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

2012 ◽  
Vol 49 (2) ◽  
pp. 92-95 ◽  
Author(s):  
S. Kumari

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.

Zootaxa ◽  
2011 ◽  
Vol 3009 (1) ◽  
pp. 46 ◽  
Author(s):  
REZA HOSSEINI ◽  
JALIL HAJIZADEH

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.


1999 ◽  
Vol 77 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Ursula Eberhardt ◽  
Lutz Walter ◽  
Ingrid Kottke

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.


2020 ◽  
Vol 8 (3) ◽  
pp. 358
Author(s):  
Md Niamul Kabir ◽  
Ali Taheri ◽  
C. Korsi Dumenyo

Pectobacterium and Dickeya species, usually referred to as soft rot Enterobacteriaceae, are phytopathogenic genera of bacteria that cause soft rot and blackleg diseases and are responsible for significant yield losses in many crops across the globe. Diagnosis of soft rot disease is difficult through visual disease symptoms. Pathogen detection and identification methods based on cultural and morphological identification are time-consuming and not always reliable. A polymerase chain reaction (PCR)-based detection method with the species-specific primers is fast and reliable for detecting soft rot pathogens. We have developed a specific and sensitive detection system for some species of soft rot Pectobacteriaceae pathogens in the Pectobacterium and Dickeya genera based on the use of species-specific primers to amplify unique genomic segments. The specificities of primers were verified by PCR analysis of genomic DNA from 14 strains of Pectobacterium, 8 strains of Dickeya, and 6 strains of non-soft rot bacteria. This PCR assay provides a quick, simple, powerful, and reliable method for detection of soft rot bacteria.


Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 437-453 ◽  
Author(s):  
Ana Catarina Penas ◽  
Petra Correia ◽  
Maria Antónia Bravo ◽  
Manuel Mota ◽  
Rogério Tenreiro

Abstract Species of Bursaphelenchus associated with maritime pine, Pinus pinaster, from Portugal – within and outside the quarantine restricted demarcated zone of B. xylophilus – are described and characterised both morphologically (LM and SEM) and with the use of molecular biology (ITS-RFLP). A new staining method for spicules is proposed. Species include B. hellenicus, B. hylobianum, B. leoni, B. pinophilus, B. sexdentati, B. tusciae, B. teratospicularis, B. xylophilus and Bursaphelenchus sp. 1. Bursaphelenchus hylobianum was collected from the insect Hylobius sp. The most frequent species in the demarcated zone, besides B. xylophilus, was Bursaphelenchus sp. 1. Morphological characterisation is compared with the original descriptions and discussed. The differentiation between B. pinophilus and B. sexdentati is not clear in the literature and is discussed. Since differentiation of B. xylophilus (mucronate form) from B. mucronatus, and B. pinophilus from B. sexdentati, as well as their juvenile forms, is almost im possible on the basis of morphological features, a molecular approach based on ITS-RFLPs was used. Ribosomal DNA containing the 5.8S gene, the internal transcribed spacer region 1 and 2, and partial regions of 18S and 28S gene were amplified by PCR. Restriction profiles of the amplified products generated species-specific differences, leading to the unambiguous identification of isolates belonging to B. xylophilus, B. mucronatus, B. sexdentati, B. tusciae and B. hylobianum.


2017 ◽  
Vol 57 (3) ◽  
pp. 219-227 ◽  
Author(s):  
Fouad Mokrini ◽  
Nicole Viaene ◽  
Lieven Waeyenberge ◽  
Abdelfattah A. Dababat ◽  
Maurice Moens

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.


Nematology ◽  
2009 ◽  
Vol 11 (6) ◽  
pp. 847-857 ◽  
Author(s):  
Lieven Waeyenberge ◽  
Nicole Viaene ◽  
Maurice Moens

Abstract ITS1, the 5.8S rRNA gene and ITS2 of the rDNA region were sequenced from 20 different Pratylenchus species. Additionally, the same region was sequenced from seven populations of P. penetrans. After purifying, cloning and sequencing the PCR products, all sequences were aligned in order to find unique sites suitable for the design of species-specific primers for P. penetrans. Since ITS regions showed variability between and even within populations of P. penetrans, only three small DNA sequences were suitable for the construction of three potentially useful species-specific primers. New species-specific primers were paired with existing universal ITS primers and tested in all possible primer combinations. The best performing primer set, supplemented with a universal 28S rDNA primer set that served as an internal control, was tested in duplex PCR. The ideal annealing temperature, Mg2+ concentration and primer ratios were then determined for the most promising primer set. The optimised duplex PCR was subsequently tested on a wide range of different Pratylenchus spp. and 25 P. penetrans populations originating from all over the world. To test the sensitivity, the duplex PCR was conducted on DNA extracted from a single P. penetrans nematode mixed with varying amounts of nematodes belonging to another Pratylenchus species. Results showed that a reliable and sensitive P. penetrans species-specific duplex PCR was constructed.


Sign in / Sign up

Export Citation Format

Share Document