Laimaphelenchus persicus, Asghari, Ramazan, Pourjam, Ebrahim, Heydari, Ramin & Zhao, Zeng Qi, 2012

Asghari, Ramazan, Pourjam, Ebrahim, Heydari, Ramin & Zhao, Zeng Qi, 2012, Laimaphelenchus persicus n. sp. (Nematoda: Aphelenchoididae) from Iran, Zootaxa 3325, pp. 59-67 : 60-65

Laimaphelenchus persicus n. sp.

( Figs 1–3 )

Measurements. Table 1 .

Material examined. The description presented here is based on measurements of 18 ♀s and seven ♂s; Gorgan, Golestan province, north of Iran (GPS coordinates: N 36° 49', E 54° 23'). Extracted from bark of a dead pine ( Pinus sylvestris ) in the Hezarpich region. Coll. Ramazan Asghari, in May and June 2010.

Holotype female, ten paratype females and four males deposited in the Nematode Collection of the Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran (slide no, LP 0012,1–LP 0012,4).

Vouchers (collection data as above): Five paratype females and two males deposited at the National Nematode Collection, New Zealand ( NNCNZ). Three paratype females and one male deposited in the Canadian National Nematode Collection, Ottawa, Canada.

Description. Female. Body ventrally arcuate in heat relaxed specimens. Cuticle with fine transverse annulations about 1.4–1.8 µm apart at mid-body. Lateral fields with 4 incisures, inner 2 incisures closer together than outer pair, not areolate, extending to origin of tubercle.

Head region rounded, slightly offset, and slightly wider than body at base, 3–3.5 µm high and 6–7.5 µm wide. Cephalids not seen. Stylet slender with small basal swellings.

Procorpus cylindrical, 40–43 µm long, median bulb rounded to oval, 16–20 μm long, 11.5–13 μm wide with crescentic valves centrally, located 56–68 μm from the anterior end; isthmus 37–44 µm long, encircled by nerve ring at about its mid-length. Nerve ring located anterior to excretory pore.

Excretory pore conspicuous. Hemizonid not seen. Pharyngeal glands overlapping intestine on dorsal side, extending for 51–85 μm.

Reproductive system with outstretched ovary with oocytes in single file; conspicuous spermatheca filled with sperm cells; vagina sloping anteriorly, with massive sclerotization ( Fig. 1 F, G). Post-vulval uterine sac (PUS) occupying 46–75% of distance from vulva to anus. Vulva with well-developed anterior vulval flap ( Fig. 2 C).

Tail conoid, ventrally curved, with a single stalk-like terminus and four pedunculate tubercles ending with 4–6 finger-like protrusions which curve towards body.

Male. Morphology similar to that of female. Testis outstretched, spermatocytes in a single column. Spicules paired, rosethorn–shaped, with prominent capitulum and rostrum broad with bluntly rounded tip. No gubernaculum present.

Caudal papillae located at three positions: first pair preanal subventral, second pair postanal subventral, at about 48–62 % of distance between cloacal aperture to tail tip and third pair subventrally, very small, in some specimens obscure and at 78–81% of distance between cloaca and tail tip ( Fig. 2 E, F).

Tail conoid, ventrally curved, with a single stalk-like terminus and four pedunculate tubercles ending with 4–6 finger-like protrusions which curve towards body.

Diagnosis and Relationships. Laimaphelenchus persicus n. sp. is characterised by having a distinct tail shape with an offset terminus, with 4 clearly pedunculate tubercles ending in 4–6 finger-like protrusions which curve towards the nematode body in both sexes; lateral fields with four lines; female with vulval flap; male with three pairs of caudal papillae, one pair pre-anal subventral, one pair post-anal subventral at 40–62% of distance between cloaca and tail end and one small pair anterior to tail terminus at 78–81% of distance between cloaca and tail tip. The species in the genus Laimaphelenchus are divided into those with and those without a vulval flap ( Baujard 1981; Hunt 1993). Laimaphelenchus persicus n. sp. belongs to the first group, bringing its members to nine. The other species in this group are L. penardi , L. deconincki , L. pensobrinus , L. cocuccii , L. unituberculus , L. helicosoma , L. preissii and L. simlaensis .

Laimaphelenchus persicus n. sp. is morphologically close to L. penardi , L. pensobrinus , L. deconincki , L. phloesini , L. pini , L. australis , L. cocuccii , L. pannocaudus and L. patulus .

L. persicus n. sp. differs from L. penardi by having a shorter stylet (10–11.5 vs 13–14 μm), smaller b value (6.5–8 vs 9–11), different number of incisures in lateral field (4 vs 2) and the form of the cuticle surrounding the vagina (thick vs thin) ( Filipjev & Schuurmans Stekhoven, 1941); from L. pensobrinus by its longer body length (615–925 vs 610), smaller b value (6.5–8 vs 9–12), shorter female genital tract not reaching the pharynx vs longer genital tract, longer post–vulval uterine sac (100–162 μm or 46.1–75.5% of distance from vulva to anus vs 84 μm or 29–46% of distance from vulva to anus), shape of the cuticle surrounding the vagina (thick vs thin cuticularised tube), number of incisures in lateral field (4 vs 2) and shorter spicules (19–21 vs 33–37 μm) ( Massey 1966); from L. deconincki by length of post-vulval uterine sac (100–162 vs 36–42 μm), number of incisures in lateral field (4 vs 3) and presence of males (Elmiligy & Geraert 1972); from L. cocuccii by number of incisures in lateral field (4 vs 3), longer post-vulval uterine sac (100–162 vs 40–64 μm), and presence of males (Doucet 1992).

L. persicus n. sp. is separated from L. australis , L. pannocaudus , L. phloesini , L. pini , and L. patulus by having a vulval flap ( Zhao et al. 2006b; Massey 1966, 1974; Baujard 1981; Swart 1997). It is separated from L. unituberculus , L. helicosoma , L. preissii and L. simlaensis by tail shape (tail ending in a single stalk with 4 tubercles vs with one broad tubercle) ( Bajaj & Walia 2000; Peneva & Chipev 1999; Zhao et al. 2006a; Negi et al. 2009).

Based on the LSU molecular phylogenetic studies ( Fig. 4 ), L. persicus n. sp. differs genetically from all the Laimaphelenchus species with LSU sequences available in the GenBank. When compared with the two closest species, L. persicus n. sp. differed from L. preissii (accession number EU287598 ) by 19.4% (137 in 705 bp), and L. australis (accession number EU287600 ) by 22.3% (154 in 692 bp).

Etymology. The species epithet “ persicus ” refers to the Latin name of Iran, the country of origin of this species.

Figures

FIGURE 1. Laimaphelenchus persicus n. sp. Female (B – G, I – J). B: Anterior body region; C: Pharyngeal region; D: Entire body; E: Lateral field at mid body; F, G: Vulval region; I, J: Tail. Male (A, H). A: Entire body; H: Tail. Scale bars A, D = 100 μm; C = 50 μm; E, F, G = 30 μm; B, H, I, J = 20 μm.

FIGURE 2. Light microscopy observation of Laimaphelenchus persicus n. sp. Female (A – D, G). A: Post-vulval uterine sac region (arrow showing its end); B: Pharyngeal region; C: Vulval region; D: Position of excretory pore (arrow); G: Female tail. Male (E, F, H). E and F: Male tail showing position of papillae, E: Second pair (arrow), F: First and third pairs (upper and lower arrow respectively); H: Spicules. Scale bars A, B, C, D and H = 20 μm, E, F, G = 10 μm.

FIGURE 3. Scanning Electron Microscopy (SEM) observation of Laimaphelenchus persicus n. sp. Female. A: Lateral field at mid body; B: Tail. Scale bars A, B = 2 μm.

FIGURE 4. Bayesian tree inferred from LSU gene DNA sequences. Posterior probabilities exceeding 50 % are given on appropriate clades. Nematode species and GenBank numbers are listed for each taxon.

Tables

TABLE 1. Morphometric data for Laimaphelenchus persicus n. sp. (measurements in μm) from Iran.

Population Characters	Holotype female Paratype females mean±s.d. range	Paratype males mean±s.d. range
n L a	1 18 – 888.0 767.6±75.0 615.0–925.0 40.3 42.6±3.1 35.9–48.7	7 – 769.0±73.9 641.0–857.0 49.2±4.6 42.7–56.7
b b' c	7.7 7.0±0.5 6.4–8.0 5 4.3±0.4 3.9–5.4 26.9 21.8±1.7 17.5–24.7	6.7±0.4 6.1–7.4 4.5±0.3 4.2–5.1 17.8±1.4 16.4–20.1
c' V or T Head height	2.7 3.1±0.2 2.8–3.7 67.7 68.0±0.6 66.6–68.9 4.0 3.1±0.3 3.0–3.5	3.1±0.2 2.7–3.6 65.6±2.1 63.6–68.5 3.2±0.3 3.0–4.0
Head width Stylet m Anterior end to valves of median bulb MB Pharynx length Head–vulva	7.0 6.5±0.5 6.0–7.5 10.0 10.9±0.4 10.0–11.5 45.0 42.8±2.7 36.3–45.4 59.0 63.3±3.6 56.0–68.0 51.7 58.3±2.6 54.8–64.7 114.0 109.4±7.3 95.0–121.0 602.0 521.9±49.0 423.0–630.0	6.3±0.3 6.0–7.0 10.9±0.5 10.0–11.5 43.7±4.6 36.4–50.0 63.4±1.9 62.0–67.0 56.2±3.7 52.9–63.6 113.1±6.5 99.0–117 – –
Maximum body width PUS length PUS/maximum body width Vulva –anus Tail length PUS/V–A	22.0 18.0±1.1 16.0–20.0 153.0 130.8±20.0 100.0–162.0 6.9 7.2±1.0 5.5–9.0 253.0 210.4±25.0 164.0–255.0 33.0 35.2±2.7 28.0–40.0 60.4 62.4±8.5 46.0–75.5	15.6±1.1 14.0–17.5 – – – – – – 43.1±4.2 39.0–51.0 – –
PUS/L Spicule length	– 17.0±2.4 12.6–20.5 – – –	– – 20.4±0.7 19.0–21.0