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Morphological and molecular analyses of three populations of Meloidoderita whittoni (Sledge & Christie, 1962) comb. n. (syn. Sphaeronema whittoni; Tumiota whittoni) collected in Florida from sweet gum (Liquidambar styraciflua L.) indicated that this species is a representative of Meloidoderita rather than Sphaeronema, where it was included in the original description, or Tumiota, to where it was subsequently transferred. However, this species can be considered an atypical representative of the genus, because it differs from the other species of this genus in having females retaining the eggs inside a thin-walled uterus, which remains encased inside their body. After egg deposition inside the uterus, the female dies and its body is transformed into a persistent tanned sac with a thick cuticle, devoid of ornamentations, which protects the eggs like a heteroderid cyst. The female secretes from the vulva a gelatinous matrix, which becomes hardened in time and encases its body for protection against predation and parasitism by biological antagonists as has been suggested for other tylenchuloid nematodes. No egg deposition outside the female body was observed. Second-stage juveniles of this species have a semi-endoparasitic, rather than endoparasitic, habit as in other known Meloidoderita species. This is the first report of a sphaeronematid having a cyst stage fitting the definition of a heteroderid cyst. Phylogenetic relationships between some species of Tylenchuloidea and Criconematina are analysed using the partial 18S rRNA, the D2-D3 of 28S rRNA and the ITS rRNA gene sequences. [ABSTRACT FROM AUTHOR]

The results of morphological and molecular analyses of a Florida topotype and other populations of Hemicriconemoides strictathecatus showed that this sheathoid nematode consists of two morphotypes, both with an average stylet length of more than 70 µm, but having different tail termini, bluntly pointed or rounded. These findings confirmed the morphological similarity of H. strictathecatus with H. mangiferae, which was considered a junior synonym of this species as previously proposed by Decraemer & Geraert (1992, 1996). Populations of a sheathoid nematode with a stylet length ranging from 62.5 to 72.0 µm from Taiwan, China, South Africa and Venezuela and identified in previous studies as H. strictathecatus were found to be morphologically and molecularly different from this species and are now considered as representatives of H. litchi. Another sheathoid nematode population from Florida, considered to be H. mangiferae by McSorley et al. (1980), was also found to be morphologically and molecularly congruous with H. litchi. During nematological surveys in Florida, a new sheathoid nematode was detected on date palms imported from California into Florida and is described herein as H. phoenicis sp. n. This new species is related morphologically to the H. strictathecatus morphotype with pointed tail terminus. Both have a stylet longer than 70 µm. The new species is phylogenetically related to H. strictathecatus and H. litchi. It differs morphologically from other Hemicriconemoides species by the cuticular ornamentation of the annuli, which are marked by coarse longitudinal ridges, grooves and thick margins. Morphological and molecular characterisations of H. cocophillus from Mozambique and Florida, USA are also elucidated in this study. New phylogenies of the genus Hemicriconemoides as inferred from the analyses of the ITS rRNA, D2-D3 of 28S rRNA and partial coxI gene sequences are provided. [ABSTRACT FROM AUTHOR]

During a survey for Trichodoridae in cultivated and natural environments, mainly from southern Spain, 7 new Trichodorus species were found. Four of them, T. andalusicus n. sp., Z asturanus n. sp., T. silvestris n. sp. and T. parasilvestris n. sp., belong to the T. lusitanicus morpho-species group characterised in the male by the slightly ventrally curved spicules with a mid-blade constriction with bristles, and in the female by well developed, rounded triangular to quadrangular, vaginal sclerotised pieces. They were mainly differentiated based upon differences in body length, onchiostyle length, spicule shape and number of ventromedian cervical papillae in the male, and size and shape of the vaginal sclerotised pieces in the female. The presence of the T. lusitanicus morpho-species group with 8 species, apparently endemic to the Iberian Peninsula, could point to a recent speciation event. Additionally, 3 new species, T. onubensis n. sp., T. iliplaensis n. sp. and T. paragiennensis n. sp., more closely resembling the morpho-species group of T. sparsus, to which the Spanish species T. giennensis also belongs, were identified. They were differentiated based on body length, length of onchiostyle and position of the secretory-excretory pore and, in the male, by length and shape of the spicules and number of ventromedian cervical papillae and in the female by the vaginal sclerotised pieces. Molecular support to differentiate the new species using the D2-D3 expansion segments of 28S rDNA is also provided. In addition, a new population of T. variabilis from Greece was studied as well as T. lusitanicus type specimens, and a population of T. giennensis and T. lusitanicus were also sequenced. [ABSTRACT FROM AUTHOR]

The occurrence of a male-less population of Sphaeronema alni parasitising chestnut (Castanea sativa) roots and inducing a stelar syncytium is reported for the first time in Pola de Somiedo (Oviedo province), Spain. Morphometric and molecular characters of the Spanish population matched those of a topotype population from Russia. SEM observations showed swollen females having the first lip annulus wider than the second and appearing as a cap-like, circumoral elevation. The second-stage juveniles, having a single band in the lateral fields, were characterised by a non-annulated dome-shaped lip region derived from the fusion of the oral disc with all the lip sectors and lip annuli, and showing slit-like amphidial apertures and an oval prestoma. The sequences of the D2-D3 expansion segments of 28S rRNA, partial 18S rRNA and ITS rRNA gene for the Spanish and topotype populations of S. alni were congruent and matched those deposited in GenBank for another population from Germany, thereby confirming their conspecificity. A PCR-RFLP profile of D2-D3 of 28S rRNA for identification of this species was also provided. The phylogenetic relationships between S. alni populations and representatives of the suborder Criconematina, as inferred from analysis of partial 18S rRNA and D2-D3 of 28S gene sequences obtained in this and previous studies, indicated that S. alni formed a basal clade on the majority consensus Bayesian phylogenetic trees, standing together with Meloidoderita sp. or alone. These findings provide additional evidence of the need to clarify the position of Sphaeronema within Criconematina and its relationships with representatives of Tylenchulinae. [ABSTRACT FROM AUTHOR]

A new amphimictic species, Pratylenchus hispaniensis n. sp., parasitising the roots of gum cistus in Andújar (Jaén), southern Spain, is described. The new species is characterised by the presence of numerous males and by the female having a lip region with three annuli, a divided face, a robust stylet (14.5-17.0 μm) with rounded knobs, lateral fields with four lines, V = 80-84, a round spermatheca full of sperm, well developed post-vulval uterine sac and an obliquely truncate tail with irregularly annulated terminus. Morphologically this species is related to P. bhatti, P. kralli, P. mediterraneus, P. pseudofallax and P. thornei. A phenetic study of the 25 most useful diagnostic morphological and allometric characters for Pratylenchus species was done using multivariate factor and linear discriminant analyses. In the factor analysis the first seven factors accounted for 71.1% of the total variance of the characters selected. These factors were related to female tail, pharyngeal overlap, reproductive behaviour, stylet length, L/post-vulval uterine sac ratio, body length and number of lip annuli. Discriminant analysis differentiated Pratylenchus spp. from the three valid species of Zygotylenchus. The results of the phylogenetic analysis based on sequences of the D2-D3 expansion regions of 28S, partial 18S and ITS rRNA genes confirmed the close relationship of P. hispaniensis n. sp. with P. mediterraneus and inferred molecular affinity with P. brzeskii, P. neglectus and P. thornei, in spite of variation in the position of P. hispaniensis n. sp. in the clades. Additional phylogenetic analyses based on the same sets of sequences for P. hispaniensis n. sp., Zygotylenchus guevarai and other Pratylenchidae indicated that Pratylenchus includes several paraphyletic lineages; however, likelihood tests did not reject monophyly of the genus. The inclusion of Pratylenchus, Zygotylenchus, Hirschmanniella, Nacobbus and Apratylenchus in Pratylenchidae was supported. [ABSTRACT FROM AUTHOR]

A population of the amphimictic root-lesion nematode Pratylenchus pseudocoffeae is reported infecting chrysanthemum in glasshouses and open fields in Mahallat Town, Markazi province, central Iran. This population shares similar morphological features with P. pseudocoffeae from Japan and also has the same D3 sequences as a population from Florida (no molecular data are available for the type Japanese population). The Iranian population of P. pseudocoffeae is characterised by a labial region with two (60%) or three annuli (40%), stylet ca 16 μm long, presence of males, vulva at 80% of body, oval spermatheca and subhemispherical tail with smooth terminus. Morphologically, P. pseudocoffeae from Iran resembles P. coffeae, from which it differs in a divided face vs smooth and flat in P. coffeae. However, the morphological and biological characters of P. pseudocoffeae are more closely related to those of P. gutierrezi and the related undescribed species K1 and K2 from coffee in Costa Rica and Guatemala, respectively, from which it differs by the shorter stylet and shape of tail tip. In contrast, the comparison of molecular characteristics, including ITS-RFLP patterns and sequences of the D3 region between P. pseudocoffeae from Iran and other related species, indicates a close relationship between P. pseudocoffeae and P. hexincisus and P. agilis, in spite of the fact that the latter two species are not amphimictic and lack males and functional spermatheca. In Iran, P. pseudocoffeae causes root lesions, distinct necrosis and large cavities within the cortical parenchyma, resulting in stunting of chrysanthemum stands. The detection of P. pseudocoffeae in Iran is a new country record and also represents the second detection of this species outside Japan. [ABSTRACT FROM AUTHOR]

Paralongidorus litoralis sp. n., a new bisexual species of the genus, is described and illustrated by light microscopy, scanning electron microscopy and molecular studies from specimens collected in a coastal sand dune soil around roots of lentisc (Pistacia lentiscus L.) from Zahara de los Atunes (Cadiz), southern Spain. Paralongidorus litoralis sp. n. is characterised by the large body size (7.5-10.0 mm), a rounded lip region, clearly offset from the body by a collar-like constriction, and bearing a very large stirrup-shaped, amphidial fovea, with conspicuous slit-like aperture, a very long and flexible odontostyle ca 190 μm long, guiding ring located at 35 μm from anterior end, and males with spicules ca 70 μm long. In addition, identification data of a Spanish population of P. paramaximus Heyns, 1965 recovered from sandy soil of a commercial citrus orchard at Alcala de Guadaira (Seville), southern Spain, agree very well with the original description of the species from South Africa. The 18S rRNA and D2 and D3 expansion regions of 28S rRNA gene sequences were obtained for P. litoralis sp. n. and P. paramaximus. Phylogenetic analyses of P. litoralis sp. n. and P. paramaximus rRNA gene sequences and of Longidoridae sequences published in GenBank were done using maximum likelihood and Bayesian inference. In trees generated from the 18S data set Paralongidorus clustered as an external clade from Longidorus, and in trees generated from D2-D3 of 28S dataset Paralongidorus was monophyletic and nested within Longidorus. Maximum likelihood test supported the hypothesis of validity of the Paralongidorus genus. [ABSTRACT FROM AUTHOR]