Report of Six Dorylaim Nematodes from Arasbaran Forestry- Iran

Document Type : Research Article

Authors

1 university of Maragheh

2 Universirty of Tabriz

3 university of Tabriz

Abstract

Introduction: Nematodes are an abundant and very diverse group among the living organisms of soils. They are few information about them as animals which can live in all habitats including fresh waters, marines, soil of farms, gardens, forests and pastures. In addition to plant parasitic nematodes, which have parasitic relationship with different plants in agricultural soils, nematodes belonging to other trophic groups also have indirect impacts on the growth of plants in the agroecosystems and nature. They are used as biological indicators of soil health. The knowledge on their abundance, presence or absence of different groups of nematodes in the soils are considered important in various biological sciences.
Materials and Methods: In order to study the diversity of dorylaimid nematodes in Arasbaran forests, 65 soil samples were collected during 2015-2016 from different plant rhizosphere. The soil samples were transferred to the Nematology laboratory- University of Tabriz and kept at four degree centigrade until extraction time. They processed and the nematodes extracted, killed, fixed and transferred to anhydrous glycerin using common nematology methods. After preparing permanent microscopic slides, their morphometric and morphological characteristics were studied under optical microscope and identification was done using related valid literature. The morphometric data of nematode and microscopic images prepared using Motik optical microscope connected to scaled lens and future wine camera, respectively. All figures were prepared by Corel draw® 12 software.
Results and Discussion: As a result 20 dorylaim species (Crassolabium saccatum, C. himalum, C. ettersbargense, Syncheilaxonchium nairi, Paravulvus hartingii, Eudorylaimus spaulli, Epidorylaimus lugdunensis, Nygolaimus brachyuris, Paraxonchium carmenae, Metaxonchium persicum, Aulolaimus oxycephalus, A. nanocephalus, Discolaimus mariae, Longidorella soadi, Sectonema demani, Xiphinema macroacanthum, X. vuittenezi, X. uthahense, Longidorus africanus, Tylencholaimus constricus, T. tahatikus, Xiphinemella globilabiata, Enchodelus macrodorus which are belonging to 16 genera and ten different families. The family Qudsianematidae had more number of genera (five) and two genera, Crassolabium (three species) and Xiphinema (three species) were found having the most number of species compared to the other genera. Six species namely Discolaimus mariae, Crassolabium saccatum, C. himalum, C. ettersbargense, Xiphinema uthahense and Tylencholaimus tahatikus that are new records for Iran nematode fauna described here in.

mariae has been reported for the first time around the roots of olive trees in Spain by Pen-santiago. In this study, the nematode was collected and identified in Arasbaran forests -Shirin Bolagh. Comparing the present population of D. mariae with its main description there were not much differences. The only difference was in the c index (80-95 vs. 88-73).

The closest species to C. saccatum is C. circuliferum which distinguished from that by non-sclerotized vulval region in C. saccatum. C. diversum as another related species to C. saccatum is characterized by a complete offset head (vs. relatively offset head) and posterior position of vulva (V= 52.9-57 vs. V = 49-50).
This population of C. ettersbargense can be compared to the morphometric characteristics of previous reports that has shorter body length (0.5-0.6 mm vs. 0.6-1 mm). In members of Crassolabium having equal to less than one millimeter body length is characteristic of C. ettersbergense, C. medianum, C. pumilum, C. goaens and C. pumilum. C. medianum species has bubble-like organs in the tail (vs. absence of them in C. ettersbergense). C. pumilum has no pars refringense, and the expanded part of the esophagus is one third of length of the esophagus (vs. absencs pars refringense in C. ettersbergense, and the above ratio is 50-60% of the esophagus). C. goaens distinguished from C. ettersbergense with longer Odontostyle (15-17 vs. 11-12 µm). The head in C. parvulum, is different in comparing C. ettersbergense (continues vs. offset).
Crassolabium himalum comparing the main description has slightly longer tail (25-27 vs. 21-24 μm. C. himalum is comparable for morphological traits with C. neohimalum and C. porosum. The C. neohimalum is characterized by a shorter body length (1.07-1.35 mm vs. 1.32 to 1.47 mm) and the asymmetrical lips (vs. symmetrical). The C. himalum is also distinguished from C. porosum by having offset head- (vs. countinouse) and a relatively tall tail (25-27 μm versus 21).
Xiphinema uthahense is member of Xiphinema americanum - group and compared to the main description and previous reports, there was no significant difference between the morphological traits and the morphology. The species X. taylori, due to the lower coefficient b (5.6-7.5 vs. 8-8.5), has a lower coefficient (39.3 -51 vs. 61-6605) and the coefficient c 'less (0.75 - 1 vs. 1.2-1.7) can be distinguished from X. utahense species. X. pacificum is relatively longer (5.8-7.8 vs. 8-8.5).
Tylencholaimus tahatikus in morphological characteristics has similarity to T. mongolicus and T. innebus. Compared to T. mongolicus it has a longer odontostyle (10.6 - 15 μm vs. 7-6 μm), longer tail (19-22 μm vs. 14-8 μm), greater c (44-50 vs. 24-30) and c 'is less (0 / 9-7 / 0 vs 1/2 - 1). In T. innebus, V is greater (V =62-64 vs. V= 57-53) and shorter body length (0.54-0.68 mm vs. 0.95 -0.90 mm).
 

Keywords


1- Ahad S., and Ahmad W. 2016. Description of two new and six known species of the genus Tylencholaimus de Man, 1876 (Nematoda: Dorylaimida) with a diagnostic compendium and key to species. Zootaxa 4107 (4): 451-490.
2- Chen D.Y., Ni H.F., Yen J.H., Cheng Y.H., and Tsay T.T. 2005. Differentiation of the Xiphinema americanum-group nematodes X. brevicollum, X. incognitum, X. diffusum and X. oxycaudatum in Taiwan by morphometrics and nuclear ribosomal DNA sequences. Nematology 7(5): 713-725.
3- Ciobanu V., Abolafia J., and Pena-Santiago R. 2010. Two remarkable new species of the genus Crassolabium Yeates, 1967 from Vietnam (Nematoda: Dorylaimida: Qudsianematidae). Journal of Natural History 44(33-34): 2049-2064.
4- De Grisse A.T. 1969. Redescription ou modification de quelqutes techniques utilissisedans L; etude des Nematode phytoparasutaires. Meded, Rijksfaculteti der LandbouVeten, Gent 34: 351- 369.
5- Jabbari H., Niknam Gh., Vinciguerra MT., Moslehi Sh., Abolafia J., and Peña-Santiago R. 2012. Description of Crassolabium persicum sp. n. (Nematoda, Dorylaimida, Qudsianematidae), an interesting species from Iran. ZooKeys 203: 55–63.
6- Jenkins W.R. 1964. A rapid centrifugal-flotation technique for separating nematodes from soil. Plant Disease Reporter 48: 692.
7- Lamberti F., and Bleve-Zacheo T. 1979. Studies on Xiphinema americanum senso lato with description of fifteen new species (Nematoda, Longidoridae). Nematologia Mediterranea 7: 51-106.
8- Lamberti F., and Carone M. 1991. A dichothomus key for the identification of the species of Xiphinema (Dorylaimida) whithin the X. americanum group. Nematologia Mediterranea 19: 341-348.
9- Lamberti F., Molinari S., Moens M., and Brown D.J.F. 2002. The Xiphinema americanum-group. 11. Morphometric relationships. Russian Journal of Nematology 10(2): 99 -112.
10- Loof P.A.A., Luc M., and Coomans A. 1993. The Xiphinema americanum group (Nematoda: Dorylaimida). 1. Comments upon the key to species published by Lmnberti and Carone (1992). Fundamental and Applied Nematology 16(4): 355-358.
11- Moslehi Sh., Niknam Gh., and Ashrafi M. 2011. First report of three known species of the genus Aulolaimus (Nematoda: Aulolaimidae) from Iran. Nematologia Mediterranea 39(1): 53-57.
12- Moslehi Sh., Niknam Gh., and Ashrafi M. 2012. One new and four known species of the genus Eudorylaimus Andrassy, 1959 (Dorylaimida: Qudsianematidae) from Iran. International Journal of Nematology 22(1): 30-40.
13- Nikdel M., Niknam Gh., and Ye W. 2011. Steinernema arasbaranense sp. n. (Nematoda: Steinernematidae), a new entomopathogenic nematode from Arasbaran, Iran. Nematologia Mediterranea 39: 17-28.
14- Niknam Gh., Jabbari H., Moslehi Sh., Vinciguerra M.T., and Nikdel M. 2010a. Some free living nematodes from Arasbaran forests. p. 657. In: Abbasi M. and Ali abadi F. (ed.) Proceeding of 19th Iranian plant protection congress. 31 Jul-3 AUG., 2010. Vol II. Iranian research institute of plant protection. Tehran. (In Persian)
15- Niknam Gh., Ashrafi M., and Naderiyan R. 2010b. Three nygolaimid species from soils of northwest Iran. P. 612. In: Abbasi M. and Ali abadi F. (ed.) Proceeding of 19th Iranian plant protection congress. 31 Jul-3 AUG., 2010. Vol II. Iranian research institute of plant protection. Tehran. (In Persian)
16- Pena-Santiago R., and Coomans A. 1994. Revision of the genus Tylencholaimus de Man, 1876. Didelphic species. Nematologica 40: 32–68.
17- Pena-Santiago R., and Coomans A. 1996. Revision of the genus Tylencholaimus de Man, 1876. General discussion and key to the species. Nematologica 40: 440–454.
18- Pena-Santiago R., Torres B., Liebanas G., and Abolafia J. 2002. Nematodes of the order Dorylaimida from Andalucia Oriental, Spain: Discolaimus Cobb, 1913. 1. Description of two new species. Nematology 4(3): 361-369.
19- Pena-Santiago R., and Ciobanu M. 2008. The genus Crassolabium Yeates, 1967 (Dorylaimida: Qudsianematidae): Diagnosis, list and compendium of species, and key to their identification. Russian Journal of Nematology 16(2): 77- 95.
20- Thorne G. 1974. Nematodes of the Northern Great Plains. Part II. Dorylaimoidea in part (Nemata: Adenophorea). Technical Bulletin of Agricultural Experiment Station, South Dakota State University, 41: 1-120.
21- Tsalolikhin S.Ya. 2017. Crassolabium alekseevi sp. n. (Nematoda, Dorylaimida, Qudsianematidae) from Taiwan Island. Zoologicheskii Zhurnal 96(6): 740-744.
22- Wu W., Yan L., Xu Ch., Wang K., Jin Sh., and Xie H. 2016. A new species of the genus Discolaimus Cobb, 1913 (Nematoda: Dorylaimida: Qudsianematidae) from Qinghai, China. Zootaxa 4088(1): 129–138.
23- Zahedi E., Niknam Gh., Decraemer W., and Karegar A. 2009. Trichodorus arasbaranensis n. sp. (Nematoda: Trichodoridae) from a natural forest in Arasbaran, north-west Iran. Nematology 11(2): 243-252.