A new stem nematode, Ditylenchus oncogenus n. sp. (Nematoda: Tylenchida), parasitizing sowthistle from Adriatic coast dunes in southern Italy

2015 ◽  
Vol 90 (2) ◽  
pp. 152-165 ◽  
Author(s):  
N. Vovlas ◽  
A. Troccoli ◽  
J.E. Palomares-Rius ◽  
F. De Luca ◽  
C. Cantalapiedra-Navarrete ◽  
...  

AbstractMorphological and molecular analyses of a stem nematode causing a severe disease on infected sowthistle (Sonchus bulbosus) plants, involving the formation of gall-like structures on infected leaves and stems, have led to the description of a new species named Ditylenchus oncogenus n. sp. Morphologically, the new species is characterized by a medium to large body size (all adults more than 1 mm in length); a delicate stylet (9.0–11.0 μm long) with minute, rounded knobs; a long post-vulval uterine sac (c. 65% of the vulva–anus distance); six incisures at the lateral fields and characteristic D. destructor-pattern of spicules (with pronounced ventral tumulus and anteriorly pointed, less sclerotized, cuticle parts present within the lamina). The results of molecular analysis of rRNA gene sequences, including the D2–D3 expansion regions of 28S rRNA, internal transcribed spacer (ITS) rRNA, partial 18S rRNA gene, the protein-coding mitochondrial gene, cytochrome oxidase c subunit I (COI), and the heat-shock protein 90 (hsp90) gene, support the new species status. The results of a host-suitability test indicated that the new species does not parasitize potato (Solanum tuberosum) tubers and broad bean (Vicia faba) seedlings. Histopathological observations on naturally infected sowthistle tissues revealed that D. oncogenus n. sp. causes floral stem neoplasia and midrib leaf gall formation on the type, and to date only known, host. The galls were characterized by extensive hyperplasia, where several necrotic cells in the neoplasic area were directly damaged by feeding of the nematode, whereas a number of adjacent cells showed typical cytological changes, such as granulated cytoplasm with hypertrophied nuclei and nucleoli.

Nematology ◽  
2013 ◽  
Vol 15 (2) ◽  
pp. 179-196 ◽  
Author(s):  
Rosângela D.L. Oliveira ◽  
Ângelo M. Santin ◽  
Dalila J. Seni ◽  
Anna Dietrich ◽  
Luis A. Salazar ◽  
...  

Ditylenchus gallaeformans sp. n. was found on several hosts at numerous locations in Brazil and Costa Rica. In its native habitats it attacks several genera in the Melastomataceae, including two species ranked as among the worst invasive weeds of Pacific island forests, namely Miconia calvescens and Clidemia hirta. The new species causes a severe disease on infected plants involving the formation of gall-like structures on infected leaves, inflorescences and stems, and may cause significant impact on its hosts. Morphological study using light and scanning electron microscopy and analysis of the partial 18S rRNA, the D2-D3 expansion fragments of 28S rRNA and the ITS rRNA gene sequences showed little variations between populations from different hosts or geographical origins. The molecular study revealed that the new species is related to D. drepanocercus, which was recently found in association with M. calvescens but causing angular leaf spots on this host. Ditylenchus gallaeformans sp. n. is distinguished from D. drepanocercus by having a bursa reaching the tail tip (vs covering around 50% of tail in D. drepanocercus) and a conical tail, regularly tapering towards a variable tip (vs tail with a distinctive apical falciform appendage in both sexes in D. drepanocercus). PCR with species-specific primers was developed for diagnostics of both Ditylenchus species. Ditylenchus gallaeformans sp. n. deserves further investigation as a potential biocontrol agent against M. calvescens and C. hirta.


Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 343-354 ◽  
Author(s):  
Gracia Liébanas ◽  
Juan Palomares-Rius ◽  
Pablo Castillo ◽  
Sergei Subbotin ◽  
Blanca Landa

AbstractNematode surveys in indigenous vegetation in northern Spain revealed the presence of a nematode population of the genus Eutylenchus associated with moist sandy soils in the rhizosphere of common reed (Phragmites sp.) on the banks of the Tera river in Garray (Soria province). Morphological and morphometrical studies on this population fits with Eutylenchus excretorius, representing the first report for Spain and southern Europe and the fifth report in Europe after Germany, Poland, Czech Republic and Russia. SEM studies were carried out for the first time on this species and showed four lips separated by deep grooves. Each lip bears an elongated, flexible, recurved projection (seta) 12 (11-13) μm long, proximal third wide, gradually attenuating, distal end rounded. Molecular characterisation of E. excretorius using several genes is provided. The sequence of D2-D3 expansion segments of 28S rRNA gene of this population was identical to a previously studied sample from Germany. Phylogenetic analysis using D2-D3 of 28S rRNA and partial 18S rRNA gene sequences of tylenchid nematodes revealed that E. excretorius clustered with moderate support with Cephalenchus hexalineatus. The position of E. excretorius on majority consensus Bayesian phylogenetic tree reconstructed using heat shock protein 90 gene sequence was not well resolved.


ZooKeys ◽  
2019 ◽  
Vol 830 ◽  
pp. 75-98 ◽  
Author(s):  
Stela S. Lazarova ◽  
Milka Elshishka ◽  
Georgi Radoslavov ◽  
Lydmila Lozanova ◽  
Peter Hristov ◽  
...  

Longidoruspolyaesp. n., a bisexual nematode species found in the rhizosphere of pear tree (Pyruscommunis L.), is described and characterised using an integrative approach. The new species has a female body length of 6.8–9.1 mm; a comparatively long odontostyle (114.0–127.5 μm); a narrow lip region (14.0–15.5 μm), anteriorly flattened and almost continuous with the body profile; pocket-like amphidial pouches long, deeply bilobed, and slightly asymmetrical, a guide ring at 37–42 μm from the anterior end; normal arrangement of pharyngeal glands; and a short bluntly rounded to hemispherical tail. Four juvenile stages identified: the first stage with a digitate tail, and the second and subsequent stages with a bluntly rounded tail. Males have one adcloacal pair and a row of 10 or 11 single ventromedian supplements; spicules 71.0–74.5 μm long. Based on morphometric data, the new species belongs to a group of species spread over Europe (L.arthensis, L.silvae, L.uroshis,), Iran (L.kheirii), and Syria (L.pauli), which share common characters such as amphidial fovea, lip region and tail shapes, similar odontostyle and body length, and similar first-stage juvenile tail shape. Codes for identifying the new species are A5, B2, C34, D3, E3, F45, G12, H1, I2, J1, K7. The phylogenetic analysis based on D2-D3 expansion domains of the rRNA gene revealed that the new species has the closest relationships with L.athesinus from Italy and three unidentified Longidorus spp. from USA (Longidorus sp. 1, Longidorus sp. 2, and Longidorus sp. 6). New morphometric and molecular data (18S rRNA gene, ITS1-5.8S-ITS2 regions and D2-D3 28S rRNA gene sequences) for three populations of L.pisi from Bulgaria were obtained and variations between populations are discussed.


Nematology ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 925-937 ◽  
Author(s):  
Solomia Susulovska ◽  
Carolina Cantalapiedra-Navarrete ◽  
Andrij Susulovsky ◽  
Pablo Castillo ◽  
Antonio Archidona-Yuste

Summary Females and juveniles from a population of Xiphinema ifacolum from Sri Lanka are described based on morphology, morphometrics and molecular analyses. Morphologically, females and juveniles from Sri Lanka are similar to original descriptions and other reports from Brazil, Cameroon, Liberia, and São Tomé and Príncipe. The identity of the species was also confirmed by 18S rRNA gene sequences deposited in NCBI from Brazil (AY297826). Integrative diagnosis was completed with molecular data using D2-D3 expansion segments of 28S rRNA, ITS1 region, partial 18S-rRNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). This is the third molecular characterisation for a species of the X. non-americanum Group 4, after X. oleae and X. tica. The use of different ribosomal and mitochondrial markers in this study, particularly, D2-D3, ITS1 and partial coxI, provided a precise and unequivocal tool for the identification of X. ifacolum and contributes to a better knowledge of the diversity within Xiphinema. Morphospecies Group 4 appears to be a paraphyletic group within the X. non-americanum assemblage.


2021 ◽  
Vol 95 ◽  
Author(s):  
M.M. Montes ◽  
J. Barneche ◽  
Y. Croci ◽  
D. Balcazar ◽  
A. Almirón ◽  
...  

Abstract During a parasitological survey of fishes at Iguazu National Park, Argentina, specimens belonging to the allocreadiid genus Auriculostoma were collected from the intestine of Characidium heirmostigmata. The erection of the new species is based on a unique combination of morphological traits as well as on phylogenetic analysis. Auriculostoma guacurarii n. sp. resembles four congeneric species – Auriculostoma diagonale, Auriculostoma platense, Auriculostoma tica and Auriculostoma totonacapanensis – in having smooth and oblique testes, but can be distinguished by a combination of several morphological features, hosts association and geographic distribution. Morphologically, the new species can be distinguished from both A. diagonale and A. platense by the egg size (bigger in the first and smaller in the last); from A. tica by a shorter body length, the genital pore position and the extension of the caeca; and from A. totonacapanensis by the size of the oral and ventral sucker and the post-testicular space. Additionally, one specimen of Auriculostoma cf. stenopteri from the characid Charax stenopterus (Characiformes) from La Plata River, Argentina, was sampled and the partial 28S rRNA gene was sequenced. The phylogenetic analysis revealed that A. guacurarii n. sp. clustered with A. tica and these two as sister taxa to A. cf. stenopteri. The new species described herein is the tenth species in the genus and the first one parasitizing a member of the family Crenuchidae.


Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 653-669 ◽  
Author(s):  
Oleg Gorgadze ◽  
Elena Fanelli ◽  
Manana Lortkhipanidze ◽  
Alberto Troccoli ◽  
Medea Burjanadze ◽  
...  

Summary A new species of entomopathogenic nematode, Steinernema borjomiense n. sp., was isolated from the body of the host insect, Oryctes nasicornis (Coleoptera: Scarabaeidae), in Georgia, in the territory of Borjomi-Kharagauli. Morphological characters indicate that the new species is closely related to species of the feltiae-group. The infective juveniles are characterised by the following morphological characters: body length of 879 (777-989) μm, distance between the head and excretory pore = 72 (62-80) μm, pharynx length = 132 (122-142) μm, tail length = 70 (60-80) μm, ratio a = 26.3 (23.0-29.3), H% = 45 (40-51), D% = 54 (47-59), E% = 102 (95-115), and lateral fields consisting of seven ridges (eight incisures) at mid-body. Steinernema borjomiense n. sp. was molecularly characterised by sequencing three ribosomal regions (the ITS, the D2-D3 expansion domains and the 18S rRNA gene) and the mitochondrial COI gene. Phylogenetic analyses revealed that S. borjomiense n. sp. differs from all other known species of Steinernema and is a member of the monticolum-group.


Zootaxa ◽  
2017 ◽  
Vol 4290 (3) ◽  
pp. 459 ◽  
Author(s):  
ALINE ANGELINA ACOSTA ◽  
LIDIANE FRANCESCHINI ◽  
ALINE CRISTINA ZAGO ◽  
TOMÁŠ SCHOLZ ◽  
REINALDO JOSÉ DA SILVA

Heteropriapulus Kritsky, 2007 (Monogenea: Dactylogyridae), which originally included only two species from the gills of loricariid catfishes, is reviewed and six newly described species from loricariids in the Paraná River basin in Brazil are added. Diagnosis of the genus is amended and a key to the species identification is provided. Heteropriapulus anchoradiatus n. sp. from Pterygoplichthys ambrosettii (Holmberg) (Hypostominae) differs from its congeners by having a long sclerotized vagina, ventral anchors with short shaft and conspicuous superficial root, and a conspicuous and robust postero-medial process on the dorsal bar; H. bitomus n. sp. from the same fish host differs by the presence of two pairs of sclerotized patches associated with the ventral anchors; H. falxus n. sp. from Hypostomus strigaticeps (Regan) (Hypostominae) and Hypostomus ancistroides (Ihering) (Hypostominae) is unique by the shape of the accessory piece composed of two strongly sclerotized subunits; H. microcleithrus n. sp. from P. ambrosettii differs by presenting the smallest length of the dorsal bar and unique shape of the longer subunit of the accessory piece resembling the ‘hammer and sickle’ shape; H. pterygoplichthyi n. sp. from the same host presents unique shape of the longer subunit of the accessory piece of the cirrus, which is represented by ‘two sickles’ jointed by the base; and H. semitortus n. sp. from Rhinelepis aspera Spix & Agassiz (Rhinelepinae) can be distinguished by the accessory piece composed of a single straight unit and a cirrus tube with the highest number of spiral rings at the proximal end (2½). First molecular data for this genus (partial sequences of the 28S rRNA gene) are provided including the type species H. heterotylus (Jogunoori, Kritsky & Venkatanarasaiah, 2004).  


2019 ◽  
Vol 151 (5) ◽  
pp. 558-583
Author(s):  
Eduardas Budrys ◽  
Anna Budrienė ◽  
Svetlana Orlovskytė ◽  
Villu Soon

AbstractTwo new species of Diodontus Curtis, 1834 (Hymenoptera: Pemphredonidae) are described. Diodontus polytylus Budrys new species is widespread in North Africa, from Libya and Chad to Morocco, as well as in southern Spain and Portugal. Diodontus guichardi Budrys new species was found in several localities in Morocco. The new species have small differences in their morphology; however, they can be easily separated using molecular characters. Comparison of 17 molecular markers has revealed that the highest evolutionary divergence is observed in mitochondrial gene ND6 and internal transcribed spacer ITS2. The variable regions of the nuclear rDNA genes 18S and 28S demonstrated the lowest evolutionary divergence; thus they were of the least use for species identification. The most coherent reconstruction of phylogeny, in comparison to other groups of markers, was obtained using exons of nuclear protein-coding genes. A provisional key to the species of D. minutus (Fabricius, 1793) species group of the Mediterranean Region is presented.


Nematology ◽  
2012 ◽  
Vol 14 (8) ◽  
pp. 949-960 ◽  
Author(s):  
Majid Pedram ◽  
Ebrahim Pourjam ◽  
Juan E. Palomares-Rius ◽  
Razieh Ghaemi ◽  
Carolina Cantalapiedra-Navarrete ◽  
...  

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.


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