scholarly journals Characterization of cereal cyst nematodes (Heterodera spp.) in Morocco based on morphology, morphometrics and rDNA-ITS sequence analysis

2017 ◽  
Vol 57 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Fouad Mokrini ◽  
Nicole Viaene ◽  
Lieven Waeyenberge ◽  
Abdelfattah A. Dababat ◽  
Maurice Moens
Keyword(s):  
Its Rdna ◽  
Heterodera Avenae ◽  
Morphological Identification ◽  
Cyst Nematodes ◽  
Specific Primers ◽  
Rdna Its ◽  
Rdna Sequences ◽  
Its Sequence Analysis ◽  
Species Specific ◽  
Production Areas

AbstractMorphological and molecular diversity among 11 populations of cereal cyst nematodes from different wheat production areas in Morocco was investigated using light microscopy, species-specific primers, complemented by the ITS-rDNA sequences. Morphometrics of cysts and second-stage juveniles (J2s) were generally within the expected ranges forHeterodera avenae; only the isolate from Aïn Jmaa showed morphometrics conforming to those ofH. latipons. When using species-specific primers forH. avenaeandH. latipons, the specific bands of 109 bp and 204 bp, respectively, confirmed the morphological identification. In addition, the internal transcribed spacer (ITS) regions were sequenced to study the diversity of the 11 populations. These sequences were compared with those ofHeteroderaspecies available in the GenBank database (www.ncbi.nlm.nih.gov) and confirmed again the identity of the species. Ten sequences of the ITS-rDNA were similar (99–100%) to the sequences ofH. avenaepublished in GenBank and three sequences, corresponding with one population, were similar (97–99%) toH. latipons.

Molecular identification of cyst-forming nematodes (Heteroderidae) from Iran and a phylogeny based on ITS-rDNA sequences

Nematology ◽  
2003 ◽  
Vol 5 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Zahra Tanha Maafi ◽  
Sergei Subbotin ◽  
Maurice Moens
Keyword(s):  
Phylogenetic Analyses ◽  
Species Level ◽  
Its Rdna ◽  
Heterodera Avenae ◽  
Published Data ◽  
Rdna Sequences ◽  
First Time ◽  
Group Species ◽  
High Support ◽  
Different Parts

Abstract RFLP and sequences of ITS-rDNA of 45 populations of cyst-forming nematodes collected from different parts of Iran were analysed and identified as representatives of 21 species. Eight enzymes generated RFLP for all studied populations. Comparison of RFLP profiles and sequences of the ITS regions with published data confirmed the presence of Heterodera avenae, H. filipjevi, H. glycines, H. hordecalis, H. latipons, H. schachtii and H. trifolii in Iran. RFLP patterns and ITS sequences for H. elachista, H. turcomanica, H. mothi and C. cacti were obtained for the first time in this study. Heterodera humuli, H. goettingiana, H. fici, H. elachista, H. turcomanica and Cactodera cacti are recorded for the first time in Iran. These results correspond with morphological and morphometric identification of the populations. Several populations were not identified at the species level and are attributed to Heterodera sp.; some of these may correspond to new species. Twenty-one new sequences from Iranian cyst-forming nematodes and 36 known sequences were used for the phylogenetic analyses. The cyst-forming nematodes formed several clades corresponding to their morphological features. Heterodera mothi and H. elachista clustered with high support with other Cyperi group species and H. turcomanica formed a moderately to highly supported clade with the Humuli group.

scholarly journals Species-Specific PCR Assays for Differentiating Heterodera filipjevi and H. avenae

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1611-1619 ◽  
Author(s):  
Guiping Yan ◽  
Richard W. Smiley ◽  
Patricia A. Okubara ◽  
Andrea M. Skantar
Keyword(s):  
Pacific Northwest ◽  
Management Practices ◽  
Pcr Amplification ◽  
Nematode Species ◽  
Heterodera Avenae ◽  
Cyst Nematodes ◽  
Specific Pcr ◽  
The Pacific ◽  
Pcr Assays ◽  
Species Specific

Heterodera avenae and H. filipjevi are economically important cyst nematodes that restrict production of cereal crops in the Pacific Northwest United States and elsewhere in the world. Identification of these two species is critical for recommending and implementing effective management practices. Primers were designed from the internal transcribed spacer (ITS) regions of H. avenae and H. filipjevi ribosomal DNA. The primers were highly specific when examined on target isolates but did not amplify DNA from nontarget Heterodera, Globodera, Meloidogyne, Pratylenchus, and other nematode species tested. Polymerase chain reaction (PCR) and amplification conditions were established, and H. avenae and H. filipjevi were clearly distinguished by PCR fragments of 242 and 170 bp, respectively. Robust PCR amplification was achieved with DNA extracted from a single egg or second-stage juvenile (J2) using a laboratory-made worm lysis buffer, and DNA from 0.5 egg or J2 using a commercial kit. The PCR assays were successfully employed for differentiation of H. filipjevi and H. avenae populations collected from eight locations in three Pacific Northwest states. This is the first report of a species-specific ITS PCR assay to detect and identify H. filipjevi. The assays for both species will enhance diagnosis of cereal cyst nematode species in infested fields.

Phakopsora pachyrhizi is the major pathogen associated with soybean rust in Colombia

2021 ◽  
Vol 47 (3) ◽  
pp. 149-156
Author(s):  
Anibal Leonidas Tapiero-Ortiz ◽  
Nathali López-Cardona ◽  
Alejandra Guevara-Castro ◽  
Sandra Milena Rodríguez-Triana ◽  
Edisson Chavarro-Mesa ◽  
...  
Keyword(s):  
Pcr Amplification ◽  
Data Bank ◽  
Soybean Rust ◽  
Infected Leaf ◽  
Morphological Identification ◽  
Department Of Agriculture ◽  
Specific Primers ◽  
Rdna Sequences ◽  
Standard Procedures ◽  
Leaf Tissues

ABSTRACT Soybean crops grown in the plains of eastern Colombia have been affected by the incidence of rust. This disease, still officially regarded as American soybean rust (caused by Phakopsora meibomiae) by the Colombian Department of Agriculture (ICA), causes serious damage to soybean growing areas. Symptoms of rust, such as reddish-brown lesions, have been observed since 2004 in the upper half of plants during vegetative stages. In 2005 and 2018, infected leaf tissues and uredinospores were collected from an experimental area and from commercial soybean fields. Once morphological identification and Koch’s postulates confirmed the presence of Phakopsora spp., molecular characterization was performed to identify the pathogen associated with the disease to species level. This was based on standard procedures using internal transcribed spacer (ITS) regions of rDNA and PCR amplification with specific primers for Phakopsora meibomiae and P. pachyrhizi. The obtained sequences were BLASTed against GenBank/NCBI data bank. Results indicated that P. pachyrhizi Sydow is in fact the causative agent of soybean rust in Colombia, considering the samples collected in 2005 and 2018. The ITS-rDNA sequences of P. pachyrhizi were deposited at GenBank under the accession numbers MK933723 to MK933731. This finding was reported to ICA, so that they could officially update the phytosanitary status of this soybean pathogen in Colombia.

Molecular identification of three of the most important mealybug species (Hemiptera: Sternorrhyncha: Coccoidea: Pseudococcidae) on ornamental plants in Guilan province, Iran

Zootaxa ◽  
2011 ◽  
Vol 3009 (1) ◽  
pp. 46 ◽  
Author(s):  
REZA HOSSEINI ◽  
JALIL HAJIZADEH
Keyword(s):  
Ornamental Plants ◽  
Accurate Method ◽  
Planococcus Citri ◽  
Morphological Identification ◽  
Specific Primers ◽  
Pseudococcus Viburni ◽  
Species Specific ◽  
Pseudococcus Comstocki ◽  
Guilan Province ◽  
Study Species

Mealybugs (Coccoidea: Pseudococcidae) are serious pests, particularly as invasive species on many agricultural products. Morphological identification of mealybugs is based on adult female characters that, in the absence of adult females or with damaged specimens, can be problematic, especially when identification is required urgently, such as that involving the exportation/importation market. In this study, species-specific primers were designed to identify three of the most abundant mealybug species found on ornamental plants in Guilan province, Iran: Planococcus citri (Risso), Pseudococcus viburni (Signoret) and Pseudococcus comstocki (Kuwana). By generating amplification products of different sizes, the three species-specific primers, along with universal COI primers, were successfully used in multiplex PCR tests to identify all three mealybug species in a single reaction. Analysis of a large array of specimens from different geographic locations on different host plants showed that this was a reliable and accurate method.

scholarly journals Pratylenchus neglectus (Nematoda: Pratylenchidae) under the rhizosphere of Brassica napus

2012 ◽  
Vol 49 (2) ◽  
pp. 92-95 ◽  
Author(s):  
S. Kumari
Keyword(s):  
Brassica Napus ◽  
Ribosomal Dna ◽  
Soil Samples ◽  
Morphological Features ◽  
Morphological Identification ◽  
Specific Primers ◽  
Pratylenchus Neglectus ◽  
Species Specific

AbstractSoil samples under the rhizosphere of Brasicca napus were collected from three localities (Bílé Podolí, Prague, Kylešovice). Two localities Prague and Kylešovice were positive for the presence of Pratylenchus neglectus. The species was identified using morphological features and the morphological identification was verified by using published species-specific primers and by sequencing 18S and 28S genes of ribosomal DNA.

Molecular and morphological discrimination betweenTylospora fibrillosaandTylospora asterophoramycorrhizae

1999 ◽  
Vol 77 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Ursula Eberhardt ◽  
Lutz Walter ◽  
Ingrid Kottke
Keyword(s):  
Fragment Length Polymorphism ◽  
Pcr Primers ◽  
Morphological Identification ◽  
Chain Reaction ◽  
Specific Primers ◽  
Specific Pcr ◽  
Pcr Rflp ◽  
Polymerase Chain ◽  
Species Specific ◽  
First Time

Among the mycorrhizal types of spruce, Tylospora-type mycorrhizae are the most constant and abundant. Two species of the genus Tylospora occur in Europe, Tylospora fibrillosa and Tylospora asterophora. Mycorrhizae of T. asterophora are described in detail for the first time. Sequences of the internal transcribed spacer (ITS) of the ribosomal genes were obtained from T. fibrillosa and T. asterophora mycorrhizae, sporocarps, and cultured mycelium. Discrimination and identification of the two species by ITS polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) are discussed in the light of inter- and intra-specific variability. Species-specific PCR primers were designed to distinguish both species. Molecular screening of Tylospora-type mycorrhizae from field material led to unambiguous results, whereas morphological identification is likely to fail because of great similarity even at the microscopic level.Key words: Tylospora asterophora, Tylospora fibrillosa, ectomycorrhizae, taxon specific primers (TSOPs), ITS sequences.

Development of two species-specific primer sets to detect the cereal cyst nematodes Heterodera avenae and Heterodera filipjevi

2013 ◽  
Vol 136 (3) ◽  
pp. 613-624 ◽  
Author(s):  
Fateh Toumi ◽  
Lieven Waeyenberge ◽  
Nicole Viaene ◽  
Amer Dababat ◽  
Julie M. Nicol ◽  
...  
Keyword(s):  
Heterodera Avenae ◽  
Specific Primer ◽  
Cyst Nematodes ◽  
Heterodera Filipjevi ◽  
Primer Sets ◽  
Species Specific

scholarly journals A Multiplex PCR for the Detection of Phytophthora nicotianae and P. cactorum, and a Survey of Their Occurrence in Strawberry Production Areas of Japan

Plant Disease ◽  
2011 ◽  
Vol 95 (10) ◽  
pp. 1270-1278 ◽  
Author(s):  
Mingzhu Li ◽  
Takahiro Asano ◽  
Haruhisa Suga ◽  
Koji Kageyama
Keyword(s):  
Multiplex Pcr ◽  
Protein Gene ◽  
Phytophthora Nicotianae ◽  
Soilborne Pathogens ◽  
Chain Reaction ◽  
Specific Primers ◽  
Phytophthora Spp ◽  
Polymerase Chain ◽  
Species Specific ◽  
Production Areas

We aimed to simultaneously detect two pathogens causing strawberry diseases, Phytophthora nicotianae and P. cactorum, by multiplex polymerase chain reaction (PCR), and to survey their occurrence in the main strawberry production areas of Japan. Due to the need to combine different primer pairs for multiplex PCR and the low specificity of published specific primers for P. nicotianae and P. cactorum, new species-specific primers for P. nicotianae and P. cactorum were designed based on the internal transcribed spacer regions of ribosomal DNA and the ras-related protein gene Ypt1, respectively. Specificity of the designed primers was demonstrated using 68 isolates, including Phytophthora spp., Pythium spp., and other soilborne pathogens. Multiplex PCR discriminated between P. nicotianae and P. cactorum in DNA mixtures of mycelia of the two species. Moreover, both species were detected in artificially and naturally infested soils, indicating that these markers can be used in diagnosis of strawberry diseases. For investigation of the geographic distribution of the two pathogens in Japan, soil samples were collected in 89 strawberry fields from eight prefectures (Gifu, Saga, Nara, Tochigi, Chiba, Shizuoka, Yamanashi, and Hokkaido) of Japan. The method that was developed was successfully applied to survey P. nicotianae and P. cactorum, and distribution of the two pathogens in strawberry plantings in Japan was determined.

scholarly journals First Report of Colletotrichum acutatum Associated with Stem Blight of Blueberry Plants in China

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 422-422 ◽  
Author(s):  
C.-N. Xu ◽  
Z.-S. Zhou ◽  
Y.-X. Wu ◽  
F.-M. Chi ◽  
Z.-R. Ji ◽  
...  
Keyword(s):  
Vaccinium Corymbosum ◽  
Colletotrichum Acutatum ◽  
Post Inoculation ◽  
Pathogenicity Test ◽  
Distilled Water ◽  
Conidial Suspension ◽  
First Report ◽  
Rdna Its ◽  
Its Sequence Analysis ◽  
Species Specific

An anthracnose disease was observed on stems of high-bush blueberry plants (Vaccinium corymbosum L.) in Liaoning Province, China in 2012. The typical symptoms consist of sudden wilting and dieback of stems during the growing season. Dark brown lesions originate from infected buds and kill portions of the stems. Lesions have grayish white centers, with the necrotic areas becoming 6 to 8 cm in length. Disinfected stem pieces were placed on potato dextrose agar (PDA) and incubated at 28°C for 5 to 7 days, after which the emerging colonies were transferred to fresh PDA. All isolates initially produced white growth, but turned pink after 7 days before becoming blackish green. The average colony diameter was 65.5 to 75.0 mm after 7 days. Conidia were aseptate, hyaline, fusiform to ellipsoid, 8.5 to 16.5 × 2.5 to 4.0 μm in size and single celled with two to seven oil globules. Setae were not found on the acervuli. These characteristics matched published descriptions of Colletotrichum acutatum (1) (teleomorph Glomerella acutata). Pathogenicity test was confirmed in 15 2-year-old healthy potted plants of cv. Berkeley. Stems of 10 plants were punctured with flamed needles and sprayed with 5 ml of conidial suspension (106 conidia per ml in sterile distilled water) of isolate LNSW1. Five control plants were inoculated with sterile distilled water. Seven days after inoculation, eight of the 10 blueberry plants exhibited stem lesions, leaf chlorosis, followed by branch dieback 15 days post-inoculation. The symptoms were similar to those observed on diseased plants in the field, and no lesions were observed on control plants. The pathogen was reisolated from the margin of lesions and identified by colony growth characteristics on PDA. PCR amplification of one isolate (LNSW1) was carried out by utilizing the universal rDNA-ITS primer pair ITS1/ITS4. The sequence (557 bp) of isolate LNSW1 (GenBank Accession No. JX392857) showed 99% identity to G. acutata (AB443950) and C. acutatum (AJ749672) in a BLAST search. An approximately 490-bp fragment was amplified from LNSW1 by the species-specific primer pair CaInt2/ITS4 (2). The pathogen was identified as G. acutata (asexual stage: C. acutatum J.H. Simmonds) on the basis of morphological characters, rDNA-ITS sequence analysis, and a PCR product with species-specific primers. To our knowledge, this is the first report of C. acutatum in high-bush blueberry plants in China. References: (1) C. Lei et al. Fungal Diversity 12:183, 2009. (2) S. Sreenivasaprasad et al. Plant Pathol. 45:650, 1996

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