Helicotylenchus vulgaris Yuen, 1964

Shokoohi, Ebrahim, Marais, Mariette, Fourie, Hendrika & Panahi, Hadi, 2018, Morphological and molecular characterization of three Helicotylenchus species from Iran, Zootaxa 4388 (2), pp. 207-220 : 211-216

Helicotylenchus vulgaris Yuen, 1964

( FiguRE 3 )

Helicotylenchus vulgaris WaS dEScRibEd fROm gRaSS, England (YuEn, 1964) and SincE REpORTEd fROm ThE AfROTROpical (MaRaiS & SWaRT, 1999), AuSTRalian (WOuTS & KnighT, 1993), ORiEnTal (HaShim, 1985) and PalEaRcTic (FORTunER, 1991) biOgEOgRaphical REgiOnS.

Measurements. SEE TablE 1.

Description. FEmalES (n= 7): HabiTuS OpEn SpiRal. AnnulES 1 TO 2 µm WidE. Lip REgiOn 5.5 ± 0.6 (5–6) high and 7.1 ± 1 (6–9) WidE, anTERiORlY flaTTEnEd and cOnTinuES WiTh bOdY cOnTOuR, WiTh fOuR TO fiVE annulES. OuTER maRginS Of labial fRamEWORk EXTEnd 2–3 µm fROm baSal plaTE. CEphalidS nOT SEEn. STYlET 24 TO 28 µm lOng, WiTh cOnuS lEngTh 10.8 TO 13.8 µm, STYlET knOb 2.55 ± 0.4 (2–2.9) µm high and 5.6 ± 0.4 (4.9–5.9) µm WidE; anTERiOR facES flaTTEnEd TO indEnTEd. POSiTiOn Of DGO 11.9 ± 1.9 (8.8–14) µm bEhind STYlET knObS. MEdian phaRYngEal bulb OVal TO ROund, 14–16 µm lOng and 10–12 µm lOng; ValVE 5–6 µm lOng and 3–5 µm WidE. HEmizOnid 1–2 annulES lOng, lOcaTEd OnE TO ThREE annulES anTERiOR TO ThE EXcRETORY pORE. HEmizOniOn nOT SEEn. NERVE Ring lOcaTEd aT iSThmuS, aT 97.7± 6.5 (85–105) fROm anTERiOR End, and aT 56–69% Of phaRYngEal lEngTh. SEcRETORY-EXcRETORY pORE OpEning OppOSiTE baSal bulb, aT 118.5± 7.1 (112–143) fROm anTERiOR End and aT 70–86% Of phaRYngEal lEngTh. DEiRidS nOT SEEn. ThE TWO bRanchES Of ThE REpROducTiVE SYSTEm bOTh funcTiOnal, lEngTh Of pOSTERiOR bRanch 94.8 ±13.1 (77–117) % Of cORRESpOnding anTERiOR bRanch lEngTh. EpipTYgma fOldEd inTO Vagina. LaTERal fiEld 6.6 ± 1.12 (4.9–7.8) µm WidE; innER TWO linES End On Tail in U-ShapEd fORm. REcTum 0.9–1.0 TimES ThE anal bOdY diamETER, nOT OVERlapping anuS. InTESTinE nOT EXTEndEd OVER REcTum. PhaSmidS lOcaTEd ThREE TO SiX annulES anTERiOR TO anuS. Tail 14 ± 2 (11– 16) lOng, bEnT and aSYmmETRical, i.E. mORE cuRVEd dORSallY, WiTh ROundEd End and 10 TO 13 VEnTRal annulES. AnnulES On Tail finE, WiTh SlighT VEnTRal pROJEcTiOn. InnER inciSORS Of laTERal fiEld fuSEd diSTallY.

standard deviation (range).

……continued on the next page MalE: nOT fOund.

Locality and habitat. ThE SpEcimEnS EXaminEd WERE cOllEcTEd fROm ThE RhizOSphERE Of Hordeum vulgaris in ThE BafT PROVincE Of KERman, SOuThERn IRan.

Other material examined (SEE TablE 1). ThE OThER pOpulaTiOn EXaminEd iS VERY SimilaR TO ThE pOpulaTiOn fROm BafT.

Remarks. ThE SpEcimEnS WERE idEnTifiEd aS H. vulgaris bEcauSE Of ThE pRESEncE Of ThE finE and SubdiVidEd annulES On ThE Tail Tip, anTERiORlY flaTTEnEd lip REgiOn, STYlET lEngTh (23 28 µm), ThE cuRREnT SpEcimEnS WERE cOmpaREd WiTh ThE TYpE dEScRipTiOn bY YuEn (1964) and REdEScRipTiOn Of paRaTYpES bY ShER (1966). ThE pRESEnT IRanian SpEcimEnS Of H. vulgaris cOnfORm TO ThOSE EXaminEd pREViOuSlY (ShER, 1966; WOuTS and KnighT, 1993; MaRaiS, 1998). ThE cuRREnT IRanian SpEcimEnS diffER fROm ThE SOuTh AfRican SpEcimEnS (WOuTS & KnighT, 1993; MaRaiS, 1998) in STYlET lEngTh (23–28 µm vs 28–33 µm) and fROm ThE NEW ZEaland SpEcimEnS in pOSiTiOn Of phaSmidS (3–6 annuli anTERiOR TO anuS vs 5–15 annuli anTERiOR TO anuS). In cOmpaRiSOn WiTh ThE maTERialS STudiEd bY MaRaiS (1998), ThEY diffEREd in STYlET lEngTh (24–28 µm VS 28–32 µm) and phaSmid pOSiTiOn (3–6 annuli anTERiOR TO anuS vs 6 annuli anTERiOR and OnE annuli pOSTERiOR TO anuS). In cOmpaRiSOn WiTh ThE IRanian SpEcimEnS STudiEd bY HaSSanzadEh et al. (2005), ThOSE EXaminEd fOR ThiS STudY diffER in bOdY lEngTh (621–858 vs 777–1063 µm), STYlET lEngTh (23–28 vs 29–34 µm) and phaSmid pOSiTiOn (3–6 annuli bEfORE anuS vs 5–18 annuli bEfORE anuS). COmpaREd WiTh ThE SpEcimEnS STudiEd bY MOhammad DEimi and MiTkOWSki (2010) ThE IRanian SpEcimEnS STudiEd diffER in bOdY lEngTh (vs 988–1112 µm) and STYlET lEngTh (vs 28.8–35.4 µm).

DNA characterisation: ThE 28S RRNA gEnE SEquEncES Of H. vulgaris amplifiEd bY ThE TWO pRimERS D2A and D3B WERE 697 ( MF996710 ) and 774 ( MF996711 ) baSE paiRS (bp) lOng, RESpEcTiVElY. WiThin ThiS fRagmEnT, 5 bp diffEREncES diSTinguiShEd ThE IRanian pOpulaTiOn ( MF996711 ) fROm ThE ITalian pOpulaTiOn Of H. vulgaris (accESSiOn nR. DQ328761 ; 99% idEnTiTY). In addiTiOn, anOThER IRanian SEquEncE ( MF996710 ) in cOmpaRiSOn TO ThE SamE pOpulaTiOn Of H. dihystera ShOWS 99% SimilaRiTY WiTh 4 bp diffEREncES.

Discriminant analysis: LinEaR DiScRiminanT AnalYSiS (LDA) WaS cOnducTEd fOR ThE ThREE SpEciES Of Helicotylenchus namElY H. digonicus , H. pseudorobustus and H. vulgaris . LDA analYSiS indicaTEd ThaT ThREE SpEciES caTEgORizES in diffEREnT gROupS ( Fig. 4 ). H. vulgaris SignificanTlY (p Ẽ 0.05) iS SEpaRaTEd fROm OThER SpEciES ( Fig. 4 ). ThE RESulTS indicaTEd ThaT LDA analYSiS can bE uSEd aS an aSSiSTanT TOOl fOR diSTinguiShing ThE IRanian indiVidualS Of Helicotylenchus . ThE ScaTTER plOT ( Fig. 4 ) ShOWEd ThaT ThE fiRST linEaR diScRiminanT “LD1” WiTh 84% accuRacY SEpaRaTES ThE SpEciES Of Helicotylenchus SuccESSfullY.

Phylogenetic analysis: PhYlOgEnETic analYSiS uSing 28S RDNA gROupEd SpEciES Of Helicotylenchus in fiVE main cladES, viz. I) Helicotylenchus leiocephalus , H. digonicus , H. pseudorobustus , H. dihystera , H. vulgaris ; II) H. labiodiscinus and H. multicinctus ; III) H. brevis and undEScRibEd Helicotylenchus ; IV) H. digonicus , H. vulgaris and undEScRibEd Helicotylenchus ; V) an undEScRibEd Helicotylenchus ( Fig. 5 ).

Figures

FIGURE 3. Helicotylenchus vulgaris YUEN, 1964. A: NECK. B: ANTERIOR END (STOMA AND DGO). C: ENTIRE FEMALE. D: FEMALE POSTERIOR END.E: FEMALE REPRODUCTIVE SYSTEM.

FIGURE 4. LINEAR DISCRIMINANT ANALYSIS (LDA) OF THREE SPECIES OF Helicotylenchus.

FIGURE 5. MRBAYES TREE OF THE Helicotylenchus POPULATIONS FROM GENBANK AND NEWLY SEqUENCED SPECIES FROM IRAN BASED ON THE 28S RDNA GENE.