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Morphologial, biochemical, molecular and karyological analyses of different populations and races of the stem and bulb nematode Ditylenchus dipsaci have suggested that it represents a species complex, of which only D. dipsaci sensu stricto and its morphologically larger variant, known as the giant race of the stem and bulb nematode, are plant parasites of economic importance. The present study singles out the giant race from this complex, herein described as a new species named Ditylenchus gigas n. sp., on the basis of morphological and molecular data obtained from several populations collected from broad beans in southern Italy, southern Spain and Lebanon. The new species epithet, which refers to the large body size of the nematode with respect to the normal races, must be considered to be conspecific with the D. dipsaci ‘giant race’ from Fabaceae in recent literature. Morphologically, the new species is characterized by a body size 1Æ5–2 times longer than the ‘normal race’, stylet delicate (11Æ5–13Æ0 lm long) with knobs distinctly sloping backwards, and long post-vulval uterine sac (81–150 lm long). Results of molecular analysis of rDNA sequences including the ITS1-5.8S-ITS2 region, the D2–D3 fragment of the 28S gene, the small 18S subunit, the partial mitochondrial gene for cytochrome c oxidase I (mtCOI), and hsp90 gene sequences, support the new taxonomic species status for the former D. dipsaci giant race from Vicia faba, and clearly distinguish D. gigas n. sp. from D. dipsaci sensu stricto. [ABSTRACT FROM AUTHOR]

Ring nematodes are obligate ectoparasites on crops and natural herbaceous and woody plants, and some species are of economic importance and cause damage to roots of several crops. Recent integrative taxonomical analyses recognized the existence of two cryptic species within the Criconema annuliferum morphotype in Spain. In this study, we corroborated that morphometric, morphological and a multi-locus analysis (including the ribosomal markers D2-D3 expansion segments of 28S rRNA, ITS rRNA, 18S RNA, and the mitochondrial DNA cytochrome oxidase I gene) identified a new lineage clearly separated from C. annuliferum, C. paraannuliferum and C. plesioannuliferum. The new lineage was described herein as Criconema pseudoannuliferum sp. nov., confirming that C. annuliferum species complex species complex comprises a hyper-cryptic species complex. This research analysed soil samples from the rhizosphere of maritime pine (Pinus pinaster Ait.) forests in Bermeja-Crestellina Mountain, located at the western part of Málaga province, southern Spain. The integrative taxonomical analyses revealed the occurrence of a new cryptic species identified using females, males and juveniles with detailed morphology, morphometry and molecular markers, described herein as Criconema pseudoannuliferum sp. nov. All molecular markers (D2-D3, ITS, 18S and COI) were obtained from the same individual that was also used for morphological and morphometric analyses. This research demonstrated the hidden diversity within the C. annuliferum species complex species complex can reach to four lineages under ribosomal and mitochondrial gene markers for one morphospecies group, which includes four species, viz. C. annuliferum, C. paraannuliferum, C. plesioannuliferum, and C. pseudoannuliferum sp. nov. Criconema pseudoannuliferum sp. nov. was detected in moderate soil density in two maritime pine forests (5 and 25 nematodes/500 cm3 of soil) suggesting that does not cause damage to maritime pine. [ABSTRACT FROM AUTHOR]

Paratylenchus species are obligate ectoparasitic nematodes on cultivated and wild herbaceous and woody plants occupying numerous soil categories. Several species may cause damage to several crops (viz. P. dianthus, P. enigmaticus, P. microdorus, P. hamatus and P. epacris on carnation, lettuce, rose and walnut, respectively). This investigation proves and emphasizes the relevance of applying integrative taxonomy for the accurate detection of Paratylenchus species in mountainous wild environments in the Malaga province, Southern Spain. This research analyzed 45 soil samples of maritimus pine and one of green heather in southern Spain and identified fourteen Paratylenchus species, two of them are described herein as new species (P. paraaonli sp. nov., P. plesiostraeleni sp. nov.), six of them were first reports for Spain (P. canchicus, P. nainianus, P. neonanus, P. salubris, Paratylenchus sp. 2 SAS, and P. wuae), and six species (P. caravaquenus, P. microdorus, P. nanus, P. neoamblycephalus, P. sheri, and P. variabilis) have been already reported in Spain. Accordingly, these data increase the biodiversity of pin nematodes in Spain comprising a total of 47 species (33.1% out of 142 total species of this genus). Phylogenetic analyses based on ribosomal and mitochondrial markers (D2-D3, ITS, and partial COI) resulted in a consistent position for the newly described Paratylenchus species in this study (P. plesiostraeleni sp. nov., P. paraaonli sp. nov.). Paratylenchus plesiostraeleni sp. nov. grouped in a separated subclade as unequivocal species from the P. straeleni-complex species (including P. straeleni and P. parastraeleni), and P. paraaonli sp. nov. clustered with P. vitecus, but clearly separate from this species. This study indicates that Paratylenchus species diversity in natural environments may be higher than expected, and this study may help in accurate identifications. [ABSTRACT FROM AUTHOR]

During nematode surveys in natural vegetation in Sierra Mágina, Jaén province, southern Spain, a Longidorus species closely resembling Longidorus carpetanensis was found, but application of integrative taxonomic approaches clearly demonstrated that it is a new species described herein as Longidorus maginicus n. sp. The new species is amphimictic, characterized by a moderately long body (4.2–5.2 mm); lip region anteriorly flattened, slightly separated from the rest of body by a depression, 9.0–11.0 μm wide and 3.5–6.0 μm high; amphidial fovea not lobed; relatively short odontostyle (61.0–70.5 μm); guiding ring located 23.5–27.0 μm from anterior end; vulva located at 42.0%–51.3% of body length; female tail 39.0–61.0 μm long, conoid, dorsally convex with rounded terminus (c′ = 1.3–2.1), with two or three pairs of caudal pores; and males common (1:2 ratio males:females), with moderately long spicules (39.0–48.5 μm) and 1 + 6–9 ventromedian supplements and three juvenile developmental stages. According to the polytomous key, codes for the new species are (codes in parentheses are exceptions): A2-B1-C2-D2-E1-F2(3)-G2-H5(4)-I2-J1-K6. The results of molecular analysis of D2–D3 28S, internal transcribed spacer region, partial 18S rDNA, and cytochrome oxidase c subunit 1 (coxI) gene sequences further characterized the new species status, and separated it from L. carpetanensis and other related species. [ABSTRACT FROM AUTHOR]

Longidorid nematodes comprise more than 500 species, and Longidorus and Xiphinema are the most diversified, prevalent, and cosmopolitan genera within plant‐parasitic nematodes. This increases the risk of species misidentification. We conducted an integrative morphometric and genetic study on two longidorid species to elucidate the existence of new cases of cryptic speciation within the genera Longidorus and Xiphinema. Detailed morphological, morphometrical, multivariate, and genetic studies were carried out, and mitochondrial and nuclear haploweb analyses were used to differentiate species within the L. iliturgiensis and X. hispanum complexes. Species delimitation using multivariate and haplonet tools of L. iliturgiensis species complex clearly separated L. tabernensis sp. nov. from L. iliturgiensis and L. indalus, and X. subbaetense sp. nov. from X. hispanum and X. adenohystherum. D2‐D3, partial 18S, and partial coxI regions were used for inferring their phylogenetic relationships with other species in each genus. The present study provides new insights into the diversity of Longidorus and Xiphinema species detected in southern Spain, and new evidence of cryptic speciation in both genera. These results support our hypothesis that the biodiversity of Longidoridae in southern Europe is higher than previously supposed and is still not fully clarified. [ABSTRACT FROM AUTHOR]

This contribution provides new insights in the phylogeny and taxonomy of the nematode genus Sectonema with an integrative approach. A brief historical outline of the matter is presented. Then, the morphological pattern of the genus is revised and illustrated, the nature of its stomatal protruding structure, either a reduced odontostyle or a mural tooth, being its most relevant diagnostic feature. The existence of cilia‐ or seta‐like structures in the perioral area and/or at the anterior part of cheilostom of some species is evidenced by SEM observations for the first time. Available molecular data (D2–D3 LSU‐rRNA gene) are analysed, including two new sequences of S. septentrionale from Spain. The monophyly of the genus is confirmed, and two species groups with geographical projection are tentatively identified. A close relationship with Metaporcelaimus is also demonstrated as both taxa constitute a highly supported clade. A likely polyphyly of the family Aporcelaimidae is once more demonstrated. Finally, an updated taxonomy of the genus is proposed, including revised diagnosis, list of species, identification key and a compendium of their main morphometrics. [ABSTRACT FROM AUTHOR]

Root-knot nematodes of the genus Meloidogyne are recognised worldwide as a major production constraint in crops of primary economic importance. Knowledge of their diversity and prevalence, as well as the major environmental and agronomical cues for understanding their distribution in specific areas is of vital importance for designing control measures to reduce significant damage. We provide the first detailed information on the diversity, distribution and levels of Meloidogyne species infecting wild and cultivated olive soils in a wide-region in southern Spain that included 499 sampling sites. Overall Meloidogyne spp. were found in 6.6% of sampled olive plants, with 6.6% and 6.5% for cultivated and wild olive, respectively. We identified five previously described Meloidogyne spp. (Meloidogyne arenaria, M. baetica, M. hapla, M. incognita, M. javanica) and one new species (Meloidogyne oleae sp. nov.) which, characterized using integrative taxonomy, increases the known biodiversity of Meloidogyne spp. affecting olive. Meloidogyne arenaria and M. incognita were only found infecting cultivated olive varieties, while, M. baetica was only found infecting wild olive. Three major parameters drive the distribution of Meloidogyne spp. in cultivated olives in southern Spain, cover vegetation on alley, irrigation and soil texture, but different species respond differently to them. In particular the presence of M. incognita is highly correlated with sandy loamy soils, the presence of M. javanica with irrigated soils and cover vegetation, while the presence of M. arenaria is correlated with the absence of cover vegetation on alley and absence of irrigation. These parameters likely influence the selection of each particular Meloidogyne species from a major dispersal source, such as the rooted plantlets used to establish the orchards. [ABSTRACT FROM AUTHOR]

The genus Xiphinema constitutes a large group of ~275 species of polyphagous, plant-ectoparasitic nematodes that are distributed almost worldwide. Some species affect agricultural crops by feeding directly on root cells as well as by transmitting nepoviruses. Despite their agricultural importance, species discrimination in Xiphinema is difficult, leading to potential misidentification. Integrative taxonomy, based on the combination of molecular analyses and morphology, constitutes a new insight into Xiphinema species identification. In this study we describe two new species of Xiphinema from the Iberian Peninsula (X. macrodora, sp. nov. and X. oleae, sp. nov.) associated with cultivated and wild olive trees. Both species have specific rRNA sequences. Morphologically, Xiphinema macrodora, sp. nov. is characterised by a very long body (7.2-8.7 mm), a very long odontostyle and odontophore (190-206 and 105-120 µm, respectively), and a well developed pseudo-Z-organ, comprising 8 to 12 sclerotised bodies. Xiphinema oleae, sp. nov. is characterised by an odontostyle and an odontophore 136-149 and 65-80 µm long, respectively, and a well developed Z-organ with refractive inclusions (3-5), variable in shape. Additionally, X. macrodora, sp. nov. has the longest body size, and the longest odontostyle and odontophore of any Xiphinema, whereas X. oleae, sp. nov. is the first species with a well developed Z-organ from the Iberian Peninsula. [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]

Rotylenchus vitis n. sp., a new amphimictic species infesting soil and roots of commercial vineyards in southern Spain, is described. Rotylenchus vitis n. sp. is characterised by a truncate lip region with 7-9 annuli and continuous with the body contour, lateral fields areolated at pharyngeal region only, body without longitudinal striations, stylet length of 36-48 μm, vulva position at 47-57%, tail rounded to hemispherical with 13-21 annuli. Morphologically, this species is related to R. cazorlaensis, R. capitatus, R. elegans, R. fabalus, R. iranicus, R. labiodiscus, R. montanus and R. troncapitatus. The results of the phylogenetic analysis based on the sequences of the D2-D3 expansion regions of the 28S and ITS1-rRNA genes confirmed the species differentiation and the close molecular relationship between R. eximius and R. montanus, respectively. [ABSTRACT FROM AUTHOR]

During a recent nematode survey in natural environments of the Los Alcornocales Regional Park narrow valleys, viz., the renowned 'canutos' excavated in the mountains that maintain a humid microclimate, in southern Spain, an amphimictic population of Xiphinema globosum was identified. Morphological and morphometric studies on this population fit the original and previous descriptions and represent the first report from Spain and southern Europe. Molecular characterisation of X. globosum from Spain using D2-D3 expansion regions of 28S rRNA, 18S rRNA and ITS1-rRNA is provided and maximum likelihood and Bayesian inference analysis were used to reconstruct phylogenetic relationships within X. globosum and other Xiphinema species. A supertree solution of the different phylogenetic trees obtained in this study and in other published studies using rDNA genes are presented using the matrix representation parsimony method (MRP) and the most similar supertree method (MSSA). The results revealed a closer phylogenetic relationship of X. globosum with X. diversicaudatum, X. bakeri and with some sequences of unidentified Xiphinema spp. deposited in GenBank. [ABSTRACT FROM AUTHOR]

During recent nematode surveys in a muddy soil around undetermined graminaceous plants in El Rocío, Huelva Province, in southern Spain, and from the rhizosphere of date palm associated with graminaceous vegetation from Abadan, in Khuzestan Province, south-west Iran, populations of Longidorus orientalis were identified. Morphological and morphometrical studies on these populations fit the original description and represent the first report from Spain and Europe. Molecular characterisation of L. orientalis from Spain and Iran, using D2-D3 expansion regions of 28S rRNA, 18S rRNA and ITS-rRNA, is provided. Sequences of the D2-D3 expansion regions and partial 18S genes were analysed using maximum likelihood and Bayesian inference to reconstruct phylogenetic relationships within L. orientalis and other Longidorus species. The results revealed a closer phylogenetic relationship with L. goodeyi for the D2-D3 expansion region and with L. vineacola for the partial 18S region. [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]

High infection rates of European holly ( Ilex aquifolium) feeder roots by an unknown root-knot nematode were found in a holly forest at Arévalo de la Sierra (Soria province) in northern Spain. Holly trees infected by the root-knot nematode showed some decline and low growth. Infected feeder roots were distorted and showed numerous root galls of large (8–10 mm) to moderate (2–3 mm) size. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes and phylogenetic trees of sequences within the ribosomal DNA (rDNA) demonstrated that this nematode species differs clearly from other previously described root-knot nematodes. Studies of host-parasite relationships showed a typical susceptible reaction in naturally infected European holly plants, but did not reproduce on a number of cultivated plants, including tomato, grapevine, princess-tree and olive. The species is described here, illustrated and named as Meloidogyne silvestris n. sp. The new root-knot nematode can be morphologically distinguished from other Meloidogyne spp. by: (i) roundish perineal pattern, dorsal arch low, with fine, sinuous cuticle striae, lateral fields faintly visible; (ii) female excretory pore level with stylet knobs, or just anterior to them, EP/ST ratio about 0·8; (iii) second-stage juveniles with hemizonid located 1 to 2 annuli anterior to excretory pore and short, sub-digitate tail; and (iv) males with lateral fields composed of four incisures, with areolated outer bands. Phylogenetic trees derived from maximum parsimony analysis based on 18S, ITS1-5·8S-ITS2 and D2–D3 of 28S rDNA showed that M. silvestris n. sp. can be differentiated from all described root-knot nematode species, and it is clearly separated from other species with resemblance in morphology, such as M. ardenensis, M. dunensis and M. lusitanica. [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]

A new species of awl nematode, Dolichodorus mediterraneus sp. n., is described from southern Spain. The new species is described and illustrated by light microscopy and scanning electron microscopy studies from specimens collected in a sandy soil around roots of cork oak (Quercus suber L.) from Hato Raton, Aznalcázar (Seville), southern Spain. Dolichodorus mediterraneus sp. n. is characterised by a prominent, rounded, lip region, which is offset from the body and has four to six very fine annuli; lateral fields areolated with three lines, ending posterior to anus level; tail 72-122 μm long, abruptly tapering to an acuminate, often spicate, terminus; tail projection 51-79 μ m long; spicules ventrally arcuate, 33-42 μm long; gubernaculum slightly ventrally curved, 14-22 μm long. Scanning electron microscopy observations showed a similar en face pattern to other Dolichodorus spp. Molecular data from the ribosomal large subunit D2-D3 expansion segment of 28S rDNA from paratypes yielded a single fragment of approximately 800 bp. This is the first record of the genus Dolichodorus in Spain and only the second in Europe. A key to species is provided. [ABSTRACT FROM AUTHOR]

SEM studies on a Meloidogyne baetica population provided additional details of the external morphology for female, male and second-stage juveniles. The labial disc in female and male specimens is fused with the medial lips forming a single structure. In second-stage juveniles the lateral lips are triangular with rounded margins. The amphidial opening for all life stages appears oval to rectangular in shape and is located between the labial disc and lateral lips. Lateral fields of male and second-stage juveniles have four incisures irregularly areolated along the entire body. The results of a host-range study for additional natural hosts of M. baetica conducted in wild olive communities growing at Vejer de la Frontera (Cádiz province) in southern Spain are also reported. Apart from the type host, M. baetica was found to infect two natural woody host plants, lentisc (Pistacia lentiscus) and Aristolochia baetica. Hostparasite relationships in these new hosts confirmed the typical susceptible reaction observed in wild and cultivated olives. Similarly, the reproductive fitness, evaluated as the number of eggs per egg mass, was not significantly different in all plant hosts. No infections or galled roots were observed in herbaceous plant species studied and M. baetica must therefore be considered as a parasite of woody plants. [ABSTRACT FROM AUTHOR]

Simple Summary: Paratylenchus spp. are vermiform organisms distributed throughout the world that can parasitize a wide variety of cultivated and wild plants. Some species are considered pathogenic in crops; therefore, correct identification is essential to design management strategies. However, the conserved morphology, similarity of morphometric characters and other factors as co-occurrence of more than one species of Paratylenchus in the same soil sample hinder identification to species level. In consequence, this identification should be carried out jointly with morphological, morphometrical and molecular data. The present research aims to provide morphological and molecular characterization of some Paratylenchus species found in Spain and the description of several new species. In previous studies, fifteen species of Paratylenchus, commonly known as pin nematodes, have been reported in Spain. These plant-parasitic nematodes are ectoparasites with a wide host range and global distribution. In this research, 27 populations from twelve Paratylenchus species from 18 municipalities in Spain were studied using morphological, morphometrical and molecular data. This integrative taxonomic approach allowed the identification of twelve species, four of them were considered new undescribed species and eight were already known described. The new species described here are P. caravaquenus sp. nov., P. indalus sp. nov., P. pedrami sp. nov. and P. zurgenerus sp. nov. As for the already known described species, five were considered as first reports for the country, specifically P.enigmaticus, P. hamatus, P. holdemani, P. israelensis, and P. veruculatus, while P. baldaccii, P. goodeyi and P. tenuicaudatus had already been recorded in Spain. This study provides detail morphological and molecular data, including the D2-D3 expansion segments of 28S rRNA, ITS rRNA, and partial mitochondrial COI regions for the identification of different Paratylenchus species found in Spain. These results confirm the extraordinary cryptic diversity in Spain and with examples of morphostatic speciation within the genus Paratylenchus. [ABSTRACT FROM AUTHOR]