Description of Nothotylenchus savadkoohensis n. sp. (Rhabditida, Anguinidae) from Iran based on morphological and molecular data.

Nothotylenchus savadkoohensis n. sp. was recovered from rotten wood samples of an unidentified forest tree in the Mazandaran province and described herein. It is mainly characterized by an elongated conoid tail ending in a sharply pointed tip and four lines in the lateral field. Females of the new species have 379-662 µm long bodies with 5.8-6.9 µm long stylets ending in fine posteriorly sloping knobs, the metacorpus not valvate, the pharyngeal bulb slightly overlapping the intestine, and the vulva at 76.5-84.0% of body length. Males are also common and have 13.0-14.5 µm long spicules and bursa cloacal. By having an elongated conoid tail and four lines in the lateral field, the new species comes close to four known species, namely N. acris, N. acutus, N. antricolus, and N. truncatus. The morphological differences between the new species and the abovementioned species are discussed. The new species was sequenced for its D2-D3 segment of LSU and ITS rDNA regions. In the LSU phylogenetic tree, the currently available LSU sequences of the genus Nothotylenchus occupied distant placements from each other and the LSU sequence of the new species formed clade with a sequence assigned to Neotylenchus sp. In ITS phylogeny, the newly generated sequence of the new species formed a clade with a clade that includes sequences of Ditylenchus sp. and Neomisticius platypi and N. variabilis.

Morphological and Molecular Characterization of Ottolenchus isfahanicus n. sp. (Tylenchomorpha: Tylenchoidea) from Rhizosphere of Gramineous Plants in Isfahan Province, Iran.

A new species from the family Tylenchidae was recovered in the grasslands of Isfahan province, Iran, and is herein described based on morphological and molecular data. Ottolenchus isfahanicus n. sp. is mainly characterized by having a faintly annulated cuticle; elongated, slightly sigmoid amphidial apertures developed metacorpus with distinct valve under LM; vulva located at 69.472.3% of body length; large spermatheca about 2.75 times of corresponding body width; and elongated conoid tail with broadly rounded tip. SEM observations showed that the lip region is smooth; the amphidial apertures are elongated, slightly sigmoid slits; and the lateral field is a simple band. It is further characterized by 477-to-515-µm-long females with delicate 5.7-to-6.9-µm-long stylets with small, slightly posteriorly sloping knobs, as well as functional males, in the population. The new species closely resembles O. facultativus, but is separated from it based on morphological and molecular data. It was further morphologically compared with O. discrepans, O. fungivorus, and O. sinipersici. The phylogenetic relationships of the new species with other relevant genera and species were reconstructed using near-full-length sequences of small subunit and D2-D3 expansion segments of large subunit (SSU and LSU D2-D3). In the inferred SSU phylogeny, the newly generated sequence of Ottolenchus isfahanicus n. sp. formed a clade with two sequences of O. sinipersici and sequences assigned to O. facultativus and O. fungivorus. In the inferred LSU phylogeny, the three newly generated sequences of the new species and LSU sequences of O. sinipersici and O. discrepans formed a clade.

Description of Boleodorus Bushehrensis n. Sp. (Rhabditida: Tylenchidae) from Southern Iran, and Observations on a Commonly Known Species.

A new species of the genus Boleodorus, recovered from southern Iran, is described and illustrated based upon morphological and molecular data. B. bushehrensis n. sp. is mainly characterized by having a wide and low cephalic region (which is continuous with the adjacent body), the oral aperture in a depression in side view under a light microscope, four lines in the lateral field, weak metacorpus with a vestigial-to-invisible valve, and short (26-38 mm long) hooked tail with rounded tip. The females are 334-464 mm long and have a spherical spermatheca filled with spheroid sperm; males have 11.5- to 12.0-mm-long spicules and weakly developed bursa. The new species has an annulated low cephalic region, four large cephalic papillae, and small crescent-shaped amphidial openings when observed by scanning electron microscopy (SEM). Its morphological and morphometric differences with seven known species are discussed. The phylogenetic relationships of the new species with other relevant genera and species have been studied using partial sequences of small and large subunit ribosomal DNA (SSU and LSU rDNA). In both the SSU and LSU phylogenies, the sequences of B. bushehrensis n. sp. and other Boleodorus spp. formed a clade. A second species, B. thylactus, when studied under SEM, has a raised, smooth cephalic region, four large cephalic papillae, and oblique amphidial slits, with the oral opening in a depression.

Description of Longidorella (Saevadorella) caspica n. sp. (Dorylaimida: Nordiidae) from north Iran.

This contribution provides the morphological and molecular identification of a new species of the genus Longidorella (Saevadorella). L. (S.) caspica n. sp., was recovered from the rhizospheric soil of grasses in Mazandaran province in the seashore of the Caspian Sea. It is characterized by females with a length of 788 to 874 µm and a cephalic region with prominent papillae; and separated from the rest of the body by a remarkable constriction, an odontostyle of 32 to 33 µm, vulva at 52.5 to 59.0%, and a tail of 33 to 38 µm with a rounded tip. Males have 32 to 35 µm long spicules of dorylaimoid form and five to seven ventral supplements ending at 48 to 55 µm distance from cloacal pair. The new species was morphologically compared with seven nominal species viz. L. (S.) arenicola, L. (S.) cuspidata, L. (S.) magna, L. (S.) perplexa, L. (S.) saadi, L. (S.) saevae, and L. (S.) tharensis. It was further compared with similar species under the subgenus Longidorella (Enchodorella) viz. L. (E.) deliblatica and L. (E.) murithi. Besides morphological studies, molecular phylogenetic studies using partial sequences of D2 to D3 expansion fragments of 28S rDNA were performed for the new species and its phylogenetic relationships with other species and genera were discussed.

Molecular insights into the compatible and incompatible interactions between sugar beet and the beet cyst nematode.

BACKGROUND: Sugar beet (Beta vulgaris subsp. vulgaris) is an economically important crop that provides nearly one third of the global sugar production. The beet cyst nematode (BCN), Heterodera schachtii, causes major yield losses in sugar beet and other crops worldwide. The most effective and economic approach to control this nematode is growing tolerant or resistant cultivars. To identify candidate genes involved in susceptibility and resistance, the transcriptome of sugar beet and BCN in compatible and incompatible interactions at two time points was studied using mRNA-seq. RESULTS: In the susceptible cultivar, most defense-related genes were induced at 4 dai while suppressed at 10 dai but in the resistant cultivar Nemakill, induction of genes involved in the plant defense response was observed at both time points. In the compatible interaction, alterations in phytohormone-related genes were detected. The effect of exogenous application of Methyl Jasmonate and ET-generator ethephon on susceptible plants was therefore investigated and the results revealed significant reduction in plant susceptibility. Genes putatively involved in the resistance of Nemakill were identified, such as genes involved in phenylpropanoid pathway and genes encoding CYSTM domain-containing proteins, F-box proteins, chitinase, galactono-1,4-lactone dehydrogenase and CASP-like protein. Also, the transcriptome of the BCN was analyzed in infected root samples and several novel potential nematode effector genes were found. CONCLUSIONS: Our data provides detailed insights into the plant and nematode transcriptional changes occurring during compatible and incompatible interactions between sugar beet and BCN. Many important genes playing potential roles in susceptibility or resistance of sugar beet against BCN, as well as some BCN effectors with a potential role as avr proteins were identified. In addition, our findings indicate the effective role of jasmonate and ethylene in enhancing sugar beet defense response against BCN. This research provides new molecular insights into the plant-nematode interactions that can be used to design novel management strategies against BCN.

Labrys khuzestanensis n. sp. (Nematoda, Tylenchidae), a new member of the genus with large labial plate.

Labrys khuzestanensis n. sp. was recovered from the rhizosphere of a palm tree in southwestern Iran and described using morphological and molecular data. The new species was characterized by combination of the following features: its 590-675 µm long body, finely annulated cuticle in light microscopy (LM), lateral field with two smooth incisures, cephalic region dorso-ventrally flattened with protuberant, elongate and laterally extended labial plate, appearing a V-shaped piece in lateral view, amphidial openings as longitudinal slits confined to labial plate in scanning electron microscopic (SEM) images, stylet 7.5-9.0 µm long, elongated fusiform median bulb with faint valvular apparatus, excretory pore wide with moderately sclerotized duct and elongate filiform tail with finely rounded tip. Compared to four currently known species under the genus, the new species has a remarkably larger and more prominent labial plate as revealed by SEM and trapezoid cephalic region under LM. The molecular phylogenetic analyses of the new species using partial SSU rDNA revealed it has close affinity with three species of Labrys (L. chinensis, L. fuzhouensis and L. filiformis) in Bayesian inference (BI) and maximum likelihood (ML) methods and occupied a placement inside their clade. L. fujianensis, the other species of the genus, occupied a distant placement to the aforementioned clade. This is the second species of Labrys being originally described from Iran, representing the third species of Labrys occurring in the country.

Genetic diversity, and description of a new dagger nematode, Xiphinema afratakhtehnsis sp. nov., (Dorylaimida: Longidoridae) in natural forests of southeastern Gorgan, northern Iran.

The most prevalent dagger nematode recovered from rhizospheric soil samples of forest trees in the Afratakhteh region of Golestan province (Iran) was Xiphinema afratakhtehnsis sp. nov. and it is described and illustrated with integrative approaches using both morphological and molecular criteria. It belongs to the morphospecies group 6 of the intragenic historical grouping of Xiphinema non-americanum species. The new species is characterized by females with 3.3-4.9 mm sized body, lip region separated from the rest of body by a depression, anteriorly expanded, 16-18 µm wide, vulva located at 47.2-58.5%, odontostyle 155-173 µm and odontophore 89-107 µm long, female genital system composed of two equally developed branches, the tubular part of each having spines, short symmetrically rounded female tail to symmetrically rounded with a small mucro-like projection at the end in a few females, rare males (n = 1 out of 74 females) with 83 µm long dorylaimoid spicules and four juvenile developmental stages. The third-stage juveniles (J3) have a characteristic tail shape (short, symmetrically conical with a club-shaped long mucro) demarcating the species, and being typologically useful for its separation from closely similar species (except X. cohni, with currently no data on its juvenile stages) viz. X. adenohystherum, X. iranicum, X. mazandaranense, X. nuragicum, X. pyrenaicum, X. robbinsi, X. sphaerocephalum and X. zagrosense. Molecular phylogenetic studies using genomic (partial large subunit and internal transcribed spacer 1 ribosomal RNA genes: D2-D3 and ITS1 rDNA) and mitochondrial cytochrome c oxidase subunit I gene (COI mtDNA) revealed the new species forming a unique lineage in all reconstructed trees using Bayesian inference (BI) and maximum likelihood (ML) methods. The sequenced isolates of the new species formed a monophyletic group in the D2-D3 tree. The sequenced isolates of the new species for their COI mtDNA formed four subclades in COI mtDNA phylogeny, and four haplotypes in corresponding analysis.

Morphological and Molecular Characterization of Labrys filiformis n. sp. (Rhabditida: Tylenchidae) from Iran.

Labrys filiformis n. sp., the second species of the rare genus Labrys , was recovered from natural forests of Gilan province and is described based upon morphological and molecular characters. The new species is characterized by its smooth cuticle under light microscopy, lateral field with two incisures forming a single plain band, lip region continuous with body contour, dorso-ventrally flattened and forming four poorly prominent lobes, having a dorso-ventrally narrower protuberant labial plate laterally extended to the amphidial margins, oral area (oral plate) dorso-ventrally elongated and embedded in the labial plate with six small labial sensilla surrounding the slightly prominent oral aperture, amphidial apertures as longitudinally lemniscatic slits bordered by the labial plate extensions which are overlapped at the middle length of amphids, stylet delicate, 6 to 7 µm long, elongate weakly developed fusiform median bulb with weak valve, wide excretory pore with long and heavily sclerotized duct, offset spermatheca filled with small spheroid sperm cells, 106 to 127 µm long elongate-conoid tail with filiform distal region and finely rounded tip. Molecular phylogenetic analyses were performed using a near-full length fragment of the 18S rDNA and the D2-D3 expansion segments of the 28S rDNA using Bayesian inference and maximum likelihood methods. In the inferred phylogenetic tree with 18S rDNA, the new species has a close affinity with several isolates of the type species, Labrys chinensis . The reconstructed phylogenetic tree using partial 28S rDNA, revealed the new species is nested inside the putative monophyletic group of several populations of L. chinensis .

Description of Aphelenchoides giblindavisi n. sp. (Nematoda: Aphelenchoididae), and Proposal for a New Combination.

One new and one known species of the genus Aphelenchoides from Iran are studied. Aphelenchoides giblindavisi n. sp. is mainly characterized by having five lines in the lateral fields at mid-body, and a single mucro with several tiny nodular protuberances, giving a warty appearance to it, as revealed by detailed scanning electron microscopic (SEM) studies. The new species is further characterized by having a body length of 546 to 795 µm in females and 523 to 679 µm in males, rounded lip region separated from the rest body by a shallow depression, 10 to 11 µm long stylet with small basal swellings, its conus shorter than the shaft ( m = 36-43), 52 to 69 µm long postvulval uterine sac (PUS), males with 16 to 18 µm long arcuate spicules, and three pairs of caudal papillae. The new species was morphologically compared with two species of the genus having five lines in the lateral fields namely A. paramonovi and A. shamimi and species having a warty-surfaced mucro at tail end and similar morphometric data ranges. The morphological features and morphometrics of the second studied species, A. helicus , agreed well with the data given for the type population. However, detailed study of fresh females revealed it has three drop-shaped stylet knobs and long PUS, making it typologically similar to the genus Robustodorus , meriting its taxonomic revision, i.e., transferring to it. In molecular phylogenetic analyses using partial small and large subunit ribosomal RNA gene (SSU and LSU rDNA) sequences, the new species formed a clade with A. heidelbergi in both SSU and LSU D2-D3 trees. The species A. helicus , however, clustered inside a well-supported clade of the genus Robustodorus in both trees, corroborating its newly proposed taxonomic placement as Robustodorus helicus n. comb.

Description of Longidorus azarbaijanensis n. sp. (Dorylaimida: Longidoridae) from Iran.

Longidorus azarbaijanensis n. sp. is described and illustrated using morphological and molecular data. It was recovered in West Azarbaijan province, northwestern Iran, from the rhizospheric soil of foxtail weed. The new species is characterized by having 5.4 to 6.8 mm long females, offset, anteriorly flat lip region and separated from the rest of the body by a shallow constriction, funnel-shaped amphidial pouches, the guiding ring at 23 to 27 µm from the anterior end, 73 to 81 and 44 to 50 µm long odontostyle and odontophore, respectively, 95.0 to 113.5 µm long pharyngeal bulb, didelphic-amphidelphic reproductive system with long tubular uteri lacking sperm cells, vulva located at 52.0% to 56.4%, conical tail dorsally convex, ventrally flat, with bluntly rounded wide tip, for juvenile developmental stages and absence of males. The general body shape of the new species is similar to that of five known species of the genus namely L. euonymus, L. perangustus, L. persicus, L. protae and L. sturhani . The morphological differences of the new species with the aforementioned species are discussed. For all the aforementioned species (except L. protae, currently lacking molecular data) the differences of the new species was also confirmed with differences in molecular sequences of D2-D3 expansion domains of 28S rDNA and the corresponding phylogenetic analyses. The partial sequence of the internal transcribed spacer 1 (ITS1) of the new species was also used in phylogenetic analyses. In partial 28S tree, the clade including the new species and six other species ( L. attenuatus, Longidorus sp. and four above-mentioned species having molecular data for this fragment) was well supported in Bayesian inference. In the ITS1 tree, the new species formed a clade with L. euonymus , L. perangustus and L. persicus , as in 28S tree. This is one of the cases from which the morphologically similar species are separated using molecular sequences.

Observations on Malenchus geraerti n. sp. (Rhabditida: Tylenchidae), a morphological and molecular phylogenetic study.

Malenchus geraerti n. sp., recovered from natural regions of northern Iran, is described and illustrated based on morphological, morphometric and molecular data. The new species is characterized by having females with a short body, an anteriorly wide S-shaped amphidial opening narrowing posteriorly, cuticle with prominent annuli, lateral field a plain band with smooth margins, muscular metacorpus with well-developed valve and corresponding plates, spermatheca filled with small spheroid sperm cells, vulva sunken in body with large epiptygma and no flap, and conical tail tapering gradually to a more or less pointed tip. Males of the new species are characterized by having a short body, tylenchoid spicules, adcloacal bursa with smooth margin and tail similar to that of the female. Morphologically, the new species is similar to five known species of the genus: M. fusiformis, M. machadoi, M. pachycephalus, M. solovjovae and M. undulatus. It most closely resembles M. pachycephalus, but as a cryptic species it can be differentiated using morphological and molecular characteristics. Comparisons with the four other aforementioned species are also discussed. Molecular phylogenetic studies using partial sequences of small and large subunit ribosomal DNA fragments reveal that the new species forms a clade with the species M. neosulcus in the small subunit (SSU) rDNA, and two species of Lelenchus in the large subunit (LSU) rDNA tree.

Two rare species of tylenchids, Discotylenchus biannulatus n. sp. and Labrys chinensis Qing Bert, 2018 (Nematoda: Tylenchidae) from western Iran.

Two rare species of the family Tylenchidae are described and illustrated based on morphological and morphometric characters. Scanning electron microscope (SEM) studies provided details of anterior end structures, helpful in generic identification of the studied populations. Discotylenchus biannulatus n. sp. is characterized by its dorso-ventrally flattened smooth cephalic region having two proximal annuli and a rectangular perioral disc, short longitudinal amphidial slits, lateral field with four incisures, stylet 9-10 µm long, with the conus shorter than half the total stylet length and with posteriorly directed knobs, well-developed median bulb, mono-prodelphic reproductive system with rounded empty spermatheca and short postvulval uterine sac (PUS), and filiform tail with pointed end. It is compared with other species of Discotylenchus having four lines in the lateral field. The Iranian population of Labrys chinensis is characterized by its long and slender (a = 45.2-57.2) body, smooth rounded cephalic region and an offset disc-like apical labial plate, short longitudinal lateral amphidial slits, lateral field with two incisures, moderately developed stylet with the conus less than half the total length and posteriorly directed knobs, median bulb fusiform with distinct but weak valve, gradually joining the isthmus, vulva at 57.2-59.1% with small flaps, elongate conoid tail, uniformly and slightly narrowing toward end with broadly rounded terminus and rare males. The minor morphological differences of the recovered population with the type population are discussed.

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.

Discopersicus n. gen., a New Member of the Family Tylenchidae Örley, 1880 with Detailed SEM Study on Two Known Species of the Genus Discotylenchus Siddiqi, 1980 (Nematoda; Tylenchidae) from Iran.

Discopersicus iranicus n. gen., n. comb., previously described from Iran as a new species under the genus Discotylenchus, is illustrated using light microscope and scanning electron microscope (SEM) observations and further studied using molecular characters. SEM studies revealed the newly proposed genus has oblique amphidial apertures on the lateral sides of the lip region. SEM images are also provided for two species of Discotylenchus, namely D. discretus and D. brevicaudatus, as the first SEM study of the genus. These results confirmed longitudinal amphidial aperture type on lateral sides of the lip region in genus Discotylenchus, as noted by Siddiqi while erecting the genus with D. discretus as the type species. Molecular phylogenetic analyses using partial small subunit (SSU) and large subunit (LSU) rDNA sequences revealed the affinity of the genus Discopersicus n. gen. with members of the subfamily Boleodorinae, as supported by morphological characters (mainly, the oblique amphidial opening).

Data on Some Species of the Genus Coslenchus Siddiqi, 1978 (Rhabditida, Tylenchidae) from Iran.

Data on five known species of the genus Coslenchus are provided. Morphological and morphometric data are given for all studied species. Three of the recovered species were also characterized by molecular phylogenetic data. The species C. leiocephalus was studied for the first time since its original description. Males of the species, C. franklinae and C. oligogyrus were described for the first time and the species C. oligogyrus was reported from Iran for the first time. In molecular phylogenetic studies based on partial sequences of 28S rDNA D2/D3 fragments, all species formed a clade with high Bayesian posterior probability in Bayesian inference, indicating the monophyly of the genus. The clade of Coslenchus spp. formed a highly supported monophyletic group, a sister clade to two species of the genus Aglenchus.

Further Studies on Soil Nematode Fauna in North Western Iran with the Description of One New Species.

Heterodorus youbertghostai n. sp. is described and illustrated based on morphological, morphometric, and molecular data. The new species was found in two geographically distant points in northwestern Iran and is characterized by having angular lip region, separated from the rest body by a constriction, body length of 1,432.5 to 1,751.3 µm, odontostyle length of 24 to 28 µm, rod-like odontophore, 37.0 to 42.5 µm long, lacking flanges at base, double guiding ring at 14 to 16 µm distance from anterior end, pharyngeal bulb comprising 40% to 48% of pharynx, intestine usually containing green material, female reproductive system amphidelphic with less divided short uterus, specific structure of pars distalis vaginae, bluntly conical tail, dorsally convex and ventrally flat, with rounded tip and saccate bodies in ventral side. The new species comes more close to H. conicaudatus and H. irregularis by its morphology and morphometric characters. Compared to former, it has remarkable difference in vulva position and tail characters, and compared to the latter, it could be separated by shorter body, posteriorly located vulva, wider lip region, and longer tail. In phylogenetic analyses using partial sequences of 28S rDNA D2-D3, the new species formed a fully supported clade with several isolates of H. brevidentatus, prevalent in Iran. The other nordiid taxon, Enchodorus dolichurus, already reported from Iran, was also sequenced for the same genomic region and included in phylogenetic analyses.

Rotylenchus castilloi n. sp. (Nematoda: Hoplolaimidae), a new species with long stylet from northern Iran.

Rotylenchus castilloi n. sp., a new bisexual species is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by having a hemispherical, continuous lip region with an irregular corncob-like appearance under SEM, very long stylet (62-68 µm), vulva located at 49.7-62.2% of body length from anterior end, with a protruding double epiptygma, a rounded to convex-conoid (rarely bi-lobed) tail with 8-12 annuli and specific sequences of D2-D3 segments of 28S and ITS1-rRNA genes. Differences between the new species and four other species of the genus (R. mesorobustus, R. cazorlaensis, R. magnus and R. jaeni) are discussed. Morphologically, the new species can be separated from these species mostly by its body length, lip region characters, stylet length and location of phasmid. Phylogenetic analyses using 721 bp partial sequences of D2-D3 expansion segments of the 28S and 590 bp ITS1-rRNA genes revealed the new species forming a clade with two isolates of R. eximius and two isolates of R. unisexus, two morphologically unrelated species.

Description of Ektaphelenchoides fuchsi n. sp. (Nematoda: Ektaphelenchinae) from western Iran.

Ektaphelenchoides fuchsi n. sp., recovered from a soil sample around the rhizosphere of Cucurbita maxima in western Iran, is described and illustrated based on morphological and molecular characters. The new species is characterized by its body length of 529-712 µm, continuous lip region, lateral fields with three incisures, total stylet length of 14-18 µm with rounded basal knobs, excretory pore 70-84 µm and hemizonid 87-96 µm from the anterior end, post-uterine sac short, 6-9 µm long in female and tail conoid with long filiform terminus in male. Based on morphological and molecular characters, the new species is close to E. kelardashtensis, E. attenuata, and E. musae. It differs from the closest species E. kelardashtensis by its longer sylet (14-18 vs 13-16 µm) and stylet with basal knobs vs not, longer post uterine sac (6-9 vs 3-6 µm), more posterior position of excretory pore and hemizonid (70-84 vs 55-66 and 87-96 vs 67-78 µm, respectively), and longer spicules (12-13 vs 8-10 µm). Comparisons with other species of Ektaphelenchoides are also discussed. Molecular analyses were performed based on 631 bp of the partial ribosomal RNA large subunit gene (D2/D3 of LSU) and showed that E. fuchsi n. sp. is unique when compared with other species of the genus for which sequences of that region are available. 

Description of Abursanema iranicum n. gen., n. sp. (Nematoda: Hexatylina, Sphaerularioidea) from Iran and its phylogenetic relationships.

Abursanema iranicum n. gen., n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new genus is characterized by its smooth outer and annulated inner cuticle, having two incisures in lateral field, lacking stylet knobs, having pyriform terminal bulb with stem-like extension projecting into the intestine and lacking of bursa in male. The new genus belongs to the family Paurodontidae. It most closely resembles the genera Paurodontoides and Paurodontus, but has affinities based on male characters with Gymnotylenchus of the family Neotylenchidae too. From Paurodontoides, it differs by the absence of stylet knobs and having six sectors in the head framework. Compared to Paurodontus, the new genus differs by the absence of stylet knobs, structure of the pharynx and absence of a bursa in male. It differs from Gymnotylenchus mainly by lacking of stylet knobs, presence of a basal pharyngeal bulb with an extension into the intestine and in the structure of the spicules. Molecular phylogenetic studies of the new genus using 706 bp partial sequences of the 28S rDNA D2/D3 segment revealed it forming a clade with two species of Sphaerularia in both Bayesian Inference (BI) and maximum likelihood (ML) analyses with 1.00 Bayesian posterior probability (BPP) and 0.96 bootstrap support values (BS). Using 942 bp partial sequences of 18S ribosomal RNA gene, the new genus formed a clade with a species of Deladenus with 0.86 BPP and 0.62 BS in BI and ML methods, respectively. With both BI and ML methods, this clade forms a larger highly supported clade with two species of Sphaerularia.

Description of Trichodorus iranicus sp. n. (Diphtherophorina, Trichodoridae) from Iran.

Trichodorus iranicus sp. n. is described and illustrated based on morphological and molecular characters and morphometric data. It belongs to the T. lusitanicus morphospecies group based on the shape of the spicules and vaginal sclerotised pieces. Males have a body length of 844-942 µm, onchiostyle length of 59 µm, three cervical papillae (CP), curved spicules, 28-30 µm in length, with narrow mid-part, sometimes provided with a few bristles, and slightly developed manubrium. Females of the new species are 727-870 µm long with secretory-excretory pore located opposite anterior end of pharyngeal bulb, vagina length 46-57% of corresponding body width, with triangular to triangular-rounded sclerotised pieces 3.5 µm long, 1-2 µm apart from each other, and vulva a transverse slit. In its morphology, the new species resembles T. andalusicus, T. asturanus, T. azorensis, T. beirensis, T. lusitanicus, T. velatus and T. viruliferus and the morphological and morphometric differences separating T. iranicus from these known species are discussed. The D2-D3 region of 28S rDNA for the new species was amplified and the 679 bp newly-obtained sequence was used in a Bayesian inference (BI) analysis which confirmed the close relationship of the new species with T. lusitanicus morphospecies group members and placed it as a sister taxon to T. andalusicus in a well-supported clade that also includes T. asturanus.