass in the grass community increases. There is sufficient inoculum present in the brome grass population in the San Luis Valley to cause sporadic disease in barley fields when environmental conditions are optimal for infection. Future disease management strategies should take into account the large pool of inoculum in the grass population near barley production fields.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"15 - 29"},"PeriodicalIF":2.0,"publicationDate":"2022-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49618880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-14DOI: 10.1080/07060661.2022.2088621
A. Miamoto, A. P. Mattos, A. Calandrelli, L. Rinaldi, T. M. Mioranza, M. T. Silva, L. P. S. Chidichima, C. R. Dias-Arieira
Abstract This study aimed to examine the relationship between Macrotyloma axillare ‘Java’ and Meloidogyne javanica at different levels of nematode inoculum, and to assess the activity of plant defence enzymes in the presence of nematodes. In Experiment 1, ‘Java’ and soybean (control) were inoculated with 300 to 8000 eggs + second-stage juveniles (J2) of M. javanica in two different periods (Trials 1 and 2). To confirm the results, a third trial was conducted using 1000 to 4000 eggs + J2 per plant. In Experiment 2, β-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL), peroxidase (POX), and polyphenol oxidase (PPO) activities were measured in non-inoculated plants and in plants inoculated with 2000 eggs + J2. ‘Java’ presented a reproduction factor (RF) < 1 at all inoculum levels in Trial 1 (RF of 0.17–0.78) and at 2000, 3000, and 6000 eggs + J2 in Trial 2 (RF of 0.47, 0.86, and 0.59, respectively). In Trial 3, ‘Java’ showed a RF < 1 at all inoculum levels except for 3000 eggs + J2 (RF = 1.1). There was no difference in ‘Java’ vegetative variables in relation to inoculum levels in any experiment. In Experiment 2, inoculated plants showed increased GLU, PAL, POX, and PPO activities, when compared with non-inoculated plants. ‘Java’ appears to be moderately resistant to M. javanica, reducing nematode reproduction at different inoculum levels. The plant exhibits increased GLU, PAL, POX, and PPO activities in the presence of M. javanica.
{"title":"Response of the legume Macrotyloma axillare ‘Java’ to different inoculum levels of Meloidogyne javanica and defence responses","authors":"A. Miamoto, A. P. Mattos, A. Calandrelli, L. Rinaldi, T. M. Mioranza, M. T. Silva, L. P. S. Chidichima, C. R. Dias-Arieira","doi":"10.1080/07060661.2022.2088621","DOIUrl":"https://doi.org/10.1080/07060661.2022.2088621","url":null,"abstract":"Abstract This study aimed to examine the relationship between Macrotyloma axillare ‘Java’ and Meloidogyne javanica at different levels of nematode inoculum, and to assess the activity of plant defence enzymes in the presence of nematodes. In Experiment 1, ‘Java’ and soybean (control) were inoculated with 300 to 8000 eggs + second-stage juveniles (J2) of M. javanica in two different periods (Trials 1 and 2). To confirm the results, a third trial was conducted using 1000 to 4000 eggs + J2 per plant. In Experiment 2, β-1,3-glucanase (GLU), phenylalanine ammonia-lyase (PAL), peroxidase (POX), and polyphenol oxidase (PPO) activities were measured in non-inoculated plants and in plants inoculated with 2000 eggs + J2. ‘Java’ presented a reproduction factor (RF) < 1 at all inoculum levels in Trial 1 (RF of 0.17–0.78) and at 2000, 3000, and 6000 eggs + J2 in Trial 2 (RF of 0.47, 0.86, and 0.59, respectively). In Trial 3, ‘Java’ showed a RF < 1 at all inoculum levels except for 3000 eggs + J2 (RF = 1.1). There was no difference in ‘Java’ vegetative variables in relation to inoculum levels in any experiment. In Experiment 2, inoculated plants showed increased GLU, PAL, POX, and PPO activities, when compared with non-inoculated plants. ‘Java’ appears to be moderately resistant to M. javanica, reducing nematode reproduction at different inoculum levels. The plant exhibits increased GLU, PAL, POX, and PPO activities in the presence of M. javanica.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"44 1","pages":"907 - 917"},"PeriodicalIF":2.0,"publicationDate":"2022-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44446024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-13DOI: 10.1080/07060661.2022.2089235
Y. Ait Rahou, A. Douira, A. Tahiri, El Modafar Cherkaoui, R. Benkirane, A. Meddich
Abstract This study aimed to evaluate the effect of plant growth-promoting rhizobacteria (PGPR) and compost, applied alone or in combination, on tomato resistance to vascular wilt caused by Verticillium dahliae. Improved management of vascular wilt is important for enhanced productivity of greenhouse-grown susceptible tomato plants. The application of compost and PGPR resulted in a reduction in infection parameters compared with untreated plants inoculated with the pathogen, as well as activation of plant defence mechanisms. In the presence of the pathogen, compost application significantly improved the total fresh and dry weights by 97% and 71%, respectively, compared with pathogen-inoculated controls. The combination of compost with PGPR significantly increased chlorophyll fluorescence and stomatal conductance compared with the infected-control. In addition, the combination of compost and PGPR reduced the accumulation of stress markers such as malondialdehyde and hydrogen peroxide by 48% and 77%, respectively, and promoted the activity of antioxidant enzymes. Fruit yield and quality were also significantly improved relative to the control. The results suggest that compost applied alone or in combination with PGPR helps to suppress vascular wilt and to improve the yield and quality of tomatoes.
{"title":"Application of plant growth-promoting rhizobacteria combined with compost as a management strategy against Verticillium dahliae in tomato","authors":"Y. Ait Rahou, A. Douira, A. Tahiri, El Modafar Cherkaoui, R. Benkirane, A. Meddich","doi":"10.1080/07060661.2022.2089235","DOIUrl":"https://doi.org/10.1080/07060661.2022.2089235","url":null,"abstract":"Abstract This study aimed to evaluate the effect of plant growth-promoting rhizobacteria (PGPR) and compost, applied alone or in combination, on tomato resistance to vascular wilt caused by Verticillium dahliae. Improved management of vascular wilt is important for enhanced productivity of greenhouse-grown susceptible tomato plants. The application of compost and PGPR resulted in a reduction in infection parameters compared with untreated plants inoculated with the pathogen, as well as activation of plant defence mechanisms. In the presence of the pathogen, compost application significantly improved the total fresh and dry weights by 97% and 71%, respectively, compared with pathogen-inoculated controls. The combination of compost with PGPR significantly increased chlorophyll fluorescence and stomatal conductance compared with the infected-control. In addition, the combination of compost and PGPR reduced the accumulation of stress markers such as malondialdehyde and hydrogen peroxide by 48% and 77%, respectively, and promoted the activity of antioxidant enzymes. Fruit yield and quality were also significantly improved relative to the control. The results suggest that compost applied alone or in combination with PGPR helps to suppress vascular wilt and to improve the yield and quality of tomatoes.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"44 1","pages":"806 - 827"},"PeriodicalIF":2.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43214775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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