scholarly journals First Report of the Giant Stem Nematode, Ditylenchus gigas, from Broad Bean in Iran

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 1005-1005 ◽  
Author(s):  
Z. Tanha Maafi ◽  
Z. Majd Taheri ◽  
S. A. Subbotin
Keyword(s):  
Broad Bean ◽  
Morphological Identification ◽  
Rrna Gene ◽  
28S Rrna ◽  
African Countries ◽  
First Report ◽  
28S Rrna Gene ◽  
The North ◽  
Plant Samples ◽  
Its Rrna

The giant stem nematode, Ditylenchus gigas (Nematoda: Tylenchida) has been recorded from several European and African countries mainly bordering the Mediterranean Sea (2). This nematode causes considerable yield loss of broad bean, Vicia faba, and it may induce more severe damage than the typical faba bean race of D. dipsaci. Spread of infestation through seed limits export of broad bean and has made these nematodes quarantine pests in many countries (2). Broad bean is cultivated in the north, west, southwest, and central parts of Iran. Although D. dipsaci has been reported from different crops and regions in Iran, there is no record of broad bean infection by this nematode. A survey of broad bean fields was conducted in the north and west provinces in a continuation of a study on different populations of D. dipsaci in Iran in May to July of 2007 and 2008 and resampling from some farms in June 2012. The sampling was performed at flowering stage and after. The aboveground plant samples were collected and cut into pieces of 2 to 3 cm, then incubated for 5 to 6 h in Whitehead trays. Morphological and molecular analysis of isolated nematodes from Kermanshah and Lorestan provinces revealed the presence of D. gigas in the samples. Of the 23 plant samples of cv. Barekat collected from Mazandaran and Golestan provinces in the north, 47.8% were infected with stem nematode, mostly with high population density of over 20,000 nematodes per 5 plant stems. The percentage of infected samples of broad bean cv. Shakhbozy collected in Lorestan and Kermanshah provinces in the west was 76.5%. The symptoms of infection were observed as necrotic lesions on the stem surface and reduction of internode distances in severe infection. The giant stem nematode population from Kermanshah showed the following characters: females (n = 20), L = 1,650 ± 140 (1,270 to 1,875) μm; b′ = 8.6 ± 0.6 (7.7 to 10.0), c = 19.0 ± 1.3 (19.2 to 21.2), c′ = 4.7 ± 0.5 (1.1 to 5.3), stylet = 11.6 ± 0.5 (11 to 12) μm; post vulval sac = 96 ± 16 (58 to 140) μm; vulval-anus distance = 217.0 ± 21.0 (178 to 272) μm, tail = 86.4 ± 9.4 (66 to 102) μm; males (n = 10), L = 1,495 ± 148 (1,236 to 1,636) μm; b′ = 7.7 ± 0.3 (7.3 to 8.1), c = 17.3 ± 0.7 (16.3 to 18.6), stylet = 11.3 ± 0.5 (11 to 12) μm, tail = 86.5 ± 8.5 (71 to 95) μm, spicules = 24.8 ± 1.7 (23 to 28) μm. The morphological and morpohometric features were generally in agreement with those published for D. gigas (2). The morphological identification of D. gigas from Iran was supported by the analyses of the ITS rRNA and the D2-D3 expansion segments of the 28S rRNA gene sequences. The rRNA gene of D. gigas from broad bean and D. dipsaci from garlic were amplified and sequenced using two primer sets: (i) the TW81 and AB28 for the ITS-rRNA and (ii) D2A and D3B for partly 28S rRNA gene, as described by (2). New sequences were deposited in the GenBank under accession numbers KC310732 through KC310735. The Iranian D. gigas sequences showed 100% similarity with those of the Italian D. gigas isolates (ITS rRNA: HQ219231, HQ219232; D2-D3 of 28S rRNA: HQ219217 and HQ219216). The identification was further supported by PCR with species specific SCAR (sequence characterized amplified region) primers for this species (1). The specimens from broad bean generated a specific fragment ∼200 bp for D. gigas, whereas the samples with D. dipsaci from garlic and alfalfa produced one fragment ∼250 bp specific for this species. To our knowledge, this is the first report of D. gigas from broad bean in Iran. References: (1) M. Esquibet et al. Genome 46:1077, 2003. (2) N. Vovlas et al. Plant Pathol. 60:762, 2011.

Synonymy of Afenestrata with Heterodera supported by phylogenetics with molecular and morphological characterisation of H. koreana comb. n. and H. orientalis comb. n. (Tylenchida: Heteroderidae)

Nematology ◽  
2008 ◽  
Vol 10 (5) ◽  
pp. 611-632 ◽  
Author(s):  
Manuel Mundo-Ocampo ◽  
Alberto Troccoli ◽  
Sergei A. Subbotin ◽  
Julio Del Cid ◽  
James G. Baldwin ◽  
...  
Keyword(s):  
Morphological Identification ◽  
Rrna Gene ◽  
Similar Species ◽  
28S Rrna ◽  
Diagnostic Pcr ◽  
Second Stage ◽  
Pcr Rflp ◽  
Identification Of Species ◽  
Its Rrna ◽  
Labial Disc

Abstract Phylogenetic analysis of five gene fragments: ITS-rRNA, D2 and D3 of 28S rRNA, 18S rRNA, Hsp90 and actin, of Heterodera species and two representative Afenestrata species, A. koreana and A. orientalis, form a clade with H. cynodontis, H. bifenestra and an unidentified Heterodera sp. infecting grasses. Based on these results and the consideration that the key diagnostic characters of Afenestrata are convergent and do not define a clade, synonymisation of Afenestrata with Heterodera is proposed. The following new combinations are made: H. africana comb. n., H. axonopi comb. n., H. koreana comb. n., and H. orientalis comb. n. Furthermore, H. (= Afenestrata) sacchari is renamed as H. saccharophila nom. nov. to avoid homonymy. All these species, together with H. bamboosi, are regarded as members of a paraphyletic ‘Afenestrata group’ within Heterodera. Whilst recognised as artificial, the Afenestrata group is nevertheless an aid to discussion about these similar species. Morphological and molecular characterisation of populations of H. koreana comb. n. from Florida and H. orientalis comb. n. from Florida and Guatemala verify the identification of these populations as valid representatives for molecular studies of the species. Light and SEM observations also provide new detail and a broader understanding of the morphological range of both species. These include a longer stylet for females of H. koreana comb. n. and H. orientalis comb. n. than reported in the original descriptions. In addition, previously unreported tuberculate ridges are noted on the surface of vulval lips of H. orientalis comb. n. The lip region of second-stage juveniles of H. koreana comb. n. and H. orientalis comb. n. both include fused adjacent submedian lips that also fuse with the labial disc and the second lip annulus. The ITS-rRNA gene sequences of H. orientalis comb. n. populations from Florida and Guatemala were similar to those from the Russian type locality. Diagnostic PCR-RFLP of ITS-rRNA profiles with six enzymes for H. orientalis comb. n. and H. koreana comb. n. are given. A key for the morphological identification of species of the Afenestrata group is provided.

Morphological and molecular characterisation of several Paratylenchus Micoletzky, 1922 (Tylenchida: Paratylenchidae) species from South Africa and USA, together with some taxonomic notes

Nematology ◽  
2014 ◽  
Vol 16 (3) ◽  
pp. 323-358 ◽  
Author(s):  
Esther Van den Berg ◽  
Esther Van den Berg ◽  
Louwrens R. Tiedt ◽  
Esther Van den Berg ◽  
Louwrens R. Tiedt ◽  
...  
Keyword(s):  
South Africa ◽  
Rrna Genes ◽  
Morphological Identification ◽  
Rrna Gene ◽  
28S Rrna ◽  
Molecular Characterisation ◽  
Electron Microscopic ◽  
Wide Range ◽  
Its Rrna Gene ◽  
Its Rrna

Pin nematodes of the genus Paratylenchus are widely distributed across the world and associated with many plant species. Morphological identification of Paratylenchus species is a difficult task because it relies on many characters with a wide range of intraspecific variation. In this study we provide morphological and molecular characterisation of several pin nematodes: Paratylenchus aquaticus, P. dianthus, P. hamatus, P. nanus and P. straeleni, collected in different states of the USA and South Africa. Paratylenchus aquaticus is reported from South Africa and Hawaii and P. nanus is found from South Africa for the first time. Morphological descriptions, morphometrics, light and scanning electron microscopic photos and drawings are given for these species. Molecular characterisation of nematodes using the D2-D3 of 28S rRNA and ITS rRNA gene sequence revealed that samples morphologically identified as P. aquaticus, P. hamatus and P. nanus indeed represent species complexes containing several species. Sequences of the rRNA genes are also provided for several unidentified Paratylenchus. Phylogenetic relationships within the genus Paratylenchus are given as inferred from the analyses of the D2-D3 of 28S rRNA and ITS rRNA gene sequences. We present here the most complete phylogenetic analysis of the genus.

scholarly journals Diversity of cultured photosynthetic flagellates in the North East Pacific and Arctic Oceans in summer

2012 ◽  
Vol 9 (6) ◽  
pp. 6219-6259 ◽  
Author(s):  
S. Balzano ◽  
P. Gourvil ◽  
R. Siano ◽  
M. Chanoine ◽  
D. Marie ◽  
...  
Keyword(s):  
18S Rrna ◽  
Gene Sequencing ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
28S Rrna ◽  
28S Rrna Gene ◽  
North East ◽  
The North ◽  
Green Algal ◽  
Rrna Gene Sequencing

Abstract. During the MALINA cruise (summer 2009) an extensive effort was undertaken to isolate phytoplankton strains from the North East (NE) Pacific Ocean, the Bering Strait, and the Beaufort Sea. Strains were isolated by flow cytometry sorting (FCS) and pipetting before or after phytoplankton enrichment of seawater samples. Strains were isolated both onboard and back in the laboratory and cultured at 4 °C under light/dark conditions. Overall, we isolated and characterised by light microscopy and 18S rRNA gene sequencing 104 strains of photosynthetic flagellates which grouped into 21 genotypes (defined by 99.5% 18S rRNA gene sequence similarity) mainly affiliated to Chlorophyta and Heterokontophyta. The taxon most frequently isolated was an Arctic ecotype of the green algal genus Micromonas (Arctic Micromonas) which was almost the only phytoplankter recovered within picoplankton (≤ 2 μm) size range. Strains of Arctic Micromonas as well as three unidentified strains related to the same genus were identified in further details by sequencing the Internal Transcribed Spacer (ITS) region of the rRNA operon. The MALINA Micromonas strains share identical 18S rRNA and ITS sequences suggesting high genetic homogeneity within Arctic Micromonas. The unidentified strains form a genotype likely belonging to a new genus within the family Mamiellaceae to which Micromonas belongs. Other green algae genotypes from the genera Nephroselmis, Chlamydomonas, Pyramimonas were also isolated whereas Heterokontophyta included Pelagophyceae, Dictyochophyceae and Chrysophyceae. Dictyochophyceae included Pedinellales which could not be identified to the genus level whereas Chrysophyceae comprised Dinobryon faculiferum. Moreover, we isolated Rhodomonas sp. as well as a few Haptophyta and dinoflagellates. We identified the dinoflagellate Woloszynskia cincta by Scanning Electron Microscopy (SEM) and 28S rRNA gene sequencing. Our morphological analyses show that this species possess the diagnostic features of the genus Biecheleria, and the 28S rRNA gene topology corroborates this affiliation. We thus propose the transfer of W. cincta to the genus Biecheleria and its recombination as Biecheleria cincta.

scholarly journals Intra-species sequence variability in 28s rRNA gene of Oesophagostomum venulosum isolated from goats of West Bengal, India

2010 ◽  
Vol 3 (7) ◽  
pp. 515-518 ◽  
Author(s):  
Subhasish Bandyopadhyay ◽  
Asit Kumar Bera ◽  
Sourav Sikdar ◽  
Sumanta De ◽  
Subhashree Ghosh ◽  
...  
Keyword(s):  
West Bengal ◽  
Rrna Gene ◽  
28S Rrna ◽  
Sequence Variability ◽  
28S Rrna Gene

scholarly journals First Report of Ditylenchus dipsaci on Garlic in Minnesota

Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1707-1707 ◽  
Author(s):  
D. S. Mollov ◽  
S. A. Subbotin ◽  
Carl Rosen
Keyword(s):  
The Body ◽  
Parasitic Nematodes ◽  
Rrna Gene ◽  
28S Rrna ◽  
Gene Sequences ◽  
Surrounding Water ◽  
Pharyngeal Bulb ◽  
First Report ◽  
Plant Parts ◽  
Ditylenchus Dipsaci

In the summer of 2011, two independent garlic samples from Morrison and Dakota counties and in 2012 one garlic sample from Carver county in Minnesota were submitted by commercial growers to the University of Minnesota Plant Disease Clinic for disease analyses. Symptoms of the above-ground plant parts were stunting and chlorosis. Symptoms of bulbs were necrosis, underdevelopment, and distortion. Upon microscopic examination, phytonematodes exuded into the surrounding water droplet. Nematodes were present in the protective leaves, abscission zone, and cloves in all submitted bulbs (n = 18) for analyses. Morphometric examination of females, males, and juveniles determined that they were Ditylenchus dipsaci. Nematodes extracted from garlic cloves were fixed in TAF (97 ml formalin [40%], 2 ml triethanolamine, and 91 ml dH2O). Morphological observations and measurements were made under an Olympus BX51 microscope equipped with a Nomarski differential interference contrast. Female (n = 6) measurements were: L = 1.411 to 1.636 mm, a = 38 to 44, b = 5.8 to 8.0, c = 14 to 17, stylet = 11.5 to 12.3 μm, V = 79 to 81%, and tail = 95 to 105 μm. The body was almost straight, when heat relaxed, lip region flattened, median bulb oval, and isthmus elongate and slender. The basal pharyngeal bulb overlapped the intestine. The post-vulval uterine branch was about half of vulva-anus distance. The tail was conoid with a pointed terminus. Male (n = 9) measurements were: L = 1.372 to 1.558 mm, a = 40 to 50, b = 6.5 to 7.0, c = 14 to 16, stylet = 11.5 to 12.3 μm, spicules = 22 to 27 μm, and gubernaculum = 9 to 10 μm. The bursa was leptoderan and spicules were curved with simple gubernaculum. Morphology and morphometrics of females and males of D. dipsaci from Minnesota generally fit the descriptions provided for the type and other populations by Hopper (1) and other authors. Several specimens were also taken for molecular identification. DNA extraction, PCR, and sequencing protocols were as described by Subbotin et al. (2). The TW81 and AB28 primers were used for amplification of ITS-rRNA region and the D2A and D3B primers were used for amplification of the D2-D3 expansion segments of 28S rRNA gene. Comparison of the ITS and D2-D3 of 28 rRNA gene sequences showed 100 and 99% identity with corresponding gene sequences of D. dipsaci published in the GenBank (2). The sequences were submitted in the GenBank under accession numbers JX123258 and X123259. This nematode problem has not been known to occur in either of these locations previously. The most likely source of introduction of D. dipsaci are imported garlic seed bulbs. To our knowledge, this is the first report of D. dipsaci affecting garlic or any other crops in Minnesota. The garlic produced in these locations was considered unmarketable and complete loss to the farmers. The presence of D. dipsaci could have a significant economic impact in the emerging multi-million dollar garlic industry in Minnesota. References: (1) D. J. Hooper. Ditylenchus dipsaci. CIH Descriptions of Plant-Parasitic Nematodes Set 1, No. 14, 1972. (2) S. A. Subbotin et al. Phytopathology 95:1308, 2005.

scholarly journals Phylogenetic Analysis of 28S rRNA Gene of Indigenous Xiphinema pachydermum

2019 ◽  
Vol 8 (07) ◽  
pp. 1960-1968
Author(s):  
Anju Sharma ◽  
Satish K. Sharma ◽  
Kiran Rana ◽  
Anil Kumar Verma
Keyword(s):  
Phylogenetic Analysis ◽  
Rrna Gene ◽  
28S Rrna ◽  
28S Rrna Gene

scholarly journals Molecular and morphological characterisation of Xiphinema granatum n. sp. and Longidorus pisi Edward, Misra & Singh, 1964 (Dorylaimida: Longidoridae) from Iran

Nematology ◽  
2012 ◽  
Vol 14 (8) ◽  
pp. 949-960 ◽  
Author(s):  
Majid Pedram ◽  
Ebrahim Pourjam ◽  
Juan E. Palomares-Rius ◽  
Razieh Ghaemi ◽  
Carolina Cantalapiedra-Navarrete ◽  
...  
Keyword(s):  
New Species ◽  
Species Group ◽  
Rrna Gene ◽  
28S Rrna ◽  
Morphometric Data ◽  
Molecular Analyses ◽  
Morphological Characterisation ◽  
28S Rrna Gene ◽  
Close Relationship ◽  
Female Genital

Xiphinema granatum n. sp. from pomegranate in Saveh, Markazi province, central Iran, is described and illustrated. The new species belongs to species group 8 of the genus Xiphinema sensu Loof & Luc, 1990. The new species is characterised by a body 3.5-4.1 mm long, 37-49 μm diam., odontostyle and odontophore 118-132 and 65-74 μm long, respectively, presence of sperm in the female genital tracts, uterus devoid of any Z-differentiation or spines, and abundant males with spicules 45-58 μm long. The polytomous identification codes of the new species are: A4, B4, C5a, D5, E56, F4, G23, H2, I3, J4, K2, L2. Beside morphological and morphometric data, molecular analyses of D2-D3 fragments of 28S rRNA gene placed the new species in close relationship with X. vuittenezi and X. italiae and some species belonging to Xiphinema morphospecies group 6, but clearly separated from X. index. In addition, an Iranian population of Longidorus pisi from the same locality is morphologically and molecularly characterised.

Placement of Cacoceria and phylogenetic relationships of the xylotine genera of the tribe Milesiini (Diptera, Syrphidae: Eristalinae) based on molecular characters

Zootaxa ◽  
2006 ◽  
Vol 1171 (1) ◽  
pp. 17 ◽  
Author(s):  
GUNILLA STÅHLS
Keyword(s):  
Intraspecific Variation ◽  
Phylogenetic Relationships ◽  
Rrna Gene ◽  
28S Rrna ◽  
Large Fragment ◽  
Mitochondrial Coi ◽  
Phylogenetic Placement ◽  
28S Rrna Gene ◽  
Molecular Characters

The phylogenetic relationships of traditional xylotine genera of tribe Milesiini (Diptera, Syrphidae: Eristalinae) were explored using molecular character of a large fragment of the mitochondrial COI and the D2-3 region of the nuclear ribosomal 28S rRNA gene. Of particular interest was the phylogenetic placement of the enigmatic Neotropical genus Cacoceria. The ingroup included 48 taxa, and Cheilosia illustrata (Rhingiini, Eristalinae) was used as outgroup. Multiple specimens of more common taxa were sequenced for surveying levels of intraspecific variation. The combined dataset was analysed using parsimony and optimisation alignment, using the program POY. Cacoceria was resolved within the Chalcosyrphus clade. Earlier hypotheses placed the taxon in the tribe Myoleptini or Chrysogasterini, or in Xylotini without stating a closer relationship to any particular xylotine taxon. The representatives of traditional xylotine taxa were resolved as ((Hadromyia + (Brachypalpoides + Blera + Lejota) + (Xylota sg. Hovaxylota + Xylota sg. Sterphoides) + (Xylota (including Sterphus)) while Neplas and Brachypalpus were resolved in the Myoleptini albeit with very low support.

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