Lines In Lateral Field Research Articles

Description of Ektaphelenchus phoenicis n. sp. (Rhabditida: Ektaphelenchinae), a morphological and molecular phylogenetic study

Summary A new species of Ektaphelenchinae was recovered from the bark of a dead date palm (Phoenix dactylifera) tree, and from a soil sample collected from the rhizosphere of gramineous grasses in Iraq and Iran, respectively. It was assigned to the genus Ektaphelenchus mainly by the lack of a functional anus and rectum, and having a conical posterior body end (tail) in female, not ending to a filiform tip, and males lacking a bursa. The recovered populations were described based on morphological and molecular data. Ektaphelenchus phoenicis n. sp. is characterised by 346-441 μm long females, having three lines in lateral field, a 12.3-15.8 μm long stylet with wide lumen lacking basal knobs or swellings, high lip region separated from the rest of body by a depression, metacorpus elliptical with refractive valve plates almost in the middle to slightly posterior, excretory pore posterior to metacorpus, postvulval uterine sac (PUS) 9.3-14.8 μm long, usually containing sperm, posterior body end (tail) with ventrally bent distal end, males common in population with seven precloacal + cloacal + caudal papillae and slightly elevated cloacal lips under SEM, appearing as a differentiated flap-like structure under LM. The new species was morphologically compared with typologically similar species of Ektaphelenchus with a similar body size, namely: E. golestanicus, E. oleae and E. taiwanensis; a similar female posterior body end, namely: E. cupressi, E. kanzakii, E. prolobos and E. riograndensis; and E. goffarti having a similar postcloacal structure. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near full length sequences of small and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3) rDNA. In both inferred phylogenies, the newly generated sequences of Ektaphelenchus phoenicis n. sp. occupied a placement inside a maximally supported clade including sequences of three genera Ektaphelenchus, Ektaphelenchoides and Devibursaphelenchus.

Deladenus Bonabensis n. Sp. (Tylenchomorpha: Neotylenchidae) from East Azarbaijan Province, Northwestern Iran: A Morphological and Molecular Phylogenetic Study.

A population of Deladenus, representing a new species, was recovered from Bonab's Ghara-Gheshlagh lagoon. It is mainly characterized by having a long body (1051-1185 μm), long distance of anterior end to pharyngeal glands end (270-312 μm), six lines in lateral fields, and a short mucro-like differentiation on the tail tip. Furthermore, it has a small-sized stylet (8.5-11.0 μm) with three knobs, no postvulval uterine sac, and males with 24- to 28-μm-long tylenchoid spicules and penial tube. With six lateral lines, the new species is comparable with seven species of the genus: D. apopkaetus, D. brevis, D. cocophilus, D. durus, D. obtusicaudatus, D. processus, and D. ulani. It was furthermore compared with D. oryzae with an unknown number of lateral lines and D. aridus, D. obesus, and D. parvus having a different number of lateral lines but similar morphology. In the molecular phylogenic analyses using small and large subunit ribosomal DNA (SSU and LSU D2-D3 rDNA) sequences, the relationships of the new species with other species and genera were not resolved in SSU phylogeny. However, it formed a clade with Deladenus sp. and D. brevis in LSU phylogeny.

Morphological and Molecular Characterization of Filenchus multistriatus n. sp. (Tylenchomorpha: Tylenchidae) and Data on a Known Species of the Genus from Bushehr Province, Southern Iran.

During a nematological survey in southern Iran, a population belonging to the family Tylenchidae was recovered from a tomato field in Bushehr province. The recovered population belongs to the genus Filenchus, was described and illustrated herein as F. multistriatus n. sp. It is mainly characterized by having a wide and low annulated lip region continuous with adjacent body; amphidial openings confined to the labial plate; four lines in lateral fields forming three bands, with the two outer bands broken by transverse, and the inner one broken by both transverse and longitudinal lines; and median bulb oval with visible valve and elongate-conoid tail uniformly and gradually narrowing toward the distal region, ending in a widely rounded tip. Its morphological and morphometric differences with three closely similar species were discussed. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using partial sequences of small, and large subunit ribosomal DNA (SSU and LSU rDNA) sequences. Morphometric and morphological data were also provided for an Iranian population of F. sandneri recovered from Bushehr province. Both populations were characterised using SEM data.

An interesting rare tylenchid species, Antarctenchus urmiensis n. sp. (Tylenchomorpha; Psilenchidae) from Urmia Lake islands, northwest Iran, with a discussion on the taxonomy of related genera

Abstract A population of an amphidelphic tylenchid nematode was recovered from Urmia Lake islands in association with native shrubs of the region. It had a Tylenchidae-type cloacal bursa in male and looked morphologically similar to the genera under the family Psilenchidae sensu Siddiqi, representing a new species, described and illustrated in present study as Antarctenchus urmiensis n. sp. It is characterized by the slender body at anterior region, gradually narrowing toward posterior end. Four lines in lateral fields in extremities, increasing to six at mid-body. Deirids at secretory-excretory pore (S-E pore) level and phasmids at 38–62% of the tail. Low-expanded cephalic region having a moderately sclerotized cephalic framework, continuous with body, and not flattened dorso-ventrally. Finely annulated cuticle. Amphidial apertures pore-like. Short (13–15 µm long) stylet, its conus 35–42% of the total length and three small tear-drop like knobs. Pharynx with ellipsoid metacorpus and small valve, small saccate pharyngeal bulb offset from intestine. Reproductive system didelphic-amphidelphic, vulva with no membrane or epyptigma. Tail conical, not elongate or filiform, usually slightly ventrally bent, with a sharp or blunt tip and a small indentation at dorsal side close to tip. Males with similar anterior body region and tail to those of female, tylenchoid spicules and small cloacal bursa. In molecular phylogenetic analyses using partial small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3) sequences, the new species appeared as an independent lineage between the clades of Hoplolaimina sensu Siddiqi and the clades of Atetylenchus spp. + Psilenchus spp. in the SSU phylogeny. In LSU phylogeny, it placed in a clade including representatives of Atetylenchus, Psilenchus, Amplimerlinius, Pratylenchoides, Nagelus, and Geocenamus. The currently available phylogenies and taxonomic frameworks were re-evaluated for the placement of the didelphic Tylenchidae-like genera, the overall results showing the best resolution is achieved with the family concept of Psilenchidae under Dolichodoroidea.

Description of Ektaphelenchus masseyi n. sp. (Rhabditida: Ektaphelenchinae) found in dead wood, from Iran

Summary Ektaphelenchus masseyi n. sp. is described and illustrated. The new species was isolated from dead/rotten wood collected from natural forests in north Iran. It is characterised by 501-758 μm long females having three lines in lateral field, more or less continuous cephalic region separated from the body only by a shallow depression, relatively short tripartite stylet (total length 13-14 μm) lacking basal knobs or swellings, excretory pore at base of metacorpus or slightly anterior to it, post-vulval uterine sac 24-32 μm long, rectum and anus absent, posterior body region conical with finely rounded terminus, and males rare, with a dorsally convex and ventrally flat tail with a small mucron at terminus, 13-15 μm long spicules, and seven caudal papillae. The new species was morphologically compared with typologically similar species of Ektaphelenchus having three lines in the lateral field, namely E. joyceae, E. macrobulbosus, E. taiwanensis, and E. winteri. It was further compared with E. olitorius and E. prolobos having a similar female posterior body end shape and with an unknown number of incisures in the lateral field. It was also compared with three species currently placed under Ektaphelenchoides, namely E. andrassyi and E. poinari with three lines in the lateral field, and E. compsi with obscure lateral lines. The molecular phylogenetic relationships of the new species with other ektaphelenchid species were investigated using partial small, and large subunit ribosomal RNA gene (SSU and LSU rDNA D2-D3) sequences using the maximal number of currently sequenced ektaphelenchid and seinurid taxa.

A new cystoid nematode, Cryphodera japonicum n. sp. (Nematoda: Heteroderidae), from the rhizosphere of Japanese Podocarpus macrophyllus

Summary Cryphodera japonicum n. sp., detected at Ningbo port, China, from the rhizosphere of imported Japanese Podocarpus macrophyllus, is described. The new species is characterised by females with a globose body, protruding vulval lips, slightly concave anus-vulva profile, a stylet length of 37.2 (31.1-41.3) μm and a vulva-anus distance of 38.1 (34.7-44.1) μm. Males possess two lip annuli, a stylet length of 27 (22.5-30.6) μm long, three lines in lateral fields and a spicule 21.5 (19.1-23.0) μm long. Second-stage juveniles have bodies 543 (506-588) μm long, three lip annuli, a stylet 31.7 (29.2-34.5) μm long, three lines in the lateral fields, a conoid tail with a narrow rounded terminus, and a relatively long hyaline region occupying half of the tail length. Phylogenetic analyses based on the D2-D3 expansion segments of the 28S, ITS, partial 18S rRNA, and COI gene revealed the unique position of this species with other heteroderid nematodes, supporting its status as a new species of Cryphodera. The new species showed a close relationship with C. brinkmani.

Bursaphelenchus juglandis n. sp. (Nematoda: Aphelenchoididae), an associate of walnut twig beetle, Pityophthorus juglandis, the vector of thousand cankers disease

Summary Bursaphelenchus juglandis n. sp. was isolated from the walnut twig beetle, Pityophthorus juglandis, and walnut trees, Juglans spp. with symptoms of thousand cankers disease, in California, USA. Based on analysis of three rRNA genes and morphological features (three lines in lateral field, small arched vulval flap in female, broad spicule with two lines along blade and small cucullus, digitate dorsally bent condylus, male tail pattern of five papilliform papillae and one pair of glandpapillae (P5), and curved conical female tail), the new species belongs to the Abietinus group within Bursaphelenchus. It differs from similar species of this group by the presence of a cephalic disc with lateral labial sensilla at the disc border, and in having thick spicules with the capitulum surface almost parallel to a virtual direct line extending from the spicule end. An emended diagnosis, tabular polytomous identification key and compendium of species with the lists of their vectors, plant hosts, and distribution are provided for the Abietinus group. The diagnostics of the propagative developmental stages is given, including sex differences; the transmission dauer stage was identified as the third stage and its description given with sexual differences. A molecular phylogeny of Bursaphelenchus is provided based on partial 18S rRNA, ITS rRNA and the D2-D3 expansion fragments of 28S rRNA gene sequences. A PCR with a species-specific primer was developed for detection of B. juglandis n. sp.

Two Ektaphelenchinae Paramonov, 1964 (Nematoda: Rhabditida) from Iran have tripartite stylet, with similar observations in other species.

Two ektaphelenchid nematodes representing one new and one known species are illustrated and characterized using morphological and molecular data. Ektaphelenchus kanzakii n. sp. is mainly characterized by its tripartite stylet having a well visible wide lumen, encompassing a sclerotized and acute anterior part (the conus), a short and slightly tapering middle part (the conophore) that is equally sclerotized but clearly separate from the conus, and a long posterior part that is cylindrical and only weakly sclerotized (the shaft) without basal knobs or swellings. It is further characterized by 863.5 (772–926) μm long females having 23.8 (21.2–27.0) μm long total stylet, distinctly annulated cuticle, three lines in lateral field, vulva at 76.6 (75.3–80.0)%, no rectum, vestigial anus in some individuals, conical posterior body end (tail) with narrow ventrally bent tip, common males in population with two pairs of caudal papillae (the single precloacal papilla and the third caudal pair lacking), spicules with dorsally bent tip and conical tail with sharp or blunt tip. The new species is morphologically compared with close species having conical posterior body end and stylet lacking basal knobs or swellings. Iranian population of Devibursaphelenchus teratospicularis, the second studied species, is characterized by 679.5 (620–709) μm long females having 18.6 (17.5–20.0) μm long total stylet with similar structure to the previous species, subcylindrical body end with widely rounded tip, and rare males with typical spicules of this species and a pair of precloacal and a pair of caudal papillae. Molecular phylogenetic studies of the two recovered species using small and large subunit ribosomal DNA (SSU and LSU rDNA) partial sequences revealed they have close phylogenetic affinities with Ektaphelenchus obtusus in both reconstructed trees. However, species of both genera Ektaphelenchus and Devibursaphelenchus don’t form monophyletic groups in SSU and LSU trees. New observations on stylet structure of the two presently studied and some other ektaphelenchid species having available light microphotographs (LM) yielded on definition of a new term “conophore” for the middle part of the ektaphelenchid-type tripartite stylet.

Morphological and molecular characterisation of Ditylenchus stenurus n. sp. (Nematoda: Anguinidae) from western Iran

A new species in the genus Ditylenchus, D. stenurus n. sp. collected from western Iran, is described and illustrated herein based on morphological and molecular studies. The new species is characterised by a body length of 772 (663–863) μm, delicate stylet 6 (5–7) μm long, six lines in the lateral field. Median bulb of pharynx well-developed, muscular with crescentic valve. Post-vulval uterine sac well-developed, 35 (30–45) μm long, female tail elongate-conoid, becoming narrow suddenly with finely rounded terminus. The new species comes close in morphology and morphometrics to five known species of the genus, namely D. arachis, D. caudatus, D. clarus, D. myceliophagus, and D. nanus. DNA sequencing data was obtained on the partial 18S, D2/D3 expansion segments of the 28S rRNA gene and internal transcribed spacer (ITS). The phylogenetic relationships of this species with other Ditylenchus spp. using partial 18S–rDNA and D2/D3 indicated that D. stenurus n. sp. clustered together with several species belongs to the D. triformis-group i. e. D. africanus, D. destructor and D. halictus: all sharing a rounded tail terminus and six lines in lateral fields.

A New Species of the Rare Genus Anguillonema Fuchs, 1938 (Nematoda: Hexatylina, Sphaerularioidea) with Its Molecular Phylogenetic Study

Anguillonema amolensis n. sp. is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterized by its 575 to 820 μm long and wide body (body width at vulva = 30 to 59 μm), irregularly ventrally curved after fixation, five to six lines in lateral fields, 6.0 to 7.5 μm long stylet with small rounded knobs, pharynx lacking a median bulb, pharyngo-intestinal junction anterior to nerve ring and excretory pore, females with monodelphic-prodelphic reproductive system, 15 to 19 μm long conical tail with broad rounded tip, and males absent. The new species is compared with two known species of the genus, Anguillonema poligraphi and A. crenati. Molecular phylogenetic studies of the new species using partial sequences of small subunit (SSU) rDNA revealed that it forms a clade with an unidentified nematode species and two species of the genus Howardula. In phylogenetic analyses using partial sequences of the 28S rDNA (D2-D3 segment), the new species formed a monophyletic group with species belonging to two genera Howardula and Parasitylenchus.

Description of a new species of seed-gall nematode, Anguina obesa n. sp. (Nematoda: Anguinidae) from northern Iran, and its phylogenetic relations with other species and genera

Anguina obesa n. sp., a new species of the genus, causing small seed galls inside the ovaries of foxtail weed plants (Alopecurus mysuroides Huds.) is described and illustrated based on its morphological and molecular characters. The new species is characterized by its 1516–2564 μm long obese females irregularly ventrally curved after fixation, having six lines in lateral fields, 6–9 μm long stylet with well-developed rounded knobs, constriction at junction of isthmus with the pharyngeal bulb, monodelphic-prodelphic female reproductive system, and conical, 60–80 μm long tail. Males of the new species are characterized with their slender 936–1420 μm long body, 25–30 μm long tylenchoid spicules, and bursa not reaching tail tip. Second stage juveniles of the new species were also common inside the galls and also recovered from soil in type locality. The new species is morphologically close to Anguina agropyronifloris, A. amsinckiae, A. paludicola and A. tumefaciens, but is more closely related to A. paludicola, from which it can be separated based on differences in morphological characters and internal transcribed spacer sequence. In Bayesian inference using sequences of the aforementioned genomic fragment, the new species formed a clade with A. agrostis, A. funesta, A. graminis, A. phalaridis and some unidentified isolates, with robust Bayesian posterior probability (BPP). The morphologically closest species, A. paludicola, occupied a separate position, outside of the clade containing the new species. The sequences of two other genomic fragments, 18S and 28S rDNA (D2/D3 region) were also made available for the new species. Morphological comparisons of the new species with the related species are discussed.

New record of three species of Ditylenchus Filipjev, 1936 (Nematoda: Anguinidae), with a key to the species reported from Iran

Fifteen species of the genus Ditylenchus were recovered and identified from Kermanshah province, western Iran. Morphological and morphometric characters of three known species namely D. filimus, D. hexaglyphus and D. nanus, being new records for Iran's nematode fauna, are given and discussed. Ditylenchus filimus is characterized by having a short stylet (7-8 µm), four lines in lateral fields, well-developed and valvate median bulb, and the typical female tail ending to a filamentous process. D. hexaglyphus, is characterized by having a short stylet (6.5-8.0 µm), six lines in lateral fields, not developed and non-valvate median bulb, and conoid tail with rounded tip. D. nanus, is characterised by having a short stylet (6-7 µm), six lines in lateral fields, median bulb well-developed and valvate, and tail conoid with finely rounded tip. A dichotomous key for identification of the species occurring in Iran is also provided.

Morphological and molecular characterization of Laimaphelenchus deconincki (Nematoda: Aphelenchoididae) based on specimens from Iran

During a survey for nematodes associated with conifers in northern Iran, a known species of Laimaphelenchus was found in the bark samples of Taxus baccata L. trees and is described and illustrated here as L. deconincki Elmiligy & Geraert, 1972. It is characterized by lacking a distinct labial disc on the cephalic region; having six amalgamated labial sectors of equal width, separated by pairs of well-developed ribs; three lines in lateral field; the presence of a vulva flap; vagina surrounded by a cuticularised tube in which the walls vary in thickness; the post-uterine sac 25–62 μm long; tail with a single stalk-like terminus and four pedunculate tubercles; and absence of males. L. deconincki is morphologically very similar to L. cocuccii, but differs in the shape of the vaginal musculature (more angular vs round). Additional information on morphological characters and also the phylogenetic relationships of this known species using sequences of the D2/D3 region of the 28S ribosomal RNA gene is provided and added herein.

Devibursaphelenchus kheirii sp. n. (Nematoda: Ektaphelenchinae) from Iran with remarks on Devibursaphelenchus Kakuliya, 1967

Devibursaphelenchus kheirii sp. n. is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by females with 370-472 μm body length, lip region separated from the body by a shallow constriction, three lines in lateral field, stylet short, 13.5-15.0 μm long, lacking basal knobs or swellings, excretory pore posterior to metacorpus, vulval flap absent, post-uterine sac short, without sperm, rectum and anus obscure, posterior end of the body elongate-conoid with finely rounded terminus. Males of the new species are characterised by their tail ventrally curved after fixation, having two pairs of caudal papillae, spicules 9-11 μm long with an elongated condylus, with rounded tip, pointed rostrum, lacking cucullus and having small conical terminal bursa. The new species comes close to D. hunanensis, D. lini and D. wangi. Beside morphological comparisons, the molecular phylogenetic analyses based on 778 bp of partial sequences of 28S rDNA D2-D3 were performed using two Bayesian inference (BI) and maximum likelihood (ML) methods and revealed that D. kheirii sp. n. formed a clade with the remaining species of the genus and one species of Ektaphelenchoides. This is the first report on occurrence of the genus Devibursaphelenchus in Iran. Devibursaphelenchus eproctatus syn. n. is proposed as a junior synonym of D. hunanensis.

Morphology and genetics characteristics of Steinernema guangdongense Qiu, Fang & Zhou, 2004 from Vietnam

During survey on entomopathogenic nematodes carried out in 2004, a new record of the genus Steinernema (S-XT) was isolated from a soil sample that collected from Xuan Trach, Quang Binh province. The morphological and molecular identification of S-XT isolate have revealed scientific name as Steinernema guangdongense Qiu, Fang & Zhou, 2004. Generally, the specimens from Vietnam are similar to the original description of S. guangdongense by having eight lines in the lateral fields at infective juveniles; the presence of a small double flapped epiptygma, a small projection on the dorsal side of the tail tips and its prominent post-anal swelling part, which is typical for S. guangdongense. In males, the spicules paired, brown color, head (manubrium) of spicules with rounded anterior end, almost continuous with shaft, except body length of females at the first generation always larger. The morphology, morphometrics and molecular characterization based on Vietnamese specimens were supplemented data for the redescription of S. guangdongense and confirmed it belonging to “glaseri” group with the body length of infective juveniles fluctuated between 1,055 µm and 1,063 µm and eight lines in lateral fields. The newly recorded species is also close to S. longicaudum, which was also recorded from Vietnam but differed from it by having another morphological structure of the spicules apparatus, present of the paired epiptigma in the female and the numbers of the lateral fields in the infective juveniles.

Species of Teratorhabditis (Osche, 1952) Dougherty, 1953 (Nematoda:Rhabditida) from sewage and manure samples in India including a discussion on relationships within the genus

Three species of the genus Teratorhabditis (Osche, 1952) Dougherty, 1953 collected from sewage and manure samples of North India are described. The species T. andrassyi Tahseen & Jairajpuri (1988) synonymised by Sudhaus (1991) has been reinstated and is characterized by oviparous females having bluntly rounded lips with labial sensilla not raised beyond labial contour; lip margins and axils heavily cuticularised; three lines in lateral field; considerably wide and tubular stoma having swollen metastegostomal walls with prismatic inner lining bearing five teeth on each plate; basal bulb with usually single haustrulum; tail conoid with a terminal spike; eggs with ridged shells and males with 40–45% distally-fused spicules and a smooth, non-indented bursa having slender papillae in 2/4 + p + 3 configuration. Other populations identified as T. synpapillata and T. palmarum Gerber and Giblin-Davis (1990) are reported for the first time from India. An identification key to species is provided. Relationships within the genus are discussed.

Descriptions of Four New Species of Criconematidae, Male of Ogma Terrestris (Tylenchida: Criconematoidea) and Tylaphelenchus Yamani Sp. N. (Aphelenchina: Aphelenchoididae)

Four new species of Criconematidae, the male of Ogma terrestris Raski & Valenzuela-A., 1986, and Tylaphelenchus yamani sp. n. are described from soil and root samples taken in southern Chile. Females of Ogma sagi sp. n. are distinguished by up to seven large, cuticular scales per annulus, bearing many, fine spines at tip of each; also by the single, smooth, cephalic annulus set off by distinct 'collar', length = 437-632 μm, stylet = 77-92 μm and total body annuli (65-74). The males have four lines in lateral field, coarse annuli, prominent caudal alae, long, graceful spicules. The male of Ogma terrestris is characterized by its lateral field with two prominent lines and many, shallow, irregular, longitudinal lines between; also by its conoid tail with ragged appearance from angular annuli; and by low caudal alae, graceful spicules. Criconema orellanai sp. n. is distinguished by its single, smooth, cephalic annulus, rounded not retrorse; tail with last 4-5 annuli markedly narrowing giving a slightly spicate outline; its body length = 359-479 μm, stylet = 64-75 μm, and 108-117 body annuli. Criconema navarinoense sp. n. is distinguished by its 63-71 coarse annuli, single cephalic annulus set off by narrow 'collar', robust stylet 67-72 μm, and tail shape bluntly conoid. Criconema osornoense sp. n. is distinguished by 46-52 coarse annuli, smooth except for small bead-like to scalloped cuticular markings on last 3-4, terminus rounded, nipple-shaped; also by its body length 329-414 μm, stylet = 76-83 μm. Tylaphelenchus yamani sp. n. is distinguished by its stylet 11-14 μm, body length 450-809 μm, long overlapping oesophageal glands, obscure isthmus with lumen extending 22-25 μm to oesophago-intestinal junction, tail bearing many microvillae-like cuticular projections, lateral field a narrow band set off by two prominent lines reaching to terminus.