Canadian Journal of Plant Pathology最新文献

{"title":"Inoculum threshold for stripe rust infection in wheat","authors":"Gabriela T. Araujo, D. Gaudet, Eric Amundsen, M. Frick, R. Aboukhaddour, B. Selinger, A. Laroche","doi":"10.1080/07060661.2023.2177888","DOIUrl":"https://doi.org/10.1080/07060661.2023.2177888","url":null,"abstract":"Abstract Stripe rust (Puccinia striiformis f. sp. tritici (Pst)) and powdery mildew (Blumeria graminis f. sp. tritici (Bgt)) are important diseases of wheat in Canada and worldwide. Molecular detection methods permit spore detection of few spores; therefore, there is a need to determine initial inoculum thresholds for pathogens to cause disease under both controlled environments and in the field. Susceptible wheat cultivars ‘Avocet’ and ‘AC Barrie’ were inoculated with different quantities of spores (0, 103, 104, 105, 106, and 107) of Pst and Bgt. Disease incidence, severity and infection type were evaluated. Results of controlled environment studies showed that the minimum number of spores necessary to cause appreciable incidence and severity for Pst was at higher spore concentrations of 105–106 spores. Conversely, low incidence and severity levels were observed at 103–104 spores for Bgt. Despite occurrence of natural Pst infection, results of field studies in 2016 and 2017 in Southern Alberta demonstrated that significant increases in severity levels were observed following application of 1.2 × 107 spores. Collectively, these results demonstrated that stripe rust severities increased with increasing spore concentration only at high spore levels. In contrast, Bgt severity increased with spore concentration from 103 to 107 spores mL−1. In vitro and in vivo spore germination tests demonstrated germination rates of Pst spores were reduced at lower spore concentrations compared to germination rates at the higher concentrations. Understanding of minimum spore numbers required for disease development will be a prerequisite for predicting epidemics and devising fungicide control measures for future sustainable agricultural systems.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"304 - 319"},"PeriodicalIF":2.0,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47056766","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}

{"title":"Systemically induced resistance against disease of wheat caused by Fusarium graminearum","authors":"A. Abaya, A. Xue, T. Hsiang","doi":"10.1080/07060661.2023.2177749","DOIUrl":"https://doi.org/10.1080/07060661.2023.2177749","url":null,"abstract":"Abstract The endophytic fungi Simplicillium lamellicola and Clonostachys rosea were assayed for their ability to induce resistance in wheat against disease caused by Fusarium graminearum Schwabe in growth room and outdoor tests. Agar inoculum of the endophytes was applied 4 days before agar inoculum of F. graminearum was applied to adjacent leaves. Simplicillium lamellicola or C. rosea treatments applied on one leaf significantly reduced the disease on another leaf by between 68 and 70% in growth room tests at 11 days post pathogen inoculation and by between 43 and 49% in outdoor tests at 9 days after inoculation compared to pathogen-inoculated controls with no biocontrols. Simplicillium lamellicola is a promising biocontrol agent since it systemically induced disease resistance in wheat against Fusarium graminearum. Future work is needed to investigate the mode of action of the defence responses and the proper formulation and application of this biocontrol agent.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"320 - 329"},"PeriodicalIF":2.0,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46045562","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}

{"title":"Combined effects of Ascophyllum nodosum seaweed extract and biological control agents on Meloidogyne javanica in soybean","authors":"L. Rinaldi, M. T. Silva, A. Miamoto, A. Calandrelli, C. R. Dias-Arieira","doi":"10.1080/07060661.2023.2175913","DOIUrl":"https://doi.org/10.1080/07060661.2023.2175913","url":null,"abstract":"Abstract This study aimed to investigate the efficacy of Ascophyllum nodosum extract, in combination or not with biocontrol agents, in the management of Meloidogyne javanica in soybean, assess treatment effects on soil biological activity, and determine the total phenolic content of the extract. The experiment was conducted according to a 5 × 2 factorial design, with three biocontrol agents (Bacillus methylotrophicus, Pochonia chlamydosporia, and Trichoderma harzianum), a chemical nematicide (abamectin, positive control), and an untreated (negative) control, each in the presence and absence of A. nodosum extract. Treatments included six replications. Nematode inoculation (2000 eggs + juveniles of M. javanica per plant) was performed at the time of sowing. Sixty days later, plants were evaluated for height, shoot weights, numbers of M. javanica eggs and J2 extracted from roots, and soil biological activity. Biological and chemical nematicide treatments were effective in reducing M. javanica multiplication. There was a synergic effect of A. nodosum extract on M. javanica multiplication for the treatments with A. nodosum + T. harzianum, A. nodosum + abamectin (Trial 1) and A. nodosum + P. chlamydosporia (Trial 2). B. methylotrophicus and T. harzianum treatments enhanced plant development and soil microbial biomass carbon. Higher values of soil basal respiration and metabolic quotient (qCO2) were observed in the A. nodosum + abamectin treatment. A. nodosum extracts at 75 g L−1 had a total phenolic content of 13 255 and 11 608 mg GAE 100−1 g in Trials 1 and 2, respectively.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"340 - 350"},"PeriodicalIF":2.0,"publicationDate":"2023-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49613210","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}

{"title":"Biological control of Fusarium oxysporum causing damping-off and Pythium myriotylum causing root and crown rot on cannabis (Cannabis sativa L.) plants","authors":"C. Scott, Z. Punja","doi":"10.1080/07060661.2023.2172082","DOIUrl":"https://doi.org/10.1080/07060661.2023.2172082","url":null,"abstract":"Abstract Damping-off, crown rot, and root rot caused by Fusarium oxysporum and Pythium spp. are important diseases that reduce the growth of cannabis plants and cause mortality. There are currently limited management options available to producers in the absence of registered chemical fungicides. The comparative efficacy of five biological-control agents in reducing disease severity was evaluated in this study. Rhapsody® ASO (Bacillus subtilis), Stargus® (Bacillus amyloliquefaciens), Lalstop® (Gliocladium catenulatum, Prestop®), RootShield® Plus WP (Trichoderma harzianum and Trichoderma virens), and Asperello® (Trichoderma asperellum) were applied to cannabis cuttings in rockwool blocks followed 48 hr later by inoculation with a F. oxysporum spore and mycelial suspension. Disease was rated 7, 14 and 21 days post-inoculation. The most effective treatments were Lalstop, Rootshield, Asperello and Stargus, which provided a significant (P < 0.05) reduction (30 to 56.3%) in mean disease severity 14 days post-inoculation compared to the Fusarium inoculated control. Application of Rootshield, Asperello and Lalstop resulted in endophytic colonization of cannabis cuttings when assessed after 2 and 7 days. For Pythium biocontrol, Rootshield Plus WP, Asperello, and Lalstop were applied as a drench to rooted plants 7 days before inoculation with P. myriotylum. Based on disease severity ratings and plant measurements in two experiments, the most effective treatments were Rootshield and Lalstop. Plants receiving Lalstop or Rootshield had significantly (P < 0.05) higher fresh root weights compared to the pathogen only treatment. These results indicate that several biological control agents can protect cannabis plants from infection by Fusarium and Pythium spp. through pre-emptive colonization.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"238 - 252"},"PeriodicalIF":2.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48691349","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}

{"title":"Virulence characterization of the wheat stripe rust pathogen, Puccinia striiformis f. sp. tritici, in Turkey from 2018 to 2020","authors":"A. Cat, M. Tekin, K. Akan, T. Akar, M. Catal","doi":"10.1080/07060661.2023.2166126","DOIUrl":"https://doi.org/10.1080/07060661.2023.2166126","url":null,"abstract":"Abstract Stripe (yellow) rust caused by Puccinia striiformis f. sp. tritici (Pst) is the most devastating disease of wheat in Turkey. Virulence characterization of the Pst population is critical to prevent large-scale epidemics, by developing wheat cultivars with durable resistance against the disease. In this study, 38 Pst races, including 25 races that were not previously reported, were identified from 140 isolates obtained from most regions of Turkey from 2018 to 2020 using a differential set containing 18 single Yr gene wheat lines (NILs) of ‘Avocet’. Virulence to Yr15 was not observed among any of the isolates. Virulence to the remaining 17-Yr genes was detected at various frequencies. The frequencies of virulence to Yr6, Yr9, Yr7, Yr8, Yr43, YrExp2, Yr44, YrTr1, and Yr27 were high (57.1 to 100.0%), to Yr1, Yr17, Yr32, and YrTye were moderate (24.3 to 42.9%), and to YrSP, Yr24, and Yr10 were low (9.3 to 17.1%). Only one race was virulent to Yr5 (0.7%). Many of the races identified were common among regions, indicating that Pst races migrate throughout Turkey. However, the Black Sea (BS) and the Mediterranean (ME) regions were differentiated from other regions by unique races absent in other regions, and the Yr5-virulent race, respectively. To sum up, the virulences of the races identified and their distributions among regions provided an understanding of pathogen migration and may contribute to the development of resistant wheat cultivars against stripe rust.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"158 - 167"},"PeriodicalIF":2.0,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47626215","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}

{"title":"First report of Ceratobasidium sp. AG-I (binucleate Rhizoctonia) causing root rot of Hedychium coronarium Koen in China","authors":"Jiaqi J. Zheng, L. Yao, Chaoran Liu, Changfeng Wu, Yuzhu Han","doi":"10.1080/07060661.2022.2162607","DOIUrl":"https://doi.org/10.1080/07060661.2022.2162607","url":null,"abstract":"Abstract Hedychium coronarium Koen is a perennial flowering plant that has ornamental, nutritional and medicinal value. In October 2019, root rot symptoms were observed in fields of H. coronarium in Yunnan Province, China. Fungal isolates were obtained from the diseased samples and the pathogenicity was confirmed by fulfilling Koch’s postulates using wounded and unwounded plant inoculations. The pathogen was identified as Ceratobasidium sp. (binucleate Rhizoctonia) through morphological characterization and anastomosis grouping as well as sequence analysis of both rDNA-ITS and EF-1α. To our knowledge, this is the first report of Ceratobasidium sp. AG-I (binucleate Rhizoctonia) causing root rot on H. coronarium.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"168 - 175"},"PeriodicalIF":2.0,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47853459","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}

{"title":"Alberta regional meeting, 2021/Réunion régionale de l’Alberta, 2021","authors":"J. R. Tucker, X. Wang, XU W., A. D. Beattie, T. K. Turkington","doi":"10.1080/07060661.2022.2102282","DOIUrl":"https://doi.org/10.1080/07060661.2022.2102282","url":null,"abstract":"antibodies against fungal spores by using different concentrations of both antigens and antibodies. Alterations in the concentrations can be adapted to measure either spores or the antibody. The experiment was repeated twice with three replicates in each. The linear range of detection was between 1300 and 115,000 spores for FHB while being smaller for TS spores. Cross-reactivity of the TS antibodies will be verified against FHB spores and vice-versa FHB antibodies will be challenged with TS spores. These results suggest that these new antibodies will be very useful for antigenic detection of TS and FHB","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"6 - 14"},"PeriodicalIF":2.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47732582","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}

{"title":"British Columbia regional meeting, 2021/Réunion régionale de la Colombie-Britannique, 2021","authors":"L. Tauleigne, F. Lonjon, H. Desaint, L. Boyrie, M. Bonhomme, L. Deslandes, F. Vailleau, F. Roux, R. Berthomé","doi":"10.1080/07060661.2022.2102280","DOIUrl":"https://doi.org/10.1080/07060661.2022.2102280","url":null,"abstract":"s / Résumés British Columbia regional meeting, 2021/Réunion régionale de la Colombie-Britannique, 2021 Dissecting the mechanisms underlying the complex plant–Ralstonia--environment interactions. N. AOUN, L. TAULEIGNE, F. LONJON, H. DESAINT, L. BOYRIE, M. BONHOMME, L. DESLANDES, F. VAILLEAU, F. ROUX, R. BERTHOME AND T. LOWEPOWER. (N. A., T.L.) Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA 95616851, USA; (N.A., L.T., F.L., L.D., F.V., F.R., R.B.) Laboratory of Plant-Microorganisms-Environment Interactions, National Research Institute for Agriculture, Food and Environment, French National Centre for Scientific Research, 31320 Castanet-Tolosan France; (H.D.) SYNGENTA seeds, 84260 Sarrians France; and (L.B., M. B.) Plant Science Research Laboratory, French National Centre for Scientific Research, Paul Sabatier University, 31320 Castanet-Tolosan, France The central concept of ‘disease triangle’ in plant pathology highlights the importance of environment– host–pathogen interaction for disease severity. Warmer temperatures have been shown to inhibit most of the known resistance mechanisms in plants. However, the underlying molecular mechanisms remain poorly understood. In this talk, I will unify my PhD research and planned postdoctoral research around the Ralstonia wilt disease triangle. Ralstonia are a major threat to food security around the world. During my PhD (LIPME/ INRAE-France), we dissected mechanisms underlying the interaction of temperature and plant natural variation in Ralstonia disease outcome. By exploiting the natural genetic variation in Arabidopsis thaliana, we identified and characterized the genetic basis of resistance mechanisms remaining effective at elevated temperatures. Using genome wide association (GWA) approaches on two collections of A. thaliana, we uncovered quantitative trait loci associated with natural variation of Ralstonia disease outcome. GWA analysis revealed a polygenic architecture underlying disease symptom progression that is different between both collections. We functionally validated three genes involved in plant defence responses to R. solanacearum. However, the disease triangle of bacterial wilt could not be complete without understanding how genetic variation of the pathogen affects disease outcome. My current postdoc project aims to explore the molecular mechanisms promoting fitness of diverse Ralstonia species across different tomato cultivars and across different plant species. By adopting a random barcoded transposon mutant sequencing (RB-TnSeq), I aim to identify the genetic requirements of bacterial fitness in planta. Deciphering the plant–host environment interactions is fundamental to provide solutions for crop improvement. Race typing of Puccinia striiformis f. sp. tritici in western Canada. R. BAMRAH, K. LOU, M. ABBASI, H. R. KUTCHER AND G. S. BRAR. Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; and","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"1 - 5"},"PeriodicalIF":2.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47204677","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}

{"title":"Corynespora leaf spot of Ligustrum quihoui caused by Corynespora cassiicola in China","authors":"Bixia Yu, Ping Li, Yan Zhang, Dong Liu","doi":"10.1080/07060661.2022.2148129","DOIUrl":"https://doi.org/10.1080/07060661.2022.2148129","url":null,"abstract":"<p><b>Abstract</b></p><p><i>Ligustrum quihoui</i> is a perennial shrub that has been cultivated in China as a landscape plant. In November 2020, leaf spots on <i>L. quihoui</i> were observed in several residential areas in the east of Anqing city. Symptoms first appeared as small dark brown dots on the leaf surface which then became larger, forming necrotic lesions and resulting in intense defoliation. To identify the pathogen, infected leaves were collected and cultured on potato dextrose agar (PDA). Three cultures were isolated from the diseased leaves, which grew to form olive green colonies after 5 days of incubation on PDA. Based on colony characteristics, morphology phylogenetic analysis of ribosome transcriptional spacers (rDNA-ITS), and pathogenicity tests, the causal agent of leaf spot on <i>L. quihoui</i> was identified as <i>Corynespora cassiicola</i>. This is the first report to show that <i>C. cassiicola</i> can cause leaf spot on <i>L. quihoui</i>.</p>","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"11 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138532945","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}

{"title":"Diatrype genheensis sp. nov. – a new wood-inhabiting species of Diatrypaceae (Xylariales, Ascomycota) from China","authors":"Zhanen Yang, An-Hong Zhu, Bo Zhang, Zhi Qu, Hai-Xia Ma","doi":"10.1080/07060661.2022.2154388","DOIUrl":"https://doi.org/10.1080/07060661.2022.2154388","url":null,"abstract":"Abstract A new species of Diatrype (Diatrypaceae, Xylariales), D. genheensis, is proposed based on a combination of morphological features and molecular evidence. Diatrype genheensis, from a fallen angiosperm branch in Inner Mongolia, is characterized by having 3–14 perithecia embedded within a stroma, polysporous asci and ascospores that are allantoid, slightly curved, aseptate and subhyaline. The phylogeny of Diatrypaceae was inferred from a combined dataset of ITS and β-tubulin sequences. The phylogenetic tree indicated that D. genheensis belongs to a clade with two other polysporous species, D. betulaceicola and D. larissae. In the phylogenetic trees, D. genheensis was clearly separated from other sampled species of Diatrype.","PeriodicalId":9468,"journal":{"name":"Canadian Journal of Plant Pathology","volume":"45 1","pages":"148 - 157"},"PeriodicalIF":2.0,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43515425","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}