Ditylenchus sarvarae, Shokoohi & Iranpour & Peneva & Elshishka & Fourie & Swart, 2018

Shokoohi, Ebrahim, Iranpour, Fahime, Peneva, Vlada, Elshishka, Milka, Fourie, Hendrika & Swart, Antoinette, 2018, Ditylenchus sarvarae sp. n. (Tylenchina: Anguinidae) from Iran, Zootaxa 4399 (2), pp. 197-206 : 198-204

Ditylenchus sarvarae sp. n.

(See Figs. 1 & 2 )

Measurements. See Table 1.

Description. Population from Bam, province of Kerman (4♀♀, 3♂♂):

Female. Body almost straight to open “C” shape When heat relaxed. Lip region loW, measuring 7–9 µm in diameter and 3–4 µm in height. Head flattened, appearing almost smooth. Stoma opening pore-like at the centre of a small oral disc. Amphidial openings small and slit-like, posterior to lateral lips. Cuticle annuli about 1 µm Wide at midbody. Stylet delicate, With Well developed, rounded knobs, 2 µm in Width. Dorsal pharyngeal gland orifice (DGO) at 22–25% of stylet length. Pharyngeal procorpus cylindrical, Without a constriction at the junction With median bulb. Median bulb mostly oval in shape, 17–18 µm long and 10–11 µm in diameter, valve Well developed. Isthmus long, slender, encircled nearly at its midpoint by the nerve ring. Nerve ring located at 47–55% of neck length. Basal pharyngeal bulb spatulate. Hemizonid located opposite anterior part of pharyngeal basal bulb at 63– 78% of neck length, about three cuticular annuli long. Excretory pore at basal bulb level, at 73–79% of neck length. Lateral fields With seven plain incisures, often difficult to see under the light microscope. Reproductive system monodelphic-prodelphic, Well developed. Ovary Without flexure toWards vulva. Anterior genital tract 200 µm long, 15–20% of body length, With the apex of the germinal zone not reaching the pharyngeal bulb. Spermatheca broad, elongated, 35–38 µm long, 6–10 µm in diameter, filled With rounded sperm. Anterior part of uterus in the form of a quadricolumella, folloWed by a short, narroWer tract and ending in a sWollen posterior part near the vagina. Postvulval uterine sac Well developed, 1.8–2.8 times the vulval body diameter; 25–51% the vulva–anus distance. Tail conoid, ending in a finely pointed terminus. Phasmids conspicuous, 29–33 µm distant from anus.

Male. Smaller than female, but similar in shape, except in reproductive system. Lip region 3–4 µm high, 7–8 µm in diameter, slightly narroWer than the rest of the body. Lip region With 3 annuli. Stylet delicate, knobs small, rounded, 2.0–3.0 µm in diameter. DGO 22–23% of stylet length. Median bulb oval, 18 µm length and 11 µm in diameter, respectively. Isthmus slender, elongate, 60–61 µm long, encircled approximately in the middle by the nerve ring. Basal pharyngeal bulb spatulate, slightly abutting intestine. Lateral fields With seven smooth incisures. Testis Well developed, 544–888 µm long, not reaching the basal bulb. Bursa leptoderan, slightly longer than tail in overall extension, starting anterior to the cloaca at a distance slightly more than one anal body diameter and extending 66–95% of tail length. Spicules ventrally arcuate, slightly cephalated anteriorly. Gubernaculum simple, 30–43% of spicule length.

Locality and habitat. The material studied Was isolated from rhizosphere soil associated With alfalfa roots ( Medicago sativa L.) in Bam, in the province of Kerman, Iran (N: 29°06′22″; E: 58°21′25″).

Type material. TWo females and tWo males (holotype and paratypes) deposited in the National Collection of Nematodes (NCN) at the ARC-PPRI (Nematology Unit of Biosystematics) . The other paratypes (tWo females and one male) Were deposited in the nematode collection of Nematology Laboratory of North West University, Potchefstroom, South Africa .

Diagnosis. Ditylenchus sarvarae sp. n. is characterized by body length (1000–1438 µm in females and 780– 933 µm in males), stylet length (9–10 µm), number of lateral lines (seven), post uterine sac length (55–62 µm), tail length (73–89 µm in females and 64–69 µm in males), spicule length (22–25 µm), leptoderan bursa (94–95% of tail length) and unique D2D3 sequence.

Relationships. The neW species is morphologically similar to D. valveus Thorne & Malek, 1968 and D. destructor Thorne, 1945 . Compared With D. valveus , it has a longer bursa (94–95% of tail length vs 23–47% of tail length) (Brzeski 1991). Compared With D. destructor , D. sarvarae sp. n. differs in shape of the tail terminus (sharply pointed vs rounded), number of lateral field insicures (7 vs 6) and a longer bursa (50–90% in D. destructor ) (SWart et al. 2015). Compared With D. gigas Vovlas, Troccoli, Palomares-Rius, De Luca, Liébanas, Landa, Subbotin & Castillo 2011 , the neW species differs in body length (1000–1438 µm vs 1561–1932 µm in females and 933–1152 µm vs 1373–1716 µm in males), female tail length (68–89 µm vs 69–103 µm), length of postuterine sac (55–62 µm vs 81–150 µm), number of lateral incisures line (7 vs 4) and bursa length (94–95% of tail length vs 50–90% of tail length) ( Vovlas et al. 2011). In comparison With D. oncogenus Vovlas, Troccoli, Palomares-Rius, De Luca, Cantalapiedra-Navarrete, Liébanas, Landa, Subbotin & Castillo, 2015 the neW species differ in having more lateral field incisures (7 vs 6) and a longer bursa (62–67% of tail length in D. oncogenus ) ( Vovlas et al. 2015). Compared With D. gallaeformans Oliveira, Santini, Seni, Dietrich, Salazar, Subbotin , Mundo- Ocampo, Goldenberg & Barreto, 2013, it differs in having more lateral field incsicures (7 vs 4) and shorter bursa (94–95% of tail length vs 100% of tail length). In comparison With D. halictus Giblin-Davis, Erteld, Kanzaki, Ye, Zeng & Center, 2010 , it differs in lateral field incisures (7 vs 6) and bursa length (94–95% of tail length vs 20–55% of tail length). The neW species shoWs differences With D. drepanocercus Goodey, 1953 in spicule length (22–26 µm vs 10 µm) and bursa length (94–95% of tail length vs 50% of tail length; according to Brzeski 1991). D. persicus and D. sarvarae differ in body length (vs 635-928 µm in females and 670-715 µm in males), stylet length (vs 5-7 µm), post uterine sac length (69-139 vs 14-18 µm), female tail length (68-98 vs 45-68 µm), the number of lateral field incisures (7 vs 6) and spicule length (22-26 vs 15-17 µm).

Etymology. The specific epithet is in honor of the mother, Lady Sarvar Ourang, of the first author in grateful recognition of her efforts to raise him from childhood, and is also dedicated to all mothers in the World.

DNA characterization. The sequence flanked by the tWo primers D2a and D2b of the D2–D3 segment of 28S region of D. sarvarae sp. n. contains 762 base pairs (bps). A Blast search demonstrated that this population has 125 base pair differences from the Chinese populations of D. destructor ( EU400628 , EU400624 ; EU400623 ; 83% identity). The Iranian population shoWs less similarity With other Ditylenchus sequnces deposited in the NCBI GenBank.

Figures

FIGURE 1. Ditylenchus sarvarae sp. n. A, G: Anterior end; B: Entire male; C: Entire Female; D, E: Lip region and stylet; F: FemalereprodUctive system; H:Lateral Field incisUres;I: Cross sectionoF midbodyshowing lateral Field;J: Post Uterine sac; K, L: Femaleposterior end; M:Male posterior end.

FIGURE 2. Ditylenchus sarvarae sp. n. (LM) A:Anterior end; B: Stylet; C: Entire Female; D: Entire male; E:Lateral Field.