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Sun Y, Jiang R, Peng D, Zhang Y, Peng H, Long H. Morphological and Molecular Characterization of a New Root-Knot Nematode, Meloidogyne limonae n. sp. (Nematoda: Meloidogynidae), Parasitizing Lemon in China. PLANT DISEASE 2024; 108:833-846. [PMID: 37877995 DOI: 10.1094/pdis-05-23-0919-sr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Root-knot nematodes of the genus Meloidogyne parasitize the roots of thousands of plants and can cause severe damage and yield losses. Here, we report a new root-knot nematode, Meloidogyne limonae n. sp., parasitizing "lemon" (Citrus limon) in Hainan Province, South China. Lemon trees infected by the root-knot nematode showed poor-quality lemons, chlorosis of foliage, weak growth, and numerous root galls with white females and egg masses protruding outside. Phylogenetic trees of sequences within the ribosomal and mitochondrial DNA demonstrated that this species differs clearly from other previously described root-knot nematodes. Morphologically, the new species is characterized by an oval-shaped perineal pattern and the lateral field marked by a ridge of cuticle on one or both sides; the dorsal arch is low, with fine to coarse, smooth cuticle striae; the vulva slit is centrally located at the unstriated area; the spicules of males are arcuate and curved ventrally; the gubernaculum is distinct and curved; the labial disc of second-stage juveniles is prominent and dumbbell shaped; stylet knobs are oval and sloping backwardly; pharyngeal glands are not filling the body cavity and overlapping the intestine ventrally; and the conical tail is gradually tapering. Phylogenetic trees based on the ITS1-5.8S-ITS2, D2-D3 of the 28S rDNA, and COI and COII-16S rRNA genes of the mtDNA showed that M. limonae n. sp. belongs to an undescribed root-knot nematode lineage that is separated from other species with the resemblance in morphology, such as M. floridensis, M. hispanica, M. acronea, and M. paranaensis.
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Affiliation(s)
- Yangfang Sun
- Key Laboratory of Integrated Pests Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, P.R. China
| | - Ru Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China
| | - Deliang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China
| | - Yan Zhang
- Modern Agricultural Inspection Testing and Control Center of Hainan Province, Haikou 571100, P.R. China
| | - Huan Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P.R. China
| | - Haibo Long
- Key Laboratory of Integrated Pests Management on Tropical Crops, Ministry of Agriculture and Rural Affairs, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, P.R. China
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Barbosa P, Faria JMS, Cavaco T, Figueiredo AC, Mota M, Vicente CSL. Nematicidal Activity of Phytochemicals against the Root-Lesion Nematode Pratylenchus penetrans. PLANTS (BASEL, SWITZERLAND) 2024; 13:726. [PMID: 38475572 DOI: 10.3390/plants13050726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 02/23/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024]
Abstract
Plant-parasitic nematodes (PPNs) are highly damaging pests responsible for heavy losses in worldwide productivity in a significant number of important plant crops. Common pest management strategies rely on the use of synthetic chemical nematicides, which have led to serious concerns regarding their impacts on human health and the environment. Plant natural products, or phytochemicals, can provide a good source of agents for sustainable control of PPNs, due to their intrinsic characteristics such as higher biodegradability, generally low toxicity for mammals, and lower bioaccumulation in the environment. In this work, the nematicidal activity of 39 phytochemicals was determined against the root-lesion nematode (RLN) Pratylenchus penetrans using standard direct and indirect contact methodologies. Overall, the RLN was tolerant to the tested phytochemicals at the highest concentration, 2 mg/mL, seldom reaching full mortality. However, high activities were obtained for benzaldehyde, carvacrol, 3-octanol, and thymol, in comparison to other phytochemicals or the synthetic nematicide oxamyl. These phytochemicals were seen to damage nematode internal tissues but not its cuticle shape. Also, the environmental and (eco)toxicological parameters reported for these compounds suggest lower toxicity and higher safety of use than oxamyl. These compounds appear to be good candidates for the development of biopesticides for a more sustainable pest management strategy.
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Affiliation(s)
- Pedro Barbosa
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Jorge M S Faria
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, 2780-157 Oeiras, Portugal
- GREEN-IT Bioresources for Sustainability, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, 2780-157 Oeiras, Portugal
| | - Tomás Cavaco
- Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Quinta do Marquês, 2780-157 Oeiras, Portugal
| | - Ana Cristina Figueiredo
- Centro de Estudos do Ambiente e do Mar (CESAM Lisboa), Faculdade de Ciências, Universidade de Lisboa, Biotecnologia Vegetal, DBV, C2, Piso 1, Campo Grande, 1749-016 Lisboa, Portugal
| | - Manuel Mota
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Cláudia S L Vicente
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal
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Asgari M, Eskandari A, Castillo P, Palomares-Rius JE. A new needle nematode, Longidorus zanjanensis sp. nov. (Nematoda: Longidoridae) from north-western Iran. J Helminthol 2023; 97:e81. [PMID: 37933563 DOI: 10.1017/s0022149x23000664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
During a survey of soil nematodes in 2022, a new species of the genus Longidorus, described here as Longidorus zanjanensis sp. nov., was discovered in the rhizosphere of Astragalus sp. in Zanjan Province, Iran. The new needle nematode is described and illustrated based on morphological, morphometric, and molecular traits. Further, its females are characterized by having a long body ranging 5.6-7.7 mm long, lip region anteriorly flattened and almost continuous or slightly offset by a depression with body contour, ca 16.5-18.5 μm wide, amphidial fovea pouch-like without basal lobes, guiding ring at 35-41 μm distance from the anterior end, and an odontostyle and odontophore ranging 102-115 and 47-75 μm long, respectively. The pharyngeal bulb is 123-153 μm long, female reproductive system didelphic-amphidelphic containing sperm, vulva almost equatorial, located at 46.7-51.4% of body length, tail short, rounded to bluntly conoid, bearing two pairs of caudal pores and terminus widely rounded with distinct radial lines in hyaline region (39-50 μm long, c = 122.4-189.4, c' = 0.6-0.8). Males are common, making up to 60% of the adults, and are functional, with spicules 68.0-80.0 μm long, as well as having 8-14 ventromedian copulatory supplements. All four juvenile life developmental stages were present, with the tail of first-stage juvenile conoid shape, dorso-ventrally curved with rounded terminus. The polytomous codes delimiting the new species are: A4-B3-C3-D3-E1-F34-G12-H1-I2-J1-K6. Morphologically, the new species comes close to eight known species of the genus, namely L. apulus, L. armeniacae, L. crassus, L. kheirii, L. soosanae, L. proximus, L. pauli, and L. ferrisi. The morphological differences between the new species and the aforementioned species are discussed. Molecular phylogenetic analyses based on D2-D3 of large subunit (LSU) and internal transcribed spacer 1 (ITS1) rRNA sequences indicate that Longidorus zanjanensis sp. nov. is closely related to L. hyrcanus, L. soosanae, and L. elongatus.
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Affiliation(s)
- M Asgari
- Department of Plant Protection, Faculty of Agriculture, University of Zanjan, 45371-38791, Zanjan, Iran
| | - A Eskandari
- Department of Plant Protection, Faculty of Agriculture, University of Zanjan, 45371-38791, Zanjan, Iran
| | - P Castillo
- Institute for Sustainable Agriculture (IAS), Spanish National Research Council (CSIC), Avenida Menéndez Pidal s/n, Campus de Excelencia Internacional Agroalimentario, ceiA3, CSIC, Córdoba, Spain
| | - J E Palomares-Rius
- Institute for Sustainable Agriculture (IAS), Spanish National Research Council (CSIC), Avenida Menéndez Pidal s/n, Campus de Excelencia Internacional Agroalimentario, ceiA3, CSIC, Córdoba, Spain
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Nguyen TD, Nguyen HT, LE TML, Trinh QP. First report of Pratylenchus penetrans (Nematoda: Pratylenchidae) associated with artichokes in Vietnam. J Nematol 2023; 55:20230060. [PMID: 38264458 PMCID: PMC10805579 DOI: 10.2478/jofnem-2023-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Indexed: 01/25/2024] Open
Abstract
Pratylenchus penetrans is one of the world's most common and destructive root-lesion nematodes and can parasitize more than 400 plant species. P. penetrans has been reported to cause serious damage to artichokes in several countries, such as Greece, Brazil, and France. Until now, there have been no reports of P. penetrans associated with artichokes in Vietnam. In this study, we recorded this species in artichoke fields in Lam Dong province, Vietnam with an average density of 50 nematodes/100g of soil (frequency of appearance at 64.7%). This nematode was associated with symptoms such as yellowing leaves, stunt, and root necrosis of artichokes in Vietnam, indicating its high damaging potential and a need for suitable control strategies. The identification of this species in our study was confirmed by morphology, morphometric data, and molecular characterization of 18S and 28S rRNA regions. Our study also provides the first molecular data of P. penetrans in Vietnam. The inclusion of molecular data for P. penetrans in Vietnam represents a significant contribution to the scientific community and a pivotal advancement in addressing nematode-related challenges in agriculture. This dataset serves as an invaluable reference for various molecular-focused endeavors, including but not limited to molecular identification, pathogenicity studies, and the development of effective management strategies.
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Affiliation(s)
- Thi Duyen Nguyen
- Institute of Ecology and Biological Resources, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
| | - Huu Tien Nguyen
- Institute of Ecology and Biological Resources, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
| | - Thi Mai Linh LE
- Institute of Ecology and Biological Resources, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
| | - Quang Phap Trinh
- Institute of Ecology and Biological Resources, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
- Graduate University of Science and Technology, Vietnam Academy of Sciences and Technology, 18 Hoang Quoc Viet, Cau Giay, 100000Hanoi, Vietnam
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Kefelegn H, Meressa BH, Yon S, Couvreur M, Wesemael WML, Teklu MG, Bert W. First Reports and Morphological and Molecular Characterization of Pratylenchus delattrei and Quinisulcius capitatus Associated with Chickpea in Ethiopia. J Nematol 2023; 55:20230027. [PMID: 37313350 PMCID: PMC10258564 DOI: 10.2478/jofnem-2023-0027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Indexed: 06/15/2023] Open
Abstract
Chickpea (Cicer arietinum L.) is classed among the most important leguminous crops of high economic value in Ethiopia. Two plant-parasitic nematode species, Pratylenchus delattrei and Quinisulcius capitatus, were recovered from chickpea-growing areas in Ethiopia and characterized using molecular and morphological data, including the first scanning electron microscopy data for P. delattrei. New sequences of D2-D3 of 28S, ITS rDNA and mtDNA COI genes have been obtained from these species, providing the first COI sequences for P. delattrei and Q. capitatus, with both species being found for the first time on chickpea in Ethiopia. Furthermore, Pratylenchus delattrei was recovered in Ethiopia for the first time. The information obtained about these nematodes will be crucial to developing effective nematode management plans for future chickpea production.
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Affiliation(s)
- Habtamu Kefelegn
- Nematology Research Unit, Department of Biology, Ghent University, Campus Ledeganck, Ledeganckstraat 35, B-9000Ghent, Belgium
- College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box, 307, Jimma, Ethiopia
| | - Beira Hailu Meressa
- College of Agriculture and Veterinary Medicine, Jimma University, P.O. Box, 307, Jimma, Ethiopia
| | - Sunheng Yon
- Nematology Research Unit, Department of Biology, Ghent University, Campus Ledeganck, Ledeganckstraat 35, B-9000Ghent, Belgium
| | - Marjolein Couvreur
- Nematology Research Unit, Department of Biology, Ghent University, Campus Ledeganck, Ledeganckstraat 35, B-9000Ghent, Belgium
| | - Wim M. L. Wesemael
- Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Burg Van Gansberghelaan 96, B-9820Merelbeke, Belgium
- Laboratory for Agrozoology, Department of Plants and Crops, Ghent University, Coupure links 653, B-9000Ghent, Belgium
| | - Misghina G. Teklu
- Plant Research, Plant Sciences Group, Wageningen University and Research Centre, P.O. Box 16, 6700AA Wageningen, The Netherlands
| | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, Campus Ledeganck, Ledeganckstraat 35, B-9000Ghent, Belgium
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The Fight against Plant-Parasitic Nematodes: Current Status of Bacterial and Fungal Biocontrol Agents. Pathogens 2022; 11:pathogens11101178. [PMID: 36297235 PMCID: PMC9606992 DOI: 10.3390/pathogens11101178] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/08/2022] [Accepted: 10/10/2022] [Indexed: 11/24/2022] Open
Abstract
Plant-parasitic nematodes (PPNs) are among the most notorious and underrated threats to food security and plant health worldwide, compromising crop yields and causing billions of dollars of losses annually. Chemical control strategies rely heavily on synthetic chemical nematicides to reduce PPN population densities, but their use is being progressively restricted due to environmental and human health concerns, so alternative control methods are urgently needed. Here, we review the potential of bacterial and fungal agents to suppress the most important PPNs, namely Aphelenchoides besseyi, Bursaphelenchus xylophilus, Ditylenchus dipsaci, Globodera spp., Heterodera spp., Meloidogyne spp., Nacobbus aberrans, Pratylenchus spp., Radopholus similis, Rotylenchulus reniformis, and Xiphinema index.
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Chowdhury IA, Yan G, Kandel H, Plaisance A. Population Development of the Root-Lesion Nematode Pratylenchus dakotaensis on Soybean Cultivars. PLANT DISEASE 2022; 106:2117-2126. [PMID: 35147453 DOI: 10.1094/pdis-11-21-2444-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two greenhouse experiments were conducted with the new species of root-lesion nematode, Pratylenchus dakotaensis, discovered in North Dakota, USA in 2017 and named in 2021. Experiment 1 was conducted to ascertain resistance levels of soybean (Glycine max [L.] Merr.) cultivars to the new species P. dakotaensis and Experiment 2 was conducted to evaluate the population levels of P. dakotaensis in roots versus soil. A total of 20 soybean cultivars, and the positive control, cultivar Barnes, accompanying a nonplanted control, were evaluated in both experiments; they each had five replicates and the experiments were repeated. Among the 20 soybean cultivars evaluated, a cultivar with the ID# 13 consistently produced the greatest population densities of P. dakotaensis across all the experiments and therefore it was selected as the susceptible check. The ratio of the final nematode population density of a test cultivar relative to the final population density of the susceptible check was used to scale resistance rating. Combined results of all the trials indicated that seven of the cultivars were moderately resistant, nine of the cultivars plus 'Barnes' were moderately susceptible, and four of the cultivars were susceptible. However, none of the cultivars tested were classified as resistant. Analysis of P. dakotaensis population levels revealed that ≥50% of the population resided in the root habitat and the remaining nematodes were recovered from soil at 9 weeks after planting for a majority of the cultivars tested. These results provide an insight into the virulence of P. dakotaensis on commercial soybean cultivars.
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Affiliation(s)
| | - Guiping Yan
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
| | - Hans Kandel
- Department of Plant Sciences, North Dakota State University, Fargo, ND 58108
| | - Addison Plaisance
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
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Ecological and morphological differentiation among COI haplotype groups in the plant parasitic nematode species Mesocriconema xenoplax. J Nematol 2022; 54:20220009. [PMID: 35860518 PMCID: PMC9260820 DOI: 10.2478/jofnem-2022-0009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Indexed: 11/20/2022] Open
Abstract
DNA barcoding with the mitochondrial COI gene reveals distinct haplotype subgroups within the monophyletic and parthenogenetic nematode species, Mesocriconema xenoplax. Biological attributes of these haplotype groups (HG) have not been explored. An analysis of M. xenoplax from 40 North American sites representing both native plant communities and agroecosystems was conducted to identify possible subgroup associations with ecological, physiological, or geographic factors. A dataset of 132 M. xenoplax specimens was used to generate sequences of a 712 bp region of the cytochrome oxidase subunit I gene. Maximum-likelihood and Bayesian phylogenies recognized seven COI HG (≥99/0.99 posterior probability/bootstrap value). Species delimitation metrics largely supported the genetic integrity of the HG. Discriminant function analysis of HG morphological traits identified stylet length, total body length, and stylet knob width as the strongest distinguishing features among the seven groups, with stylet length as the strongest single distinguishing morphological feature. Multivariate analysis identified land cover, ecoregion, and maximum temperature as predictors of 53.6% of the total variation (P = 0.001). Within land cover, HG categorized under “herbaceous,” “woody wetlands,” and “deciduous forest” were distinct in DAPC and RDA analyses and were significantly different (analysis of molecular variance P = 0.001). These results provide empirical evidence for molecular, morphological, and ecological differentiation associated with HG within the monophyletic clade that represents the species Mesocriconema xenoplax.
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Singh PR, van de Vossenberg BTLH, Rybarczyk-Mydłowska K, Kowalewska-Groszkowska M, Bert W, Karssen G. An Integrated Approach for Synonymization of Rotylenchus rhomboides with R. goodeyi (Nematoda: Hoplolaimidae) Reveals High Intraspecific Mitogenomic Variation. PHYTOPATHOLOGY 2022; 112:1152-1164. [PMID: 34818905 DOI: 10.1094/phyto-08-21-0363-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rotylenchus is a widely distributed, economically important plant-parasitic nematode group whose species-level identification relies largely on limited morphological characters, including character-based tabular keys and molecular data of ribosomal and mitochondrial genes. In this study, a combined morphological and molecular analysis of three populations of Rotylenchus goodeyi from Belgium, Poland, and the Netherlands revealed important character variations of this species, leading to synonymization of R. rhomboides with R. goodeyi and a high nucleotide variation within cox1 gene sequences in these populations. Additional Illumina sequencing of DNA from individuals of the Dutch population revealed two variants of mitogenomes, each approximately 23 Kb in size, differing by approximately 9% and containing 11 protein-coding genes, 2 ribosomal RNA genes, and as many as 29 transfer RNA genes. In addition to the first representative whole-genome shotgun sequence datasets of the genus Rotylenchus, this study also provides the full-length mitogenome and the ribosomal DNA sequences of R. goodeyi.
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Affiliation(s)
| | - Bart T L H van de Vossenberg
- National Plant Protection Organization, National Reference Centre for Plant Health, 6706 EA Wageningen, The Netherlands
| | | | | | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, 9000 Ghent, Belgium
| | - Gerrit Karssen
- Nematology Research Unit, Department of Biology, Ghent University, 9000 Ghent, Belgium
- National Plant Protection Organization, National Reference Centre for Plant Health, 6706 EA Wageningen, The Netherlands
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Molecular and morphological characterization of the root -lesion nematode, Pratylenchus neglectus, on corn from Henan Province of China. Helminthologia 2021; 58:385-393. [PMID: 35095314 PMCID: PMC8776298 DOI: 10.2478/helm-2021-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 10/29/2021] [Indexed: 11/21/2022] Open
Abstract
Root-lesion nematodes, Pratylenchus spp., are economically important pathogens because of their detrimental and economic impact on a wide range of crops. In August 2018, two samples of both roots and rhizosphere soil were collected from a corn field in Liangyuanqu of Shangqiu city, Henan Province, China. Root-lesion nematodes were recovered from the roots and soil samples using the modified Baermann funnel extraction method. Both the morphological characters and molecular analysis of the internal transcribed spacer (ITS) and D2-D3 expansion region of 28S ribosomal RNA sequences confirmed that the root-lesion nematode population collected from corn in this study was P. neglectus. Phylogenetic analyses showed that this isolate formed a highly supported clade with other P. neglectus isolates. To the best of our knowledge, this is the first report of P. neglectus on corn in Henan Province of China. This study reports the first partial sequences of 28S D2-D3 region of P. neglectus on corn in China. Due to the great harmfulness of root-lesion nematodes to corn, care should be taken to prevent the spread of P. neglectus to other regions in China. At the same time, further study on the biological characteristics of P. neglectus is needed, which will be helpful to develop corresponding management and control strategies.
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Powers T, Todd T, Harris T, Higgins R, MacGuidwin A, Mullin P, Ozbayrak M, Powers K, Sakai K. Pratylenchus smoliki, a new nematode species (Pratylenchidae: Tylenchomorpha) from the Great Plains region of North America. J Nematol 2021; 53:e2021-100. [PMID: 34901874 PMCID: PMC8662978 DOI: 10.21307/jofnem-2021-100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Indexed: 11/29/2022] Open
Abstract
Pratylenchus smoliki is a new species of root-lesion nematode described from corn-soybean production fields in the Central Great Plains of North America. It is characterized by populations with relatively abundant males, two lip annuli, females with a round functional spermatheca and a conoid to subcylindrical tail with a non-crenate, smooth terminus. In host preference tests, corn and wheat produce the largest nematode populations, whereas sorghum and soybeans produce less than 20% the numbers observed on corn. Scanning electron microscopy reveals that the en face patterns compare to those seen in Pratylenchus pseudocoffeae, P. scribneri, P. hexincisus, and P. alleni. The pattern is described as rectangular to trapezoidal subdorsal and subventral lips adjoining oral disc, but with a clear demarcation between the oral disc and the subdorsal and subventral sectors. A Maximum Likelihood COI tree recognizes P. smoliki as a moderately-well-supported clade with several haplotype subgroups. A Maximum Likelihood partial 28S tree provides strong support for the P. smoliki clade and reinforces the close relationships between species with similar en face patterns. Topotype specimens of P. alleni were demonstrably different from P. smoliki using DNA markers. The geographic range of P. smoliki overlaps with the ranges of P. alleni, P. scribneri, P. neglectus, P. hexicisus, and P. dakotaensis. The observed host range (corn, rye, sunflower, and wheat) suggests that P. smoliki may be native to the tallgrass prairie region of the Great Plains.
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Affiliation(s)
- Thomas Powers
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722
| | - Timothy Todd
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506
| | - Tim Harris
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722
| | - Rebecca Higgins
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722
| | - Ann MacGuidwin
- Department of Plant Pathology, University of Wisconsin-Madison, Madison WI
| | - Peter Mullin
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722
| | - Mehmet Ozbayrak
- Department of Entomology, Bornova Plant Protection Research Institute, 35040 Bornova/Izmir, Turkey
| | - Kirsten Powers
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE 68583-0722
| | - Kanan Sakai
- International Institute of Tropical Agriculture, Nairobi 00100, Kenya
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Tessens B, Monnens M, Backeljau T, Jordaens K, Van Steenkiste N, Breman FC, Smeets K, Artois T. Is ‘everything everywhere’? Unprecedented cryptic diversity in the cosmopolitan flatworm
Gyratrix hermaphroditus. ZOOL SCR 2021. [DOI: 10.1111/zsc.12507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Bart Tessens
- Research Group Zoology: Biodiversity and Toxicology Centre for Environmental Sciences Hasselt University Diepenbeek Belgium
| | - Marlies Monnens
- Research Group Zoology: Biodiversity and Toxicology Centre for Environmental Sciences Hasselt University Diepenbeek Belgium
| | - Thierry Backeljau
- Department of Biology Evolutionary Ecology Group University of Antwerp Antwerp Belgium
- Royal Belgian Institute of Natural Sciences (RBINS: Taxonomy and Phylogeny & JEMU) Brussels Belgium
| | - Kurt Jordaens
- Royal Museum for Central Africa (RMCA: Entomology Section & JEMU) Tervuren Belgium
| | - Niels Van Steenkiste
- Research Group Zoology: Biodiversity and Toxicology Centre for Environmental Sciences Hasselt University Diepenbeek Belgium
- Departments of Botany and Zoology University of British Columbia Vancouver BC Canada
| | - Floris C. Breman
- Royal Belgian Institute of Natural Sciences (RBINS: Taxonomy and Phylogeny & JEMU) Brussels Belgium
| | - Karen Smeets
- Research Group Zoology: Biodiversity and Toxicology Centre for Environmental Sciences Hasselt University Diepenbeek Belgium
| | - Tom Artois
- Research Group Zoology: Biodiversity and Toxicology Centre for Environmental Sciences Hasselt University Diepenbeek Belgium
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13
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Lax P, Gonzalez‐Ittig RE, Rondan Dueñas JC, Andrade AJ, Gardenal CN, Franco J, Doucet ME. Decrypting species in the
Nacobbus aberrans
(Nematoda: Pratylenchidae) complex using integrative taxonomy. ZOOL SCR 2021. [DOI: 10.1111/zsc.12494] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Paola Lax
- Instituto de Diversidad y Ecología Animal (CONICET‐UNC) and Centro de Zoología Aplicada, Facultad de Ciencias Exactas, Físicas y Naturales Universidad Nacional de Córdoba Córdoba Argentina
| | - Raúl E. Gonzalez‐Ittig
- Instituto de Diversidad y Ecología Animal (CONICET‐UNC), Facultad de Ciencias Exactas, Físicas y Naturales Universidad Nacional de Córdoba Córdoba Argentina
| | - Juan C. Rondan Dueñas
- Laboratorio de Biología Molecular Pabellón CEPROCOR Santa María de Punilla Córdoba, Argentina
| | - Alberto J. Andrade
- Instituto de Biología de la Altura Universidad Nacional de Jujuy San Salvador de Jujuy Argentina
| | - Cristina N. Gardenal
- Instituto de Diversidad y Ecología Animal (CONICET‐UNC), Facultad de Ciencias Exactas, Físicas y Naturales Universidad Nacional de Córdoba Córdoba Argentina
| | | | - Marcelo E. Doucet
- Instituto de Diversidad y Ecología Animal (CONICET‐UNC) and Centro de Zoología Aplicada, Facultad de Ciencias Exactas, Físicas y Naturales Universidad Nacional de Córdoba Córdoba Argentina
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14
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Karaca MS, Yavuzaslanoglu E, Imriz G, Sonmezoglu OA. Molecular characterization of the Pratylenchus vulnus populations on cereals in Turkey. J Nematol 2021; 52:e2020-84. [PMID: 33829183 PMCID: PMC8015327 DOI: 10.21307/jofnem-2020-084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Indexed: 11/11/2022] Open
Abstract
Pratylenchus vulnus (walnut root lesion nematode) is one of the most damaging root lesion nematode species worldwide. In this study, 17 populations of P. vulnus obtained from wheat and barley cultivated fields in 2016 to 2017 in Turkey (Karaman and Konya provinces) were identified using real-time PCR and melting curve analysis. Samples provided a single peak at 87.3˚C with real-time PCR. D2 to D3 expansion segments of the 28S rRNA of one population from Cihanbeyli district in Konya province was sequenced and recorded in GenBank (Accession number: MT320536.1). Alignments of the population was identical 98.66% to the populations of P. vulnus available in GenBank (Accs. nos: LT985479.1 and LT965052.1) and 98.65% (Accs. nos: KY424305.1 and KY424304.1).
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Affiliation(s)
- Mehmet Sait Karaca
- Department of Plant Protection, Ministry of Agriculture and Forestry, International Bahri Dagdas Agricultural Research Institute, Konya, Turkey
| | - Elif Yavuzaslanoglu
- Department of Plant and Animal Production, Vocational School, Karamanoglu Mehmetbey University, Karaman, Turkey
| | - Gul Imriz
- Department of Plant Protection, Dicle University, Faculty of Agriculture, Diyarbakir, Turkey
| | - Ozlem Ates Sonmezoglu
- Department of Bioengineering, Faculty of Engineering, Karamanoglu Mehmetbey University, Karaman, Turkey
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15
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Bogale M, Tadesse B, Nuaima RH, Honermeier B, Hallmann J, DiGennaro P. Morphometric and Molecular Diversity among Seven European Isolates of Pratylenchus penetrans. PLANTS 2021; 10:plants10040674. [PMID: 33807482 PMCID: PMC8066575 DOI: 10.3390/plants10040674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022]
Abstract
Pratylenchus penetrans is an economically important root-lesion nematode species that affects agronomic and ornamental plants. Understanding its diversity is of paramount importance to develop effective control and management strategies. This study aimed to characterize the morphological and genetic diversity among seven European isolates. An isolate from the USA was included in the molecular analyses for comparative purposes. Morphometrics of the European P. penetrans isolates generally were within the range of the original descriptions for this species. However, multiple morphometric characteristics, including body length, maximum body width, tail length and length of the post-vulval uterine sac showed discrepancies when compared to other populations. Nucleotide sequence-based analyses revealed a high level of intraspecific diversity among the isolates. We observed no correlation between D2-D3 rDNA- and COXI-based phylogenetic similarities and geographic origin. Our phylogenetic analyses including selected GenBank sequences also suggest that the controversy surrounding the distinction between P. penetrans and P. fallax remains.
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Affiliation(s)
- Mesfin Bogale
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA;
| | - Betre Tadesse
- Justus Liebig University, Schubertstraße 81, 35392 Gießen, Germany; (B.T.); (B.H.); (J.H.)
| | - Rasha Haj Nuaima
- Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Institute for Epidemiology and Pathogen Diagnostics, Toppheideweg 88, 48161 Münster, Germany;
| | - Bernd Honermeier
- Justus Liebig University, Schubertstraße 81, 35392 Gießen, Germany; (B.T.); (B.H.); (J.H.)
| | - Johannes Hallmann
- Justus Liebig University, Schubertstraße 81, 35392 Gießen, Germany; (B.T.); (B.H.); (J.H.)
| | - Peter DiGennaro
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA;
- Correspondence:
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16
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Pratylenchus penetrans Parasitizing Potato Crops: Morphometric and Genetic Variability of Portuguese Isolates. PLANTS 2021; 10:plants10030603. [PMID: 33806880 PMCID: PMC8004771 DOI: 10.3390/plants10030603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/19/2021] [Accepted: 03/19/2021] [Indexed: 11/16/2022]
Abstract
The root lesion Pratylenchus penetrans is an economically important pest affecting a wide range of plants. The morphometry of five P. penetrans isolates, parasitizing potato roots in Portugal, was compared and variability within and between isolates was observed. Of the 15 characters assessed, vulva position (V%) in females and the stylet length in both females/males showed the lowest coefficient of intra and inter-isolate variability. Moreover, DNA sequencing of the internal transcribed spacers (ITS) genomic region and cytochrome c oxidase subunit 1 (COI) gene was performed, in order to evaluate the intraspecific genetic variability of this species. ITS revealed higher isolate genetic diversity than the COI gene, with 15 and 7 different haplotypes from the 15 ITS and 14 COI sequences, respectively. Intra- and inter-isolate genetic diversity was found considering both genomic regions. The differentiation of these isolates was not related with their geographical origin. In spite of the high intraspecific variability, phylogenetic analyses revealed that both ITS region and COI gene separate P. penetrans from other related species. Our findings contribute to increasing the understanding of P. penetrans variability.
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17
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Singh PR, Karssen G, Couvreur M, Subbotin SA, Bert W. Integrative Taxonomy and Molecular Phylogeny of the Plant-Parasitic Nematode Genus Paratylenchus (Nematoda: Paratylenchinae): Linking Species with Molecular Barcodes. PLANTS (BASEL, SWITZERLAND) 2021; 10:408. [PMID: 33671787 PMCID: PMC7926417 DOI: 10.3390/plants10020408] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 01/18/2023]
Abstract
Pin nematodes of the genus Paratylenchus are obligate ectoparasites of a wide variety of plants that are distributed worldwide. In this study, individual morphologically vouchered nematode specimens of fourteen Paratylenchus species, including P. aculentus, P. elachistus, P. goodeyi, P. holdemani, P. idalimus, P. microdorus, P. nanus, P. neoamblycephalus, P. straeleni and P. veruculatus, are unequivocally linked to the D2-D3 of 28S, ITS, 18S rRNA and COI gene sequences. Combined with scanning electron microscopy and a molecular analysis of an additional nine known and thirteen unknown species originating from diverse geographic regions, a total of 92 D2-D3 of 28S, 41 ITS, 57 18S rRNA and 111 COI new gene sequences are presented. Paratylenchus elachistus, P. holdemani and P. neoamblycephalus are recorded for the first time in Belgium and P. idalimus for the first time in Europe. Paratylenchus is an excellent example of an incredibly diverse yet morphologically minimalistic plant-parasitic genus, and this study provides an integrated analysis of all available data, including coalescence-based molecular species delimitation, resulting in an updated Paratylenchus phylogeny and the corrective reassignment of 18 D2-D3 of 28S, 3 ITS, 3 18S rRNA and 25 COI gene sequences that were previously unidentified or incorrectly classified.
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Affiliation(s)
- Phougeishangbam Rolish Singh
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium; (G.K.); (M.C.); (W.B.)
| | - Gerrit Karssen
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium; (G.K.); (M.C.); (W.B.)
- National Plant Protection Organization, Wageningen Nematode Collection, P.O. Box 9102, 6700 HC Wageningen, The Netherlands
| | - Marjolein Couvreur
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium; (G.K.); (M.C.); (W.B.)
| | - Sergei A. Subbotin
- Plant Pest Diagnostic Center, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832, USA;
- Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian, Academy of Sciences, Leninskii Prospect 33, 117071 Moscow, Russia
| | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium; (G.K.); (M.C.); (W.B.)
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18
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Saikai K, MacGuidwin AE. Intraspecific variation in phenotypic and phylogenetic features among Pratylenchus penetrans isolates from Wisconsin, USA. J Nematol 2020; 52:e2020-102. [PMID: 33829190 PMCID: PMC8015340 DOI: 10.21307/jofnem-2020-102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Indexed: 12/01/2022] Open
Abstract
Pratylenchus penetrans is a common and important agricultural pest in Wisconsin, a USA state with a diverse agriculture. We compared populations from around the state to each other and to data published for populations around the world to gain insight on the variability of features important for identification of this cosmopolitan species. Thirteen isolates from samples collected in soybean fields in ten Wisconsin counties were established in monoxenic cultures. Analysis of morphological features revealed the least variable feature for all isolates collectively was vulva percentage. Features less variable within than among isolates were body width, lip region height, and stylet length. Some isolates showed only the smooth tail tip phenotype and others had a mix of smooth and annulated tail phenotypes. A suite of features provided sufficient pattern to group isolates into four clusters according to hierarchical agglomerative clustering and canonical discriminative analyses, but not with enough distinction to be useful for classification. Haplotype analysis based on the COI mitochondrial gene of the 13 cultured isolates, 39 Wisconsin field populations, and published sequences representing five additional USA states and six countries revealed 21 haplotypes, 15 of which occurred in Wisconsin. Ten haplotypes represented in Wisconsin were shared with populations from Europe, South America, Africa, or Asia. Five haplotypes were unique to Wisconsin, six were unique to The Netherlands, and one was unique to Japan suggesting that even more COI diversity will be revealed when more COI sequences for P. penetrans become available. The maximum pairwise sequence variation was 6% and the SNPs did not alter amino acids, indicating cryptic biodiversity within the species worldwide. The cosmopolitan to localized scale of distribution of COI haplotypes could be due to frequent and ongoing dispersal events, facilitated by life history traits and the broad host range of P. penetrans. Regions of diverse agriculture, like Wisconsin, show promise for studying this important pest and our study confirms the utility of the COI mtDNA gene for studying variation within a species.
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Affiliation(s)
- Kanan Saikai
- Department of Plant Pathology, University of Wisconsin–Madison, 484 Russell Laboratories, 1630 Linden Dr., Madison, WI, 53706
| | - Ann E. MacGuidwin
- Department of Plant Pathology, University of Wisconsin–Madison, 484 Russell Laboratories, 1630 Linden Dr., Madison, WI, 53706
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19
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Evaluation of Metabarcoding Primers for Analysis of Soil Nematode Communities. DIVERSITY-BASEL 2020. [DOI: 10.3390/d12100388] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
While recent advances in next-generation sequencing technologies have accelerated research in microbial ecology, the application of high throughput approaches to study the ecology of nematodes remains unresolved due to several issues, e.g., whether to include an initial nematode extraction step or not, the lack of consensus on the best performing primer combination, and the absence of a curated nematode reference database. The objective of this method development study was to compare different primer sets to identify the most suitable primer set for the metabarcoding of nematodes without initial nematode extraction. We tested four primer sets for amplicon sequencing: JB3/JB5 (mitochondrial, I3-M11 partition of COI gene), SSU_04F/SSU_22R (18S rRNA, V1-V2 regions), and Nemf/18Sr2b (18S rRNA, V6-V8 regions) from earlier studies, as well as MMSF/MMSR (18S rRNA, V4-V5 regions), a newly developed primer set. We used DNA from 22 nematode taxa, 10 mock communities, 20 soil samples, 4 root samples, and one bulk soil. We amplified the target regions from the DNA samples with the four different primer combinations and sequenced the amplicons on an Illumina MiSeq sequencing platform. We found that the Nemf/18Sr2b primer set was superior for detecting soil nematodes compared to the other primer sets based on our sequencing results and on the annotation of our sequence reads at the genus and species ranks. This primer set generated 74% reads of Nematoda origin in the soil samples. Additionally, this primer set did well with the mock communities, detecting all the included specimens. It also worked better in the root samples than the other primer set that was tested. Therefore, we suggest that the Nemf/18Sr2b primer set could be used to study rhizosphere soil and root associated nematodes, and this can be done without an initial nematode extraction step.
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20
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Cole E, Pu J, Chung H, Quintanilla M. Impacts of Manures and Manure-Based Composts on Root Lesion Nematodes and Verticillium dahliae in Michigan Potatoes. PHYTOPATHOLOGY 2020; 110:1226-1234. [PMID: 32106768 DOI: 10.1094/phyto-11-19-0419-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The interaction of the root lesion nematode Pratylenchus penetrans and the fungal plant pathogen Verticillium dahliae causes potato early die (PED) complex, which induces premature vine senescence and dramatically reduces yield in potatoes. Management of PED is often achieved through the use of soil fumigants and nematicides, but their adverse effects on soil, human and environmental health, and strict regulations worldwide require alternative control tactics. In this study, we investigated the effects of multiple composts and manures on nematode mortality and PED. In lab assays, root lesion nematodes were exposed to poultry manure, layer ash blend, Dairy Doo, or wood ash for 7 days at rates of 0, 0.1, 1, 10, and 20% by volume of product and assessed for nematode survivorship. Additionally, these products were evaluated for volatile fatty acid content to determine if fatty acid content affects nematode control. In a field trial, the composts and manures were evaluated at two different rates, high (11.2 t/ha) or low (2.8 t/ha), and populations of P. penetrans and V. dahliae were quantified. Our results show that a 1% application rate of poultry manure and layer ash blend provided the greatest nematode control in lab assays with 24.5 and 38.2% reduction, respectively, with greater control at higher rates. In the field, plots treated with poultry manure had significantly higher potato yields and significantly fewer nematodes than control plots. Taken together, our results suggest that poultry manure could be a promising amendment to control PED.
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Affiliation(s)
- Emilie Cole
- Department of Entomology, Michigan State University, East Lansing, MI 48824
| | - Jian Pu
- Department of Entomology, Michigan State University, East Lansing, MI 48824
| | - Henry Chung
- Department of Entomology, Michigan State University, East Lansing, MI 48824
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21
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Singh PR, Kashando BE, Couvreur M, Karssen G, Bert W. Plant-parasitic nematodes associated with sugarcane in Kilimanjaro, Tanzania. J Nematol 2020; 52:1-17. [PMID: 32628825 PMCID: PMC7366841 DOI: 10.21307/jofnem-2020-059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Indexed: 11/11/2022] Open
Abstract
Morphological and molecular analyses of plant-parasitic nematodes (PPN) from 12 sugarcane plantation sites of Tanganyika Planting Company (TPC) Limited in Kilimanjaro region of Tanzania revealed the presence of six PPN genera, i.e. Helicotylenchus, Hemicycliophora, Pratylenchus, Rotylenchulus, Scutellonema, and Tylenchorhynchus. The genera with the highest densities and present in virtually all samples were Pratylenchus and Rotylenchulus, and the most important species appeared to be R. parvus, P. zeae, T. crassicaudatus, and T. ventrosignatus. A total sequences of 11 partial ITS, 15 D2-D3 of 28S, and 6 partial 18S of rRNA gene, and 7 partial COI gene of mtDNA of these species were obtained in this study. Morphology and molecular data comparisons between the Tanzanian R. parvus and the South African R. parvus indicated that R. parvus is a cryptic species complex. Based on the results of morphological and molecular analyses of T. crassicaudatus and T. agri from China, Haiti, Indonesia, Iran, Niger and the USA, T. agri syn. n. is proposed as a junior synonym of T. crassicaudatus.
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Affiliation(s)
| | - Beatrice E Kashando
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium ; Tanzania Agricultural Research Institute (TARI), P.O. Box 30031, Tumbi Road, Kibaha Coast region, Tanzania
| | - Marjolein Couvreur
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Gerrit Karssen
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium ; National Plant Protection Organization, Wageningen Nematode Collection, P.O. Box 9102, 6700 HC Wageningen, The Netherlands
| | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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22
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Bai M, Qing X, Qiao K, Ning X, Xiao S, Cheng X, Liu G. Mitochondrial COI gene is valid to delimitate Tylenchidae (Nematoda: Tylenchomorpha) species. J Nematol 2020; 52:1-12. [PMID: 32330378 PMCID: PMC7266042 DOI: 10.21307/jofnem-2020-038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Indexed: 11/28/2022] Open
Abstract
Tylenchidae is a widely distributed soil-inhabiting nematode family. Regardless their abundance, molecular phylogeny based on rRNA genes is problematic, and the delimitation of taxa in this group remains poorly documented and highly uncertain. Mitochondrial Cytochrome Oxidase I (COI) gene is an important barcoding gene that has been widely used species identifications and phylogenetic analyses. However, currently COI data are only available for one species in Tylenchidae. In present study, we newly obtained 27 COI sequences from 12 species and 26 sequences from rRNA genes. The results suggest that the COI gene is valid to delimitate Tylenchidae species but fails to resolve phylogenetic relationships.
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Affiliation(s)
- Mengxin Bai
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China
| | - Xue Qing
- Department of Plant Pathology, Nanjing Agricultural University , Nanjing, 210095, China
| | - Kaikai Qiao
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China ; State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, 455000, Anyang, Henan, China
| | - Xulan Ning
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China
| | - Shun Xiao
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China
| | - Xi Cheng
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China
| | - Guokun Liu
- Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University , 350002, Fuzhou, Fujian, China
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23
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Qing X, Bert W, Gamliel A, Bucki P, Duvrinin S, Alon T, Braun Miyara S. Phylogeography and Molecular Species Delimitation of Pratylenchus capsici n. sp., a New Root-Lesion Nematode in Israel on Pepper ( Capsicum annuum). PHYTOPATHOLOGY 2019; 109:847-858. [PMID: 30422745 DOI: 10.1094/phyto-09-18-0324-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Root-lesion nematodes of the genus Pratylenchus parasitize the roots of numerous plants and can cause severe damage and yield loss. Here, we report on a new species, Pratylenchus capsici n. sp., from the Arava rift, Israel, which was characterized by integrative methods, including detailed morphology, molecular phylogeny, population genetics, and phylogeography. This species is widely spread across the Arava rift, causing significant infection in pepper (Capsicum annuum) roots and inhibiting plant growth. Both morphological and molecular species delimitation support the recovered species as a new species. We found high cytochrome oxidase subunit I haplotype diversity, and phylogeography analysis suggests that contemporary gene flow is prevented among different agricultural farms, while population dispersal from weeds (Chenopodium album and Sonchus oleraceus) to pepper occurs on a relatively small scale. Our results suggest that weeds are an important reservoir for the dispersal of P. capsici n. sp., either as the original nematode source or at least in maintaining the population between growing seasons.
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Affiliation(s)
- Xue Qing
- 1 Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan 50250, Israel
| | - Wim Bert
- 2 Nematology Research Unit, Department of Biology, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Abraham Gamliel
- 3 Laboratory for Pest Management Research, Institute of Agricultural Engineering, ARO, The Volcani Center; and
| | - Patricia Bucki
- 1 Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan 50250, Israel
| | - Svetlana Duvrinin
- 4 Extension Service (Shaham); Israel Ministry of Agriculture & Rural Development, Israel
| | - Tamar Alon
- 4 Extension Service (Shaham); Israel Ministry of Agriculture & Rural Development, Israel
| | - Sigal Braun Miyara
- 1 Department of Entomology, Nematology and Chemistry Units, Agricultural Research Organization (ARO), The Volcani Center, Bet Dagan 50250, Israel
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24
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Zimik P, Roy B. Molecular identification of two cestodes species parasitizing freshwater fishes in India. J Parasit Dis 2019; 43:59-65. [PMID: 30956447 DOI: 10.1007/s12639-018-1058-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/15/2018] [Indexed: 11/29/2022] Open
Abstract
In the present study, molecular identification of two species of cestodes, Lytocestus indicus and Senga lucknowensis infecting freshwater fishes Clarias magur and Channa punctata, respectively in Manipur is carried out. To ascertain the taxonomic status of these helminth parasites, 18S gene marker was used. Phylogenetic analysis of 18S of Lytocestus sp. showed that it claded with L. indicus from Indian Isolate with a sequence similarity index of 99%. In case of Senga sp., the phylogenetic analysis revealed that it formed a separate clade with S. lucknowensis and Senga vishakapatnamensis, and the sequence similarity index showed maximum homogeneity with S. lucknowensis i.e., 99.8%. Thus, molecular characterization revealed that the two species of cestodes belong to L. indicus and S. lucknowensis.
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Affiliation(s)
- Philayung Zimik
- Department of Zoology, North-Eastern Hill University, Shillong, Meghalaya 793022 India
| | - Bishnupada Roy
- Department of Zoology, North-Eastern Hill University, Shillong, Meghalaya 793022 India
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25
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Ozbayrak M, Todd T, Harris T, Higgins R, Powers K, Mullin P, Sutton L, Powers T. A COI DNA barcoding survey of Pratylenchus species in the Great Plains Region of North America. J Nematol 2019. [DOI: 10.21307/jofnem-2019-081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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26
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Molecular and morphological variation of the root-lesion nematode Pratylenchus neglectus. Biologia (Bratisl) 2018. [DOI: 10.2478/s11756-018-00165-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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27
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Huang D, Yan G, Gudmestad N, Whitworth J, Frost K, Brown C, Ye W, Agudelo P, Crow W. Molecular Characterization and Identification of Stubby Root Nematode Species From Multiple States in the United States. PLANT DISEASE 2018; 102:2101-2111. [PMID: 30169136 DOI: 10.1094/pdis-10-17-1668-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Stubby root nematodes (SRN) are important plant parasites infecting many crops and widely distributed in many regions of the United States. SRN transmit Tobacco rattle virus, which causes potato corky ringspot disease, thereby having a significant economic impact on the potato industry. In 2015 to 2017, 184 soil samples and 16 nematode suspensions from North Dakota, Minnesota, Idaho, Oregon, Washington, South Carolina, North Carolina, and Florida were assayed for the presence of SRN. SRN were found in 106 soil samples with population densities of 10 to 320 SRN per 200 g of soil and in eight of the nematode suspensions. Sequencing of ribosomal DNA (rDNA) or species-specific polymerase chain reaction assays revealed the presence of four SRN species, including Paratrichodorus allius, P. minor, P. porosus, and Trichodorus obtusus. Accordingly, their rDNA sequences were characterized by analyzing D2-D3 of 28S rDNA, 18S rDNA, and internal transcribed spacer (ITS) rDNA obtained in this study and retrieved from GenBank. Both intra- and interspecies variations were higher in ITS rDNA than 18S rDNA and D2-D3 of 28S rDNA. Based on phylogenetic analysis, the four SRN species formed a monophyletic group, with P. allius more closely related to P. porosus than P. minor and T. obtusus. Indel variation of ITS2 rDNA was present in P. allius populations from the same geographic regions. This study documented the occurrence of SRN species across multiple states. The intra- and interspecies genetic diversity of rDNA in this study will provide more information for understanding the evolutionary relationships of SRN and will be valuable for future studies of SRN species identification and management.
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Affiliation(s)
- Danqiong Huang
- North Dakota State University, Department of Plant Pathology, Fargo 58102
| | - Guiping Yan
- North Dakota State University, Department of Plant Pathology, Fargo 58102
| | - Neil Gudmestad
- North Dakota State University, Department of Plant Pathology, Fargo 58102
| | - Jonathan Whitworth
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Aberdeen, ID 83210
| | - Kenneth Frost
- Oregon State University, Hermiston Agricultural Research and Extension Center, Hermiston 97838
| | | | - Weimin Ye
- North Carolina Department of Agriculture and Consumer Services, Raleigh 27607
| | - Paula Agudelo
- Clemson University, Plant and Environmental Sciences Department, Clemson, SC 29634
| | - William Crow
- University of Florida, Entomology and Nematology Department, Gainesville 32611
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Spirocerca vulpis sp. nov. (Spiruridae: Spirocercidae): description of a new nematode species of the red fox, Vulpes vulpes (Carnivora: Canidae). Parasitology 2018; 145:1917-1928. [PMID: 29781422 DOI: 10.1017/s0031182018000707] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Previous studies have reported nematodes of the Spirocercidae family in the stomach nodules of red foxes (Vulpes vulpes) described as Spirocerca sp. or Spirocerca lupi (Rudolphi, 1819). We characterized spirurid worms collected from red foxes and compared them to S. lupi from domestic dogs by morphometric and phylogenetic analyses. Nematodes from red foxes differed from S. lupi by the presence of six triangular teeth-like buccal capsule structures, which are absent in the latter. Additionally, in female worms from red foxes, the distance of the vulva opening to the anterior end and the ratio of the glandular-to-muscular oesophagus lengths were larger than those of S. lupi (P < 0.006). In males, the lengths of the whole oesophagus and glandular part, the ratio of the glandular-to-muscular oesophagus and the comparison of the oesophagus to the total body length were smaller in S. lupi (all P < 0.044). Phylogenetic analyses revealed that S. lupi and the red foxes spirurid represent monophyletic sister groups with pairwise nucleotide distances of 9.2 and 0.2% in the cytochrome oxidase 1 and 18S genes, respectively. Based on these comparisons, the nematodes from red foxes were considered to belong to a separate species, for which the name Spirocerca vulpis sp. nov. is proposed.
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Flis Ł, Dobosz R, Rybarczyk-Mydłowska K, Wasilewska-Nascimento B, Kubicz M, Winiszewska G. First Report of the Lesion Nematodes: Pratylenchus Brachyurus and Pratylenchus Delattrei on Tomato ( Solanum Lycopersicum L.) Plants in Cape Verde. Helminthologia 2018; 55:88-94. [PMID: 31662632 PMCID: PMC6799531 DOI: 10.1515/helm-2017-0053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 09/28/2017] [Indexed: 11/15/2022] Open
Abstract
Roots of Solanum lycopersicum L. were collected in growing season of year 2015, on the island of Santiago in Cape Verde. Morphological, morphometric and molecular (18S rDNA and 28S rDNA) studies revealed the presence of Pratylenchus brachyurus and P. delattrei in root systems and root zones of tomato plants. To our knowledge, this is the first record of the occurrence of these nematode species in Cape Verde.
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Affiliation(s)
- Ł Flis
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland
| | - R Dobosz
- Institute of Plant Protection-National Research Institute, Węgorka 20, 60-318, Poznań, Poland
| | - K Rybarczyk-Mydłowska
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland
| | | | - M Kubicz
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland
| | - G Winiszewska
- Museum and Institute of Zoology, Polish Academy of Sciences, Wilcza 64, 00-679 Warszawa, Poland
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Singh PR, Nyiragatare A, Janssen T, Couvreur M, Decraemer W, Bert W. Morphological and molecular characterisation of Pratylenchus rwandae n. sp. (Tylenchida: Pratylenchidae) associated with maize in Rwanda. NEMATOLOGY 2018. [DOI: 10.1163/15685411-00003175] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Summary
Pratylenchus rwandae n. sp., a root-lesion nematode associated with maize (Zea mays) from Rwanda, is described. This new species is characterised by females of medium to large size (469-600 μm) having an offset lip region with three annuli, stylet of 13-14.6 μm long with prominent rounded or anteriorly concave knobs, short to long pharyngeal gland overlap of 10.9-34.7 μm long, variable number of lateral lines (4-14) in different regions of the body, lateral field consisting of smooth bands, oval to slightly rounded spermatheca, vulva located at 75-80% of the total body length, post-vulval uterine sac (PUS) 20.3-26.5 μm long, tail subcylindrical to conoid with variation in tail tip shape from rounded to truncate or indented with generally smooth tip, and male unknown. The results of the phylogenetic analyses based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS of rDNA and COI of mitochondrial DNA indicate that P. rwandae n. sp. is a species within the Penetrans group and appears as a sister species to a group comprising P. convallariae, P. dunensis, P. fallax, P. oleae, P. penetrans, P. pinguicaudatus, and three other unidentified species. A comparison of important morphological characters of the closely related Pratylenchus spp. is provided.
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Affiliation(s)
- Phougeishangbam Rolish Singh
- 1Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Alliance Nyiragatare
- 2Biological Science Department, School of Science, College of Science and Technology, University of Rwanda, PO BOX-3900 Kigali, Rwanda
| | - Toon Janssen
- 1Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
- 3Centre for Medical Genetics, Reproduction and Genetics, Reproduction Genetics and Regenerative Medicine, Vrije Universiteit Brussel, UZ Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Marjolein Couvreur
- 1Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Wilfrida Decraemer
- 1Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Wim Bert
- 1Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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Subbotin SA, Toumi F, Elekçioğlu IH, Waeyenberge L, Tanha Maafi Z. DNA barcoding, phylogeny and phylogeography of the cyst nematode species of the Avenae group from the genus Heterodera (Tylenchida: Heteroderidae). NEMATOLOGY 2018. [DOI: 10.1163/15685411-00003170] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Summary
Among the recognised species groups of Heterodera, the Avenae group is one of the largest with a total of 12 species. Ten of them, H. arenaria, H. aucklandica, H. australis, H. avenae, H. filipjevi, H. mani, H. pratensis, H. riparia, H. sturhani and H. ustinovi, are morphologically closely related and represent the H. avenae species complex, and the other two, H. hordecalis and H. latipons, are morphologically more distinct from this complex. In this study we provide comprehensive phylogenetic analyses of several hundred COI and ITS rRNA gene sequences from the Avenae group using Bayesian inference, maximum likelihood and statistical parsimony. Some 220 COI and 11 ITS rRNA new gene sequences from 147 nematode populations collected in 26 countries were obtained in this study. Our study showed that the COI gene is a powerful DNA barcoding marker for identification of populations and species from the Avenae group. A putatively new cyst nematode species related to H. latipons was revealed from the analysis of COI and ITS rRNA gene datasets. COI gene sequences allow distinguishing H. arenaria, H. australis and H. sturhani from each other and other species. Problems of species delimiting of these species are discussed. The results of the analysis showed that COI haplotypes corresponded to certain pathotypes of the cereal cyst nematodes. It is recommended that information on COI haplotypes of studied populations be included in research with these nematodes. Based on the results of phylogeographical analysis and age estimation of clades with a molecular clock approach, it was hypothesised that several species of the Avenae group primarily originated and diversified in the Irano-Anatolian hotspot during the Pleistocene and Holocene periods and then dispersed from this region across the world. Different geographic barriers, centres and times of origin might explain current known distribution patterns for species of the Avenae group. Possible pathways, including a long distance trans-Atlantic dispersal, and secondary centres of diversification are proposed and discussed.
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Affiliation(s)
- Sergei A. Subbotin
- 1Plant Pest Diagnostic Center, California Department of Food and Agriculture, 3294 Meadowview Road, 95832 Sacramento, CA, USA
- 2Center of Parasitology of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Leninskii Prospect 33, 117071 Moscow, Russia
| | - Fateh Toumi
- 3ILVO, Plant, Crop Protection, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium
| | - Ibrahim Halil Elekçioğlu
- 4Çukurova University, Faculty of Agriculture, Plant Protection Department, 01330 Sarıçam, Adana, Turkey
| | - Lieven Waeyenberge
- 3ILVO, Plant, Crop Protection, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium
| | - Zahra Tanha Maafi
- 5Iranian Research Institute of Plant Protection, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran
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Chihani-Hammas N, Hajji-Hedfi L, Regaieg H, Larayedh A, Badiss A, Qing Y, Najet HR. First report of Pratylenchus vulnus associated with apple in Tunisia. J Nematol 2018; 50:579-586. [PMID: 31094160 DOI: 10.21307/jofnem-2018-056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The root-lesion nematode of the genus Pratylenchus Filipjev (1936) has a worldwide distribution and cause severe production constraints on numerous important crops. In 2013-14, during a survey of the apple nurseries and orchards in center of Tunisia (Kairouan, Zaghouan, Monastir and Kasserine), 70 different roots and soil samples were collected. The populations of root-lesion nematode were identified on the basis of their morphological and morphometric characters, and by molecular methods. Microscopic observation of females and males demonstrated the occurrence of Pratylenchusd vulnus on apple trees. The ribosomal DNA D2-D3 expansion segments of the 28S rRNA and of the Pratylenchus populations were PCR amplified and sequenced. The sequences were compared with those of Pratylenchus species in the GenBank database with high similarity (99%). This comparison reconfirmed the morphological identifications. Phylogenetic studies placed those populations with P. vulnus. This is the first report of P. vulnus infecting apple in Tunisia. The root-lesion nematode of the genus Pratylenchus Filipjev (1936) has a worldwide distribution and cause severe production constraints on numerous important crops. In 2013-14, during a survey of the apple nurseries and orchards in center of Tunisia (Kairouan, Zaghouan, Monastir and Kasserine), 70 different roots and soil samples were collected. The populations of root-lesion nematode were identified on the basis of their morphological and morphometric characters, and by molecular methods. Microscopic observation of females and males demonstrated the occurrence of Pratylenchusd vulnus on apple trees. The ribosomal DNA D2-D3 expansion segments of the 28S rRNA and of the Pratylenchus populations were PCR amplified and sequenced. The sequences were compared with those of Pratylenchus species in the GenBank database with high similarity (99%). This comparison reconfirmed the morphological identifications. Phylogenetic studies placed those populations with P. vulnus. This is the first report of P. vulnus infecting apple in Tunisia.
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Affiliation(s)
| | | | - Hajer Regaieg
- Higher Agronomic Institute of Chott-Mariem , Sousse , Tunisia
| | - Asma Larayedh
- Higher Agronomic Institute of Chott-Mariem , Sousse , Tunisia
| | - Ahmed Badiss
- Agriculture and Agri-Food Canada (AAFC) , Ontario , Canada
| | - Yu Qing
- Agriculture and Agri-Food Canada (AAFC) , Ontario , Canada
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Janssen T, Karssen G, Couvreur M, Waeyenberge L, Bert W. The pitfalls of molecular species identification: a case study within the genus Pratylenchus (Nematoda: Pratylenchidae). NEMATOLOGY 2017. [DOI: 10.1163/15685411-00003117] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Comprehensive morphological and molecular analyses revealed that published ITS sequences of the economically important plant-parasitic nematodePratylenchus goodeyiare actually sequences from distantly free-living bacterivorous ‘cephalobids’. We demonstrated that this incorrect labelling resulted in a cascade of erroneous interpretations, as shown by the reports of ‘P. goodeyi’ on banana in China and on cotton in India. This clearly illustrates the risk of mislabelled sequences in public databases. Other mislabelledPratylenchuscases are discussed to illustrate that this is not an isolated case. Herein,P. lentisn. syn. is considered a junior synonym ofP. pratensiswhileP. flakkensiswas for the first time linked to DNA sequences using topotype material. As taxonomic expertise is decreasing and sequence-based identification is growing rapidly, the highlighted problem may yet increase and a strong link between morphology and DNA sequences will be of crucial importance in order to prevent, or at least minimise, sequence-based misidentifications.
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Affiliation(s)
- Toon Janssen
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
- Center for Medical Genetics, Reproduction and Genetics, Reproduction Genetics and Regenerative Medicine, Vrije Universiteit Brussel, UZ Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Gerrit Karssen
- National Plant Protection Organization, Wageningen Nematode Collection, P.O. Box 9102, 6700 HC Wageningen, The Netherlands
| | - Marjolein Couvreur
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Lieven Waeyenberge
- ILVO, Crop Protection, Burg. Van Gansberghelaan 96 bus 2, 9820 Merelbeke, Belgium
| | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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