First report of Longidorus mindanaoensis Coomans, De Ley, Jimenez and De Ley, 2012 (Nematoda: Longidoridae) from a mangrove forest in Vietnam

Longidorus mindanaoensis was recovered from a mangrove forest in Vietnam. The recovered population is in general morphological agreement with the type population, and the characters of pharyngeal bulb, i.e. the same unique pattern of pharyngeal glands nuclei as well as the lip region morphology, amphidial fovea shape and size and position of vulva corroborated its identity. Molecular studies of the recovered population using D2-D3 expansion segments of large subunit ribosomal DNA (LSU rDNA D2-D3) revealed the D2-D3 sequence of the recovered population is 99.6% similar to the sequence of the type population. A new morphometric range for body size was recorded for the species based upon present Vietnamese population, and the present study emphasized that the diversity of Longidorus spp. in Vietnam could be higher than previously assumed

Morphological diversity of Meloidogyne spp. from carrot (Daucus carota subsp. Sativus) in Vietnam

Carrot (Daucus carota subsp. Sativus) is known as one of the most widely cultivated and widely consumed vegetables in the world due to its nutritional and economic values. During a survey of nematodes parasites carrots from Vietnam, six populations of three species of root-knot nematodes, namely M. incognita, M. arenaria, and M. graminicola were found. The species specific primers were confirmed before morphological studies. By combining the morphology and morphometry of the females, males, and juveniles, this study provided useful references for classification of Meloidogyne on carrots in the future. Quantitative morphological studies reveal profound changes corresponding with the generation of morphological disparity at high taxonomic diversity. Especially, this study provided the first morphological and morphometric information of M. graminicola, that is known as aquatic root-knot nematodes, on carrots

Description of Geocenamus vietnamensis sp. n. (Nematoda : Merliniidae) from Vietnam

A new species of the genus Geocenamus was isolated from soil and root samples from the rhizosphere of Casuarina equisetifolia (Casuarinaceae) in Quang Nam province, Vietnam. This species is characterized by a round-to-hexagonal labial disc, the presence of a labial region, which is continuous or slightly offset from the body with six sectors, lateral sectors of first labial annulus being smaller than the submedian sectors, the presence of six to seven labial annules; the absence of deirids; stylet length 24 to 28 mu m long, body length 776 to 979 mu m long; lateral field with six to eight lateral lines, without areolation at mid-body and with areolation in outer bands at the tail region and a pointed tail terminus. Geocenamus vietnamensis n. sp. most closely resembles G. boghiae in having a non-sclerotized head framework and lacking a bursa in the males. It can be clearly distinguished from all other species of the genus Geocenamus by these characteristics. The combination of morphology, morphometric features, and phylogenetic trees, based on D2-D3 of 28S and ITS rDNA sequences, showed that this new species can be clearly separated from all other sequenced species. This record is the first for Geocenamus in Vietnam

First report of Mesocriconema sphaerocephalum (Taylor, 1936) Loof, 1989 associated with carrot (Daucus carota subsp. Stativus) in Vietnam

Our study recorded the presence of Mesocriconema sphaeroce phalum on carrot in Hanoi city and Hai Duong province in Vietnam. This species was identified by morphometric, morphological characterizations, and molecular characterization of D2D3 of 28S rDNA sequence. To our knowledge, this is the first report of M. sphaerocephalum on carrot in Vietnam

Morphological and molecular characteristics of Pratylenchus haiduongensis sp. n., a new species of root-lesion nematodes associated with carrot in Vietnam

Pratylenchus haiduongensis sp. n. is described as associated with carrot (Daucus carota subsp. sativus (Hoffm.) Schubl. & G. Martens) in Hai Duong Province, Vietnam. P. haiduongensis sp. n. is characterized by the lip region with three annuli and slightly separated from the body. Stylet knobs are rounded (never indented anteriorly). The lateral field includes four incisures, bearing areolation at the pharynx region and tail region and occasionally appears in the vulval region. Sometimes the appearances of oblique broken striaes divide the lateral field into five or six incisures. The ovary is distinct with one row of oocytes. Spermatheca is oval in shape with round central cavity, without sperm or reduced in some specimens. The postvuval uterine sac is long surpassing the vulva body diameter by 2 to 2.5 times (PUS = 31 to 65 mm). High vulva position with V = 66 to 75%. The tail shape can be subhemispherical with a smooth, slightly indented, broadly smooth, or cleft terminus observed in some specimens. The matrix code of P. haiduongensis sp. n. is: A2, B1, C4, D(1,3), E1, F(5,6), G(1,2), H(1,4); I(1,2,3,4), J1, K(1,2) according to Castillo and Vovlas (2007). The LSU-D2D3 segment and the ITS-rDNA region of this species were amplified and sequenced. The morphological characters and molecular phylogenetic analyses confirmed that this is a new species of the genus Pratylenchus in Vietnam

First report of Paratylenchus lepidus Raski, 1975 associated with green tea (Camellia sinensis (L.) Kuntze) in Vietnam

The pin nematodes, Paratylenchus spp., are relatively small nematodes that can feed on a wide range of host plants. The morphological identification of this nematode is greatly hampered by their small size and variable characters. This study provides the first report of Paratylenchus lepidus from Vietnam with a combination of morphological and molecular characterizations. The 28S rDNA phylogenetic tree of the genus and the first COI mtDNA barcode of this species are also provided

First report of Xiphinema hunaniense Wang & Wu, 1992 (Nematoda : Longidoridae) in Vietnam

For the first time, a survey of plant-parasitic nematodes in the Central Highlands of Vietnam discovered a population of Xiphinema hunaniense Wang & Wu, 1992. The Vietnamese population of X. hunaniense is characterized by having an offset lip region, lack of anterior genital branch, vagina directed backward, and a digitate tail. Morphological features and morphometrics of this population are in agreement with the type population of X. hunaniense except for some variations. In addition, molecular characterization of this population and phylogenetic tree of 28S rDNA sequences of the genus are also provided

First report of Hemicriconemoides litchi associated with Piper sarmentosum and revision of the genus Hemicriconemoides in Vietnam

The taxonomic status of Hemicriconemoides litchi, H. mangiferae, and H. strictathecatus has been in debates for many years. In this study, a population of H. litchi collected from the rhizosphere of Piper sarmentosum is characterized using a combination of morphology and molecular data. Our results are in agreement with other authors to maintain the validity of H. litchi and provide sequences of H. litchi with correct names on GenBank. A revision on the genus Hemicriconemoides in Vietnam is also discussed

First report and new molecular and morphological characterizations of root-knot nematode, Meloidogyne javanica, infecting ginger and long coriander in Vietnam

Ginger (Zingiber offcinale Roscoe) and long coriander (Eryngium foetidum L.) are commonly grown and used as important spices and medicinal plants in Vietnam. Our study recovered for the frst time one of the most damaging tropical root-knot nematodes, Meloidogyne javanica, associated with these plants in the Western Highlands of Vietnam. In this study, M. javanica was characterized based on morphology and molecular characterization of D2-D3 fragment of 28S rRNA, ITS, and Nad5 mtDNA regions. The identifcation of this species was done based on a combination of morphology, multiplexPCR with specifc primer, network haplotype analysis, and PPNID program