Two new species of the genus Sectonema Thorne, 1930 (Nematoda, Dorylaimida, Aporcelaimidae) from Iran, with new insights into its evolutionary relationships.

Two new species of the genus Sectonema found in northern Iran are characterized, including morphological descriptions and molecular (18S-, 28S-rDNA) analyses. Sectonema tehranense sp. nov. is distinguished by its 7.22 - 8.53 mm long body, lip region offset by constriction and 24 - 31 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, mural tooth 15.5 - 17 µm long at its ventral side, neck 1091 - 1478 µm long, pharyngeal expansion occupying 61 - 71% of the total neck length, female genital system diovarian, uterus simple and 3.9 - 4.2 times the corresponding body diameter long, transverse vulva (V = 49 - 59), tail short and rounded (44 - 65 µm, c = 99 - 162, c' = 0.6 - 0.8), spicules 111 - 127 µm long, and 7 - 10 spaced ventromedian supplements with hiatus. Sectonema noshahrense sp. nov. displays a 4.07 - 4.73 mm long body, lip region offset by constriction and 23 - 25 µm wide with perioral lobes and abundant setae- or cilia-like projections covering the oral field, odontostyle 14 - 14.5 µm long, neck 722 - 822 µm long, pharyngeal expansion occupying 66 - 68% of the total neck length, female genital system diovarian, uterus simple and 2.4 - 2.7 times the corresponding body diameter long, transverse vulva (V = 54 - 55), tail convex conoid (39 - 47 µm, c = 91 - 111, c' = 0.8 - 0.9), spicules 82 µm long, and seven spaced ventromedian supplements with hiatus. Molecular analyses confirm a maximally supported (Epacrolaimus + Metaporcelaimus + Sectonema) clade and a tentative biogeographical pattern, with sequences of Indolamayan taxa forming a clade separated from those of Palearctic ones. Parallel or convergent evolution processes might be involved in the phylogeny of the species currently classified under Sectonema. This genus is certainly more heterogeneous than previously assumed.

New and known species of the genus Pungentus Thorne & Swanger, 1936 (Dorylaimida, Nordiidae) from Iran.

This contribution provides morphological and molecular data for one new and one known species of the genus Pungentus. The first species, P. azarbaijanensis n. sp., was recovered from the rhizospheric soil of grasses, collected in West Azarbaijan province, Iran, and was characterized by 2082-2365 µm long females having an angular lip region separated from the rest of the body by a constriction, 33-35 µm long odontostyle, vulva at 43.5-51.0%, 27.0-29.5 µm long rounded-conoid tail, and males unknown. It was compared morphologically with five species: P. angulosus, P. crassus, P. marietani, P. parapungens and P. pungens, which have didelphic-amphidelphic female reproductive system, body longer than 1.5 mm, and odontostyle longer than 20 µm. The second species, P. engadinensis, was recovered in three different regions of Iran (Mazandaran, Semnan and East Azarbaijan provinces). It was compared morphologically with some other populations reported all over the world. Besides morphological studies, molecular phylogenetic studies using partial sequences of 28S rDNA D2-D3 fragments were performed, and the phylogenetic relations of the two Iranian populations with other species and genera were discussed.

Description of a new species of the genus Anguillonema Fuchs, 1938 (Nematoda: Sphaerularioidea) with an identification key to the species.

Anguillonema iranicum n. sp. is described and illustrated as the second species of this genus from Iran, based on morphological, morphometric and molecular characteristics. It is identified by a short, thin body, a continuous lip region, six lines on the lateral field, a short, thin stylet, a posteriorly located pharyngo-intestinal junction to excretory pore, the presence of a post-vulval uterine sac, vulval position at 89% (87.4-89.9%) of body length, an elongate conoid tail with a rounded to pointed tip and not dorsally bent, and common functional males with short spicules and lacking a bursa. Morphological differences between the new species and the three known species of the genus, namely A. amolensis, A. crenati and A. poligraphi, are discussed. Molecular phylogenetic studies of the new species using partial 18S rDNA sequence revealed that it formed a sister clade with three species of Howardula, one species of Anguillonema and one unidentified isolate. In phylogenetic analyses using partial sequences of 28S rDNA D2-D3 segment, the new species formed a clade with two isolates of Parasitylenchus. A key to identification of Anguillonema species is also presented.

Interaction between root lesion nematode Pratylenchus vulnus and two species of Fusarium on growth and development of maple seedlings.

Producing healthy seedlings and distributing them to far areas, is one of the most important factor for developing forests. Because of easy planting, rapid growth and good wood quality, Acer velutinum is the most useful species, among the softwood and hardwood trees. Growth and development of the nurseries were effected by different pests and diseases, the nematodes are one of these agents. They are not actively surveyed in the forest nurseries in Iran. On a survey of maple seedling in the forest nurseries Pratylenchus vulnus, Fusarium solani and F. oxysporum were identified. The interaction between these two fungi and nematode were studied in randomized complete block design with four replications and six treatments. For mass production and multiplication of the nematodes, they were sterilized with Streptomycin Sulfate, they were reared on carrot disc culture. The nematodes were then added to each pot. The results showed a highly significant difference (p = 0.01) between different treatments. In the treatment with nematodes alone growth of seedlings was minimum and population density of nematodes in soil and root tissue was maximum. In this treatments 75% of seedlings were died and seedling average height were 2.25 cm. In the treatments with nematode and fungi together the population of nematodes were decreased and the growth of seedlings were increased, in comparison with nematode alone. F. oxysporum showed more antagonistic effect on nematodes than F. solani. In the nematode + F. oxysporum treatment, 25% of seedlings were died and seedling average height was 12.75 cm. In the nematode + F. solani treatment, 50% of seedlings were died and the seedling average height was 5.5 cm. This is the first report of pathogenecity of Pratylenchus vulnus and its interaction whit fungi on maple seedlings in Iran.