species of superfamily aphelenchoidea (nematoda: rhabditida) associated with (crocus sativus, berberis vulgaris, ziziphus zizyphus) from south khorasan province

introduction: south khorasan province is the main area for production of berberis vulgaris (family), crocus sativus (family) and ziziphus zizyphus (family). nematodes belong to superfamily aphelenchoidea are easy to be identified by the size of the body, stylet without knobs, large median bulb, long overlapping on the intestine and placement of the vulva in the posterior part of body. in this survey, we identified nematodes belong the superfamily aphelenchoidea in these three important plant. four species of genus aphelenchoides and one species of each genus aphelenchus, aprutides and ektaphelenchoides were identified. among them, two species aphelenchoides lichenicola and a. varicaudatus are new records for iranian nematofauna. materials and methods: soil sampling: 360 soil samples were collected from the rhizosphere of three important yields (b. vulgaris, c. sativus and z. zizyphus) in south khorasan province. samples were taken from the depth of 5-40 cm different points with a soil auger, put in polyethylene bags with necessary labeling and brought to the laboratory, kept in the refrigerator at 4 °c, until processed. processing of samples and preparation of slides: nematodes were extracted from soil samples using the jenkins (1964) and whitehead (1965) method. they were then handpicked, killed and fixed according to de grisse (1969) method. genera and species were identified based on morphological and morphometerical characters by valid keys and references. measurements and drawings: measurements were done with an ocular micrometer of “olympus” model microscope results and discussion: this survey resulted in 10 species belong to superfamily aphelenchoidea which two species of them are new for iranian nematode fauna. aphelenchoides lichenicola and a. varicaudatus are new records from south khorasan province. lichenicola characterized by: body straight to slightly arcuate ventrally. lip region rounded, offset by constriction. transverse striae of cuticle faint, about 0.8 µm apart near mid-body. lateral fields with four incisures, inner ones faint. stylet about 9.5-10.5 µm, conus 42-44% of stylet length. median oesophageal bulb oval to somewhat rectangular with rounded corners, offset from procorpus. oesophageal glands dorsal to intestine, extending to 46-58µm. nerve ring just behind isthmus. excretory pore opposite or close to posterior margins of nerve ring. vulva a transverse slit, raised. vagina usually directed anteriorly. ovary outstretched, with a single row of oocytes. post-vulval uterine sac half or more of vulva-anus distance. vulval-anus distance 127-211 µm. rectum about 1.5 times anal body-width long. tail elongate-conoid with terminus bearing a ventral somewhat stellate projection whose axial ray is more prominent than the others. varicaudatus characterized by: the elongate body is slightly curved ventrally when killed by heat. lip region distinctly offset with rounded sides and flattened anteriorly. cuticular annulations are fine. lateral fields with four incisures. stylet 12.5-14 µm long with small basal thickenings. median oesophageal bulb roundly rectangular just slightly longer than wide. excretory pore placed in 63-75.5µm from the anterior end. nerve ring behind the excretory pore. vagina slopes forward into the body. reproductive tract with a single anterior ovary which is often reflexed, sometimes almost back to the beginning of the ovary. post vulval sac prominent, extending one third to half the vulva to anus distance. tail terminus variable, sometimes bifid, often with the dorsal process decreased to give an angular indented region adjacent to the longer ventral mucro, occasionally the tail terminus tapers gradually to a terminal mucro.