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... The present study focuses on antifungal potential of 1,2,4-triazole derivatives of allyl sulfides. The antifungal potential of synthesized 2-(allylthio)-1-(1'H-1',2',4'-triazol-1'-yl)ethanone (ATT) was compared with its diallyl analogue (a natural occurring) against Fusarium fujikuroito unveil its improved antifungal potential. The synthesized compound ATT had significantly better antifungal poten ...
... Bakanae disease of rice caused by Fusarium fujikuroi is a significant disease of rice worldwide. The use of inoculum free seeds works well to act against this seed borne disease. Increased restrictions by the environmental protection agency (EPA) on the use of chemical seed-dressing products have made this disease a major concern among seed producers. In the present studies, 1,2,4-triazole derivat ...
... Root drench-treatment of tobacco seedlings with Bacillus sp. BS107 (BS107) suppressed disease development caused by the pathogen Pectobacterium carotovorum subsp. carotovotrum SCC1 (SCC1). A determinant of BS107 involved in induced systemic resistance (ISR) against SCC1 was isolated from cell-free culture. ISR bioassay-guided isolation was involved in determining active fractions during chromatogr ...
... This study aimed at evaluating the ability of 6-pentyl-α-pyrone (6PP) isolated from Trichoderma koningii CTX1172 (AUMC 11520), an endophytic fungal strain to induce systemic resistance in tobacco (Nicotiana tabacum cv. White Burley) plant against tobacco mosaic virus (TMV). 6PP exhibited 10–60% symptoms inhibition at low concentrations (10–30 μg mL⁻¹) achieving 100% biocontrol efficacy at high con ...
... Leptosphaeria maculans, the cause of stem canker of oilseed rape (OSR), exhibits gene-for-gene interactions with its host plant. The race structure of L. maculans was assessed on the basis of the analysis of 1011 isolates collected in France between 1990 and 2000, with regards to three AVR genes, AvrLm1, AvrLm2 and AvrLm4. The effect of selection pressure, due to large-scale cropping of Rlm1 culti ...
... Two binucleate Rhizoctonia (BNR) isolates (HLJ-21 and HLJ-57) were recovered from diseased sugar beet seedlings in Heilongjiang Province, Northeastern China in May, 2015. The two isolates were identified as members of the anastomosis group (AG)-W based on morphological characteristics, hyphal anastomosis, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), and phylogenet ...
... Botrytis cinerea (anamorph of Botryotinia fuckeliana) is a filamentous ascomycete that causes grey mould on grapevine. We had previously described two distinct populations, named HydR1 and non-HydR1, that comprise two distinct genetic entities based on genetic polymorphism, natural resistance towards the fungicide hydroxyanilide fenhexamid, and vegetative incompatibility between them. Here, we use ...
... Bursaphelenchus xylophilus is an economically important pathogen that has caused serious damage to pine forests. Fatty acid and retinol-binding proteins (FARs) are nematode-specific proteins. One FAR gene, Bx-FAR-1, was identified from the transcriptome of B. xylophilus as a putative effector. It was upregulated in both highly and weakly virulent isolates in early infection stages. Transient expre ...
... Root-knot nematodes are obligate parasites that invade the roots of agricultural plants and induce the formation of specialized feeding structures, especially races 3 and 4 of the southern root-knot nematode. However, not much is known about the defense mechanisms of plants against the invasion of M. incognita race 1. In this study, we characterized and performed functional analysis of the CC-NBS- ...
... Nine avirulence genes (AvrLm1-AvrLm9) were identified in Leptosphaeria maculans, the causal agent of stem canker of oilseed rape (OSR), combinations of which could theoretically generate up to 512 different races of the fungus. L. maculans displays a high evolutionary potential to adapt to novel resistance genes as illustrated by the Rlm1 breakdown in France, where virulent populations became prev ...
... Fusarium graminearum and Zymoseptoria tritici cause economically important diseases of wheat. F. graminearum is one of the primary causal agents of Fusarium head blight (FHB) and Z. tritici is the causal agent of Septoria tritici blotch (STB). Alternative control methods are required in the face of fungicide resistance and EU legislation which seek to cut pesticide use by 2030. Both fungal pathoge ...
... The cereal root-knot nematode Meloidogyne naasi can cause serious cereal crop losses. The nematode is also found in agricultural fields where non-host crops are grown. Control of M. naasi can be based on preventing its spread, host resistance and crop management as well as on the design of crop rotation systems. Detection methods are required for these purposes and can also be helpful for inspecti ...
... The partial nucleotide sequence of the RNA polymerase gene from one isolate of Pepino mosaic virus (PepMV) was determined. Phylogenetic and distance analysis indicated that this isolate was related to other isolates of PepMV previously reported. To develop a method for detecting PepMV by reverse transcriptase-polymerase chain reaction (RT-PCR), a pair of primers was designated from RNA polymerase ...
... Zeamines are family of potent antibiotics and virulence determinants produced by the rice foot rot bacterial pathogen Dickeya zeae. So zeamines are important for the pathogenesis of D. zeae and development of new strategies against this devastating disease. In this study, we show that production of zeamines is positively modulated by ZmsO, which is a conserved Sfp-type phosphopantetheinyl thransfe ...
... Rhizoctonia cerealis causes sharp eyespot in cereals and the pathogen survives as mycelia or sclerotia in soil. Real-time Polymerase Chain Reaction (qPCR) assays based on TaqMan chemistry are highly suitable for use on DNA extracted from soil. We report here the first qPCR assay for R. cerealis using TaqMan primers and a probe based on a unique Sequence Characterised Amplified Region (SCAR). The a ...
... Watermelon mosaic virus (WMV), a plus-strand RNA virus that belongs to the family Potyviridae, is one of the most damaging viruses that infect cucurbit crops. However, isolates of this species frequently induce mild symptoms, which makes difficult to manage the disease in the field and breeding programs. A new generation of marker genes has been recently developed to visually track plant virus inf ...
... ‘Gold Veined Oxalis’ (Oxalis debilis) is an ornamental plant cultivar with attractive yellow vein foliage. After grafting scions of this plant to O. debilis plants that lacked the yellow vein foliage, grafted plants developed yellow vein suggesting that an infectious agent was the cause of the yellow vein. DNA extracts from O. debilis plants showing yellow vein were used in rolling circle amplific ...
... The root knot nematode Meloidogyne javanicaa plant parasite that is an agricultural pest, establishes and maintains a permanent feeding site within plant roots. In order to gain a broad view of gene expression in nematode feeding sites during the compatible response of tomato to root knot nematodes, we used the tomato spotted microarray chip, followed by real-time reverse transcription polymerase ...
... Uncultivable bacteria from the genus ‘Candidatus Phytoplasma’ are associated with grapevine yellows (GY) diseases worldwide. In Euro-Mediterranean viticultural areas, GY are most frequently caused by Bois Noir (BN) and Flavescence Dorée (FD) phytoplasmas. Surveys of GY in Croatia have been conducted regularly since 1997. BN phytoplasmas have been found to be widespread, while FD phytoplasmas were ...
... Verticillium wilt is a devastating disease caused by the soil-borne fungus Verticillium dahliae that causes severe wilt symptoms in more than 400 plant species, including economically important cotton. However, the molecular mechanism of plant resistance to Verticillium remains unclear. In this study, we identified an Arabidopsis mutant, vsad1 (verticillium sensitive and anthocyanin deficient 1), ...
... Pepper yellow mosaic virus (PepYMV) is the most important potyvirus infecting sweet pepper in Brazil. In this study, twenty isolates of PepYMV were obtained from commercial sweet pepper crops. To confirm virus identity, the coat protein gene was completely sequenced for eleven of these isolates, and partially sequenced for the other nine isolates. The amino acid identities obtained were above 93% ...
... South American leaf blight (SALB) of the Pará rubber tree, Hevea brasiliensis Muell. Arg., caused by the plant pathogenic fungus Microcyclus ulei (Henn.) Arx, is recognized as the most serious threat to the natural-rubber industry worldwide. While the pathogen is currently restricted to South America, the warm humid climatic conditions in Asia and Africa, which contribute to over 97 % of world’s n ...
... Phytophthora fragariae, the cause of strawberry red stele disease, is a quarantine pathogen in Europe. Detecting low levels of infection requires sensitive and specific methods. In the past, Dutch and English inspection services have used bait plants to test strawberry propagation stocks destined for export. Increasingly though, PCR is being incorporated into these testing procedures in an effort ...
... Control of septoria tritici blotch in Irish winter wheat crops has been reliant on the application of azoles fungicides for over a decade. The resulting intensive applications of azole fungicides have placed the Irish Zymoseptoria tritici populations under immense pressures to adapt. Evidence of this adaptation is observed in the decreasing sensitivity of the Irish population to the azole fungicid ...
H+/K+-exchanging ATPase; H-transporting ATP synthase; Potato virus Y; Solanum tuberosum; alleles; breeding; cultivars; gene dosage; hypersensitive response; leaves; liquid chromatography; mitochondria; monodehydroascorbate reductase (NADH); photosynthesis; potatoes; protein composition; proteins; proteomics; resistance genes; screening; tandem mass spectrometry; tetraploidy; two-dimensional gel electrophoresis
Abstract:
... The Ny-1 gene confers hypersensitive response (HR) to Potato virus Y (PVY) in potato cultivars (Solanum tuberosum L.). Tetraploid potato breeding clone PB07–37 possessing the allele Ny-1 in a duplex state was developed. After PVY infection, the size of necrotic lesions in leaves of PB07–37 was reduced by approximately 68% in relation to cultivar Rywal plants displaying Ny-1 in a simplex dosage. Tw ...
climate change; crop production; cropping systems; disease control; farms; field crops; food security; greenhouse gas emissions; greenhouse gases; land use change; nitrogen fertilizers; reduced tillage; soil organic carbon; United Kingdom
Abstract:
... Crop disease not only threatens global food security by reducing crop production at a time of growing demand, but also contributes to greenhouse gas (GHG) emissions by reducing efficiency of N fertiliser use and farm operations and by driving land use change. GHG emissions associated with adoption of reduced tillage, organic and integrated systems of field crop production across the UK and selecte ...
von der Ohe, Christiane; Gauthier, Victoria; Tamburic-Ilincic, Lily; Brule-Babel, Anita; Fernando, W. G. Dilantha; Clear, Randy; Ward, Todd J.; Miedaner, Thomas
Fusarium graminearum; cultivars; risk; chemotypes; hosts; breeding; spring wheat; Fusarium head blight; field experimentation; deoxynivalenol; Germany; Canada
Abstract:
... Twenty four isolates of Fusarium graminearum, half of which were 3-acetyldeoxynivalenol (3-ADON) and half 15-acetyldeoxynivalenol (15-ADON) chemotypes, were tested for their ability to produce deoxynivalenol and to cause Fusarium head blight (FHB) in spring wheat cultivars. The objectives of this study were to determine (1) whether 3-ADON isolates differ in aggressiveness, as measured by the FHB i ...
... Bacterial spot caused by several Xanthomonas spp. is an economically important disease of tomato (Solanum lycopersicum L.). Host resistance to the disease is partially dominant or incomplete, which requires accurate assessment of disease severity for genetic studies of resistance. In the present study, three independent experiments were conducted to investigate the feasibility of using image analy ...
... Potato seed certification is a disease management tool that minimises the risk of spreading seed tuber-borne inoculum of infectious diseases. Traditionally, certification sampling strategies have relied upon visual assessment of a seedlot from samples taken at one or two points within the load of seed tubers. However methodologies in selection of tuber samples have not been critically assessed for ...
Xanthomonas campestris pv. musacearum; bananas; carrier state; cutting; disease incidence; farmers; farms; inoculum; labor; planting; production technology; shoots; stems; Burundi; Democratic Republic of the Congo; Uganda
Abstract:
... Xanthomonas campestris pv. musacearum, the causal agent of Xanthomonas wilt of banana (XW), does not infect or cause symptom development in all physically attached shoots in an infected mat. Incomplete/partial systemicity and latent infections often occur. The single diseased stem removal (SDSR, the removal of only symptomatic plants) technique depends on these observations. The SDSR technique, as ...
... Aflatoxin contamination of tree nuts is a growing concern for pistachio producing countries. Development of competitive exclusion strategies through application of atoxigenic Aspergillus flavus isolates is a highly effective route of natural aflatoxin mitigation. Aflatoxin assays conducted on a high number of native A. flavus isolates are a first step to identify potential biological control isola ...
... A protocol involving PCR, shot-gun cloning and sequencing was developed as a pre-diagnostic screening tool working directly on disease symptoms. The method was used to show the presence of biotrophic and non-biotrophic eukaryotic plant pathogens in leaves and fruits. ...
... Southern corn leaf blight (SCLB), caused by the fungus Bipolaris maydis, is a disease that significantly affects maize productivity across the globe. A detached leaf assay (DLA) was developed to rapidly assess maize resistance to SCLB. Several experiments were conducted to: (i) identify a highly virulent B. maydis isolate; and to determine the most appropriate (ii) phytohormone to maintain viabili ...
... A semi-selective medium for isolation of Xanthomonas axonopodis pv. vignicola from cowpea (Vigna unguiculata) plant and soil samples was developed. Twelve carbon and five nitrogen sources were tested with four strains of X. axonopodispv.vignicola, and 25 antibiotics were screened against saprophytes. D-cellobiose (10g) was selected as the optimal carbon source. Among the antibiotics, cefazoline in ...
... The association of Fusarium graminearum isolate China-9 with the dsRNA mycovirus FgV-ch9 was evaluated for hypovirulence-related traits. Single conidia-originating cultures of China-9 isolate can be associated either with high, medium or low amounts of the viral dsRNAs. At high and medium dsRNA levels, China-9 isolates exhibit reduced mycelia growth rate and conidiation capacity, abnormal colony m ...
... In a field experiment conducted over two growing seasons, the effectiveness and phytotoxicity of inorganic fungicides such as sulphur, lime sulphur, copper, silicon and Armicarb (a new formulation of potassium bicarbonate) was compared with water for the control of primary apple scab infections in Belgium on high, medium and low scab-susceptible cultivars (cvs 'Pinova', 'Pirouette' and 'Reinette d ...
... A dynamic model, called VenInf, was developed to forecast infection of pear leaves by conidia of Venturia nashicola. By simulating conidial infection processes following a rain event, the model estimates % conidia that successfully infected leaves at the end of an infection period. The model is mainly derived from logistic models developed from recent laboratory and glasshouse experimental results ...
... The quarantine nematode Bursaphelenchus xylophilus is the causal agent of pine wilt disease in Asia and Europe. Differentiation between B. xylophilus and other related, non-pathogenic species can be ambiguous when based exclusively on morphological characters. The morphology of B. mucronatus and B. fraudulentus most closely resembles that of B. xylophilus. Moreover, all of these nematodes are foun ...
... This paper describes a factorial trial designed to investigate the delivery systems of fungal biological agents (Clonostachys rosea), applied as single strain or as strain mixture, in comparison with copper hydroxide as a chemical standard against Moniliophthora roreri in cocoa. Application techniques compared were motorised mistblowers fitted with rotary atomisers and hydraulic sprayers fitted wi ...
... Resistance of anthurium cultivars to infection by Acidovorax anthurii, the causal agent of bacterial leaf spot disease was investigated using seven inoculation methods, four inoculum concentrations and two different plant ages towards developing a screening method for identification of disease resistance. Injection of 1 mL of 1.5 × 10⁹ CFU mL⁻¹ three-quarter way down the intact petiole from the in ...
... A fuzzy control system (FCS) was developed to determine whether a fungicide application is needed to control Plasmopara viticola, the causal agent of downy mildew, in a vineyard. The FCS was conceived as an expert system to be used in connection with vite.net , which is a decision support system (DSS) for sustainable vineyard management. Using the information provided by the DSS, the FCS was able ...
... A soil-based glasshouse crop procedure was developed to screen lettuce lines for resistance to Sclerotinia sclerotiorum. Six sequential crops of 19 different lettuce lines with a range of cultural morphologies, reported previously to exhibit some form of resistance to S. sclerotiorum, were planted in a glasshouse infested with S. sclerotiorum and natural disease development compared with a standar ...
... Rhizoctonia solani Kuhn is a serious plant pathogenic fungus, causing various types of damage to sugar beet (Beta vulgaris L.). In Europe, the disease is spreading and becoming a threat for the growing of this crop. Plant resistance seems to be the most practical and economical way to control the disease. Experiments were carried out to optimise a greenhouse procedure to screen plants of sugar bee ...
... Fusarium graminearum, a fungal pathogen of wheat, barley, and corn, produces a variety of trichothecene mycotoxins that are important as virulence factors and as seed contaminants reducing grain quality. A previous survey of the pathogen in New York State identified variation in genes indicative of trichothecene diversity. Recently F. graminearum strains that produce a newly characterized trichoth ...
Puccinia striiformis f. tritici; center of diversity; center of origin; genes; genetic improvement; genetic recombination; isogenic lines; pathogens; pathotypes; stripe rust; virulence; wheat; Europe; Pakistan
Abstract:
... Information on the pathogen virulence profile and diversity across locations is crucial for host germplasm improvement and deployment. The rapid acquisition of virulence to host resistance by the wheat yellow/stripe rust pathogen (Puccinia striiformis f.sp. tritici: PST), makes it crucial to know about its virulence and pathotype diversity. Recent studies have shown the plausible centre of origin ...
... Root-knot nematodes (Meloidogyne spp.) threaten the livelihood of millions of farmers producing coffee worldwide. The use of resistant plants either as cultivars or rootstocks appears to be the single most effective method of control. A screening method was developed to evaluate large populations of plants for resistance to root-knot nematodes. Two coffee cultivars, one susceptible and the other r ...
Passiflora; Potyviridae; cosmetics; floriculture; fruit growing; pathogens; plant breeding; research and development; Africa; Asia; Australia; Brazil
Abstract:
... Plants of the Passiflora genus are widely cultivated for the production of fruit, cosmetics and pharmacological products and for floriculture. Here, we review the history of the identification of viral pathogens involved in passion fruit woodiness disease, which can affect different species of Passiflora. Additionally, we discuss prospects for research and development related to this pathosystem a ...
... Anguina wevelli is a pathogenic grass parasitic nematode, however it is difficult to identify based simply on morphology. This study developed a loop-mediated isothermal amplification (LAMP) assay to detect A. wevelli. The LAMP method developed could specifically detect A. wevelli in 45 min, and the detection limit was 1/80000 of the total DNA extracted from a single juvenile (J2), an equivalent o ...
Guignardia; imports; pycnidia; European Union; Phyllosticta; Citrus; new species; United States
Abstract:
... Guignardia citricarpa Kiely (anamorph Phyllosticta citricarpa Van der Aa), the causal agent of citrus black spot disease, is subject to phytosanitary restrictions in the EU and USA, such that consignments of citrus are rejected at import if citrus black spot is identified on inspection. Due to the variability of black spot symptoms, positive identification solely on the basis of visual inspection ...
... Apple scab caused by the fungus Venturia inaequalis can result in significant crop losses if not managed effectively. Sanitation as part of an integrated management strategy aims to significantly reduce primary inoculum to lower the disease pressure. This study evaluates the possibility of molecular detection and quantification of ascospore discharge and the use of this method to test for efficacy ...
... Biological farming using a mixture of bio-agents that are compatible with each other and adapted to the plant rhizosphere is a strategic approach to manage crop disease. This study is a unique approach to manage the root-rot disease complex caused by Macrophomina phaseolina, Rhizoctonia solani, and Fusarium solani in sunflower plants grown in calcareous soil using a mixture of rhizobacteria strain ...
Arabidopsis thaliana; Cherry leaf roll virus; deciduous forests; forest trees; genes; meristems; pathogenicity; phylogeny; plant organs; seedlings; seeds; virus transmission; viruses; Northern European region
Abstract:
... The wide natural incidence of Cherry leaf roll virus (CLRV) in deciduous forest trees and nurseries in northern Europe is believed to have occurred, apart from occasional mechanical spread and transmission through grafting, mainly by seed transmission. The mode of the vertical transmission and its role in the epidemiology of the virus has not been investigated, basically due to the inconvenient ho ...
... The Fusarium genus causes devastating plant diseases worldwide, in which Fusarium oxysporum is the most serious crop pathogen. Disease monitoring is the basis of integrated pest management of any disease. The lack of rapid, accurate, and reliable device to detect and identify plant pathogens is one of the main limitations in integrated disease management. This study describes an efficient and quan ...
... An improved multiplex RT-PCR assay combined with magnetic nanobeads (MNB-RT-PCR) was developed for simultaneous detection of four sweet potato viruses, Sweet potato virus G (SPVG), Sweet potato feathery mottle virus (SPFMV), Sweet potato virus C (SPVC) and Sweet potato chlorotic fleck virus (SPCFV). Four primer pairs specific for each virus were designed and the corresponding PCR products were 169 ...
... Wheat is affected by many diseases, in Germany eight fungal diseases are recorded during the cultivar registration process. For a commercially successful cultivar, therefore, at least moderate resistances to important diseases, like yellow rust (YR) and Fusarium head blight (FHB), are necessary. Additionally, in 2013 a regional stem rust (SR) epidemic occurred in Central Germany for the first time ...
... Kiwifruit (Actinidia spp.) is an important horticultural crop in the world. Previous studies showed that a number of viruses were found in kiwifruit around the world. To detect the multiple viruses in kiwifruit quickly and effectively, a multiplex reverse transcription polymerase chain reaction (multiplex RT-PCR) method was developed to detect four viruses simultaneously in kiwifruit: Actinidia ch ...
... The highly destructive chestnut blight disease can be successfully controlled by infecting the virulent strain of C. parasitica with the hyperparasitic mycovirus CHV-1. The artificial application of the virus-induced hypovirulence, however, requires that the vegetative compatibility (vc) diversity in the target C. parasitica population be determined beforehand. Conventional vc type determination b ...
... Cytokinin (CTK)-mediated pathways play essential roles in plant stress responses. How CTK receptors affect plant resistance to viral pathogens remains unclear. Tobacco mosaic virus [recombinant TMV encoding green fluorescent protein (TMV-GFP)] was used to investigate the role of Nicotiana tabacum CRE1 (CTK receptor 1) in modulating virus susceptibility in N. tabacum. CRE1 deficiency enhanced the s ...
... Kinesins, of which there are 650 members in 15 classes, have two main functions: cell separation and protein transport. In S. cerevisiae, the kinesin-like myosin passenger-protein Smy1(belonging to the TRAFAC class myosin-kinesin ATPase superfamily), which is transported by myosin-5,is part of a negative feedback mechanism that controls actin cable length and prevents overgrowth. The current study ...
... This study examines the effects of a vegetable fungicide on sugar beet powdery mildew (Erysiphe betae) and cucumber powdery mildew (Erysiphe cichoracearum). The formulations consisting of a dispersion of Brassicaceae meal in vegetable or mineral oils on infected leaves of sugar beet, reared in the greenhouse, and of musk melons cultivated under plastic tunnels, were tested in comparison to each oi ...
... The isolate BOR-3, collected in Slovakia in 1996, was recently identified as a natural recombinant between an M and D type of Plum pox virus (PPV). Biological assays demonstrated its capacity to be aphid- and graft-transmitted to various Prunus spp. hosts. A study was carried out to determine the further presence of PPV recombinants in two epidemiologically distinct areas - Slovakia and France. To ...
... Lasiodiplodia theobromae (Pat.) Griff. & Maubl, Neofusicoccum parvum Pennycook & Samuels, N. mangiferae Syd. & P. Syd., and Fusicoccum aesculi Corda, all anamorphs of Botryosphaeriaceae species, are the causal agents of mango stem-end rot and fruit rot in Taiwan. Identification of these fungal species based on morphology has not been easy due to their extensive plasticity for some of the morpholog ...
... Mycosphaerella nawae is the causal agent of circular leaf spot of persimmon. A polymerase chain reaction (PCR) based protocol was developed for M. nawae-specific identification from pure culture, or infected symptomatic and asymptomatic persimmon tissues. Variation among the internal transcribed spacer regions (ITS) of the ribosomal DNA (rDNA) sequences of potentially related fungal species in per ...
... Oospores, the only overwintering structures of Plasmopara viticola, the causal agent of grapevine downy mildew, are the unique source of inoculum for primary infections in vineyards. We show that their germination dynamics depend on both climatic and endogenous factors. In particular, overwintering in controlled conditions suggests that low temperatures prolong the oospore germinability, while con ...
databases; digital images; image analysis; leaves; signs and symptoms (plants)
Abstract:
... The segmentation of symptoms during image analysis of diseased plant leaves is an essential process for detection and classification of diseases. However, there are challenges involved in the task, many of them related to the variability of image and host/symptom characteristics and conditions. As a result of those challenges, the methods proposed in the literature so far focus on a specific probl ...
... Soybean (Glycine max (L.) Merill, cv. Williams 82) plants and cell cultures respond to avirulent pathogens with a hypersensitive reaction. After inoculation of soybean with Pseudomonas syringae pv. glycinea, carrying the avirulence gene avrA, or zoospores from the fungus Phytophthora sojae Race 1, a resistance-gene-dependent cell death programme is activated. A new gene was identified by different ...
DNA primers; Globodera; alternative splicing; cyst nematodes; diagnostic techniques; genes; messenger RNA; potatoes; quantitative polymerase chain reaction; sequence analysis; United States
Abstract:
... Globodera ellingtonae, a new cyst nematode species recently detected in Oregon and confirmed to reproduce on potato, shares key morphological features with the two species of potato cyst nematode (PCN; G. rostochiensis and G. pallida) which are of quarantine concern. Currently no methods are available for the molecular diagnosis of this new Globodera species. In this study, we cloned a chorismate ...
... A new dagger nematode, Xiphinema tica n. sp., is described and illustrated from several populations extracted from soil associated with several crops and wild plants in Costa Rica. The new dagger nematode is characterised by a moderate body size (3276–4240 μm), a rounded lip region, ca 13.5 μm wide, separated from body contour by a shallow depression, amphidial fovea large, stirrup-shaped, a moder ...
... In April 2001, stunted barley plants bearing mosaic symptoms were observed in a field in France (Marne Department, 51). Rod-shaped and flexuous particles were visualized by electron microscopy and positive serological reactions were detected by ELISA with Barley yellow mosaic virus (BaYMV) and Soil-borne cereal mosaic virus (SBCMV) polyclonal antisera. The tubular virus which was soil transmissibl ...
... Recent taxonomic advances, based on biochemical and genotypic processes demonstrate that the plant pathogenic species Pseudomonas cichorii consists of a cluster of closely related genomic groups. Prior to this study, three morphotype groups had been described (C1-C3), all sharing various phenotypic and biochemical characters but partially differing in their DNA content. All entities of the complex ...
... “Candidatus Liberibacter solanacearum”, a phloem-limited and Gram-negative bacterium that is spread from infected to healthy plants by psyllid insect vectors, is an economically important pathogen of solanaceous and carrot crops in the Americas, New Zealand and Europe. Three haplotypes of “Ca. L. solanacearum” have previously been described, two (LsoA and LsoB) in relation to solanaceous crops in ...
... Scab, caused by Venturia nashicola, is the most important disease of Asian pears. In Japan, the most popular and widely grown pear cultivar (cv.) Kousui is resistant to black spot, caused by the Japanese pear pathotype of Alternaria alternata, but highly susceptible to scab. Recently, a new interspecific pear cv. Yutaka carrying high fruit quality was registered officially after a cross between th ...
... A real-time PCR assay specific for Sclerotium cepivorum, the causal agent of white rot in onions, was developed for use with a new DNA extraction method capable of processing up to 1 kg of soil in weight. The assay was specific for S. cepivorum when tested against 24 isolates representative of 14 closely related species and other pathogens of onion. The assay was highly sensitive when used with so ...
... A new disease was observed on Trifolium dasyurum, with symptoms beginning as a halo spot and developing into a leaf blight. The causal organism was identified by microscopy and DNA sequence studies as Botrytis fabae. This strain of B. fabae was also demonstrated to cause disease on foliage of a range of pulse crops, including Vicia faba, Pisum sativum, and Lens culinaris. This study demonstrates t ...
Citrus sinensis; Guignardia citricarpa; fruit diseases; fruits; fungi; inoculation methods; oranges; orchards; pathogenicity; trees; Brazil
Abstract:
... Citrus black spot (CBS) is a fungal disease, caused by Guignardia citricarpa, that has a high economic impact on citrus. Although G. citricarpa has been associated with black spot of citrus, an adequate pathogenicity test is still not available. Thus, our objective was to develop and evaluate a simple, safe, and practical pathogenicity test. We used fruits from Pera-Rio and Valencia sweet orange t ...
... A technique to improve the sporulation of Microdochium nivale in culture and to produce mycelium-free conidial suspensions was evaluated using cellophane-covered potato dextrose agar (PDA). Time to sporulation was significantly shorter on the cellophane-covered PDA (P < 0.001), yields of conidia were higher (P < 0.01) and conidial suspensions were produced virtually free of the mycelial fragments ...
... A new disease of sugar beet called Syndrome des Basses Richesses, which appeared in Burgundy and Franche-Comte, France, in 1991, is of uncertain aetiology. However, evidence for aerial transmission of the disease, symptom similarity with yellow wilt and preliminary results of phytoplasma detection, support the hypothesis of a phytoplasma being associated to the disease. A search for a natural phyt ...
... A new longidorid nematode, Longidorus persicus n. sp., is described and illustrated from a population extracted from soil associated with wild rose (Rosa sp.) naturally growing in the mountains close to the village of Cheshmeh-e-Nezamei near the city of Gilan-e-Gharb, Kermanshah province, western Iran. The new needle nematode is characterised by a large body size (6550–7763 μm), an anteriorly flat ...
Allium cepa; Allium fistulosum; Allium porrum; Allium schoenoprasum; Pseudomonas syringae; blight; carbon; chives; essential genes; green onions; leaves; leeks; multilocus sequence typing; pathogens; pathovars; seeds; South Africa
Abstract:
... Bacterial pathogens of onion (Allium cepa) plants and their undetected presence in seed can cause substantial losses to onion producers. In this study, 23 Pseudomonas syringae strains were isolated from five onion plants and 18 onion seeds. The symptoms on leaves and seed stalks were irregular lesions with necrotic centres and water soaked margins. The aim of the study was to characterize these P. ...
... Pin nematode species are widely distributed and known to be associated with damage to a variety of shrubs, grasses, fruit and flowering trees. So far, no pin nematode species has been reported from Mulberry in China. During this study, a new Paratylenchus species recovered from the rhizosphere of mulberry tree, in Zhejiang Province is described and molecularly characterized. The species can be cha ...
Agonomycetes; plant pathogenic fungi; fungal diseases of plants; Stenotaphrum secundatum; pasture plants; pastures; mycelium; pathogenicity; sporulation; ribosomal RNA; ribosomal DNA; internal transcribed spacers; molecular systematics; phylogeny; new species; Western Australia
Abstract:
... A sterile white fungus was isolated from the healthy looking roots of buffalo grass (Stenotaphrum secundatum) grown on cleared bush land in Perth, Western Australia. The fungal strain was pathogenic on 12 plant species screened under the greenhouse conditions. The clamp connections and dolipore septa indicated that the isolate was a Basidiomycete. Mycelial features, growth rate at different temper ...
... Rhizoctonia solani is an important pathogen of potatoes causing stem canker and black scurf. The fungus is a species complex comprised of 13 known anastomosis groups (AGs). AG3-PT is the anastomosis group frequently associated with disease in potatoes. A real-time PCR assay was designed to the rDNA ITS region of AG3-PT isolates to enable the pathogen to be detected directly in tuber and soil sampl ...
Nadine Ali; Johannes Tavoillot; Thierry Mateille; Elodie Chapuis; Guillaume Besnard; Ahmed El Bakkali; Carolina Cantalapiedra-Navarrete; Gracia Liébanas; Pablo Castillo; Juan E. Palomares-Rius
... Low density of an unknown root-knot nematode was found on wild olive soils at Cape Spartel near Tanger city in northern Morocco. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes, as well as ribosomal DNA (rDNA) and mitochondrial DNA (mtDNA) sequences demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. The species is ...
Centaurea solstitialis; Lactuca tuberosa; Picris; Ramularia; Ranunculus; new species; Iran
Abstract:
... Ramularia ranunculicola sp. nov. (Mycosphaerellaceae) is described from Iran on Ranunculus muricatus and compared with other species reported on Ranunculus spp. Ramularia carletonii on Lactuca tuberosa and R. nagornyi on Centaurea solstitialis are newly reported from Iran, and Picris strigosa is a new host for R. picridis (= R. inaequalis s. lat.). ...
... Five populations of a new dagger nematode species were recovered from natural grasslands and forests of north and northwest Iran, and described based upon morphological and molecular data in present paper. Xiphinema hyrcaniense n. sp. is characterized by 3.9–5.5 mm long females, having 102–142 μm long odontostyle, 64–88 μm long odontophore, guiding ring located at 115–147 μm distance from anterior ...
... The vector-borne bacterial pathogen Xylella fastidiosa is widely distributed in the Americas; in the last decade it has emerged as a serious threat for agricultural crops, natural environment and landscape in Europe. Following the first EU outbreak in 2013 in southern Italy, associated with a severe disease in olive trees, annual mandatory surveys are now in place in the Member States, leading to ...
Talaromyces; antagonists; biological control agents; fruit diseases; mangoes; spores
Abstract:
... The antagonist, Talaromyces tratensis KUFA 0091, displayed the ability to control stem end rot caused by L. theobromae on mango cv. ‘Nam Dok Mai’ and ‘Nam Dok Mai no. 4’. The results showed that mango treated with spore suspension of T. tratensis KUFA 0091 at 10⁶ spores/ mL exhibited significant suppression (P < 0.05) of lesion development of up to 85% and 77% on mango cv. ‘Nam Dok Mai’ and ‘Nam D ...
... A previously unknown haplotype of the plant pathogen ‘Candidatus Liberibacter solanacearum’ (Lso) was found in cultivated carrots and parsnips in eastern Finland. That same haplotype was found in western Finland, over 300 km away, in the family Polygonaceae, the species Fallopia convolvulus (wild buckwheat) and Persicaria lapathifolia (pale persicaria) growing as weeds within carrot and parsnip fi ...
... Guggal (Commiphora wightii (Arnott) Bhandari comb. nov.) is a small tree which is tapped for medicinally important oleo–gum–resin. Naturally infected plant oozes oleo–gum–resin from its trunk and primary branches. However, in either case, the plant dies slowly after oozing. A bacterium was established to be responsible for these phenomena. Four isolates of this bacterium were characterised by bioc ...
... California privet (Ligustrum ovalifolium Hassk.) plants exhibiting leaf yellowing, witches’ broom, dieback and decline symptoms were observed for two years (2010–2011) in three gardens at Adana region (Turkey). DNA isolated from symptomatic and healthy plants was used to amplify 16S rDNA fragments by direct and nested-PCR. Phytoplasmas were detected in 21 symptomatic plants, out of 30 samples coll ...
... The study presents the first report on biocontrol of brown sheath rot disease of rice caused by Pseudomonas fuscovaginae using rhizo-bacterial isolate Bacillus amyloliquefaciens Bk7. Four potential bioactive antagonists were selected from 120 Bacillus isolates. Results obtained from in vitro laboratory assay showed that rhizosphere bacterial strain Bk7 and its metabolites significantly suppressed ...
... The root-knot nematode (RKN) Meloidogyne mayaguensis is considered as one of the most damaging RKN species because of its extremely wide host range. Recent surveys have shown the rapid spread of this parasite in agro-ecosytems, often making crop cultivation not viable in the heavily infested areas. Here, we report the identification, molecular cloning, genomic organisation and sequence analysis of ...
... Brown rot on cherry and plum, caused by Monilinia laxa, is an important disease, for which overwintered mummified fruit is a significant inoculum source for infection of flowers and fruit in the spring. Experiments were conducted to assess the potential of applying plant protection products in winter and/or early spring to suppress sporulation on mummified fruit. Products tested included Indar 5 E ...
... A zonal centrifugation method, known as the Hendrickx centrifuge technique, was tested for routine detection of winter sporangia of Synchytrium endobioticum in soil. In four experiments the ability of the Hendrickx centrifuge to extract the sporangia from soil was compared with a method used by the Dutch Plant Protection Service, which is a modification of the recommended EPPO method. Naturally an ...
... Downy mildew is a major disease of boysenberries in New Zealand, caused by Peronospora sparsa. Most boysenberry plant material, including tissue culture propagated plants are systemically infected and this pathogen also presents as a latent infection. The current nested PCR method to detect latent infection of P. sparsa in asymptomatic boysenberry plants is time consuming as it employs two separat ...
... Papaya apical curl necrosis (PACN) has frequently been observed in several Brazilian states. Affected plants exhibit foliar chlorosis, curvature of the apex, shortening of the internodes leading to bunching of the crown leaves, necrosis of the young apical parts, leaf drop, and dieback. Naturally infected plants were sampled and subjected to PCR assays, which confirmed that a phytoplasma was assoc ...