Molecular and morphological characterization of Paurodontella composticola n. sp. (Nematoda: Hexatylina, Sphaerulariidae) from Iran.

A new species of the genus Paurodontella, P. composticola n. sp., collected from Nazar Abad City, Alborz Province, Iran, is described and illustrated. The new species has a body length of 803-1053 µâ€Šm (females n = 10) and 620 and 739 µâ€Šm (males n = 2). The cuticle is weakly annulated with four lateral lines. Cephalic region is annulated and continuous with body contour. The stylet is 8.0 to 9.0 µâ€Šm long with asymmetrical knobs. Esophageal basal bulb is present with a small posterior extension projecting into the intestine. Excretory pore is situated at the level of esophageal basal bulb region. Post-uterine sac is 5 to 8 µâ€Šm long and uterus is without diverticulum. Tails of both sexes are similar, short and sub-cylindrical. Males have 24 to 25 µâ€Šm long bursa leptoderan and spicules 24 or 25 µm long. A non-branching oviduct is present to form a uterine diverticulum; the new species is closely related to five known species of the genus, namely P. asymmetrica, P. balochistanica, P. densa, P. iranica and P. niger. It most closely resembles P. iranica, but differs from it morphologically by a shorter stem-like extension projecting into lumen of intestine and male with sub-cylindrical tail vs conoid. In addition to morphological comparisons, the molecular phylogenetic analyses based on 733 bp of the partial sequence of 28S D2/D3 expansion segments of the large subunit rDNA gene (LSU) revealed this as a new species.A new species of the genus Paurodontella, P. composticola n. sp., collected from Nazar Abad City, Alborz Province, Iran, is described and illustrated. The new species has a body length of 803­1053 µâ€Šm (females n = 10) and 620 and 739 µâ€Šm (males n = 2). The cuticle is weakly annulated with four lateral lines. Cephalic region is annulated and continuous with body contour. The stylet is 8.0 to 9.0 µâ€Šm long with asymmetrical knobs. Esophageal basal bulb is present with a small posterior extension projecting into the intestine. Excretory pore is situated at the level of esophageal basal bulb region. Post-uterine sac is 5 to 8 µâ€Šm long and uterus is without diverticulum. Tails of both sexes are similar, short and sub-cylindrical. Males have 24 to 25 µâ€Šm long bursa leptoderan and spicules 24 or 25 µm long. A non-branching oviduct is present to form a uterine diverticulum; the new species is closely related to five known species of the genus, namely P. asymmetrica, P. balochistanica, P. densa, P. iranica and P. niger. It most closely resembles P. iranica, but differs from it morphologically by a shorter stem-like extension projecting into lumen of intestine and male with sub-cylindrical tail vs conoid. In addition to morphological comparisons, the molecular phylogenetic analyses based on 733 bp of the partial sequence of 28S D2/D3 expansion segments of the large subunit rDNA gene (LSU) revealed this as a new species.

Rotylenchus castilloi n. sp. (Nematoda: Hoplolaimidae), a new species with long stylet from northern Iran.

Rotylenchus castilloi n. sp., a new bisexual species is described and illustrated based on morphological, morphometric and molecular data. The new species is characterised by having a hemispherical, continuous lip region with an irregular corncob-like appearance under SEM, very long stylet (62-68 µm), vulva located at 49.7-62.2% of body length from anterior end, with a protruding double epiptygma, a rounded to convex-conoid (rarely bi-lobed) tail with 8-12 annuli and specific sequences of D2-D3 segments of 28S and ITS1-rRNA genes. Differences between the new species and four other species of the genus (R. mesorobustus, R. cazorlaensis, R. magnus and R. jaeni) are discussed. Morphologically, the new species can be separated from these species mostly by its body length, lip region characters, stylet length and location of phasmid. Phylogenetic analyses using 721 bp partial sequences of D2-D3 expansion segments of the 28S and 590 bp ITS1-rRNA genes revealed the new species forming a clade with two isolates of R. eximius and two isolates of R. unisexus, two morphologically unrelated species.

A study of the changes in quantitative activity of some enzymes in olive cultivars during the interaction between Verticillium wilt and root-knot nematode.

Second stage juvenile (J2) of root-knot nematode, Meloidogyne javanica, and microsclerotia of verticilliosis, Verticillium dahliae, were used as the source of inoculum for nematode and fungus respectively. One-year-old seedlings of olive cultivar, Zard, Roghani, Koroneiki and Manzanilla, were transplanted to pots containing 2000g of sterilized sandy loam soil. Experiment was conducted in completely randomized design with 32 Treatments and five replications. Treatments were as follows: control, nematode alone, fungus alone and fungus+nematode. Pots were inoculated with (0, 2000, 3000, 4000) J2 of nematode and/or (10 no/g soil) microsclerotia of fungus according to the treatments. Quantitative activity of soluble proxidase, cell wall bounded proxidase, beta-1,3-glucanase and B-1,4-glucanase were determined by the pirocatechol, hydrogen proxide, guaiacol and laminarin-dinitrosalicylilate methods, respectively, on 1,10, 20 and 30 days after inoculation. Results showed that these enzymes in leaves and roots of seedlings inoculated with pathogens increased (p < or = 0/05). In this study changes of these enzymes as compared with nematode alone and fungus alone treatments were increased in fungus+nematode treatments in seedlings (p < or = 0/05). Maximum of quantitative changes of these enzymes were observed in fungus+nematode (4000J2) treatment on cv. Koroneiki. Based on the results obtained in this study, quantitative activity of these enzymes in olive roots and leaves were be more on cvs. Koroneiki, Roghani, Zard and Manzanilla, respectively (p < or = 0/05).

A study of interaction between Verticillium wilt Verticillium dahliae and root-knot nematode Meloidogyne javanica in olive cultivars.

Second stage juvenile (J2) of root-knot nematode, Meloidogyne javanica, and microsclerotia of verticillium wilt, Verticillium dahliae, were used as the source of inoculum for nematode and fungus respectively. One-year-old seedlings of olive cultivars, Zard, Roghani, Koroneiki and Manzanilla, were transplanted to pots containing 2000g of sterilized sandy loam soil. Experiment was conducted in completely randomized design with 32 treatments and five replications. Treatments were as follows: control, nematode alone, fungus alone and fungus + nematode. Pots were inoculated with (0, 2000, 3000, 4000) J2 of nematode and/or (10 no/g soil) microsclerotia of fungus according to the treatments. Experiment was terminated after 10 months and fallowing parameters were determined i.e., fresh weight of root and stem, number of galls and egg masses per root system, and percentage of incidence of symptom on aerial parts, browning of vascular tissue, decrease of seedling height and stem/root tissue colonization by fungus. Results showed that presence of nematode caused reduction on colonization of the fungus in the root and stem and vice versa i.e. presence of fungus caused reduction on number of galls and egg masses produced by the nematode. Severe fungus wilt on aerial parts of Manzanilla cultivar was observed when both pathogens were inoculated and mild fungus wilt was observed in fungus alone treatments of Koroneiki cultivar. Galling and egg mass production in root system were reduced in cvs Manzanilla, Zard, Roghani and Koroneiki, respectively (p < or = 0/05). Based on the results obtained in this study, verticilliosis symptoms and galling of nematode in olive seedlings were be less on cvs Koroneiki, Roghani, Zard and Manzanilla, respectively (p < or = 0/05).