Molecular and morphological characterisation of Aphelenchoides kheirii n. sp. (Nematoda: Aphelenchoididae) isolated from Pinus nigra in north-western Iran

Aphelenchoides kheirii n. sp. was isolated during a survey of nematodes associated with bark samples of pine trees (Pinus nigra) in West Azerbaijan province, north-western Iran. The new species has a body length of 500 (448-520) μm in the female and 442 (402-480) μm in the male. The cuticle is weakly annulated with four lateral lines and the lip region is offset. The stylet is 10.4 (10-11) μm long with small basal swellings and the excretory pore located immediately posterior to base of metacorpus; hemizonid invisible. The post-vulval uterine sac length 37.7 (28-45) μm. Spicules are relatively short (18-20 μm in dorsal limb) and the end of the dorsal limb clearly curved ventrally like a hook. The male tail has usual three pairs of caudal papillae (2 + 2 + 2) and a well-developed mucron. The female tail is conical, terminating in a complicated step-like projection, usually with many tiny nodular protuberances. The new species belongs to the Group 2 category of Aphelenchoides species sensu Shahina in which ten known species among Groups 2 and 4 sensu Shahina, namely: A. arcticus, A. blastophthorus, A. fuchsi, A. parasaprophilus, A. paraxui, A. xui, A. dactylocercus, A. gynotylurus, A. iranicus and A. saprophilus are the most similar species. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rRNA supported the morphological results.

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 Aphelenchoides macrospica n. sp. (Nematoda: Aphelenchoididae) from Northwestern Iran

Aphelenchoides macrospica n. sp. is described and illustrated from the West Azerbayjan province, northwestern Iran. The new species is characterized by its body length of 807 to 963 μm (males) and 792 to 1,094 μm (females), offset cephalic region, lateral fields with four incisures, long stylet with 15 to 16 μm length, and excretory pore situated opposite or behind the nerve ring. Pharyngeal glands overlapping intestine dorsally and extending for 90 to 121 μm, tail terminus mucronate in both sexes. Vagina directed anteriad, and spicules are relatively large (27-32 μm) with well-developed broadly rounded apex and condylus. The new species comes close to seven known species of the genus namely A. arcticus, A. blastophthorus, A. haguei, A. huntensis, A. lucknowensis, A. parasaprophilus, and A. xui, but it differs from them by the body size, stylet length, size of spicules, and length of postvulval uterine sac. The results of phylogenetic analyses based on sequences of D2-D3 expansion region of 28S and 18S rDNA, confirmed its status as a new species.

Aphelenchoides eldaricus n. sp. (Nematoda: Aphelenchoididae) isolated from Pinus eldarica in western Iran

Aphelenchoides eldaricusn. sp. is described and illustrated from wood and bark samples of a dead Mondell pine in Kermanshah Province, western Iran. The new species has a body length of 597 (507-700) μm (females) and 662 (636-695) μm (males). The cuticle is weakly annulated with three lateral lines and the lip region is offset. The stylet is 9.6 (9-10) μm long with small basal swellings and the excretory pore is locatedcaone body diam. posterior to the metacorpus valve. The spicules are large with the dorsal limb 40 (38-42) μm long with a prominent rostrum and rounded apex. The female tail is conical, tapering gradually to an acute terminus with a simple ventral mucron. The male tail bears six (2 + 2 + 2) caudal papillae and a well-developed mucron. The new species belongs to the Group 2 category ofAphelenchoidesspecies and is close to four known species, namelyA. cibolensis,A. indicus,A. rutgersiandA. sacchari. Molecular analyses of the partial 18S and the D2-D3 expansion segments of the 28S rRNA gene confirmed its morphological status as a new species.

Aphelenchoides salixae n. sp. (Nematoda: Aphelenchoididae) isolated from Salix alba in western Iran

Aphelenchoides salixaen. sp. was isolated from wood and bark samples of a dead willow in Kermanshah Province, western Iran. The nematodes were collected directly from wood samples and were successfully reared onBotrytis cinerea. The new species has a body length of 567 (507-620) μm (females) and 382 or 400 μm (males). The cuticle is weakly annulated with four lateral lines. Lip region offset. The stylet is 9.5 (9-10) μm long with small basal swellings. The excretory pore is locatedcaone body diam. posterior to the metacorpus valve. The spicules are short with the dorsal limb 14 or 15 μm long (n = 2), apex and rostrum rounded and only slight offset. The female tail is cylindrical with a broadly rounded terminus. The male tail is conical, bearing six (2 + 2 + 2) caudal papillae with a hamate mucron at terminus. The new species belongs to the Group 1 category ofAphelenchoidesspecies and is close to seven known species, namely:A. capsuloplanus,A. confusus,A. limberi,A. obtusicaudatus,A. obtusus,A. orientalisandA. rotundicaudatus. Molecular analyses of the partial 18S, D2-D3 expansion segments of the 28S rRNA genes and internal transcribed spacer (ITS) supported it as a new species and that the new species is closest toA.besseyi,A. fujianensisandA. ritzemabosiin dendrograms inferred using 18S and 28S D2-D3 genes.

Molecular and Morphological Characterization of Aphelenchoides fuchsi sp. n. (Nematoda: Aphelenchoididae) Isolated from Pinus eldarica in Western Iran

Aphelenchoides fuchsi sp. n. is described and illustrated from bark and wood samples of a weakened Mondell pine in Kermanshah Province, western Iran. The new species has body length of 332 to 400 µm (females) and 365 to 395 µm (males). Lip region set off from body contour. The cuticle is weakly annulated, and there are four lines in the lateral field. The stylet is 8 to 10 μm long and has small basal swellings. The excretory pore is located ca one body diam. posterior to metacorpus valve or 51 to 62 μm from the head. The postuterine sac well developed (60-90 µm). Spicules are relatively short (15-16 μm in dorsal limb) with apex and rostrum rounded, well developed, and the end of the dorsal limb clearly curved ventrad like a hook. The male tail has usual three pairs of caudal papillae (2+2+2) and a well-developed mucro. The female tail is conical, terminating in a complicated step-like projection, usually with many tiny nodular protuberances. The new species belongs to the Group 2 sensu Shahina, category of Aphelenchoides species. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rRNA supported the morphological results.

Aphelenchoides iranicus n. sp. (Nematoda: Aphelenchoididae) from West Azerbaijan province, Iran

Aphelenchoidesiranicusn. sp. is described and illustrated from bark samples of an oak tree (Quercussp.) in West Azerbaijan province, north-western Iran. The new species is characterised by body length of 350 (330-383) μm in females and 343 (323-370) μm in males, lip region set off from body contour, lateral fields with three lines, stylet 8 (7-9) μm long with small basal swellings, excretory pore 59 (56-62) μm from anterior end, hemizonid invisible, pharyngeal glands overlapping intestine dorsally and extending for 48 (41-54) μm, female tail subcylindrical with many tiny finger-like appendages at the tip, and male with aphelenchoid type spicules 17.6 (17-18) μm long. The new species comes close to nine known species of the genus namely:A. brevicaudatus,A. cibolensis,A. conimucronatus,A. editocaputis,A. montanus,A. pusillus,A. rarus,A. sphaerocephalusandA. vaughani, but differs from them by the number of incisures in the lateral field, shape of tail mucron, stylet length, size of spicules and length of post-vulval uterine sac. Additionally, this species is characterised molecularly and phylogenetically by sequences of the D2-D3 expansion segments of the 28S and partial 18S rRNA genes that are unique in relation to the sequences deposited in GenBank.

Morphological and molecular characterisation of Aphelenchoides besseyi and A. fujianensis (Nematoda: Aphelenchoididae) from rice and forage grass seeds in Brazil

Morphologically similarAphelenchoidesspp. populations extracted from rice and forage grass seeds from different geographical regions in Brazil were morphologically and molecularly characterised. Overall, the populations studied separated into two groups based on morphological and phylogenetic analyses, referred to herein as ‘Group-rice’ and ‘Group-forage’. Bayesian phylogenetic analyses of SSU, LSU and mtCOI regions strongly supported the presence of two dichotomous groups with Group-rice and Group-forage populations genetically similar toA. besseyiandA. fujianensis, respectively. This study reports the presence of a morphologically similar species toA. besseyiassociated with seeds of grasses, but genetically distinct based on three genomic regions, which our results strongly suggest to beA. fujianensis, this being a new geographical record for Brazil. Additional information regarding spicule morphology of maleA. besseyiis also reported.