Aphelenchoides primadentus n. sp. is described and illustrated based on its morphological, morphometric and molecular characters. It was recovered from natural forests of northern Iran in association with mosses. The new species is characterised by its body length of 502-613 μm in females and 461-564 μm in males, presence of three lines in the lateral fields, a low lip region slightly offset by a shallow depression, 11.1-13.8 μm long stylet in females, its conus being longer than the shaft (m = 53.0-68.5) and bearing well-developed, rounded basal knobs, the excretory pore located at ca one body diam. posterior to the metacorpus, a conical tail with a multipapillate terminus or with a single, warty, wide mucron-like structure at the tip, and males with 19-22 μm long arcuate spicules that lack a well-developed condylus and rostrum. The new species was morphologically compared with species of the genus having three lines in the lateral field and a multipapillate tail tip or tail with warty mucron, namely A. iranicus and A. heidelbergi. Compared to A. ensete, A. huntensis and A. gorganensis, three species with a multipapillate tail tip or warty mucron at the tail tip, the new species has a basic difference in the number of lines in the lateral field and, compared to two species, A. composticola and A. petersi, which have three lines in the lateral field and a similar overall morphology, the new species has basic differences in tail tip morphology. The results of phylogenetic analyses using partial sequences of ribosomal small subunit RNA (SSU) and mitochondrial cytochrome c oxidase 1 (COI mtDNA) genes revealed there is currently no sequenced species of the genus phylogenetically close to the new species being sequenced for these two genomic and non-genomic regions. The new species forms a clade with A. ritzemabosi in SSU, and three other species, A. besseyi, A. ritzemabosi and A. fujianensis, in the COI tree.
Paurodontella gilanica n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new species is characterised by its small body size, four lines in the lateral field, weak stylet with minute asymmetrical knobs, female reproductive system lacking a diverticulum but with small post-vulval uterine sac, elongate conoid tail with pointed, sometimes filiform, tip, males common with small spicules and cloacal bursa not reaching tail tip. Morphological differences between the new species and seven known species of the genus, namely P. asymmetrica, P. auriculata, P. balochistanica, P. minuta, P. myceliophaga, P. parapitica and P. persica, are discussed. The new species is also compared with four known species of Paurodontus having four lines in the lateral field. Using a 1123 nt long partial 18S rDNA sequence of the new species to reconstruct the phylogenetic relationships revealed that it formed a clade with members of the Sphaerulariidae and Paurodontidae. Using a 746 nt long partial sequence of the 28S rDNA D2-D3 segment revealed that P. gilanica n. sp. formed a clade with Abursanema iranicum in both Bayesian inference (BI) and maximum likelihood (ML) analyses with 0.99 Bayesian posterior probability (BPP) and 89% bootstrap support value (BS). The morphological affinities of Paurodontella and Paurodontus are discussed.
Two populations of Xiphinema ingens were recovered and
characterised based on morphological, morphometric and molecular data.
Interesting morphological variation was observed on the nature of
differentiation in uterus of females between both populations,
i.e. one population had only a pseudo-Z-organ in the shape
of globular bodies, whilst the second population had a similar pseudo-Z-organ
but also had crystalloids which varied in size and number and were located near
the pseudo-Z-globules or sometimes at some distance from them towards the
vagina. Variation was also observed in the shape of tail of juveniles within
each population as well as between two recovered populations. Both populations
had the same range of morphometric data and formed a fully supported clade in
both Bayesian inference (BI) and maximum likelihood (ML) methods of phylogenetic
analyses using partial sequences of 28S rDNA D2-D3 and ITS1 regions. The two
populations of X. ingens formed a clade with another
Xiphinema species native to Iran (X.
castilloi) in 28S and two species, X.
macroacanthum and X. bernardi, in ITS1 trees.
A population of Hemicriconemoides phoenicis was recovered from Khuzestan province, south-western Iran, in association with date palm. The recovered population was characterised by 518-645 μm long females having a 76-82 μm long stylet, rounded to oblong spermatheca filled with sperm, a 28.0-39.8 μm long tail, juveniles common, with 14 longitudinal rows of rounded scales, and males absent. Compared to the original data, no morphological and morphometric differences were observed. In molecular phylogenetic analyses using the D2-D3 expansion segments of the 28S rRNA gene and a near-full-length fragment of the 18S rRNA gene sequences using Bayesian inference (BI) and maximal number of species of the genus, the two newly generated 28S sequences of the Iranian population formed a maximally supported clade with two original sequences of the species; and the 18S sequence formed a maximally supported clade with an unidentified isolate of the genus in the corresponding phylogeny. This is the second report of the species since its original description, Iran representing a new geographical record and supporting the suggestion that date palm could be its preferred host.
A population of Neolobocriconema serratum was recovered from the rhizosphere of Hosta sp., northern Iran, for the first time. It was studied using morphological and molecular data and new morphological observations were made. The Iranian population is characterised by females having 37-43 body annuli, their outer margin ornamented with 12-14 small lobe-like outgrowths under light microscopy, anastomoses occur sparsely in some females and the succeeding annulus is usually anteriorly bent opposite to the vulva. The cephalic region has a single smooth wavy annulus with grooves and is separated from the first, wider body annulus by a very short neck. Four prominent discoid submedian lobes and two lateral pseudolips present, appearing two layered (i.e., one above the other) in scanning electron microscopy (SEM). Body 487-607 μm long, stylet 85-93 μm long with rounded to anchor-shaped knobs, ovary very long, vulva generally closed, but open in some specimens under SEM. Tail conoid with bluntly rounded end and males absent. The recovered population agreed well with the type population based upon the morphometric data and female morphology. In having an almost identical morphology and morphometrics, N. allantoideum is proposed as a junior synonym of N. serratum. The molecular phylogenetic analyses were done by using near-full-length sequences of the small subunit ribosomal DNA (SSU rDNA), the internal transcribed spacer 1 (ITS1 rDNA) and the mitochondrial cytochrome c oxidase subunit I (COI mtDNA). The Iranian population of this species formed a clade with three other populations of the species in the SSU rDNA, and with one population in both the ITS1 rDNA and the COI mtDNA trees using Bayesian inference.
A new species with a rounded tail belonging to the Enchodelus macrodorus-group is described from a natural habitat in the vicinity of Kaleibar City, north-west Iran. Enchodelus babakicus n. sp. is characterised by its medium sized body (1.21-1.56 mm), lip region offset by a marked constriction, odontostyle 40-45 μm long, tripartite uterus and presence of abundant males with 49-61 μm long spicules and 10-14 spaced ventromedian supplements. The new species is close to E. distinctus, E. groenlandicus, E. macrodorus, E. microdoroides and E. saxifragae. A population of E. macrodorus was also found in the same sample as the new species. Molecular analysis was inferred from sequencing of 18S rDNA and ITS1 regions of three species of the genus from Iran, including E. babakicus n. sp., E. macrodorus and E. veletensis, together with other available sequences in GenBank. The sequences showed that E. babakicus n. sp. belongs to a clade formed by Enchodelus species characterised by a rounded tail.
Ektaphelenchoides shiroodensis n. sp. is described and illustrated based upon morphological, morphometric and molecular data. It was recovered from the bark samples of a dead alder tree (Alnus sp.) from countryside around Shirood city, Mazandaran province, in the north of Iran. The new species is characterised by 768-985 μm long females, its lip region separated from the body contour by constriction, lateral field with three barely visible lines, forming two weak bands, 26-29 μm long stylet with wide lumen without conophore and basal swellings, excretory pore always at the level with median bulb, post-vulval uterine sac (PUS) 43-76 μm long, elongate conoid posterior body region ending to a long filiform part with pointed tip, males common with dorsally convex conical tail ending to a short narrower region with pointed tip, seven precloacal + cloacal + caudal papillae and arcuate spicules with wide condylus, blunt rostrum and simple end. Based upon the similar posterior body region (‘tail’) and comparable PUS length, the new species was compared to three known species, viz., E. attenuata, E. hunti and E. pini. Comparisons with the aforementioned species and similar species under the genus Seinura are discussed. The phylogenetic affinities of the new species, based upon two partial small and large subunit ribosomal DNA (SSU and LSU rDNA D2-D3) sequences, are discussed. Furthermore, several ektaphelenchid and seinurid species previously described from Iran were recovered in the present study, sequenced for their aforementioned genomic markers, and included in the phylogenetic analyses.
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.
Additional information on the recently described species, Enchodelus veletensis, is provided, with females, males, intersex and juveniles being described from a population recovered from soil samples collected about grasses in a natural region of north-western Iran. This is the first report of this species for male, intersex and juveniles. Nearly full length of 1560 bp 18S rDNA and 828 bp ITS1 were sequenced. Phylogenetic analysis based on 18S rDNA supported two distinct monophyletic groups of Enchodelus species, those with rounded tail vs conical tail. Enchodelus veletensis is closely related to E. brevidentatus and E. arcuatus. It has identical sequences with E. brevidentatus in 638 bp partial 18S rDNA yet is morphologically distinct.
Lelenchus brevislitus n. sp. is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by having females with slender, 452-488 μm long, body lateral field vestigial as a plain simple band under scanning electron microscopy (SEM) in vulval region and absent in proximal and distal body ends, cephalic region short, ca 2 μm high, conical and truncate in anterior end in lateral view under SEM, dorso-ventrally flattened, amphidial pouches pocket-shaped and large under light microscopy (LM), their apertures short (ca 1 μm long in SEM) longitudinal sinuous slits remarkably wide near the small oral disc and significantly narrowing posteriad stylet, slender. 6.5-8.0 μm long, developed median bulb with distinct valvular plates, monodelphic-prodelphic reproductive system having a short post-vulval uterine sac (PUS), transverse vulval slit (V = 47.5-51.7) bearing small lateral membranes on each side, long filiform female tail (154-170 μm, c = 2.8-3.1, c′ = 21.5-28.3), and males unknown. The new species is considered to be a cryptic species inside the Tylenchidae. Morphological comparisons with all species of the genus are discussed. Phylogenetic studies were performed for further characterisation of the new species, and the results, using nearly full length 18S rDNA data, revealed it formed a clade with an isolate of L. leptosoma, both of which are in a sister clade with an isolate of Sakia. In a reconstructed phylogenetic tree using partial 28S rDNA sequences, the new species formed a monophyletic group, again with L. leptosoma, a sister clade to some Malenchus spp.