Lip Annuli Research Articles

A new ring nematode, Xenocriconemella costaricense sp. nov., (Nematoda: Criconematidae) from Costa Rica.

During nematode surveys of natural vegetation in forests of La Cima de Copey de Dota, San José, San José province, Costa Rica, a Xenocriconemella species closely resembling X. macrodora and related species was found. Integrative taxonomical approaches demonstrated that it is a new species described herein as X. costaricense sp. nov. The new species is parthenogenetic (only females have been detected) and characterised by a short body (276-404 μm); lip region with two annuli, not offset, not separated from body contour; first lip annulus partially covering the second lip annulus. Stylet thin, very long (113-133 μm) and flexible, occupying 30.5-47.8% of body length. Excretory pore located from one or two annuli anterior to one or two annuli posterior to level of stylet knobs, at 42 (37-45) μm from anterior end. Female genital tract monodelphic, prodelphic, outstretched, and occupying 35-45% of body length, with vagina slightly ventrally curved (14-18 μm long). Anus located 6-11 annuli from the tail terminus. Tail conoid and bluntly rounded terminus, the last 2-3 annuli oriented dorsally. Results of molecular characterisation and phylogenetic analyses of D2-D3 expansion segments of 28S rRNA, ITS, and partial 18S rRNA, as well as cytochrome oxidase c subunit 1 gene sequences further characterised the new species and clearly separated it from X. macrodora and other related species (X. iberica, X. paraiberica, and X. pradense).

First Report of the Root-Lesion Nematode (Pratylenchus thornei Sher and Allen, 1953) Parasitizing Oats in Gansu Province, China.

First Report of the Root-Lesion Nematode (Pratylenchus thornei Sher and Allen, 1953) Parasitizing Oats in Gansu Province, China.

A new plant-parasitic nematode species associated with coffee, Rotylenchus bunae n. sp. (Nematoda: Hoplolaimidae) from Jimma, Ethiopia

Summary Rotylenchus bunae n. sp. was discovered in the coffee rhizosphere in Gera district of Jimma, Ethiopia, and has been morphologically and molecularly characterised. The new species is identified by a female body length of 725-876 μm, hemispherical lip region with 4-5 lip annuli, stylet length of 28-30 μm, lateral field areolation only in the pharyngeal region, no cuticular striations, pharyngeal gland overlapping intestine dorsally by 15-26 μm, double epiptygma, no clear spermathecae, vulva position at 54-58% of body length from anterior end, prominent fasciculi in mid and posterior body, rounded or sometimes slightly truncated, coarsely crenated tail with 11-13 annuli, and phasmids located at 7-16 annuli anterior to anus. No males were detected. This species was found closely related to other African Rotylenchus species, such as R. unisexus and R. wimbii; however, it could be well separated from them by both morphology and molecular data (D2-D3 of 28S and partial 18S of rDNA).

Description of Hemicycliophora geraerti n. sp. (Tylenchida: Hemicycliophoridae) associated with Prunus persica L. from China

Summary Hemicycliophora species are migratory root ectoparasites of higher plants, commonly known as sheath nematodes. The present study describes a new species, Hemicycliophora geraerti n. sp., recovered from the rhizosphere of peach tree (Prunus persica) in Zhejiang Province, China. This species is characterised by a cuticular sheath loosely fitting to the body, a lip region slightly set-off with body contour bearing 3-4 annuli, oral plate narrow, ovate, and non-protruding, amphidial apertures plugged, dorsoventrally flanked in the first lip annulus, stylet 110 (103-116) μm long and flexible, excretory pore located 4-7 annuli posterior to the base of the pharyngeal bulb; vulval lips modified with a small vulval sleeve, anus located 16 (13-21) annuli posterior to vulva, tail elongated, having a narrowly rounded slightly offset spike. The molecular characterisation and phylogenetic analyses based on D2-D3 expansion segments of the 28S rRNA, ITS rRNA, and COI mtDNA gene indicated the unique status and support the novelty of this population of Hemicycliophora, therefore herein described as H. geraerti n. sp.

Occurrence of Root-Lesion Nematode Pratylenchus coffeae on Corn in Xinjiang Uygur Autonomous Region, China.

Pratylenchus coffeae Filipjev & Schuurmans Stekhoven, 1941, is one of the most important root-lesion nematodes (RLN) parasitizing many agronomic and industrial crops (Wang et al. 2021). Corn (Zea mays L.) is one economically important crop in China, with 35 million hectares cultivated annually (Li et al. 2019). In July 2019, a survey of RLN was carried out in corn field planting with cultivar Heyu 187 in Chuanba village in Qitai County, Xinjiang Uygur Autonomous Region, China. Five root/soil samples were collected from poor growing plants with distinct brown lesions. Nematodes were extracted from the collected root/soil samples with the modified Baermann funnel method (Hooper et al. 2005). The average of 157 RLN per 100 cm3 of soil and 43 RLN per gram of fresh root were extracted. The obtained RLN were sterilized with 0.3% streptomycin sulfate and cultured on carrot disks at 25°C. Twenty petri dishes with carrot disks, each inoculated with one female. The morphological and molecular characteristics of RLN cultured on carrot disks were examined for species identification. Morphological measurements of adult females (n=15) included body length (range = 529.0 to 658.0 μm, mean = 571.0 μm), head with two lip annuli, stylet (15.5 to 17.0 μm, 16.0 μm), tail length (27.5 to 32.5 μm, 30.5 μm), a (23.8 to 32.9, 28.5), b (5.8 to 7.1, 6.5), c (16.5 to 23.4, 18.9), and V (76.6 to 83.1%, 80.8%). Morphological measurements of adult males (n=15) were body length (range = 479.5 to 568.0 μm, mean = 516.0 μm), head with two lip annuli, stylet (14.5 to 15.5 μm, 15.0 μm), tail length (24.0 to 29.0 μm, 26.0 μm), spicule length (16.4 to 19.0 μm, 17.5 μm), gubernaculum length (4.4 to 5.3 μm, 4.9 μm), a (29.2 to 32.5, 31.0), b (5.7 to 6.9, 6.2), and c (18.2 to 22.6, 19.8). The morphological characters of this population are consistent with the description of P. coffeae (Castillo and Vovlas, 2007). Nematode DNA was extracted from an individual female. The primers of D2A/D3B (5'-ACAAGTACCGTGAGGGAAAGTTG-3'/5'-TCGGAAGGAACCAGCTACTA-3') (Subbotin et al. 2006) and 18S/26S (5'-TTGATTACGTCCCTGCCCTTT-3' / 5'-TTTCACTCGCCGTTACTAAGG-3') (Vrain et al. 1992) were used to amplify the D2/D3 expansion region of the 28S rRNA gene and the rDNA internal transcribed spacer (ITS) region, respectively. The PCR products were purified and transformed to E. coli strain DH5α, and then sequenced by Sangon Biotech Co. Ltd. (Shanghai, China). The obtained sequences of the D2/D3 region (793 bp) and the ITS region (1,242 bp) were submitted to GenBank, and the accession numbers for D2/D3 region were OK103614 and OK103619 which had 98.6% and 100% identity with the reported P. coffeae sequences (KC490925); the two obtained ITS sequences accession numbers OK103603 and OK103613) had more than 99% identity with published P. coffeae sequences from GenBank (e.g., LC030410, LC030395, MH134508 and LC030380). Hence, both morphological and molecular data demonstrated the presence of P. coffeae. To further confirm reproduction on corn, the obtained RLN population was used to inoculate corn plants in 2-liter pots containing 1.8-liter sterilized and mixed soil with 2 pastoral soil: 1 substrate in greenhouse at 27°C. About 15 days after sowing, each pot with one corn plant (cv. Heyu 187) with the same growth status was selected to inoculate P. coffeae. Five small holes near the roots were made using a glass rod. Approximately 1,000 mixed stage nematodes of P. coffeae were then pipetted into the holes of each plant. Eight replications were performed. Eight additional pots of uninoculated corn plants were used as control. After 2 months, corn roots were washed and brown lesions were observed on roots. The average number of RLN/pot was approximately 5,030 in soil and 2,870 in roots, and each pot had an average of 7.9 reproduction factors (final population/initial population), indicating that this nematode population infects and reproduces well on this corn cultivar. No nematodes and symptoms was detected in the control pot. The nematode of P. coffeae has only been reported on corn in Guangdong, Liaoning, Shangdong and Henan Provinces in China (Liu et al. 1996; Liu et al. 2001; Xia et al. 2021). To our knowledge, this is the first report of P. coffeae infecting corn in Xinjiang Uygur Autonomous Region of China. Since RLN can cause considerable damage to corn, one of the most important food crops produced in China, strategic measures should be taken to prevent the spread of P. coffeae to other regions.

New taxonomic information of Cryphodera kalesari (Nematoda: Heteroderidae)

Summary A population consisting of only second-stage juveniles of Cryphodera kalesari (Nematoda: Heteroderidae) was detected in the rhizosphere of bamboo in a forest in Mizoram state of India. New taxonomical information is provided for the juveniles, including the first light microscopy and scanning electron microscopy images. The juveniles are characterised by a body length of 0.3-0.4 mm, lateral field with three longitudinal incisures forming two areolated bands, a well-sclerotised and offset lip region with three lip annuli, a robust and strong stylet measuring 25-28 μm in length, anteriorly flat to slightly concave knobs, a secretory-excretory pore often at isthmus level, a conoid tail 47-52 μm long tapering to a narrow rounded terminus, a pore-like phasmid, and a distinct hyaline portion of the tail occupying roughly half of the tail length. The first molecular data of C. kalesari (sequences of 18S and D2-D3 of 28S rRNA genes and COI gene of mtDNA) were found to be almost identical to that of an unidentified Cryphodera sp. reported from Myanmar, Thailand and Vietnam, indicating that C. kalesari is widespread across south-east Asia.

Pratylenchus smoliki, a new nematode species (Pratylenchidae: Tylenchomorpha) from the Great Plains region of North America.

Pratylenchus smoliki is a new species of root-lesion nematode described from corn-soybean production fields in the Central Great Plains of North America. It is characterized by populations with relatively abundant males, two lip annuli, females with a round functional spermatheca and a conoid to subcylindrical tail with a non-crenate, smooth terminus. In host preference tests, corn and wheat produce the largest nematode populations, whereas sorghum and soybeans produce less than 20% the numbers observed on corn. Scanning electron microscopy reveals that the en face patterns compare to those seen in Pratylenchus pseudocoffeae, P. scribneri, P. hexincisus, and P. alleni. The pattern is described as rectangular to trapezoidal subdorsal and subventral lips adjoining oral disc, but with a clear demarcation between the oral disc and the subdorsal and subventral sectors. A Maximum Likelihood COI tree recognizes P. smoliki as a moderately-well-supported clade with several haplotype subgroups. A Maximum Likelihood partial 28S tree provides strong support for the P. smoliki clade and reinforces the close relationships between species with similar en face patterns. Topotype specimens of P. alleni were demonstrably different from P. smoliki using DNA markers. The geographic range of P. smoliki overlaps with the ranges of P. alleni, P. scribneri, P. neglectus, P. hexicisus, and P. dakotaensis. The observed host range (corn, rye, sunflower, and wheat) suggests that P. smoliki may be native to the tallgrass prairie region of the Great Plains.

A new cystoid nematode, Cryphodera japonicum n. sp. (Nematoda: Heteroderidae), from the rhizosphere of Japanese Podocarpus macrophyllus

Summary Cryphodera japonicum n. sp., detected at Ningbo port, China, from the rhizosphere of imported Japanese Podocarpus macrophyllus, is described. The new species is characterised by females with a globose body, protruding vulval lips, slightly concave anus-vulva profile, a stylet length of 37.2 (31.1-41.3) μm and a vulva-anus distance of 38.1 (34.7-44.1) μm. Males possess two lip annuli, a stylet length of 27 (22.5-30.6) μm long, three lines in lateral fields and a spicule 21.5 (19.1-23.0) μm long. Second-stage juveniles have bodies 543 (506-588) μm long, three lip annuli, a stylet 31.7 (29.2-34.5) μm long, three lines in the lateral fields, a conoid tail with a narrow rounded terminus, and a relatively long hyaline region occupying half of the tail length. Phylogenetic analyses based on the D2-D3 expansion segments of the 28S, ITS, partial 18S rRNA, and COI gene revealed the unique position of this species with other heteroderid nematodes, supporting its status as a new species of Cryphodera. The new species showed a close relationship with C. brinkmani.

Morphological characterisation and molecular phylogeny of several species of Criconematina (Nematoda: Tylenchida) associated with turfgrass in Korea, as inferred from ribosomal and mitochondrial DNA

Summary Six species belonging to the Criconematina, including a morphologically cryptic population within the Mesocriconema curvatum-group, are characterised based on integrative taxonomy based on morphological and molecular phylogenetic inferences from analyses of the 28S-rRNA, ITS-rRNA and COI gene sequences. Mesocriconema sp. 1 is morphologically similar to M. nebraskense and M. curvatum, differing from M. curvatum by the occasional presence of 1-2 anastomoses and a relatively higher R value, and from M. nebraskense by only a narrowed first lip annulus. However, based on COI gene sequence analysis, significant differences among the three species are evident. The sequence information in the COI gene among Mesocriconema spp. continues to reveal the existence of cryptic species within well-established species designations, and the concept of Molecular Operational Taxonomic Units might be helpful in grouping the different lineages according to sequence identities. Mesocriconema nebraskense is detailed herein for the first time outside the USA. DNA sequences of Hemicycliophora labiata were similar to those in GenBank while the existence in Korea of M. curvatum, Hemicriconemoides brachyurus and Paratylenchus nanus is molecularly confirmed.

Discovery of Root-Lesion Nematode, Pratylenchus coffeae, Infesting Sesame in China

Sesame (Sesamum indicum L.) is one of the most important oil crops in China. Root-lesion nematodes (Pratylenchus spp.) are one of the most important groups of plant-parasitic nematodes parasitizing many crops. In September 2017, a survey of root-lesion nematodes was carried out in a sesame field in Xuchang city, Henan Province of China. Samples from six plants of sesame cultivar Zhengzhi No.15 were collected about 20 days before harvest. The collected plants were growing poorly with roots that showed distinct brown lesions. Nematodes were extracted using the modified Baermann funnel method (Hooper et al. 2005). Root-lesion nematodes were found in four samples, with the average nematode population density of 461 ± 211.9 nematodes/1 kg of soil and 39 ± 12.3 nematodes/1 g of root. The extracted nematodes were cultured and reared on carrot disks to obtain the nematode inoculum. Seeds of sesame cultivar Zhengzhi No.15 were sown in 1.5-liter pots containing 1.2 liters of sterilized soil. About 25 days after sowing, eight seedlings, one per pot, were inoculated with 2,000 nematodes and maintained in a greenhouse at 25°C. Eleven weeks later, the plants were harvested, and brown lesions were observed on roots. Nematodes from soil and roots were extracted as described above. The final number of root-lesion nematodes averaged 4,316 ± 894.9 in soil and roots, and the reproduction rate was 2.2 ± 0.4. Nematodes were identified morphologically and molecularly. Morphological measurements of females (n = 17) included body length (range = 533.0 to 645.0 μm, mean = 602.0 μm), two lip annuli, stylet (15.0 to 17.0 μm, 16.0 μm), tail length (26.0 to 34.5 μm, 30.5 μm), a (24.2 to 34.6, 27.8), b (5.2 to 6.9, 6.2), c (18.1 to 21.0, 19.7), and V (79.4 to 82.2%, 80.8%). Measurements of males were (n = 17): body length (range = 451.5 to 571.0 μm, mean = 509.5 μm), two lip annuli, stylet (14.5 to 15.5 μm, 15.0 μm), tail length (23.0 to 29.5 μm, 26.0 μm), spicule length (16.5 to 19.0 μm, 18.0 μm), gubernaculum length (4.5 to 5.5 μm, 5.0 μm), a (27.0 to 33.9, 30.9), b (5.6 to 6.6, 6.0), and c (18.3 to 21.3, 19.7). The morphological characters of this population were consistent with those described for Pratylenchus coffeae (Castillo and Vovlas 2007). DNA was extracted from four individual females according to the method of Wang et al. (2011). The rDNA-internal transcribed spacer (ITS) region was amplified by primers 18S and 26S (Vrain et al. 1992). Four ITS sequences were obtained with the length of 1,248 to 1,254 bp. The D2/D3 expansion region of the 28S rDNA was amplified by primers D2A and D3B (De Ley et al. 1999). Four 781-bp D2/D3 sequences were obtained. The polymerase chain reaction products were purified and sequenced. The newly obtained sequences were deposited in GenBank. These ITS sequences (accession nos. MH729035, MN227241, MN588279, and MN588280) showed 99% similarity to several P. coffeae sequences available in GenBank (e.g., KY424205, KC218572, KR106219, and KC244205). The D2/D3 region of the 28S rDNA sequences (MH730447, MN227243, MN588282, and MN592778) showed 99 to 100% similarity to several P. coffeae sequences available in GenBank (e.g., MK829009, KY424274, KY424272, and HM469434). P. coffeae has a wide host range and is widely distributed in China (Jiang et al. 2010). However, there is no report on sesame as a host of Pratylenchus in China. Both morphological and molecular data obtained from this study confirmed the presence of P. coffeae on sesame in Xuchang, China. To our knowledge, this is the first report of P. coffeae on sesame in China.

Description of Hirschmanniella dicksoni n. sp. (Nematoda: Pratylenchidae) from rhizosphere soil of limpograss from Florida, USA

Abstract Hirschmanniella dicksoni n. sp. isolated from the rhizosphere soil of limpograss is described and illustrated based on morphology and molecular characters. The new species is characterized by its body length, 1,582 to 1,929 µm, hemispherical lip region with 6 to 7 annules, stylet length 19 to 21 µm, irregularly areolated lateral fields, oval spermatheca filled with rounded sperm, intestine not overlapping the rectum, and tail length 103 to 149 µm, usually with ventral projection with subterminal notch. Males are similar to the females except for their shorter body length and presence of secondary sexual characteristics, with spicules length 19 to 30 µm. The new species is closely related with H. mucronata, H. belli, and H. oryzae. Compared with these three species, the new species has a relatively longer tail and a terminus shape tail with a ventral projection with a subterminal notch. Other morphological and morphometric characteristics that separate these species are as follows: lip region, number of lip annuli, and spicules length. Molecular sequence analysis using the D2–D3 expansion segments of 28S and the ITS rRNA sequences showed that the new species is genetically distinct. D2–D3 sequence of H. dicksoni n. sp. showed 99 and 95% sequence homology with an undescribed species of Hirschmanniella isolated from the Colorado River in Yuma, Arizona, and H. oryzae, respectively. ITS sequence of the new species also showed 88% sequence homology with H. oryzae. The phylogenetic analysis of D2–D3 and ITS region grouped H. dicksoni n. sp., as sister species, with H. oryzae.

Intra-specific morphological and morphometric variability of Radopholus similis (Cobb, 1893) Thorne, 1949

All the root inhabiting migratory endoparasitic nematode populations of Radopholus procured from banana crop of Vellayani, Thiruvananthapuram, Kerala were identified as Radopholus similis. Heat killed females were straight to slightly ventrally curved posteriorly. Female’s head was low, rounded, continuous or slightly setoff with the body contour. Females were 500-660 µm long and were comparatively longer than males. Males had button shaped head set off by a constriction; female with three to five lip annuli, four crenate and areolated lateral incisures, stylet 14-18 µm long with rounded knobs, vulva post-equatorial (58%), sometimes with slight protuberant lips, ovary paired and equally developed, oesophageal gland overlapped the intestine dorsally, tail elongate-conoid with narrowly rounded terminus. The stylet length (µm), width of stylet knob (µm), distance of excretory pore from anterior end (µm), distance from head to basal bulb (µm), lateral field structure, shape of stylet knob, head region, position of phasmid, tail shape with its terminus, morphometric values like m%, o% and v% and a, c and c´ ratios of females were stable (CV<12%) features. There is an existence of intra-specific variability in the morphological and morphometric features of R. similis. The main morphological diversity was observed with P% of male and female, b ratio of female and stylet length, distance of DEGO from stylet base, o% and T% of male. All the root inhabiting migratory endoparasitic nematode populations of Radopholus Thorne, 1949 procured from banana of Vellayani, Thiruvananthapuram, Kerala were identified as Radopholus similis (Cobb, 1893) Thorne, 1949. A high degree of intra-specific morphometric variability was observed with regard to the total body length (µm), body width (µm), stylet length (µm), distance of dosrsal oesophageal gland orifice (DEGO) from stylet base (µm), number of lip annuli, lip height (µm), distance from head to basal bulb (µm), distance of anus from anterior end (µm), tail length (µm), anal body width (µm), distance of phasmid from tail terminus (µm), number of lateral lines, width of lateral field (µm), b ratio and P % among females of R. similis. Morphometric features like m%, o% and v% of females of R. similis showed least variability. These can be considered as the stable morphometric characters for discrimination of females of R. similis. Ratios like ‘a’ and ‘c’ of females of R. similis were found moderately variable. The morphometric feature and of male i.e. distance from head to basal bulb (µm) was found least variable; while number of lip annuli and spicule length (µm) were moderately variable.

Morphological and molecular characterisation of Hemicriconemoides paracamelliae sp. n. (Nematoda: Criconematidae) and two known species of Hemicriconemoides from China

Summary Sheathoid nematodes of the genus Hemicriconemoides are migratory root-ectoparasites of many crops but damage is documented for only a few species. Hemicriconemoides paracamelliae sp. n., isolated in Hangzhou, Zhejiang, China, from the rhizosphere of Cinninghamia lanceolata, is described together with H. kanayaensis and H. parataiwanensis. These three species are characterised morphologically and molecularly with important morphological details elucidated by SEM photographs. The new species can be characterised by the en face view having a dorsoventrally orientated oral disc with slit-like opening, and the labial plate being composed of two lateral semi-globular shaped projections on the lateral sides of the oral disc. This new species has the first lip annulus expanded and slightly wider than the second, stylet 83 (80-85) μm long, excretory pore located 5-6 annuli posterior to the base of the pharyngeal bulb, vulva slit-like, vulval flaps absent, spermatheca rounded to oblong-shaped, and anus located 5-8 annuli posterior to vulva. The tail is elongated, conoid, with the terminal annuli curving dorsally or ventrally to form a finely rounded tip. The study provides the first record of H. kanayaensis from mainland China, a new host association of H. parataiwanensis, and molecular sequencing data of the 18S, 28S D2-D3 and ITS sequences.

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.

Characterisation of amphimictic and parthenogenetic populations of Pratylenchus bolivianus Corbett, 1983 (Nematoda: Pratylenchidae) and their phylogenetic relationships with closely related species

Amphimictic populations of root-lesion nematodes with numerous males and females having three lip annuli, a functional spermatheca and non-areolated lateral field occur on sword fern (Nephrolepis exaltata) in Florida. Identified for decades asPratylenchus penetrans, they appeared to be a morphologically separated species on the basis of a longer stylet (17.8-18.3 μm) thanP. penetrans(15-17 μm) and different lip pattern inen faceview (rectangularvsdumb-bell inP. penetrans). Morphologically similar amphimictic root-lesion nematodes have also been detected on flax lily in Costa Rica. Subsequent morphological observations indicated that these amphimictic root-lesion nematodes from fern and flax lily are closely related to the parthenogenetic speciesP. bolivianus, which has areolated lateral fields. In spite of the reproductive and morphological dissimilarities between these populations, their separation into different species was not supported by the results of molecular analyses of their DNA sequences. The populations used in these analyses included those that are amphimictic from Florida and Costa Rica and others that are parthenogenetic from the type locality in Bolivia, and geographically distant localities in Chile, China, Colombia and Europe. Phylogenetic analyses of the ITS and D2-D3 expansion segments of the 28S rRNA gene indicated that they belong to the same species,P. bolivianus, which consists of two morphotypes,P. bolivianus(am) amphimictic andP. bolivianus(pm) parthenogenetic, herein described and illustrated. Contradictory results were obtained by the analyses using a portion of thehsp90gene. The phylogenetic study, which included sequences of other root-lesion nematodes, a topotype and geographical distant populations ofP. zeae, revealed thatP. bolivianusandP. zeaeformed highly supported clades in the majority consensus trees. PCR with species-specific primers for rapid diagnostics ofP. bolivianusandP. zeaewere developed and tested.

Morphological and molecular characterisation of Hemicaloosia guangzhouensis n. sp. (Nematoda: Caloosiidae) from China

A new plant nematode species, Hemicaloosia guangzhouensis n. sp., collected from the soil associated with Schima superba in a forest park in Guangzhou, China is described. The new species is characterized by having a female with a slender body, 798–961 μm in length, stylet 59–69 μm long, tail 115–145 μm long, a membranous sheath closely adpressed to the entire body, lateral fields marked by one longitudinal line with breaks and anastomoses of transverse striae, total number of annuli 282–313, two lip annuli both projecting slightly anterior, excretory pore 51–58 annuli from anterior end, the number of annulus between vulva and anus 7–11, the number of annulus from vulva to tail terminus 58–69, spermatheca empty; and male unknown. The internal transcribed spacer of ribosomal RNA (ITS rRNA) gene, D2-D3 region of 28S ribosomal RNA (28S rRNA) gene, partial 18S ribosomal RNA (18S rRNA) gene of the new species were amplified and sequenced. The 50 % majority rule consensus trees inferred from ITS rRNA, 28S rRNA, partial 18S rRNA gene sequences of H. guangzhouensis n. sp. and some other species in the suborder Criconematina are also presented in this study. PCR-ITS-RFLP diagnostic profile generated by six restriction enzymes for H. guangzhouensis n. sp. is given.

Morphological and molecular charaterisation of Pratylenchus parazeae n. sp. (Nematoda: Pratylenchidae) parasitizing sugarcane in China

A new root-lesion nematode was isolated from sugarcane (Saccharum sinensis Roxb.) in Guangxi Zhuang Autonomous Region, China. Morphology and molecular analyses of rRNA small subunit (SSU), D2D3 expansion domains of large subunit (LSU D2D3) and internal transcribed spacer (ITS) confirmed that this nematode is different from other previously described root-lesion nematodes. Herein it is described, illustrated and named as Pratylenchus parazeae n. sp. This new species is characterised by plain and smooth En face, three lip annuli, stylet with anteriorly rounded to indented knobs, 17.0–19.0 μm long, lateral field composed of four lines with areolated outer bands at vulval region, vulva position 68.9–74.9 %, small, oval and empty spermatheca, and a subhemispherical tail usually with smooth terminus and sometimes with a more or less pronounced dorsally indented terminus. Phylogenetic trees inferred from BI analysis based on SSU, LSU D2D3 and ITS revealed that P. parazeae n. sp. can be distinguished from all described root-lesion nematodes, especially from the most closely related species P. zeae. A species-specific duplex PCR was also developed to separate the new species from other nematode species.

수입식물에서 검출된 뿌리썩이선충(뿌리썩이선충과: 뿌리썩이선충속)의 진단

We identified the five root-lesion nematode species, Pratylenchus crenatus, P. fallax, P. kumamotoensis, P. panamaensis and P. penetrans from intercepted in quarantine inspection over the past five years. Their diagnostic characters are including number of lip annuli, stylet length, shape of the labial region, presence or absence of males, structure of lateral fields, shape of spermatheca, length of the post-vulval uterine sac and shape of tail and so forth. We described the photos, measurements and morphological characters.

Description of a new Pratylenchus species from China (Tylenchida, Pratylenchidae).

Pratylenchus ekrami from maize (Zea mays) roots in Shenyang and luffa (Luffa cylindrica) roots in Dalian, China, are described in this paper. Nematodes from the two areas were identified consistently, and were characterized by a heavy cephalic sclerotization, extending posteriorly up to two body annuli, stylet 11-13 μm long, elongating conoid tail, and becoming thinner from vulva. Males were not found. Pratylenchus ekrami is close to Pratylenchus vulnus, but the most critical characteristics between the two species were the number of lip annuli, stylet size, and shape of stylet knobs. This species is the first reported in China. Pratylenchus ekrami from maize (Zea mays) roots in Shenyang and luffa (Luffa cylindrica) roots in Dalian, China, are described in this paper. Nematodes from the two areas were identified consistently, and were characterized by a heavy cephalic sclerotization, extending posteriorly up to two body annuli, stylet 11-13 μm long, elongating conoid tail, and becoming thinner from vulva. Males were not found. Pratylenchus ekrami is close to Pratylenchus vulnus, but the most critical characteristics between the two species were the number of lip annuli, stylet size, and shape of stylet knobs. This species is the first reported in China.

Morphological and molecular characterisation and diagnostics of some species of Scutellonema Andrássy, 1958 (Tylenchida: Hoplolaimidae) with a molecular phylogeny of the genus

Scutellonema spp. are widely distributed across tropical and subtropical regions of the world and are associated with numerous agricultural and horticultural crops. Identification of many Scutellonema species is not always reliable, in part because many species share very similar diagnostic characters. In this study, we provide morphological and molecular characterisation of S. brachyurus from the USA and South Africa, S. bradys from Nigeria and three unidentified species from California, USA, New Zealand and Burkina Faso. Morphological descriptions, measurements, light and scanning electron microscopic photos and drawings are given for S. brachyurus. Females of S. brachyurus from the USA (type A) and South Africa (type B) showed a significant variation in the number of sectors and blocks on the lip annuli, ranging from about 4-12 and from 8-20, respectively. Molecular analysis using the D2-D3 of 28S rRNA, ITS rRNA and the COI mtDNA gene sequences revealed two distinct genotypes within S. brachyurus samples: type A (samples from USA, Italy, Korea, Taiwan) and type B (South Africa). Multivariate analyses determined that S. brachyurus from the USA and Taiwan (type A) differed from that from South Africa (type B) mainly in body, tail and DGO lengths, and ratios b′, c′, c and V. Phylogenetic relationships within Scutellonema are given as inferred from the analyses of the D2-D3 of 28S rRNA, ITS rRNA and the COI mtDNA gene sequences. PCR-RFLP diagnostic profiles and PCR with species-specific primers are developed for the studied Scutellonema species.