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Summary: During a survey, three populations of a new stem nematode were isolated from galls on the shoots of tumble thistle (Gundelia tournefortii) plants in Fars province, Iran, and identified. Ditylenchus paraoncogenus n. sp. is described based on morphometric and morphological characters. It is characterised by having long-sized females, 1252 (943-1628) μ m long, narrow lateral fields with six incisures, rather developed stylet 9.9 (9.0-11.3) μ m long with round knobs, usually elongate and offset from intestine basal pharyngeal bulb, oocytes in two rows in distal part of ovary, V = 83.3 (80.3-86.2), post-vulval uterine sac 68.1 (46.9-86.1)% of vulva to anus distance long, bursa covering 63.2 (33.3-74.4)% of tail length, spicules 24.7 (21.0-27.9) μ m long with minute processes at the base of its manubrium and anteriorly pointed cuticle parts within the lamina, and thick conical tail, usually with a pointed terminus. In addition, the ITS and 18S rDNA sequences of 17 populations of D. destructor , D. dipsaci , D. medicaginis , D. myceliophagus , D. paraoncogenus n. sp., Ditylenchus sp. and Nothotylenchus geraerti plus one population of Anguinidae sp. were analysed. The results showed a close relationship between D. paraoncogenus n. sp. and the stem nematodes D. oncogenus , D. gigas , D. weischeri and D. dipsaci. Ditylenchus species were divided into two clades, one clade comprising stem nematodes and gall-forming nematodes of the family Anguinidae, and the other clade containing fungivorous species. Observations showed that the second-stage juvenile is the dormant stage of D. paraoncogenus n. sp. and can survive in anhydrobiotic condition for at least 4 years. [ABSTRACT FROM AUTHOR]

Summary: A new species of Tylenchidae from the rhizosphere of mangrove trees in Hormozgan and Khuzestan provinces, Iran, is described based on morphological and molecular data. Ottolenchus sinipersici n. sp., is characterised by a slightly fusiform body 560-665 μ m long, lateral field in the form of a narrow band with two faint incisures that are not visible in fatter females, indistinct transverse annuli under the light microscope, cephalic region continuous with the body contour, smooth and flattened dorsoventrally, longitudinal and narrow sigmoid amphidial slits, stylet delicate, 10.1-11.2 μ m long, with small rounded to slightly posteriorly sloping knobs, well-developed median bulb, offset and pyriform pharyngeal basal bulb, vulva located at 66.9-69.6% of body length, offset spermatheca, short post-vulval uterine sac, spicules 18.5-20.5 μ m long with highly curved blades, and a 113-135 μ m long filiform tail with a hook-like or coiled terminus. In Bayesian inference phylogenetic trees based on the partial small subunit ribosomal DNA (SSU rDNA) and D2-D3 expansion segment of large subunit ribosomal DNA (D2-D3 LSU rDNA) genes, the new species clustered together with O. facultativus (KJ869310) in SSU, and forms a clade with three isolates of O. discrepans in LSU phylogeny. Ottolenchus fungivorus n. comb. (= Filenchus fungivorus) is proposed. [ABSTRACT FROM AUTHOR]

Summary: The ectoparasitic nematode, Scutylenchus rugosus , is common in Europe and Asia, feeding on several plant species and limiting productivity. Its seasonal population fluctuation was monitored on maize and wheat crops, in glasshouse and open field conditions, respectively. Its survival in the absence of a host plant was also investigated in a microplot field trial. The population of S. rugosus increased gradually during 4 months of maize growth in glasshouse conditions, and more than 50% increase occurred during the second month after sowing. Under wheat growth, in open field conditions, the lowest population was observed during July, 1 month after wheat harvesting, and the highest in August, after the first post-harvest irrigation. About 50% of the nematode population survived after a 5-month period of drought in the absence of a host and the percentage of surviving nematodes was greater under a dry soil regime than under a dry-wet regime. Most of the inactive S. rugosus were adults. After 24 h of soil wetting, most inactive nematodes resumed their activity and the optimum temperature for activation was 25°C. [ABSTRACT FROM AUTHOR]

Summary: Helicotylenchus ciceri n. sp. and H. scoticus are described and illustrated based on morphological, morphometric and molecular characters. The new species is characterised by a conical and truncated lip region with five or six distinct annuli, stylet 32-37 μ m long with anteriorly concave knobs, secretory-excretory pore posterior to the pharyngo-intestinal valve, dorsally convex-conoid tail with a terminal projection, phasmids 14 (7-20) annuli anterior to the level of anus, empty spermatheca and absence of males. Intraspecific variation of 16 populations of H. scoticus , collected from chickpea and lentil fields in Kermanshah province, western Iran, is discussed. The results of the phylogenetic analyses based on the sequences of the partial 18S rRNA, D2-D3 expansion segments of 28S rRNA and ITS rRNA genes are provided for the studied species, confirming their differences from each other and determining the position of them and their relationships with closely related species. [ABSTRACT FROM AUTHOR]

Mesocriconema abolafiai n. sp. is described by morphological, morphometric, and molecular approaches. The new species is characterized by a body slightly curved with 402 to 612 μ m length, 90 to 113 cuticular body annuli with smooth to irregular margins lacking of crenation with not more than one anastomoses, lip region not offset, small flattened submedian lobes, stylet robust (52.8-60.0 μm) with well-developed knobs, open vulva with simple anterior lip, straight vagina, filled spermatheca with globular sperms, presence of males, and conical-acute tail with last annulus bilobed or rounded. Discussions are made on the characterization of M. abolafiai n. sp. from the most closely related species, M. ozarkiense, and several other species having similar tail shape. Furthermore, results of phylogenetic analyses inferred from D2 to D3 expansion fragments of 28S rRNA, 18S rRNA, and ITS rRNA gene sequences revealed the phylogenetic position of the new species within representatives of Criconematidae and supported morphological justifications for considering this population from Iran as a new species in the genus Mesocriconema. [ABSTRACT FROM AUTHOR]

In order to investigate different species of root-knot nematodes associated with vegetable production in southern regions of Iran, 37 populations of the most predominant species, Meloidogyne javanica, were recovered. Morphological and morphometric studies were carried on the characters of females, males, J2s and perineal patterns. Species-specific Sequence Characterized Amplified Region (SCAR) primers confirmed morphological studies, and all these populations produced specific band in 670 bp using Fjav and Rjav primers. Genetic diversity of different populations was studied by Inter Simple Sequence Repeats (ISSR) and Random Amplified Polymorphic DNA (RAPD) markers implementing 10 primers for each approach. Results revealed a relatively low genetic diversity (the percentage of polymorphic bands were 19.08 and 24.60 for ISSR and RAPD, respectively). The analyses of molecular variance indicated that the variation resulted from genotypic variations within region and variances among regions are 81% and 19% for RAPD, and 86% and 14% for ISSR, respectively. On the other hand, FST and Nm values are 0.140 and 1.535 for ISSR while these values are 0.188 and 1.079 for RAPD. So it can be concluded that there is a great deal of gene flow between populations due to the movement of plant material contaminated with nematodes, which results in high mixing between populations. ISSR and RAPD datasets failed to group populations according to their geographic region. There were no pathotypes or other intraspecific biological entities observed in the species. [ABSTRACT FROM AUTHOR]

Summary: The Persian sessile nematode (Cacopaurus pestis) and pin nematodes (Paratylenchus spp.) are sedentary ectoparasitic nematodes associated with many plant species worldwide. In this study, we provide morphological and molecular characterisation of seven populations of C. pestis and eight species of Paratylenchus recovered from north-western Iran. A total of 26 new sequences of D2-D3 expansion segments of 28S rRNA and ITS rRNA were obtained and used to reconstruct phylogenetic trees. Results of phylogenetic analyses revealed that the subfamilies of Tylenchulidae form well-separated clades, but that the genera Cacopaurus and Paratylenchus (= Gracilacus) in the subfamily Paratylenchinae are clustered in one clade. It appears that the previously used character of "stylet length greater than 40 μ m" is not homologous and evolved more than once within the Paratylenchinae. [ABSTRACT FROM AUTHOR]

Two populations of the genus Trophotylenchulus and 10 species of the genus Paratylenchus from Iran were characterized based on morphometric, morphological and molecular characters. Our observations on the two populations of Trophotylenchulus from Iran revealed that T. asoensis and T. okamotoi have been distinguished from T. arenarius, on the basis of the features which cannot be longer considered as stable diagnostic characters. One of the populations shows a mixed combination of the characters of T. arenarius and T. asoensis; it has morphometrics more similar to T. arenarius but shows affinities with T. asoensis in the tail terminus shape of females and second-stage juveniles (J2) and in having a reduced stylet in males. The other population fit well with T. okamotoi; it has females with generally bluntly rounded tails typical for T. okamotoi, but sometimes with finely rounded tail termini, like those of T. arenarius or T. asoensis. The sequences of D2-D3 expansion segments of 28 S rRNA gene for the two populations are identical with each other, but only 4 bp (0.67%) difference with T. arenarius sequence deposited in the GenBank. Considering no stable difference allow separating species, synonymy of T. asoensis and T. okamotoi with T. arenarius, which has already been proposed, is supported and confirmed here. All studied Paratylenchus species with stylets longer than 40 µm, except P. straeleni, formed a basal cluster to Cacopaurus pestis and species of Paratylenchus bearing stylets shorter than 40 µm; thus, validity of Gracilacus cannot be rejected using our data sets. However, the synonymy of Paratylenchoides was supported by the positioning of P. sheri within representatives of Paratylenchus in the inferred phylogenetic tree. [ABSTRACT FROM AUTHOR]

Numerical taxonomy was used for identification and grouping of the genera, species, and populations in the families Merliniidae and Telotylenchidae. The variability of each of 44 morphometric characters was evaluated by calculation of the coefficient of variability (CV) and the ratio of extremes (max/min) in the range of 1,020 measured females. Also correlation and regression analyses were made between characters to find potential collinearities. Hierarchical cluster analysis (HCA) was used for (i) grouping 21 genera in the superfamily Dolichodoroidea based on literature data coded for states of 18 diagnostic characters, and (ii) for grouping Iranian populations belonging to selected genera. Furthermore, STEPDISC analysis was used for (i) grouping 11 genera of Merliniidae and Telotylenchidae based on the measurements of 35 characters from 1,007 Iranian female specimens, and (ii) grouping measured females of eight species of Amplimerlinius and Pratylenchoides. The multivariate data analysis approach showed robust enough to summarize relationship between morphometric characters and group genera, species, and populations of the nematodes and in particular help to identify the genera and species of Amplimerlinius and Pratylenchoides. [ABSTRACT FROM AUTHOR]

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Ektaphelenchoides caspiensis n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new species is characterised by its continuous lip region, obscure lateral field, females with body length of 499-572 µm, 9-10 µm long stylet, excretory pore posterior to base of metacorpus at 62-72 µm from anterior body end, short post-uterine sac ca 0.5 times corresponding body diam. or 4-9 µm long, and posterior body end (i.e., including 'tail') very long and filiform. Males are common and have 7-8 µm long spicules, five copulatory papillae and a long (109-140 µm) conoid tail with very long filiform terminus. Based on morphological and molecular characters, it comes close to five known species of the genus, namely: E. attenuata, E. fuchsi, E. kelardashtensis, E. musae and E. ruehmi. It differs from the closest species, E. kelardashtensis, by the shorter female stylet (9-10 vs 13-16 µm), more anterior vulva (V = 51.7-58.1 vs 61.5-68.0), more posterior excretory pore (62-72 vs 55-66 µm from anterior end), very long posterior body (i.e., including 'tail') in female, and male tail shape (conoid with very long filiform terminus vs conoid, sharply pointed). Comparisons with other close species of the genus are also discussed. Molecular analyses were performed using 732 bp of the partial ribosomal RNA large subunit gene (D2-D3 of LSU) using Bayesian inference (BI) and maximum likelihood (ML) methods and showed that the new species formed a clade with one species of the genus (E. fuchsi) and Devibursaphelenchus lini. [ABSTRACT FROM AUTHOR]

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 pm body length, lip region separated from the body by a shallow constriction, three lines in lateral field, stylet short, 13.5-15.0 pm 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 pm 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. [ABSTRACT FROM AUTHOR]

During nematode surveys in Iran two Paratylenchus populations were found. Paratylenchus conicephalus sp. n. is described and figured from the rhizosphere of Prangos ferulacea (L.) Lindl. and is characterised by having a 365-501 μm long body, stylet 29.5-35 μm long, a conical lip region with four or five indistinct annuli, large submedian lobes and four large flaps around the stoma opening, these structures appearing as a small cap-like structure when viewed laterally with the light microscope, four lines in the lateral field, and a sharply pointed tail 25.5-46 μm long. Paratylenchus similis is described and figured from the rhizosphere of Artemisia aucheri Boiss. and compared with the various descriptions of this species. [ABSTRACT FROM AUTHOR]

Six known species belonging to the genus Criconemoides, including some poorly known ones, are discussed, viz., C. parvus, C. informis, C. mongolensis, C. avicenniae, C. myungsugae and C. neoaxestis. The three latter species are reported for the first time since their original description and represent new records for Iran. Males of C. myungsugae were found for the first time and are described herein. Additional figures and measurements are provided for all of the aforementioned species, while SEM photographs, photomicrographs, illustrations and short notes are given for some of the species to supplement older or inadequate descriptions. [ABSTRACT FROM AUTHOR]

During a survey of plant-parasitic nematodes associated with walnut trees in Hamadan province, west Iran, several species of Longidoridae and infraorder Tylenchomorpha, including Paratylenchus paraperaticus sp. n., were identified. Paratylenchus paraperaticus sp. n. is characterised by its small size (255-385 μm), young female vermiform and ventrally curved, older female obese, swollen in prevulvar region and J- or W-shaped; truncate conical head with distinct and laterally protruding submedian lobes; long and flexible stylet (75.0-96.5 μm); body cuticle with fine and smooth annuli in young females, but in older females ornamented with minute reflective tubercles or irregularities that are confined mostly to the neck region; lateral field with four lines; presence of lateral vulval flaps; rounded to ovoid spermatheca filled with small, rounded sperm; and conical and ventrally curved tail with pointed to finely rounded terminus. [ABSTRACT FROM AUTHOR]

Trichodorus arasbaranensis n. sp. is described from the rhizosphere of Carpinus betulus growing in forests in Arasbaran, north-west Iran. The new species is characterised by its large body length (1020-1520 μm in males; 1100-1500 μm in females), cuticle abnormally swollen upon fixation, onchiostyle medium-sized (41-66 μm in males; 49-65 μm in females) and secretory-excretory pore at level of pharyngeal bulb. Males have a single ventromedian cervical papilla varying in position from anterior to posterior to secretory-excretory pore, sperm cells with sausage-shaped nucleus, large (74-110 μm), smooth, ventrally curved spicules, manubrium wide, not offset from lamina, lamina narrowed in mid-region and with a distal ventral velum, and gubernaculum 25.5-34.5 μm long. Females have a short, but well developed, rounded vagina with large, rounded, triangular to oval-shaped, sclerotised vaginal pieces in lateral view. Because of its large body size, the new species most closely resembles T. magnus, T. elegans, T. obtusus, T. californicus and T. nanjingensis, from which the female can be differentiated by the short vagina length in relation to the corresponding body diam. and large size of the vaginal sclerotised pieces, and the male by the longer and differently shaped spicule which bears a velum. A key to the males and females of the Trichodorus spp. recorded from Iran is provided. [ABSTRACT FROM AUTHOR]

Xiphinema iranicum n. sp. is described from soil samples collected about the rhizosphere of Rosa sp. growing in a natural mountainous region close to Maragheh city, north-western Iran. The new species belongs to group 6 of the polytomous key to species identification and is unique by having a medium body length (3.8-4.3 mm), odontostyle length of 141-162 μm, odontophore length of 90-98 μm, mid-body diam. of 69-88 μm, presence of spines in the uterus and a hemispherical to conoid tail with a rounded terminus or minute bulge. It resembles X. ingens, X. aceri, X. aequum, X. smoliki, X. illyricum, X. macedonicum and X. vuittenezi but differs from X. aceri and X. aequum by having different tail shape, longer odontophore, lower ratio a, higher ratio c and lower ratio c′. Compared to X. ingens and X. smoliki, it differs by having lower ratio a, lower ratio b, spines in uterus vs crystalline bodies plus pseudo Z-organ in X. ingens and spines plus pseudo Z-organ in X. smoliki and also by the presence of rare males, and, finally, it can be distinguished from X. vuittenezi by body and odontostyle length, characters of juveniles and molecular differences. The new species has similar polytomous identification codes to X. illyricum and X. macedonicum but can be differentiated from both by longer body, higher ratio c, higher V, longer odontostyle and odontophore and larger body diam. at mid-body and anus level. Ribosomal gene 18S rDNA and ITS1 of X. iranicum n. sp., X. aceri, X. montenegrinum and X. macedonicum, all obtained from north-western Iran in the same survey, were sequenced to investigate the phylogenetic relationships with other sequenced Xiphinema species. [ABSTRACT FROM AUTHOR]

Number of cores per citrus tree (sample size) needed to estimate the citrus nematode count (second-stage juveniles and males) in the soil was investigated. Coefficient of variation of mean (CV) was used as a measure of reliability and Taylor's power law model was used as a descriptor of nematode spatial distribution. The study was replicated twice during early winters 2018 and 2019 in two citrus orchards of Fars province, southern Iran. For each of the six selected trees, 10 cores (10–15 cm in diameter × 30 cm in depth) were systematically sampled from beneath each tree canopy; six and four cores from the outer and inner parts of irrigation dripline, respectively. Second-stage juveniles (J2s) and males of the nematode in soil were extracted using a Bearman tray method for 48 h. Besides 10 single samples from each core, the sampling patterns were designated in two forms of real and virtual compositions. Real compositions included of an average of two or three composite samples from outer and/or inner part of irrigation dripline. The virtual compositions corresponded to the real compositions and were formed by combining nematode count data rather than soil samples. Parameters of Taylor's power law model were estimated by fitting the model to the data and used for sample size calculations for this nematode. The results of the two trials revealed that in terms of reliability, and cost an average of two composite samples from the outer (six cores) and inner (four cores) areas of the irrigation dripline could be recommended as the best sampling plan for estimating the nematode population in infested orchards. • Different sampling patterns for citrus nematode were evaluated to find the best one. • Taylor power law model was used to describe variability of nematode count in soil. • Sample size was optimized using CV of the mean as a measure of precision. • Cost of sampling is the second criteria to choose the best sampling pattern. • To achieve higher reliability, larger sample sizes with higher costs are required. [ABSTRACT FROM AUTHOR]

To investigate relationships within the subfamily Telotylenchinae, more than 500 soil samples were collected from various natural and agricultural habitats in several localities of Iran. Individuals of seven known species, including Bitylenchus dubius, B. parvus, B. serranus, Sauertylenchus maximus, Tylenchorhynchus clarus, T. microconus and Trophurus ussuriensis, were recovered and characterized based on morphological and morphometric characters. Furthermore, phylogenetic relationships within representatives of the subfamily Telotylenchinae were explored using 13 sequences from the D2-D3 expansion regions of 28S ribosomal (r) DNA and 13 sequences for the partial 18S rDNA genes obtained in the present study. Analyses based on the relatively conserved 18S rDNA gene underlined the polyphyletic status of Tylenchorhynchus sensu lato, as three clusters representing Tylenchorhynchus, Bitylenchus and Sauertylenchus were well separated, and interspersed by, e.g., representatives of the Macrotrophurinae. Analysis of the more variable D2-D3 28S rDNA sequences suggested at least four clades within the subfamily Telotylenchinae: two clades dominated by Tylenchorhynchus species; a third clade harbouring representatives of Sauertylenchus, Bitylenchus, and Paratrophurus in distinct but unresolved branches;and a fourth clade dominated by Trophurus species. Although no molecular information was available from a number of genera that were originally gathered under Tylenchorhynchus sensu lato, we concluded that both Bitylenchus and Sauertylenchus should be seen as valid Telotylenchinae genera related to, but distinct from Tylenchorhynchus.

During a survey conducted during 2013-2017, five known and two new species of Nothotylenchus Thorne, 1941 were collected from the southern provinces of Iran. N. brzeskii n. sp. is characterised by a body length of 774-922 µm, lateral fields with four incisures, delicate, short stylet (7-8 µm) with small rounded knobs, pyriform, offset or slightly overlapping basal pharyngeal bulb, posterior vulva position (V = 83.4-84.4), short PUS (5-10 µm), spicules 20.5-23 µm long, and thick tail with rounded to dull terminus. N. siddiqi n. sp. is characterised by a body length of 573-645 µm, six to nine incisures in lateral fields, delicate, short stylet (6.5-7.5 µm) with rounded knobs, pyriform or slightly elongate and offset basal pharyngeal bulb, V = 79.3-81.0, PUS = 26.5-40 µm, short spicules = 14.5-16.5 µm, and tail with rounded terminus. Morphometric data of the studied species are presented and intraspecific variation of their morphometrics and morphological characters is discussed. The list of world Nothotylenchus species is updated, and a dichotomous identification key and an updated tabular compendium for 41 valid species are provided.

During a survey, 12 known and one new species of Ditylenchus Filipjev, 1936 were collected from southern provinces of Iran during 2013-2017. Ditylenchus paraparvus n. sp. is characterised by a short body length (441-543 µm), lateral field with four lines, delicate and short stylet (6-7.5 µm) with small rounded or posteriorly sloping knobs, pyriform and offset basal pharyngeal bulb, V = 67.7-76.4, short post-vulval uterine sac less than one vulval body width long, small spicules (12.5-15 µm) and almost cylindrical tail (71-90 µm) with rounded end. Morphometric data of studied species are presented and intraspecific variation of their morphometrics and morphological characters is discussed. The list of the world Ditylenchus species is updated, and a dichotomous identification key and an updated tabular compendium for 63 valid species is provided.

The list of plant parasitic nematodes of the family Tylenchulidae, collected from Iran, is updated. Forty-one species belonging to five genera and three subfamilies are included in the list. Data for seven species of Paratylenchus are added, of which two species-P. perminimus and P. salubris-are new records for the Iranian nematofauna. The list of species, further information on their morphometrics, references to full or partial descriptions, associated plants, geographical distribution and some taxonomic remarks are provided. More detailed studies on some doubtful populations are added. Information on the taxonomic position of species in different classification schemes, as well as the preferences of some species for certain climatic conditions or ecological niches is provided.

Trichotylenchus gorganiensis n. sp. is described and illustrated based on morphological and morphometric data. The new species is characterized by its 760-1073 µm long body, conoid-rounded lip region continuous with the body contour and bearing 5-7 fine striae, 22.0-24.5 µm long stylet, basal pharyngeal bulb offset or slightly overlapping intestine, post-anal sac extending 50-73 % of the tail region, and cylindrical or subclavate tail with a striated terminus. Differences of the new species from the closely related species T. astriatus, T. astriatoides, T. changlingensis and T. papyrus are discussed. Photomicrographs and several taxonomic notes on 13 other species of Telotylenchinae, collected from Iran, are provided.

Morphological and morphometric studies were conducted on the populations and paratypes of 14 species of the genus Pratylenchoides, including P. alkani, P. acuticauda, P. arenarius, P. arenicola, P. bacilisemenus, P. crenicauda, P. erzurumensis, P. heathi, P. laticauda, P. ritteri, P. rivalis, P. sheri, P. utahensis and P. variabilis. In addition, P. erzurumensis was redescribed based on a bisexual population from western Iran. The conoid head of males is an additional diagnostic character of this species distinguishing it from the closely related P. laticauda and P. camachoi. Based on detailed study of the main characters, synonymies of P. arenarius with P. bacilisemenus and P. variabilis with P. crenicauda are proposed. Synonymy of P. alkani with P. ritteri is supported also by morphological and biological evidence. Some taxonomic notes are made on some other species of the genus. Finally, a diagnostic compendium and key is provided for species identification.

A new species of the genus Amplimerlinius is described and illustrated from the rhizosphere of Vitis sp. from Kurdistan province in western Iran. A. uramanatiensis sp. n. is characterized by having seven to eight head annuli up to the end of the outer extension of the cephalic framework, 29-31 µm long stylet and cylindrical-clavate tail with a thin hyaline region (9-11 µm) and smooth terminus. Furthermore, A. paraglobigerus and A. macrurus were identified and intra-specific variability of A. globigerus was studied in detail, based on 21 populations collected from different regions of Iran. A key and diagnostic compendium to the species of the genus is provided.

In order to identify the species of Helicotylenchus Steiner, 1945 present in Iran, 497 soil and root samples were collected from the rhizosphere of different plants and localities throughout the country during 2009-2010. A new and several known species of Helicotylenchus were identified from the collected material. H. persiaensis sp. n. is characterized by its short tail (8-11 µm , c = 54.2-79.0, c' = 0.6-1.2), usually with smooth terminus or with 1-3 very coarse annules, rarely with minor ventral, dorsal or lateral projection, conical and truncate head with 4-5 distinct annules, stylet 22-26 µm long with anteriorly flattened knobs, relatively short body length (570-730 µm) and absence of males. This species was collected from the rhizosphere of zelkova (Zelkova carpinifolia) and maple (Acer sp.) forest trees in Golestan province, northern Iran. Also observed were H. abunaamai Siddiqi, 1972, with a small ventral projection at the tail terminus, and H. crenacauda Sher, 1966, with long projection and indented terminus, collected from sugarcane (Haft-Tapeh, Khuzestan province) and rice rhizosphere (Chabok-Sar, Gilan province), respectively. This is the first report of H. abunaamai from Iran. New data on H. crenacauda are provided.

The list of plant parasitic nematodes of the family Dolichodoridae, known from Iran, is updated. 81 species belonging to 13 genera and three subfamilies are included in the list. Data for 29 species are added, of which seven species viz. Neodolichorhynchus phaseoli, Pratylenchoides crenicauda, P. erzurumensis, P. utahensis, Scutylenchus paniculoides, Trophurus impar and Tylenchorhynchus variannus are new records for the Iranian nematofauna. The list of species, further information on their morphometrics, references, referring to full or partial descriptions, associated plants, geographical distribution and some taxonomic remarks are provided. More detailed studies on some doubtful populations are proposed. The information on the taxonomic position of species in different classification schemes, as well as, the tendency of the species to certain climatic condition or ecological niche are provided. Challenges on the reliable identification of this group of nematodes in Iran are discussed and finally, suggestions were proposed for future studies.