Labial Disc Research Articles

First Report of the Root-knot Nematode Meloidogyne incognita on Tomato in Cape Verde

Meloidogyne incognita is a serious pest of several economically important plants in tropical and subtropical regions. One such plant, tomato (Solanum lycopersicum L.), is one of the most widely grown vegetables on irrigated land in Cape Verde. In June 2015, tomato plants (cv. Savana) with symptoms of stunting, leaf wilting and poor fruiting, were recorded in a field in Achada Colaco, Santiago Island (15°06'35.3N, 23°31'31.9W). Roots of these plants were galled indicating the occurrence of root-knot nematodes. Detected nematodes were isolated and dissected from roots using standard procedures. Morphological and genetic studies revealed the presence of M. incognita. Female (n = 47) perineal patterns showed a high and squared dorsal arch composed of smooth to wavy striae; distinct lateral lines were absent. Stylet had cone curved dorsally, knobs broadly elongated and set off from the shaft. Males’ heads possessed a high and wide head cap with centrally concave labial disc. The measurements of males (n = 5)...

Integrative Taxonomy of Meloidogyne oryzae (Nematoda: Meloidogyninae) parasitizing rice crops in Southern Brazil

A root-knot nematode parasitizing rice (Oryza sativa L.) in Santa Catarina state (Brazil) was identified as Meloidogyne oryzae Maas, Sanders and Dede, 1978 using different approaches. The specimens studied from this Brazilian population were compared with the type description of M. oryzae from Suriname, with additional morphological, biochemical and molecular characterization. The female has a longer stylet (15.0 μm) when compared with M. graminicola (11.2 μm) with irregularly shaped knobs, vulva offset and slightly protruding in posterior region. The lip region was distinct from first body annuli, and labial disc and the medial lips form an anchor-shaped structure. Perineal patterns were similar to M. graminicola. The male has a lip region offset and the presence of few short and irregular lines; medial lips divided, not fused with labial disc and stylet (18.2 μm) longer than in M. graminicola (16.8 μm). Second-stage juvenile (J2) tail (75.8 μm) was longer than in M. graminicola (70.9 μm) with a very long narrow hyaline portion (22 μm in M. oryzae and 17.9 μm in M. graminicola). Biochemically, it presented a distinct esterase profile (Est O1=R1), differentiating it from M. graminicola (Est VS1). The number of chromosomes was 3n = 50–56, and in DNA sequences of ITS1–5.8S–ITS2 rRNA the two populations of M. oryzae clustered together with other mitotic parthenogenetic species, differentiating them from M. graminicola with n = 18 chromosomes and clustered with meiotic species. Phylogenetic analysis using neutral markers (AFLP and RAPD) showed that both M. oryzae populations form a coherent, closely related cluster separately from M. graminicola isolates. This study represented the first detection of M. oryzae in Brazil and the second in the world after the species description in 1971.

Description of a new species of the genus Caveonchus Siddiqi, 1982 (Nematoda: Dorylaimida) with diagnostic compendium and key to its species

Summary Caveonchus siddiqii n. sp. is described and illustrated based on specimens collected from both India and Japan. It is characterized by having a medium sized body (L= 0.86 - 1.12 mm); labial disc present; amphideal fovea flask-shaped; lip region cap-like, offset by slight constriction; odontostyle 8 - 9 μm, odontophore 10 - 12 μm; pharynx with slender anterior part which expands abruptly into the saccate basal bulb, occupying about 16 - 21 % of total neck length; female genital system mono-opisthodelphic; anterior genital branch 70 - 100 μm or 1.9 - 2.8 times the midbody diameter long; tail short, rounded, hemispheroid, 0.5 - 0.7 anal body diameter long; spicules 30 - 38 μm long; and three spaced ventromedian supplements. Its relationship with all the known species of the genus is discussed. A diagnostic compendium and a key to identification of the species is also provided.

First record of the root knot nematode, Meloidogyne minor in New Zealand with description, sequencing information and key to known species of Meloidogyne in New Zealand.

Meloidogyne minor Karssen et al. 2004 was collected from perennial ryegrass (Lolium perenne L.) growing in a sports ground in Christchurch, New Zealand. This is a new record for M. minor, the first report of this nematode occurring in New Zealand, and the second report from the southern hemisphere (after Chile). In general, the New Zealand isolate of M. minor corresponds well to the descriptions of M. minor given by Karssen et al. (2004). The New Zealand isolate is characterized by having a female with dorsally curved stylet, 13-14 μm long, with transversely ovoid knobs slightly sloping backwards from shaft; rounded perineal pattern; and male with stylet 16-19 μm long, large transversely ovoid knobs sloping slightly backwards from shaft; head region not set off, labial disc elevated, lateral lips prominent; and second stage juvenile 370-390 μm long, with hemizonid posterior but adjacent to excretory pore; tail 53-63 μm long; and a distinct hyaline tail terminus 14-18 μm long. In addition, molecular phylogeny using near full length small subunit (SSU), D2/D3 expansion segments of the large subunit (LSU), the internal transcribed spacer region (ITS1 and 2), and the intergenic spacer (IGS2) of the ribosomal rDNA supports the identification.

Characterisation of some Scutellonema species (Tylenchida: Hoplolaimidae) occurring in Botswana, South Africa, Costa Rica and the USA, with description of S. clavicaudatum sp. n. and a molecular phylogeny of the genus

The genusScutellonemacontains more than 40 species of spiral nematodes with enlarged phasmids called scutella. In this study, we provide morphological and molecular characterisation ofS. clavicaudatumsp. n.,S. brachyurus,S. bradys,S. cavenessi,S. transvaalense,S. truncatumandScutellonemasp. A. from North and Central America, and Africa. The new species,S. clavicaudatumsp. n., was found on sugarcane in South Africa and is characterised by a lack of lip annuli as inS. africanum,S. siamenseandS. truncatum. The lip region, in both males and females, is conical and marked by six large rectangular blocks separated or fused with the submedian and lateral lip sectors, which surround a round and distinct labial disc. Females of this new species also have large vaginal glands, a functional spermatheca, the lateral field posterior to the scutellum ending in a bluntly pointed shape and a clavate tail. Morphological descriptions, measurements, light and scanning electron microscopic photos and drawings are also given forS. bradys,S. cavenessi,S. transvaalenseandS. truncatum. The study of spiral nematode samples from Florida, USA, confirmed the presence of a morphologically and genetically atypical populations ofS. bradys. The morphology of theS. bradyspopulation from Bermuda grass in pasture land from central Florida fits that of type specimens of this species, but differs in having a truncate tail terminus rather than round and also a prominent spermatheca filled with flagellate spermatozoa. Other FloridaScutellonemasamples analysed in this study belonged toS. cavenessi, a species native to West Africa. This is the first report ofS. cavenessiin Florida, where it parasitises the ornamental plantSansevieria trifasciata. Our study showed a high level of intraspecific variation forScutellonemarRNA and mtDNA genes, which can reach 5.6% for the D2-D3 of 28S rRNA, 12.9% for the ITS rRNA genes and 14.4% for theCOIgene. Phylogenetic relationships withinScutellonemaare given as inferred from the analyses of the D2-D3 of 28S rRNA, ITS rRNA and theCOImtDNA gene sequences.

Description of two new and six known species of the genus Tylencholaimus de Man, 1876 (Nematoda: Dorylaimida) with a diagnostic compendium and key to species.

Two new and six known species of the soil-inhabiting nematode genus Tylencholaimus de Man, 1876 are described and illustrated. Tylencholaimus arakii sp. n. is characterized by having 0.56-0.65 mm long body; lip region cap-like, set off by a shallow constriction; labial disc present; odontostyle 7-8 µm and odontophore 7-8 µm long, with well-developed, asymmetrical basal knobs; total spear length 15 μm; pharynx with slender anterior part which expands abruptly into the cylindrical basal bulb occupying about 45-47% of total neck length; female genital system mono-prodelphic; transverse vulva and short, hemispheroid tail. Tylencholaimus ladakhiensis sp. n. is characterized by having 0.56-0.73 mm long, slender body; lip region cap-like, set off by a slight constriction; amphid aperture slit-like; odontostyle slender 7-9 µm, with comparatively narrow lumen, odontophore 8-9 µm long; pharynx with slender anterior part which expands abruptly into the cylindrical basal bulb, occupying about 38-45% of total neck length; female genital system didelphic-amphidelphic and rounded-conoid tail, with distinct terminal caudal pore. Tylencholaimus proximus Thorne, 1939; Tylencholaimus mongolicus Andrássy, 1967; Tylencholaimus vulvulatus Rahman, Jairajpuri, Ahmad & Ahmad, 1987; Tylencholaimus ibericus Peña-Santiago & Coomans, 1994; Tylencholaimus imperanus Mohilal & Dhanachand, 2003 and Tylencholaimus cosmos (Dhanam & Jairajpuri, 1999) Peña-Santiago, 2008 are redescribed. Tylencholaimus proximus and Tylencholaimus mongolicus are reported for the first time from India and a male is reported for the first time for T. imperanus. A diagnostic key and compendium to species of the genus Tylencholaimus is provided.

Description of Laimaphelenchus belgradiensis sp. nov. (Nematoda: Aphelenchoididae) and its phylogenetic and systematic position within Aphelenchoidoidea

Laimaphelenchus belgradiensis sp. nov. is described and illustrated, based on morphological, molecular and morphometric data. The new species belongs to the group of Laimaphelenchus species having a vulval flap. A unique combination of characters distinguishes this parthenogenetic species from others: annulated cephalic region; no labial disc; polygonal median bulb; offset tail terminus with four pedunculate tubercles in a square position that end in 10–12 finger-like protrusions. Morphologically, the new species resembles L. cocuccii and L. deconincki but differs from them by the body length, stylet length, distance from the anterior end to the median bulb, head annulations and tail shape. Bayesian phylogenetic analyses based on 18S and the D2/D3 segment of 28S rRNA genes were performed using sequences of species from 18 genera within the Aphelenchoidoidea. The resulting phylogenetic trees generated three distinct clades representing three families: Aphelenchoididae, Ektaphelenchidae and Parasitaphelenchidae. In the 18S tree L. belgradiensis sp. nov. forms a clade with L. penardi and in the 28S tree the new species is close to L. persicus and L. preissii.

A review of the taxonomy, phylogeny, distribution and co-evolution of Schistonchus Cobb, 1927 with proposal of Ficophagus n. gen. and Martininema n. gen. (Nematoda: Aphelenchoididae)

The purposes of this paper are to clarify the taxonomic status of the fig-pollinating wasp associateSchistonchussensu lato(Nematoda: Aphelenchoididae) and to suggest directions for future research on the systematics, life history and ecology of the group. Molecular phylogenetic analyses suggest thatSchistonchus s.l.is polyphyletic, and the composition of the three major clades is outlined, together with information on nematode morphology, plant host species, associated pollinating wasp species, and distribution. Biological information and collection data is presented forSchistonchus s.l.fromFicussycones (Moracea) in Africa, Australia, Asia and Central America, and its putative phylogeny is discussed based on molecular and morphological evidence. Both wasps and figs are millions of years old and have worldwide distribution in tropical areas,i.e., opportunities forSchistonchus s.l.-like nematodes to have evolved could have occurred more than once. In addition, figs and their pollinating wasps have variable life histories, which could have provided opportunities forSchistonchus s.l.to also develop different life histories. However, these histories occur inside fig sycones and in association with wasps, which has apparently led to evolutionary convergence and extreme morphological conservatism. Diagnostic characters and their states, derived from examination of described species and morphospecies ofSchistonchus s.l.and informed by molecular phylogenetic inferences, are discussed and illustrated.Schistonchus sensu strictois redefined, andFicophagusn. gen. andMartinineman. gen. are proposed.Schistonchus s.s.is morphologically characterised by having the excretory pore opening in the region of, or posterior to, the metacorpus;Ficophagusn. gen. by having the excretory pore opening very near the cephalic region; andMartinineman. gen. by having it opening at the anterior end of the metacorpus. Several species ofSchistonchus s.s.have a labial disc, but there is no evidence of this in eitherFicophagusn. gen. orMartinineman. gen.

Morphological and karyotypic differences within and among populations of Radopholussimilis.

Twenty populations of Radopholus similis from three countries and different hosts (19 populations from ornamental plants and one population from ginger) were compared using morphological characters, morphometrics and karyotype between progeny from both single females and 30 females of each population. Morphological diversity existed in and among the populations, even within the progeny nematodes from single nematodes compared to that of 30 females. The labial disc shape, the number of head annuli, the terminated position of lateral lips, the number of genital papillae before cloacal apertures and female and male tail terminal shape showed variation. In addition, genital papillae arranged in a double row before cloacal apertures was first found in two ornamental populations. The karyotype of all the 20 populations was n = 5. Combining our results and previous studies, we support that Radopholus citrophilus is a synonym of Radopholus similis, and that it is not possible to distinguish physiological races or pathotypes of Radopholus similis according to morphological characters or karyotype.

Morphological and molecular characterization of Laimaphelenchus deconincki (Nematoda: Aphelenchoididae) based on specimens from Iran

During a survey for nematodes associated with conifers in northern Iran, a known species of Laimaphelenchus was found in the bark samples of Taxus baccata L. trees and is described and illustrated here as L. deconincki Elmiligy & Geraert, 1972. It is characterized by lacking a distinct labial disc on the cephalic region; having six amalgamated labial sectors of equal width, separated by pairs of well-developed ribs; three lines in lateral field; the presence of a vulva flap; vagina surrounded by a cuticularised tube in which the walls vary in thickness; the post-uterine sac 25–62 μm long; tail with a single stalk-like terminus and four pedunculate tubercles; and absence of males. L. deconincki is morphologically very similar to L. cocuccii, but differs in the shape of the vaginal musculature (more angular vs round). Additional information on morphological characters and also the phylogenetic relationships of this known species using sequences of the D2/D3 region of the 28S ribosomal RNA gene is provided and added herein.

Meloidogyne luci n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitising different crops in Brazil, Chile and Iran

A new root-knot nematode parasitising vegetables, flowers and fruits in Brazil, Iran and Chile, is described as Meloidogyne luci n. sp. The female has an oval to squarish perineal pattern with a low to moderately high dorsal arc and without shoulders, similar to M. ethiopica. The female stylet is robust and 15-16 μm long; the distance from the dorsal pharyngeal gland orifice to the stylet base (DGO) is 3-4 μm. Males have a high, rounded head cap continuous with the body contour. The labial disc is fused with the medial lips to form an elongated lip structure. The head region is not marked by incomplete annulations. Male stylet robust, 20.8-23.0 μm long with rounded knobs; the DGO is 2.5-4.5 μm. The stylet of second-stage juveniles (J2) is 12.0-13.5 μm long and the DGO to the stylet base is 2.3-3.3 μm. The J2 tail is conoid with finely rounded terminus and is 40.0-48.5 μm long. Biochemically, the esterase phenotype L3 (: 1.05, 1.10, 1.25) is unique and is the most useful character to differentiate M. luci n. sp. from all other Meloidogyne species. Reproduction is by mitotic parthenogenesis (2n = 42-46 chromosomes). In a differential host test, the population from Lavandula spica, Caxias do Sul, RS State, Brazil, reproduced on tomato cv. Rutgers, tobacco cv. NC95 and pepper cv. California Wonder. No reproduction occurred on watermelon cv. Charleston Gray, cotton cv. Deltapine 61 or peanut cv. Florunner. In Neighbour-Joining analyses of ITS and D2-D3 rRNA sequences, populations of M. luci n. sp. from Brazil, Chile and Iran clustered together and were clearly separated from other Meloidogyne spp., thus confirming that all three populations are very similar and conspecific.

A new and three known species of the genus Tylencholaimellus Cobb in M.V. Cobb, 1915 (Nematoda: Dorylaimida) from Changbai Mountain, China

A new and three known species of the genus Tylencholaimellus Cobb in M.V. Cobb, 1915 are described from ChangbaiMountain, Northeast China. Tylencholaimellus sinensis n. sp. species is characterized by having a medium sized body (L=1.1–1.3 mm); outer cuticle with fine transverse striations; inner layer distinctly striated; radial refractive elementsabundant; labial disc absent; lip region offset by constriction; lips rounded and amalgamated; odontostyle 18–19 µm,odontophore 7–8 µm, combined length 25–27μm; anterior uterine sac 0.8–1.6 mid body diameters long; mono-opisthodelphic female genital system with small anterior uterine sac; transverse vulva and short conoid tail.Tylencholaimellus striatus Thorne, 1939, T. montanus Thorne, 1939 and T. cinctus Orr & Dickerson, 1965 are described for the first time from this region of the world.

First record of the genus Discotylenchus Siddiqi, 1980 (Nematoda: Tylenchidae) from Iran, with description of one new and data on two known species

The genus Discotylenchus is reported for the first time from Iran. Discotylenchus iranicus n. sp. is described and illustratedbased on morphological and morphometric characters. The new species is characterized by a combination of the followingmorphological features: lip region continuous and smooth, tapering to an offset prominent labial disc, lateral field withfour incisures, stylet length of 14–15μm, vulva position at 70.8–76.5 %, tail length of 81–100μm, conoid with a roundedtip and presence of males. The Iranian population of D. brevicaudatus shows a wider morphometric range compared tothe original description and the male of this species is described for the first time. The morphological characters and range of morphometric data of D. discretus are in full agreement with the original population.

New data on Labronemella labiata Andrássy, 1985 (Dorylaimida: Qudsianematidae) from Iran, with SEM study and a compendium of the genus

Labronemella labiata, the type species of its genus, is described after studying an Iranian population. An emendeddiagnosis of the species is provided, with new morphological and morphometrical features. The lip region, the mostdistinctive character of Labronemella is observed under SEM by the first time and its detailed morphology elucidated.Anterior surface (oral field) appears distinctly sunken and with its inner (perioral) area differentiated in six large, separatedliplets protruding on oral field. The lateral, perioral liplets are trapezoidal and visibly larger than subdorsal and subventralones, which are triangular, consequently the lip region shows a bi-radial symmetry. Inner labial papillae migrate to themargin of labial disc, being located close to outer labial and cephalic papillae. The systematics of Labronemella is brieflydiscussed, including diagnosis, updated list of species, key to their identification as well as a compendium of their main measurements and morphometrics.

Three new and a known species of Tylencholaimoidea (Nematoda: Dorylaimida) from Singapore

Three new and a known species of soil-inhabiting nematodes belonging to the superfamily Tylencholaimoidea Filipjev, 1934 are described and illustrated from Singapore. Tantunema enigmatum n. sp. is characterised by having 0.33–0.41 mm long body; angular, distinctly offset lip region; well developed circumoral sclerotization; odontostyle slender with aperture about one-fourth of its length; simple rod-like odontophore; anterior part of pharynx slender, weakly muscular, expanding abruptly into a cylindroid basal bulb, constriction present between two parts of pharynx; expanded portion divisible into a short conical, less muscular anterior part and a posterior muscular cylindrical part with thickened inner lining; lumen of the posterior one-third of expanded portion distinctly widened and thickened; mono-opisthodelphic female genital system and short hemispheroid tail. Dorella shamimi n. sp. is characterised by having 0.58–0.62 mm long body; continuous lip region with indistinct labial papillae; labial disc absent; 10–10.5 µm long odontostyle with a large pad-like muscular structure attached on ventral side of posterior half of its length extending to the anterior part of the odontophore; odontophore asymmetrical with round, transparent, knob-like thickening; pharynx with a short terminal oval bulb; mono-prodelphic female genital system with a short post-uterine sac; short conoid tail, with rounded terminus, and males with 18–18.5 µm long, simple arcuate spicules and a single ventromedian supplement. Tylencholaimus singaporensis n. sp. is characterized by having 0.35–0.47 mm long body; distinctly offset, cap-like lip region, 4.5–5.5 µm long, slender odontostyle, simple rod-like odontophore with small but distinct basal knobs, pharyngeal expansion abrupt, mono-prodelphic genital system with no post-uterine sac, and short hemispheroid tail with distinct terminal caudal pore. Tylencholaimus intermedius Peña-Santiago & Coomans, 1996 is reported for the first time from Singapore.

Epidemics of Meloidogyne brasilensis in Central Brazil on Processing Tomato Hybrids That Have the Root-Knot Nematode Mi Resistance Gene.

The species Meloidogyne brasilensis Charchar & Eisenback 2002 was described as causing root rot, severe wilt, and numerous galls in pea (Pisum sativum L.) in Brasília-Federal District and tomato (Solanum lycopersicum L.) cv. Rossol (known to have the root-knot nematode resistance Mi gene) in Londrina-Paraná State, Brazil. To our knowledge, this current work is the first report of the epidemics on tomato hybrids that have the Mi gene caused by infection of M. brasilensis in central Brazil. Samples were obtained from fields with two commercial hybrids that have the Mi gene ('Calroma' and 'Nemapride') that were cultivated under center-pivot irrigation in Silvânia, Goiás State. These hybrids exhibited slow vegetative development and malformed roots because of the high number of large galls. Symptomatic plants were collected from a tomato crop area of more than 100 ha. Random sampling indicated field sectors with up to 100% of symptomatic plants. Morphological and morphometric evaluations of this Meloidogyne population were carried out with the female perineal pattern, stylet, and excretory pore and also with the male body traits, labial disc, and stylet. The esterase phenotype was unique for this population with four clear bands (J. M. Charchar, unpublished data). Altogether, the morphological and biochemical characteristics of this population were in agreement with that reported for M. brasilensis (1). Koch's postulates were fulfilled using tomato 'Rutgers' (susceptible) and 'Rossol' (with the Mi resistance locus) under greenhouse conditions. The massive use of tomato hybrids with the Mi gene could be a strong selection factor favoring this pathogen under growing conditions in central Brazil. Germplasm screen searching for sources of resistance specific to this nematode species is advisable. Reference: (1) J. M. Charchar and J. D. Eisenback. Nematology 4:629, 2002.

Molecular variability and phylogeny of Schistonchus caprifici (Gasperrini, 1864) Cobb, 1927 (Nematoda: Aphelenchoididae) from Italy and Spain

Abstract Molecular characterisation of four Schistonchus caprifici populations (two from Spain and two from Italy), using the partial 18S, the D2-D3 expansion segments of 28S of ribosomal DNA (rDNA) and the partial mitochondrial gene for cytochrome c oxidase I (mtCOI), is provided. Amplicons from partial mtCOI were analysed using 'Single Strand Conformation Polymorphism' (SSCP) analysis in order to rapidly screen for genetic (haplotypic) variability. SSCP analysis of mtCOI revealed a close relationship between the Spanish and Italian populations with low intra-population variability and only two haplotypes were detected. Mitochondrial COI and ribosomal genes were analysed using Maximum Likelihood and Bayesian inference to reconstruct phylogenetic relationships within S. caprifici and other members of the family Aphelenchoididae. The phylogenetic analysis based on mtCOI showed no geographic variability among Italian, Spanish and Turkish populations. The results of phylogenetic analyses based on the D2-D3 expansion segments of 28S rDNA region and the partial 18S rDNA genes revealed a closer phylogenetic relationship between S. aureus, S. laevigatus, S. virens and S. centerae, whilst S. caprifici and S. guangzhouensis clustered separately. The phylogeny of the genus Schistonchus was well related to some morphological characters, such as position of excretory pore, presence/absence of labial disc and number and position of caudal papillae. The monophyly of the genus Schistonchus was rejected by the Shimodaira-Hasegawa test based on tree topologies.

Meloidogyne phaseoli n. sp. (Nematoda: Meloidogynidae), a root-knot nematode parasitising bean in Brazil

AbstractMeloidogyne phaseoli n. sp. is described and illustrated from specimens parasitising bean cv. Carioca in Brasilia, Brazil. The perineal pattern of the female is rounded to oval-shaped with a dorsal arch that is flattened to moderately high and squarish, sometimes with rounded shoulders. The striae are moderately spaced and often distinctly forked in the lateral field. The female stylet is 14-19 μm long and has broad, distinctly set-off knobs and several small, rounded projections on the shaft. The excretory pore opens 34-82 μm from the head near the level of metacorpus. Males are 999-2105 μm in length and have a high, wide head cap that slopes posteriorly. The labial disc and medial lips are partially fused to form an elongated lip structure. The robust stylet is 20-26 μm long and has wide knobs that are distinctly set-off from the shaft which is marked by several small, round projections. Mean second-stage juvenile length is 464 μm. The head region is not annulated and the large labial disc and crescent-shaped medial lips are fused to form a dumbbell-shaped head cap. The stylet is 10.5-12 μm long and has rounded, posteriorly sloping knobs. The slender tail, 46-64 μm long, has large irregular-sized annules in the posterior region and a slightly rounded tip. The hyaline tail terminus is long, 10.5-19.3 μm. The esterase isozyme is a unique E3 phenotype having one weak and two strong bands. Tomato, tobacco, bean and pea are good hosts, corn is a very poor host, whilst pepper, watermelon, peanut, cotton and soybean are non-hosts.

Synonymy of Afenestrata with Heterodera supported by phylogenetics with molecular and morphological characterisation of H. koreana comb. n. and H. orientalis comb. n. (Tylenchida: Heteroderidae)

Abstract Phylogenetic analysis of five gene fragments: ITS-rRNA, D2 and D3 of 28S rRNA, 18S rRNA, Hsp90 and actin, of Heterodera species and two representative Afenestrata species, A. koreana and A. orientalis, form a clade with H. cynodontis, H. bifenestra and an unidentified Heterodera sp. infecting grasses. Based on these results and the consideration that the key diagnostic characters of Afenestrata are convergent and do not define a clade, synonymisation of Afenestrata with Heterodera is proposed. The following new combinations are made: H. africana comb. n., H. axonopi comb. n., H. koreana comb. n., and H. orientalis comb. n. Furthermore, H. (= Afenestrata) sacchari is renamed as H. saccharophila nom. nov. to avoid homonymy. All these species, together with H. bamboosi, are regarded as members of a paraphyletic ‘Afenestrata group’ within Heterodera. Whilst recognised as artificial, the Afenestrata group is nevertheless an aid to discussion about these similar species. Morphological and molecular characterisation of populations of H. koreana comb. n. from Florida and H. orientalis comb. n. from Florida and Guatemala verify the identification of these populations as valid representatives for molecular studies of the species. Light and SEM observations also provide new detail and a broader understanding of the morphological range of both species. These include a longer stylet for females of H. koreana comb. n. and H. orientalis comb. n. than reported in the original descriptions. In addition, previously unreported tuberculate ridges are noted on the surface of vulval lips of H. orientalis comb. n. The lip region of second-stage juveniles of H. koreana comb. n. and H. orientalis comb. n. both include fused adjacent submedian lips that also fuse with the labial disc and the second lip annulus. The ITS-rRNA gene sequences of H. orientalis comb. n. populations from Florida and Guatemala were similar to those from the Russian type locality. Diagnostic PCR-RFLP of ITS-rRNA profiles with six enzymes for H. orientalis comb. n. and H. koreana comb. n. are given. A key for the morphological identification of species of the Afenestrata group is provided.

Additional information on Meloidogyne inornata Lordello, 1956 (Tylenchida: Meloidogynidae) and its characterisation as a valid species

Abstract A root-knot nematode parasitising yakon (Polymia sonchifolia) in São Paulo State, Brazil, is identified as Meloidogyne inornata. The species is redescribed from this material and compared with the original description of M. inornata. The female perineal patterns have a distinct, high, dorsal arch composed of smooth to wavy striae, similar to Meloidogyne incognita. The female stylet is 15.0-17.0 μm long with the cone generally slightly curved dorsally and with well developed knobs. DGO is 3.5-4.5 μm. Males have a high, rounded, head cap that is continuous with the body contour and has a large, round, centrally concave, labial disc raised above the medial lips. The head region is never marked by incomplete annulations and the stylet is robust, 20.0-25.0 μm long, with a straight cone, cylindrical shaft with several small projections and pear-shaped, backwardly sloping knobs. The stylet length of second-stage juveniles is 10.0-13.0 μm, DGO is 2.5-3.5 μm, tail length is 35.0-58.0 μm and c = 6.7-13.9. Biochemically, the esterase phenotype I3 (= Y3) is species-specific and is the most useful character for differentiating M. inornata from other Meloidogyne species. Reproduction is by mitotic parthenogenesis, 3n = 54-58. In a soybean test, cv. Abura was susceptible and cv. LA411219 was highly resistant. As the type material is lost, a neotype female is formally designated.