Andrássy (1991) proposed the genus
Jabbari et al. (2021) studied one previously undescribed and three known species from Iran, where the genus apparently is well represented and diverse. Recently, another Iranian population was collected during a nematological survey conducted in the country. Its study confirmed that it belongs to an unknown species, which is described in this contribution.
Several soil samples were collected from the Sufiyan district, East Azarbaijan province, northwestern Iran. The modified method of Brown and Boag (1988) was used to extract nematodes from soil samples. Nematodes were transferred to anhydrous glycerine according to De Grisse's (1969) method and mounted on glass slides. Morphological observations were made and morphometrics were taken using an Olympus BX41 microscope with a drawing tube device. Micrographs were taken using a DP50 digital camera attached to the same microscope, powered with differential interference contrast (DIC). Drawings were made using the CorelDRAW® software version 12.
A single nematode specimen of the new species was picked out and transferred to a small drop of distilled water or worm lysis buffer (WLB) and crushed by a sterilized scalpel. The suspension was transferred to a microtube containing 25.65 μl ddH2O, 2.85 μl 10X PCR buffer, and 1.5 μl proteinase K (600 μg/ml) (Promega, Benelux, the Netherlands). The microtube was incubated at 65°C (1 h), then at 95°C (15 min). The resulting DNA extract was stored at −20°C until used as a template for polymerase chain reaction (PCR). For DNA amplification, 1 μl of the extracted DNA was transferred to a microtube containing: 0.75 μl of each primer, 12.5 μl
The recently obtained LSU rDNA sequence was edited/trimmed and compared with other dorylaimid sequences available in the GenBank database using the BLAST homology search program of the National Centre for Biotechnology Information (NCBI). The selected DNA sequences were aligned using the Muscle software implemented in MEGA6 (Tamura et al., 2013). MrModeltest 2.3 (Nylander, 2004) was used to select the base substitution model supported by the Akaike criterion in conjunction with PAUP* v4.0b10 (Swofford, 2003). Bayesian analysis (BI) was performed using MrBayes 3.1.2 (Ronquist and Huelsenbeck, 2003) running the chains for 10 million generations. After discarding burn-in samples, the remaining samples were retained for further analyses. Posterior probabilities (PP) are given on appropriate clades. The tree was visualized using FigTree v1.4.3 and was digitally drawn in CorelDRAW software version 12.
See Table 1.
Morphometrics of
♀ | 5♀♀ | 3♂♂ | |
---|---|---|---|
Character | |||
L | 1.50 | 1.56 ± 0.08 (1.45–1.68) | 1.49 ± 0.04 (1.45–1.53) |
a | 32 | 29.2 ± 2.1 (27–32) | 27.6 ± 2.1 (27–30) |
b | 4.3 | 4.5 ± 0.2 (4.3–4.9) | 4.5 ± 0.1 (4.4–4.6) |
c | 44 | 42.1 ± 7.7 (33–56) | 39.7 ± 3.6 (37–44) |
c’ | 1.2 | 1.3 ± 0.1 (1.0–1.6) | 1.1 ± 0.1 (1.0–1.3) |
V | 55 | 56 ± 1.2 (55–58) | - |
Lip region diameter | 13 | 13.7 ± 0.1 (13–15) | 13.4 ± 0.1 (13–14) |
Odontostyle length-dorsal side | 18 | 16.4 ± 1.3 (15–18) | 17.3 ± 0.5 (17–18) |
Odontophore length | 24 | 25.1 ± 1.7 (24–27) | 26.1 ± 0.7 (25–27) |
Neck length | 344 | 349 ± 10 (341–362) | 322 ± 11 (312–337) |
Pharyngeal expansion length | 144 | 141.0 ± 7.6 (131–152) | 133.0 ± 2.1 (124–138) |
Body diameter at neck base | 45 | 51.1 ± 4.3 (45–56) | 52.0 ± 3.3 (49–56) |
mid-body | 47 | 52.3 ± 2.8 (47–59) | 53.4 ± 3.5 (50–58) |
anus/cloaca | 27 | 28.3 ± 1.2 (27–30) | 32.3 ± 1.5 (31–34) |
Prerectum length | 61 | 67 ± 10 (56–81) | 73.4 ± 8.3 (59–97) |
Rectum/cloaca length | 34 | 34.2 ± 2.8 (30–38) | 59.0 ± 4.1 (58–66) |
Tail length | 34 | 38.7 ± 3.6 (30–44) | 36.1 ± 3.8 (33–40) |
Spicules length | - | - | 52.2 ± 3.5 (49–56) |
Ventromedian supplements | - | - | (14–18) |
Moderately slender to slender (a = 27–32) nematodes of medium size, 1.45–1.68 mm long. Body cylindrical, tapering towards both ends, but more so posteriorly, as the tail is conical in both sexes. Upon fixation, habitus slightly curved ventrad, to an open C shape. Cuticle almost smooth under light microscopy, two-layered, its total thickness 1.5–2.0 μm at anterior region, 2.5–4.0 μm in mid-body, and 4.0–4.5 μm on dorsal side of tail. Lateral chord 10.5–14.5 μm or 21–24% of maximum body diameter. Lip region offset by a weak but distinct constriction, 2.5–3.2 times as wide as high and less than one-third (24–32%) of body diameter at neck base; lips moderately separate and slightly angular, and perioral liplets might be present, labial and cephalic papillae visibly protruding. Amphidial fovea cup-shaped, its aperture 7.5–9.0 μm long or up to two-thirds (57–67%) of lip region diameter. Cheilostom a truncate, thick-walled cone. Odontostyle robust, hardly but appreciably shorter at its ventral side, 6.4–7.4 times as long as wide, longer (1.1–1.2 times) than lip region diameter, its aperture 5.5–7.0 μm or one-third to two-fifths (32–41%) of the total length. Guiding ring double, fixed ring situated at 9–11 μm or 0.7 times the lip region diameter from the anterior end. Odontophore rod-like, 1.3–1.6 times longer than odontostyle. Pharynx entirely muscular, gradually enlarging into the basal expansion that is 5.9–6.9 times longer than wide, 2.6–3.2 times longer than body diameter at neck base, and occupies less than one-half (39–43%) of the total neck length; gland nuclei located as follows: DO=59–60, DN=62–68, S1N1=70–75, S1N2=77–79, S2N=85–87. Nerve ring located at 126–146 μm distance from anterior end or 34–43% of the total neck length. Pharyngo-intestinal junction consisting of a short and rounded conoid cardia enveloped by intestinal tissue, all together forming a longer conoid, 14–19 × 12–15 μm structure, bulging into the intestinal lumen.
Genital system diovarian, with equally developed branches, the anterior branch 260–322 μm long or 16–20% of body length, the posterior one 233–322 μm or 16–20% of body length. Ovaries moderately developed, often reaching and surpassing the sphincter level, 60–74 μm the anterior and 60–79 μm the posterior, with oocytes first arranged in two or more rows, then in only one row. Oviduct joining subterminally the ovary, 62–89 μm or 1.1–1.5 times the body diameter long, consisting of a slender distal region made of prismatic cells and an often well-developed proximal
Genital system diorchic, with opposite testes. In addition to the ad-cloacal pair, situated at 7.5 μm from the cloacal aperture, there is a series of 14–18, almost contiguous or shortly spaced, 6.0–7.5 μm apart, ventromedian supplements, the most posterior of them situated at 49–51 μm from the ad-cloacal pair, appreciably in front of the anterior end of spicules, then with a distinct hiatus. Spicules dorylaimid, 4.9–5.5 times as long as wide, 1.5–1.8 times the body diameter at level of the cloacal aperture: head 10.0–16.5 μm long or 18–32% of spicule length, 2.2–2.4 times longer than wide, and its dorsal side much longer and more curved than the ventral one; median piece comparatively slender, occupying 25–28% of spicule maximum width; posterior tip 3.5 μm wide; ventral hump located at 18–22 μm or 36–42% of spicule length from its anterior end; curvature 134º. Lateral guiding piece 13–14 μm long, coarse, 3.4–4.4 times as long as wide, conspicuously tapering at its posterior third. Prerectum 1.8–3.7, cloaca 1.8–1.9 body diameters long. Caudal region basically similar to that of female, but more straight or even slightly curved ventrad at the end.
Sequencing the D2–D3 region of the 28S rDNA resulted in one sequence 751 bp (OP870361) long. The BLAST homology search showed it has an 89.09% identity with
The new species is characterized by its 1.45–1.68 mm long body, lip region offset by constriction and 13–15 μm wide, odontostyle 15–18 μm long, guiding ring double, neck 312–362 μm long, pharyngeal expansion occupying 41–43% of the total neck length, uterus tripartite and 111–189 μm long or 2.1–3.2 body diameters, vulva transverse (V = 55–58), tail similar in both sexes, conical with a dorsal concavity (30–44 μm, c = 33–56, c’ = 1.0–1.6), spicules 49–56 μm long, and 14–18 shortly spaced ventromedian supplements in front of the level of the anterior end of spicules, with distinct hiatus.
Morphologically and morphometrically, the new species resembles three
The evolutionary relationships of the new species, as derived from the molecular analyses, are presented in the tree of Figure 3. The 28S rDNA sequence of
Northwestern Iran, East Azarbaijan province, Sufiyan district, Roodghat area, Zeinabad village (38°17′46″N, 46°07′37″E, elevation 1528 m a.s.l.), where the new species was collected in soil from the rhizosphere of common wheat (
Female holotype, three female paratypes and two male paratypes deposited with Collection of Nematology Laboratory, University of Tabriz, Iran. One female paratype and one male paratype deposited in the Nematode Collection of the University of Jaén, Spain.
The LSID for this publication is urn:lsid:zoobank.org:act:250EA066-7CC1-48DD-94C5-4ADD6490E015
The new species is named in honor of Dr. Hassan Eshtiaghi, the late Nematologist in the Department of Plant Protection, University of Tehran, Tehran, Iran.