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During a recent inventory survey of the nematofauna of tea plantation at Zhejiang Province, China, Discocriconemella parasinensis n. sp. was detected in the rhizosphere of Camellia sinensis. The new species can be characterized by having the uninterrupted rounded labial disc, en face view showing rectangular-rounded labial plate without submedian lobes, R = 82.6 (80–86), Rex = 22 (21–23), stylet length of 68.3 (59–76) μm, excretory pore located 1–2 annuli posterior to the esophageal bulb, vulva open, postvulval body elongated conoid, and tail conoid with bilobed terminus. Morphologically, the species shares the same lip-type with D. discolabia, D. mauritiensis, D. mineira, D. perseae, and D. sinensis. Phylogenetic relationships of the new species based on D2–D3 expansion segments of 28S, ITS, and 18S rRNA genes revealed that D. parasinensis n. sp. formed a separated clade from other criconematid species, thereby supporting its status as a new species of the genus. The new species showed close phylogenetic relationships with Criconemoides geraerti.

Summary: Cryptaphelenchus species are wood- or bark-inhabiting nematodes, generally mycetophagous and reported to have endophoretic associations with insects. In the present study, we describe two new and one known Cryptaphelenchus species detected in imported and domestic wood samples. Cryptaphelenchus americanum n. sp. and C. minutus were detected in the log samples of Pinus taeda imported from the USA, whereas C. orientalis n. sp. was isolated from the bark of dying Pinus sylvestris trees in Inner Mongolia, China. Both new species displayed characteristic features, including a relatively short body length, four lateral lines, a short post-vulval uterine sac in females, and a distinct cloacal apophysis in male tails. Newly recovered and known species were characterised molecularly, and phylogenetic trees were constructed to study their relationship with related Cryptaphelenchus species. Notably, the genetic divergence observed among Cryptaphelenchus species was found to be more significant compared to morphometrical differences, highlighting the importance of molecular data in taxonomy. The identification of new and known species expands our understanding of the genus and suggests that Cryptaphelenchus species may be under studied, underscoring the necessity for continued exploration. [ABSTRACT FROM AUTHOR]

The nematode family Aphelenchoididiae is considered fungal-feeding, predatory, or root hair feeders. Some members of this family are universally present in agricultural landscapes and are an integral part of soil health and conservation studies. In the present soil nematode biodiversity survey, we detected four species of the genera Aphelenchus, Aphelenchoides, and Robustodorus. Because fungal-feeding nematodes from southern Alberta have not previously been reported, we conducted a detailed morphological and molecular investigation, identifying these species as Aphelenchus avenae, Aphelenchoides limberi, Aphelenchoides prairiensis n. sp. and Robustodorus paramegadorus n. sp. The first two species we document as new records from southern Alberta, whereas A. prairiensis n. sp. and R. paramegadorus n. sp. we describe in detail as new taxa. Briefly, A. prairiensis n. sp. is an amphimictic species having 4 lateral lines; hemispherical anteriorly flattened lip region; delicate stylet and swelling-like stylet knobs; excretory pore at the posterior edge of nerve ring. Female tail conical, gradually tapering towards a truncated end with single mucro. Spicule 23.0 (20.0–25.0) µm long having elongated rounded condylus, small, blunt conical rostrum, and lamina that gradually tapers towards the rounded distal end; three pairs of caudal papillae were present on the male tail. Robustodorus paramegadorus n. sp., is a parthenogenetic species with 3 lines in the lateral fields; lip region rounded, anteriorly flattened; stylet robust, with knobs rounded to bean-shaped; excretory pore located posterior to nerve ring; reproductive components were quite indiscernible with a short 24.0 (18.0–27.0) µm post-vulval uterine sac; tail conical, ending with pointed to wedge-shaped tip. We performed molecular characterizations for each species and constructed phylogenetic trees to study the phylogenetic relationship of these aphelenchid species. The discovery of A. prairiensis n. sp. and R. paramegadorus n. sp. indicates that soil nematode diversity is relatively unexplored in southern Alberta. The findings of this study will significantly enhance the identification processes and may contribute towards future soil health and biodiversity efforts. [ABSTRACT FROM AUTHOR]

Summary: The present study describes two new Ditylenchus species, isolated from the growing medium of Rhododendron simsii imported from Japan, at the Ningbo plant quarantine laboratory, Ningbo, P.R. China. Ditylenchus parvicauda n. sp. is an amphimictic species. Females have six incisures in the lateral fields, a medium length slim body, a short delicate stylet with asymmetrical stylet knobs, the secretory-excretory (S-E) pore located posterior to the isthmus and in the anterior region of the basal pharyngeal bulb, a posteriorly located vulva (V = 80.9-83.0), post-uterine sac (PUS) tube-like, and the tail cylindrical, tapering gradually towards finely rounded terminus. Males are similar to females in general morphology and have 10.1-14.9 μ m long spicules. The second new species, D. gracicauda n. sp. is characterised by having a long and slender body, the presence of a vulval flap, four lines in the lateral field, a narrow and low lip region not offset, the S-E pore located posterior to the isthmus but not in the anterior region of the basal pharyngeal bulb, a posteriorly located vulva (V = 71.1-76.2), a short post-vulval uterine sac short (4.5-9.2 μ m), and the tail slender, tapering gradually towards finely rounded to wedge-shaped terminus. The two new species were also characterised molecularly using 18S, ITS and the D2-D3 expansion segments of 28S rRNA genes. Our phylogenetic analyses showed their independent place among available Ditylenchus species. Several Ditylenchus species are regulated pests, and the introduction of these species into a new environment may result in diseases among native plants or vegetation in the area. Therefore, careful attention must be directed towards newly discovered species, particularly those under quarantine observation. [ABSTRACT FROM AUTHOR]

Seven trichodorid species including a new one (Trichodorus hangzhouensis sp. nov., T. nanjingensis, T. pakistanensis, T. cedarus, Paratrichodorus porosus, Nanidorus renifer and N. minor) were recovered from the rhizosphere of different hosts in 13 provinces of China. Each of the recovered species was characterized based on morphology and molecular data using rRNA gene sequences. Trichodorus hangzhouensis sp. nov. is characterized by its males having medium-sized onchiostyle (46–49 µm) and three ventromedian cervical papillae (CP) anterior to the secretory-excretory (S-E) pore, CP1 located opposite the anterior part of isthmus, S-E pore opposite the isthmus or anterior end of pharyngeal bulb, spicules slightly ventrally curved, relatively small, 33.2 (32.0–34.5) µm long, wider slightly marked capitulum, lamina partially striated without bristles at striation; and females having rounded triangular sclerotized vaginal pieces with tips directed towards vulva, 1.5–2.0 µm sized, at about 1 µm apart, vulva pore-like in ventral view. Phylogenetic analysis based on D2-D3 28S rRNA gene sequences differentiated the new species among Trichodorus species from Europe, Asia and USA which formed a large clade. A review of the distribution of Trichodorus, Nanidorus and Paratrichodorus species revealed that T. cedarus, T. nanjingensis, T. pakistanensis and P. porosus are the most widespread species recorded from different provinces of China. This is the first extensive study of trichodorid species occurring in China.

Summary: The genus Ektaphelenchoides is a diverse group of nematodes; they are either inhabitants of trees or present in the rhizosphere of economical plants. Members of the genus have ecological relevance in terms of being associated with insects and predators of other nematodes. In the present study, a new Ektaphelenchoides species, E. factum n. sp., is described and illustrated. The new species was isolated from a log sample of Pinus taeda imported from the USA. It is characterised by the lateral field with three incisures, stylet distinctly tripartite. Females having a vulval flap, the anus and rectum indistinct, and the tail (posterior part of body) filiform. Males having arcuate and 21.5 (19.4-22.9) μ m long spicules, the lamina of the spicule is smoothly curved to distal end, condylus well developed with a broadly rounded tip, rostrum triangular with finely rounded tip and cucullus absent, tail arcuate and conical with terminus bearing a sharply pointed mucron. The new species is different from other Ektaphelenchoides species in having a vulval flap. Molecular characterisation and phylogenetic studies also supported its unique status. In addition, a Chinese native population of E. pini , detected in Pinus koraiensis branches from Liaoning province, P.R. China, is described. [ABSTRACT FROM AUTHOR]

Spiral nematodes (Helicotylenchus spp.) are polyphagous parasitic species exhibiting a broad host range and geographical distribution. However, their diversity in the cultivated regions of southern Alberta remains understudied. Hence, we conducted a comprehensive survey of the region's arable lands for the presence of spiral nematodes and revealed two Helicotylenchus species, H. crassatus and H. oscephalus. H. crassatus consisted of two distinct morphotypes: one morphotype had a conoid tail with slight ventral projection on the distal end, whereas the other had a broadly rounded tail. This study presents the first documentation of H. crassatus and H. oscephalus from southern Alberta, Canada. Molecular characterization was based on the partial 18S rRNA, the D2–D3 of 28S rRNA, ITS rRNA, and COI gene sequences, complemented by detailed morphological studies using scanning electron microscopy. In this work, Helicotylenchus species were often co-detected with root lesion nematodes, which made the evaluation of their role in crop damage more difficult. To meet the requirements for threshold and pathogenicity assessments, we introduced both spiral nematode species to sterile carrot disks and evaluated the feasibility of their multiplication and mass production in vitro. The present findings expand the taxonomic records of Helicotylenchus spp. and improve diagnostics of these morphologically similar species. Furthermore, our in vitro culture technique will provide a reliable source of the initial inoculum for future plant–nematode interaction studies. [ABSTRACT FROM AUTHOR]

Abstract The rice root-knot nematode, Meloidogyne graminicola, is a serious pest in most rice-growing countries. Usually, nematodes employ antioxidants to counteract the harm of reactive oxygen species (ROS) and facilitate their infection. Here the gene encoding M. graminicola protein disulphide isomerase (MgPDI) was identified. The deduced protein is highly conserved in the putative active-site Cys-Gly-His-Cys. In situ hybridization showed that MgPDI was specifically localized within esophageal glands of pre-parasitic second stage juveniles (J2s). MgPDI was significantly up-regulated in the late parasitic J2s. Characterization of the recombinant protein showed that the purified MgPDI exhibited similar activities to other oxidases/isomerases such as the refolding of the scrambled RNase and insulin disulfide reductase and the protection of plasmid DNA and living cells from ROS damage. In addition, silencing of MgPDI by RNA interference in the pre-parasitic J2s lowered their multiplication factor. MgPDI expression was up-regulated in the presence of exogenous H2O2, whereas MgPDI silencing resulted in an increase in mortality under H2O2 stress. MgPDI is localized in the apoplast when transient expression in Nicotiana benthamiana leaves. The results indicated that MgPDI plays important roles in the reproduction and pathogenicity of M. graminicola and it also contributes to protecting nematodes from exogenous H2O2 stress.

The soybean cyst nematode, Heterodeara glycines, is a serious pathogen of soybean, and reported to be the host of a wide range of Fabaceae. In the present study, the host specificity and reproductivity of two populations of H. glycines collected from soybean and tobacco were identified and characterized. The comparative identity between β-1,4-endoglucanase, pectate lyase and chorismate mutase of H. glycines parasitizing on soybean and tobacco were 99, 97 and 98%, respectively. The qRT-PCR analysis indicated that the expression of pectate lyase 2 gene was significantly higher in second-stage juveniles of H. glycines Henan population parasitizing on tobacco than that of H. glycines Shanxi population parasitizing on soybean. In addition, the pectic acid content of cell wall was significantly higher (45%) in the roots of tobacco than the roots of soybean. Our results indicate that the changes in transcript parasitism genes may be a result of long-term evolution illustrating how a plant-parasitic nematode adapts to the host environment for optimal infestation and survival.

The rice root-knot nematode Meloidogyne graminicola is a severe pest of rice. In China, it was first reported from Hainan Province, and later from several other provinces. In the present study, a rice root-knot nematode population found from the rice cultivation areas of Zhejiang Province, China is characterized via molecular analysis using internal transcribed spacer (ITS) and cytochrome c oxidase subunit II (coxII)-16S rRNA genes and scanning electron microscopy (SEM) observations of males and the second-stage juveniles. Morphometric data and molecular sequence comparisons for all M. graminicola populations occurring in China are also provided. The overall morphology of M. graminicola found in Zhejiang match well with the original description, though males have a slightly longer body and stylet, and a shorter tail, while the second-stage juvenile is also slightly longer than in the original description. This is the first report of M. graminicola from Zhejiang. Phylogenetic studies based on coxII suggest that all the Chinese populations belong to Type B. This study expands knowledge of the increasing distribution and phylogenetic relationships of M. graminicola that occur in China.

Summary: The present study describes a new Ditylenchus species, isolated from the bulbs of the Persian buttercup (Ranunculus asiaticus L.) imported from Israel at the Ningbo plant quarantine lab, Ningbo, P.R. China. Ditylenchus israelensis n. sp. is an amphimictic species; females have six incisures in the lateral field, a long and slim body, a delicate, short stylet (7-8 μ m) with small and rounded knobs, excretory pore in the anterior region of the basal pharyngeal bulb, posteriorly located vulva (V = 78.6-83.1), a short PUS (15.0-24.0 μ m), and a long conical tail with a pointed terminus. Males are similar to females in general morphology and have 14.0-18.0 μ m long spicules. The new species was also characterised molecularly using 18S, ITS and D2-D3 expansion segments of 28S rDNA genes. Our phylogenetic analyses showed its independent position among available Ditylenchus species and a close phylogenetic affinity with D. valveus. Several Ditylenchus species are regulated pests; their detection in a given sample can implement quarantine measures. However, to our knowledge D. israelensis n. sp. did not cause any damage to the R. asiaticus bulbs. In addition, future studies regarding fecundity and host association may shed some light on the pathogenic potential of D. israelensis n. sp. [ABSTRACT FROM AUTHOR]

Summary: The study aims to provide the morphological and molecular characterisation of two newly discovered Cryptaphelenchus species, namely: C. curvatum n. sp. and C. tumidus n. sp. Morphologically both species are minute nematodes, possess medium-sized stylets with basal knobs laterally directed, and short post-uterine sacs (PUS). Cryptaphelenchus curvatum n. sp. was detected from the local Pinus branch samples and is characterised by having an equal proportion of adult males and females, medium-sized body lengths of females 353 (320-388) μ m and males 277 (256-293) μ m, lateral fields with four lateral lines, 8-10 μ m long stylet, PUS about one vulva body width long and conical posterior body end with a blunt pointed tip. Cryptaphelenchus tumidus n. sp. was detected in a packaging wood sample from Japan and is characterised by having rare male, short body lengths of females 236 (217-270) μ m and males 180 μ m, obscure lateral fields, stylet 6.8 (6.0-7.5) μ m, PUS about half vulva body width long and a slim conical posterior body end with a finely rounded tip. The phylogenetic trees were also constructed based on rRNA gene sequences (D2-D3 segments of the 28S, ITS and 18S) and discussed in detail. Since Cryptaphelenchus species offer multitrophic relationships among their insect vectors and associated microbiota, species recognition and molecular studies of recovered populations will facilitate researchers to determine whether these species might play any ecological roles in insect bionomics or the residing host tree. [ABSTRACT FROM AUTHOR]

The presence of plant-parasitic nematodes (PPNs) in cultivated areas is a limiting factor in achieving marketable crop yield. To control and alleviate the effects of these nematodes and determine appropriate management strategies, species-level identification is crucial. Therefore, we conducted a nematode diversity survey, which resulted in the detection of four Ditylenchus species in cultivated areas of southern Alberta, Canada. The recovered species had six lines in the lateral field, delicate stylets (>10 µm long), distinct postvulval uterine sacs, and pointed to rounded tail tips. The morphological and molecular characterization of these nematodes revealed their identity as D. anchilisposomus, D. clarus, D. tenuidens and D. valveus, all of which are members of the D. triformis group. All of the identified species were found to be new records in Canada except for D. valveus. Accurate Ditylenchus species identification is crucial because false-positive identification can result in the implementation of quarantine measures over the detected area. Our current study not only documented the presence of Ditylenchus species from southern Alberta, but also described their morpho-molecular characteristics and subsequent phylogenetic relationships with related species. The results of our study will aid in the decision on whether these species should become a part of nematode management programs since nontarget species can become pests due to changes in cropping patterns or climate. [ABSTRACT FROM AUTHOR]

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) μ m 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. [ABSTRACT FROM AUTHOR]

Summary: A new species of Xiphinema americanum group was recovered in the rhizosphere of holly (Ilex purpurea) imported from Japan. It is described and illustrated in the present study as X. purpureum n. sp. The new species is characterised by moderately long females 2267 (2115-2550) μ m, round lip region slightly offset from the rest of the body, 103.5 (98.5-109.0) μ m long odontostyle, genital branches without discernible endosymbiotic bacteria, vulva located at 54.1 (51.6-57.1)% of the body, tail 30 (24.3-33.4) μ m long with a broadly rounded terminus, male absent and four juvenile developmental stages. The polytomous codes of the new species are as follows: A4/5, B2/3, C1/2, D2/3, E3, F1, G1, H2, I1/2/3. The new species was molecularly characterised using near full length 18S, ITS1, and 28S D2-D3 regions of rRNA, and mitochondrial cytochrome c oxidase subunit I gene sequences. The phylogenetic analyses placed X. purpureum n. sp. with X. americanum group species, particularly with X. brevicolle complex species. This is the third X. americanum group species described from Japan. [ABSTRACT FROM AUTHOR]

Summary: Understanding the occurrence and distribution of parasitic nematodes is crucial – some are economic pests, and some are important predators of their insect associates. In our recent nematode inventory survey, two populations of an ektaphelechid nematode were detected in the branches of Pinus trees; later the same nematode population was detected in plant quarantine examinations of wood packaging material imported from Japan. The species was processed and identified as Ektaphelenchoides diversislocis sp. n. The new species can be characterised by having three lateral lines, stylet long and tripartite, excretory pore at the level of nerve ring, comparatively longer post-vulval uterine sac, indistinct rectum and anus. Female posterior body region conical, gradually narrowing, like a mucron or filiform. Male spicule with well-developed condylus, triangular rostrum, and cucullus absent. The species is morphologically and molecularly close to E. compsi. The new species was characterised with near full-length 18S, 28S D2-D3 regions, and internal transcribed spacer (ITS) rRNA genes and mitochondrial cytochrome oxidase I (COI) gene sequences. The species within the Ektaphelenchoides genus are considered to have predatory roles against insect associates; therefore, the discovery of E. diversislocis sp. n. from local and foreign woodlands warrants increased sampling and research attention. [ABSTRACT FROM AUTHOR]

Summary: Ektaphelenchoides compsi is redescribed morphologically with new molecular characterisation. It was isolated from a dead Pinus massoniana tree in Ningde City, Fujian Province, China. Detailed morphology of the spicule, female gonad, hemizonid position, arrangement of male caudal papillae and female tail terminus shape are documented. It is characterised by a lateral field with three lines (forming two bands), tripartite stylet 17.8 (17.0-19.4) μ m long without basal thickenings, metacorpus rectangular with anterior 40% granular and posterior part weakly muscular, metacorpal valve slightly posterior to middle of metacorpus, excretory pore at level of nerve ring, vagina with thickened walls and strongly developed muscular bundles, vulval lips slightly protuberant, vulval flap absent, distal region of post-vulval uterine sac appearing as a weakly developed oogonia, anus and rectum indistinct, female posterior part ('tail') dorsally convex, conical, terminal region contracted into a bluntly pointed tip. The spicules are arcuate, 15.6 (14.3-16.3) μ m along the chord, lamina smoothly curved to distal end, capitulum slightly concave, condylus well-developed with broadly rounded tip and slightly depressed at dorsal end, rostrum triangular with finely rounded tip, cucullus absent, and with seven caudal papillae present. The near full length 18S and 28S D2-D3 regions of rRNA genes sequences were characterised. The phylogenetic analyses revealed that the Fujian population of E. compsi grouped with the Zhejiang population of E. compsi , both being morphologically identical. [ABSTRACT FROM AUTHOR]

Members of the family Tylenchidae are highly abundant in soil habitats, including agricultural settings, where they play key ecological roles. In the present study, we identified three Tylenchidae species, namely Basiria bhabi, Coslenchus acceptus, and Filenchus vulgaris, using integrative taxonomy. The detailed morphological and morphometric characteristics, distribution, and host associations of each species were also discussed. Phylogenetic analyses of these populations with other Tylenchidae nematodes indicated the presence of divergent lineages in Filenchus and Basiria, whereas Coslenchus appeared to be a monophyletic genus. Herein, we aim to grow awareness about this common but least studied group of nematodes. The species reported in this study are new records for Canada, revealing that the identified nematode diversity in our cultivated areas is relatively underrepresented. Our analyses also provided greater taxonomic resolution and captured rare taxa that might have been missed or misidentified in prior nematode inventory surveys. These findings will add to our understanding of the nematofauna of southern Alberta, thereby providing a more complete picture of existing nematode diversity present in the fields of this highly cultivated region. [ABSTRACT FROM AUTHOR]

The present study was conducted to document the ethno-medicinal uses of wild herbs and shrubs of Tehsil Yazman, District Bahawalpur, Punjab. Information was gathered by interviewing local people. The collected plants were identified with the help of Flora of Pakistan. Plants were preserved and mounted on herbarium sheets and placed in the Department of Botany, Government Sadiq College Women University, Bahawalpur, Pakistan. A total of 118 species belonging to 35 families were identified. It was noticed that the indigenous people of the study area use plants in different ways in their daily life such as medicines, fuel, fruit, vegetable, forage/fodder, ornamental etc. Three families were found in abundance i.e. Poaceae, Fabaceae and Asteraceae. To the best of our knowledge, it is the first report on the ethno-medicinal uses of wild herbs and shrubs of Tehsil Yazman. It will be helpful in providing a baseline for future studies relating to pharmacological as well as biochemical studies of these wild plant species. [ABSTRACT FROM AUTHOR]

Populations of Criconemoides parvus, Discocriconemella hengsungica, and Discocriconemella limitanea, isolated in Hangzhou, China from the rhizosphere soil of woody perennials were characterized morphologically and molecularly. The morphometric data of the Chinese populations were compared with populations from other regions of the world. DNA barcoding with the mitochondrial COI gene confirmed conspecificity of Chinese and Costa Rican populations of D. limitanea. Phylogenetic assessment using a near full-length 18S ribosomal DNA sequence provided weak support for a grouping of Criconemoides parvus from China and C. annulatus from western North America. The phylogenetic position of D. hengsungica from China and an unknown species of Discocriconemella from Thailand relative to D. limitanea suggests that the genus Discocriconemella is not monophyletic. The study provides the first record of D. hengsungica in China and confirms the presence of C. parvus previously reported from China. Biogeographic implications of these nematode distributions are discussed. [ABSTRACT FROM AUTHOR]

Three populations of neotylenchid nematodes were isolated in Ningbo, P. R. China, from white pine lumber (Pinus monticola) imported from the USA. The nematodes were morphologically intermediate between Hexatylus and Deladenus. The nematodes were molecularly characterized based on sequences of the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer sequences. The phylogenetic inferences placed the nematodes with other neotylenchid nematodes, i.e., Fergusobia and Rubzovinema. Based on the morphology and phylogenetic analysis, this nematode is described herein as Delatylus andersoni n. gen., n. sp. The new genus/ species is characterized by the female body habitus ranging from nonobese to semiobese and from straight to dorsally curved when heat relaxed, cephalic framework with six unequal sized lip sectors, lateral fields having 10 to 12 lines, 4 to 5 guide rings on the stylet, excretory pore posterior to the nerve ring, spermatheca diminished or absent, vulvar opening large, and relative proximity of vulva to the anus. Detailed morphological and molecular characterization of the new genus/species is presented along with the comparison of the related genera. [ABSTRACT FROM AUTHOR]

The potential of biocontrol agents Purpureocillium lilacinum (Paecilomyces lilacinus) and Trichodenna harzianum was evaluated against tomato wilt complex, caused by a combination of Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici, under both laboratory and field conditions. Biocontrol agents at spore concentration of 1 x 106 spores ml-1 were applied alone and in combined treatments. The results of combined application revealed maximum mortality and inhibition of hatching of M. incognita under in vitro conditions. Combined application of both antagonistic fungi was found to be more effective in mycelial inhibition of Fusarium oxysporum f. sp. lycopersici. In glasshouse trials, application of T. harzianum promoted overall plant growth, followed by combined application of P. lilacinum and T. harzianum; nematode development parameters and fungus damage were significantly reduced. Under field conditions, the combined application of P. lilacinum and T. harzianum increased the number of leaves, shoot length, shoot weight and root length, and decreased root weight, with minimum number of females and egg masses of M. incognita per root system and mycelia inhibition of F. oxysporum. [ABSTRACT FROM AUTHOR]

Understanding the existing nematode biodiversity is of significant concern because nematodes may divert nutrients from plants and use them for their own development and reproduction. The presence and diagnostics of Filenchus species occurring in southern Alberta have not been addressed in previous studies. Herein, we provide a comprehensive characterization of adult females of four known Filenchus species (F. cylindricus, F. hazenensis, F. sheri, and F. thornei) recovered from cultivated fields in southern Alberta. Three of the species are new records in Canada, while one is a native species that was previously described from the Canadian high arctic area. These organisms are mild parasitic species; we describe them here to enhance the visibility of soil nematodes and facilitate accurate species identification. The diagnostic resolution within Filenchus is low, because many species are described without adequate consideration of intra-specific variation. The species descriptions and molecular data obtained during the present study will reduce the confusion in examining the existing lineages among Filenchus species and will aid in improving phylogenetic resolution. Our results suggest that the known diversity of Canadian nemato-fauna has increased. However, more research is needed to further identify other genera and species of phytoparasitic nematodes that may occur in grasses, weeds, and wild plants present in cultivated areas. Moreover, the molecular characterization of these species from Canada, in comparison to a reference dataset (NCBI) of Tylenchidae nematodes, provides insight into the biogeography of nematodes. [ABSTRACT FROM AUTHOR]

The nematode family, Anguinidae, is a diverse group of polyphagous nematodes, generally known as fungal feeders or parasites of aerial plant parts. Here, we present the morphological and molecular characterization of adult females of two Nothotylenchus species, N. medians and N. similis, along with host association and geographical distribution data of the genus. Both species are recorded as new reports from Canada and designated as reference populations for future studies. Morphological or morphometrical variation was not observed in the Canadian population of N. medians and N. similis, in comparison with the original description. Phylogenetic analyses based on 18S and D2–D3 of 28S genes placed both species within Anguinidae. Since the biology of the genus Nothotylenchus has not been rigorously characterized, the habitat and distribution information presented in this study will shed some light on the ecology of these nematodes. Notably, the detection of N. medians and N. similis in our nematode inventory survey indicates that considerable Nothotylenchus diversity is hidden in these soils. Consequently, increased surveys and more in-depth research are needed to explore the full diversity of anguinids inhabiting these cultivated areas. [ABSTRACT FROM AUTHOR]

Simple Summary: Two Boleodorus species were detected in cultivated areas of southern Alberta. The aim of the present work was to characterize the discovered populations of Boleodorus using morphological and molecular methods. Boleodorus is the least studied genus in family Tylenchidae, with very few species reported after formal descriptions and outside their type locality. To date, Boleodorus species are not considered nematode pest species, rather they can serve as environmental indicators. Therefore, it is important to quantify and monitor the population densities of these species for soil health management studies. The current study encompasses the distribution and host association of all described Boleodorus species. In addition, morphometrical characters of all valid species are listed for their prompt identification. The present study provides the morphological and molecular characterization of Boleodorus thylactus and B. volutus populations, recovered from agricultural fields of southern Alberta. Despite a significant abundance of this group of nematodes, none of the Boleodorus species were previously reported in Canada. Therefore, representative adult specimens of each population were photographed and examined morphometrically. Phylogenetic trees were reconstructed using partial D2–D3 expansion segments of the 28S and 18S rDNA sequences to understand the relationships of Boleodorus species with Tylenchidae-related genera. Boleodorus species are relevant to soil ecological studies and therefore we summarized the important morphological and morphometric characters in tabular form for easy and efficient species identification. Moreover, we discuss the associated hosts and the distribution of all described Boleodorus species. This study will serve as a guide and basic framework for species diagnostics in the genus Boleodorus and will aid in filling the gaps in our knowledge of the species present in our cultivated lands. [ABSTRACT FROM AUTHOR]

Pin nematodes (Paratylenchus spp.) are polyphagous parasitic species with a wide host range and geographical distribution; their diversity is unknown in the potato growing region of Alberta, Canada. The present study aims to provide morphological and molecular characterization of three pin nematode species, namely P. neoprojectus, P. tateae, and a new species, Paratylenchus enigmaticus sp. nov. All of them were recovered from the potato growing region of southern Alberta. The nematodes were isolated using the sieving and flotation-centrifugation method, and their morphology was assessed by light microscopy. Molecular characterization was performed using partial 18S, D2–D3 expansion domains of the 28S and ITS ribosomal genes. This study is the first report of molecular characterization of P. tateae and P. neoprojectus, being new records from southern Alberta, and two Spanish populations of P. tateae comprising the first report of this species in Europe. The phylogenetic analysis of the 18S, D2–D3 expansion domains of the 28S and ITS ribosomal DNA regions underscores the importance of using molecular data for accurate species identification and clarifies the status of P. nanus type B and P. sheri. Moreover, our findings will be useful to determine the impact of pin nematodes on potato production in future field research. [ABSTRACT FROM AUTHOR]

Protein disulfide isomerase (PDI) is a multifunctional enzyme that catalyzes rate-limiting reactions such as disulfide bond formation, isomerization, and reduction. There is some evidence that indicates that PDI is also involved in host-pathogen interactions in plants. In this study, we show that the rice root-knot nematode, Meloidogyne graminicola, has evolved a secreted effector, MgPDI2, which is expressed in the subventral esophageal glands and up-regulated during the early parasitic stage of M. graminicola. Purified recombinant MgPDI2 functions as an insulin disulfide reductase and protects plasmid DNA from nicking. As an effector, MgPDI2 contributes to nematode parasitism. Silencing of MgPDI2 by RNA interference in the pre-parasitic second-stage juveniles (J2s) reduced M. graminicola multiplication and also increased M. graminicola mortality under H2O2 stress. In addition, an Agrobacterium-mediated transient expression assay found that MgPDI2 caused noticeable cell death in Nicotiana benthamiana. An intact C-terminal region containing the first catalytic domain (a) with an active motif (Cys-Gly-His-Cys, CGHC) and the two non-active domains (b and b′) is required for cell death induction in N. benthamiana. This research may provide a promising target for the development of new strategies to combat M. graminicola infections. [ABSTRACT FROM AUTHOR]

A new stunt nematode species, Geocenamus persici n. sp. was recovered from the rhizosphere of peach (Prunus persica) in Zhejiang Province, China. This species is characterized by a dome-shaped labial region with six bulging sectors. The lip region is slightly offset from the rest of the body with five annuli; cuticle with over 30 longitudinal striae; stylet slender, 19 to 21 m long; excretory pore at the anterior region of the basal pharyngeal bulb; tail cylindrical, 55 to 79 m long with striated terminus. Males are common. Morphologically, the species is close to G. brevicaudatus, G. chengi, G. conicaudatus, G. quadrifer, G. rugosus, and G. tartuensis. Phylogenetic relationships of the new species placed G. persici n. sp. with other species of subfamily Merliniinae. However, it has a sister relationship with G. chengi. Since the new species is found in the peach plantations, our study will lay a foundation to initiate investigations on the occurrence of stunt nematodes in peach growing areas and will aid the researchers to determine whether this group of nematodes cause peach plantation diseases.

A stunt nematode species, Quinisulcius curvus , recovered from the rhizosphere of sea randa ( Guettarda speciosa ), is described and characterized herein based on integrative taxonomy. Morphometrics and distribution of all reported populations of Q. curvus are also discussed. The Chinese population of Q. curvus displayed slight variation in stylet length; however, the rest of the characters matches well with the original description. This is the first record of Q. curvus from Hainan, China, and the first molecular characterization for this species. Phylogenetic analysis based on partial 18S, 28S and ITS sequences placed Q. curvus with related stunt nematodes species, but clearly separated from them. The present study expanded the geographic record and provided molecular data on Q. curvus from China., (© 2021 Authors.)

Two stunt nematode species, Geocenamus brevidens and Quinisulcius capitatus , were recovered from the potato growing regions of southern Alberta, described and characterized based on integrative taxonomy. Morphometrics, distribution, and host associations of both species are discussed. The Canadian populations of both species displayed minor variations in morphometrical characteristics (viz., slightly longer bodies and tails) from the original descriptions. The populations of G. brevidens and Q. capitatus species examined in this study are proposed as standard and reference populations for each respective species until topotype specimens become available and molecularly characterized. Phylogenetic analyses, based on partial 18S, 28S, and ITS sequences, placed both species with related stunt nematode species. The present study updates the taxonomic records of G. brevidens and Q. capitatus from a new location, southern Alberta, Canada, and will aid in the decision whether these stunt nematodes should be included in nematode management programs., (© 2021 Authors.)

Three populations of neotylenchid nematodes were isolated in Ningbo, P. R. China, from white pine lumber (Pinus monticola) imported from the USA. The nematodes were morphologically intermediate between Hexatylus and Deladenus. The nematodes were molecularly characterized based on sequences of the rDNA small subunit 18S, large subunit 28S D2/D3, and internal transcribed spacer sequences. The phylogenetic inferences placed the nematodes with other neotylenchid nematodes, i.e., Fergusobia and Rubzovinema. Based on the morphology and phylogenetic analysis, this nematode is described herein as Delatylus andersoni n. gen., n. sp. The new genus/species is characterized by the female body habitus ranging from nonobese to semiobese and from straight to dorsally curved when heat relaxed, cephalic framework with six unequal sized lip sectors, lateral fields having 10 to 12 lines, 4 to 5 guide rings on the stylet, excretory pore posterior to the nerve ring, spermatheca diminished or absent, vulvar opening large, and relative proximity of vulva to the anus. Detailed morphological and molecular characterization of the new genus/species is presented along with the comparison of the related genera.

Populations of Criconemoides parvus , Discocriconemella hengsungica , and Discocriconemella limitanea , isolated in Hangzhou, China from the rhizosphere soil of woody perennials were characterized morphologically and molecularly. The morphometric data of the Chinese populations were compared with populations from other regions of the world. DNA barcoding with the mitochondrial COI gene confirmed conspecificity of Chinese and Costa Rican populations of D. limitanea . Phylogenetic assessment using a near full-length 18S ribosomal DNA sequence provided weak support for a grouping of Criconemoides parvus from China and C. annulatus from western North America. The phylogenetic position of D. hengsungica from China and an unknown species of Discocriconemella from Thailand relative to D. limitanea suggests that the genus Discocriconemella is not monophyletic. The study provides the first record of D. hengsungica in China and confirms the presence of C. parvus previously reported from China. Biogeographic implications of these nematode distributions are discussed., (© The Society of Nematologists.)