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1.
Int J Mol Sci ; 23(2)2022 Jan 11.
Article in English | MEDLINE | ID: mdl-35054970

ABSTRACT

The voltage-gated calcium channel (VGCC) ß subunit (Cavß) protein is a kind of cytosolic auxiliary subunit that plays an important role in regulating the surface expression and gating characteristics of high-voltage-activated (HVA) calcium channels. Ditylenchus destructor is an important plant-parasitic nematode. In the present study, the putative Cavß subunit gene of D. destructor, namely, DdCavß, was subjected to molecular characterization. In situ hybridization assays showed that DdCavß was expressed in all nematode tissues. Transcriptional analyses showed that DdCavß was expressed during each developmental stage of D. destructor, and the highest expression level was recorded in the third-stage juveniles. The crucial role of DdCavß was verified by dsRNA soaking-mediated RNA interference (RNAi). Silencing of DdCavß or HVA Cavα1 alone and co-silencing of the DdCavß and HVA Cavα1 genes resulted in defective locomotion, stylet thrusting, chemotaxis, protein secretion and reproduction in D. destructor. Co-silencing of the HVA Cavα1 and Cavß subunits showed stronger interference effects than single-gene silencing. This study provides insights for further study of VGCCs in plant-parasitic nematodes.


Subject(s)
Calcium Channels, L-Type/genetics , Gene Silencing , Phenotype , Protein Subunits/genetics , RNA, Double-Stranded/genetics , Tylenchida/physiology , Amino Acid Sequence , Animals , Calcium Channels, L-Type/chemistry , Chemotaxis/genetics , Gene Knockdown Techniques , Genetic Association Studies , Locomotion/genetics , Models, Molecular , Protein Biosynthesis , Protein Conformation , Protein Subunits/chemistry , RNA Interference , Reproduction/genetics , Structure-Activity Relationship , Tylenchida/genetics , Tylenchida/growth & development
2.
RNA Biol ; 18(10): 1424-1433, 2021 10.
Article in English | MEDLINE | ID: mdl-33218290

ABSTRACT

RNA interference (RNAi) is a powerful tool for gene functional analysis of plant-parasitic nematodes (PPNs). RNAi involving soaking in a dsRNA solution and in planta methods is commonly applied in the study of gene function in PPNs. However, certain problems restrict the application of these methods. Therefore, more convenient and effective RNAi methods need to be established for different PPNs according to their biological characteristics. In this study, the fatty acid and retinoid binding protein genes (Ab-far-1, Ab-far-4, and combinatorial Ab-far-1 and Ab-far-4) of the rice white tip nematode (RWTN), Aphelenchoides besseyi, were used as target genes to construct a fungal RNAi vector, and the Ab-far-n dsRNA transgenic Botrytis cinerea (ARTBn) were generated using Agrobacterium-mediated transformation technology. After RWTN feeding on ARTBn, the expression of Ab-far-1 and Ab-far-4 in the nematodes was efficiently silenced, and the reproduction and pathogenicity of the nematodes were clearly inhibited. The Ab-far-1 and Ab-far-4 co-RNAi effects were better than the effects when each gene was individually targeted with RNAi. Additionally, the RNAi induced when RWTNs fed on ARTB1 were persistent and heritable. Thus, a new method of fungus-mediated RNAi was established for fungivorous PPNs and was verified as effective and applicable to the study of nematode gene function. This technique will remove the technological bottlenecks and provide a new method to studying the multiple genes with polygene co-RNAi in fungivorous PPNs. This study also provides a theoretical basis and new thought for further study of the gene function in PPNs.Abbreviations: FAR(Fatty acid and retinol-binding proteins); RWTN (The rice white tip nematode, Aphelenchoides besseyi); Ab-far-n (Fatty acid and retinol binding protein gene of A. besseyi); ARTB1 (Ab-far-1 hpRNA transgenic Botrytis cinerea); ARTB4 (Ab-far-4 hpRNA transgenic Botrytis cinerea); ARTB1/4 (combinatorial Ab-far-1 and Ab-far-4 hpRNA transgenic B. cinerea); EVTB (Empty vector transgenic B. cinerea); GRTB (eGFP hpRNA transgenic B. cinerea); WTB (Wild-type B. cinerea).


Subject(s)
Botrytis/growth & development , Fatty Acid-Binding Proteins/genetics , Retinol-Binding Proteins/genetics , Tylenchida/growth & development , Animals , Botrytis/genetics , Gene Silencing , Helminth Proteins/genetics , Oryza/parasitology , RNA Interference , RNA, Double-Stranded/genetics , Transfection , Tylenchida/genetics , Tylenchida/metabolism
3.
Sci Rep ; 9(1): 591, 2019 01 24.
Article in English | MEDLINE | ID: mdl-30679719

ABSTRACT

Heterodera glycines is the most pervasive soybean pests worldwide. Biocontrol provides a strategy to sustainably control nematodes. In this study, 22 fungal isolates were obtained and identified from cysts of Heterodera spp. Among them, Aspergillus niger NBC001 showed high nematicidal activity against H. glycines. The 2-fold dilution of NBC001 culture filtrate caused 89% mortality of second-stage juveniles and inhibited more than 98% of egg hatching in vitro. In both pot and field experiments, the numbers of H. glycines cysts in soybean seedlings dressed with the the 5-fold concentrated culture filtrate of NBC001 were significantly reduced by 43% and 28%, respectively. In addition, application of NBC001 remarkably reduced the penetration of nematodes into the roots. Histochemical and fluorometric staining analyses indicate that application of NBC001 stimulated hydrogen peroxide activity in the roots and triggered callose deposition in the leaves and roots. Transcription of the PR1a and EREBP genes in the salicylic acid and ethylene signaling pathways was upregulated in soybean plants treated with NBC001. However, the application of concentrated culture filtrate of NBC001 had no significant impacts on the soil microbial community based on next generation DNA sequencing technology. In summary, NBC001 may be a good biocontrol agent against H. glycines via stimulation of the immunity/defense of the plant host.


Subject(s)
Aspergillus niger/physiology , Biological Control Agents/pharmacology , Tylenchida/drug effects , Animals , Aspergillus niger/isolation & purification , Hydrogen Peroxide/metabolism , Larva/drug effects , Larva/growth & development , Plant Diseases/microbiology , Plant Diseases/parasitology , Plant Diseases/prevention & control , Plant Leaves/metabolism , Plant Leaves/parasitology , Plant Proteins/genetics , Plant Roots/growth & development , Plant Roots/metabolism , Plant Roots/parasitology , Salicylic Acid/metabolism , Soil Microbiology , Glycine max/growth & development , Glycine max/metabolism , Glycine max/parasitology , Tylenchida/growth & development
4.
Int J Mol Sci ; 20(1)2019 Jan 08.
Article in English | MEDLINE | ID: mdl-30626082

ABSTRACT

The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the pathogen of pine wilt disease (PWD), resulting in huge losses in pine forests. However, its pathogenic mechanism remains unclear. The cathepsin L-like cysteine proteinase (CPL) genes are multifunctional genes related to the parasitic abilities of plant-parasitic nematodes, but their functions in PWN remain unclear. We cloned three cpl genes of PWN (Bx-cpls) by rapid amplification of cDNA ends (RACE) and analyzed their characteristics using bioinformatic methods. The tissue specificity of cpl gene of PWN (Bx-cpl) was studied using in situ mRNA hybridization (ISH). The functions of Bx-cpls in development and pathogenicity were investigated using real-time quantitative PCR (qPCR) and RNA interference (RNAi). The results showed that the full-length cDNAs of Bx-cpl-1, Bx-cpl-2, and Bx-cpl-3 were 1163 bp, 1305 bp, and 1302 bp, respectively. Bx-cpls could accumulate specifically in the egg, intestine, and genital system of PWN. During different developmental stages of PWN, the expression of Bx-cpls in the egg stage was highest. After infection, the expression levels of Bx-cpls increased and reached their highest at the initial stage of PWD, then declined gradually. The silencing of Bx-cpl could reduce the feeding, reproduction, and pathogenicity of PWN. These results revealed that Bx-cpls play multiple roles in the development and pathogenic processes of PWN.


Subject(s)
Cathepsin L/genetics , Pinus/parasitology , Tylenchida/growth & development , Tylenchida/pathogenicity , Animals , Cathepsin L/metabolism , Feeding Behavior , Gene Expression Regulation, Developmental , Phylogeny , Plant Diseases/parasitology , RNA Interference , RNA, Double-Stranded/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Reproduction/genetics , Sequence Analysis, DNA , Tylenchida/enzymology , Tylenchida/genetics
5.
Pest Manag Sci ; 75(6): 1734-1742, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30525290

ABSTRACT

BACKGROUND: Nacobbus aberrans (Tylenchida: Pratylenchidae) is one of the main plant-parasitic nematodes species that affects crops in Mexico, generating substantial economic losses. Traditionally, the control of the nematodes is carried out using chemical products; however, research efforts are presently focused on the search for new methods for the control of this pest. Natural products derived from plants are an alternative for the control of populations of plant-parasitic nematodes. The genus Heterotheca (Asteraceae) is characterized by containing sesquiterpenes with cadinane skeleton, and some species of this genus exert nematicidal activity. RESULTS: We determined the effects of selected Heterotheca inuloides plant metabolites and some semisynthetic derivatives on the hatching of eggs isolated from the gelatinous matrix and infective second-stage juveniles (J2) of the false root-knot nematode N. aberrans using an in vitro experimental model. Among the evaluated compounds, nematodes were more susceptible to hydroxylated and quinone compounds, whereas the remaining compounds showed moderate or no activity. The presence of the hydroxyl group is essential for nematicidal potential, with changes at the hydroxyl group modifying the nematicidal activity. CONCLUSION: Flowers of Heterotheca inuloides contain bioactive compounds that showed nematicidal activity against N. aberrans. Here we report the nematicidal activities of cadinenes isolated from the flowers of H. inuloides and their semisynthetic derivatives against the false root-knot nematode N. aberrans. © 2018 Society of Chemical Industry.


Subject(s)
Antinematodal Agents/toxicity , Asteraceae/metabolism , Asteraceae/parasitology , Biological Products/toxicity , Sesquiterpenes/toxicity , Tylenchida/drug effects , Animals , Antinematodal Agents/metabolism , Biological Products/metabolism , Flowers/metabolism , Oviposition/drug effects , Tylenchida/growth & development , Tylenchida/physiology
6.
J Helminthol ; 94: e16, 2018 Nov 29.
Article in English | MEDLINE | ID: mdl-30486905

ABSTRACT

A new species of Paurodontoides, P. siddiqii n. sp., is described and illustrated based on its morphological, morphometric, and molecular characters. The new species is characterized by a female 550-729 µm long, lip region continuous with body contour, stylet length 7.0-8.0 µm long or c. 1.0-1.2 times the lip region diameter, lateral fields with four smooth incisures, excretory pore at 85-125 µm from anterior end located at the base of the pharyngeal bulb or posterior to it, basal pharyngeal bulb with a short posterior extension projecting into the intestine, monodelphic-prodelphic reproductive system with prominent 19-22 µm long post-uterine sac, and elongate conoid tail with a filiform terminus. The new species is compared with two known species of the genus. It differs from the type species of the genus, P. linfordi, by having slightly shorter stylet, lateral field with smooth incisures, different position of the excretory pore, and absence of male. Compared to P. latus, the new species has a shorter body, shorter stylet, different position of the excretory pore, female tail shape and absence of male. The new species was also compared with close species of the genus Paurodontus because of lateral field marked with four lines, asymmetrical stylet knobs and absence of male. Molecular phylogenetic studies of the new species using partial sequences of 18S rDNA revealed that it forms a clade with a species of the genus Ficotylus. In phylogenetic analyses using partial sequences of the 28S rDNA D2-D3 domain, the new species formed a monophyletic group with a species of the genus Veleshkinema and Sphaerularia spp. (Sphaerulariinae).


Subject(s)
Genitalia/growth & development , Pinus/parasitology , Plant Bark/parasitology , Tylenchida/growth & development , Tylenchida/genetics , Animals , Body Size , DNA, Helminth/genetics , DNA, Ribosomal/genetics , Female , Genitalia/anatomy & histology , Iran , Male , Phylogeny , Tylenchida/classification , Tylenchida/isolation & purification
7.
Sci Rep ; 8(1): 15938, 2018 10 29.
Article in English | MEDLINE | ID: mdl-30374104

ABSTRACT

The harlequin ladybird Harmonia axyridis is native to Asia but has been introduced into many countries as a biological control agent. It is now considered an invasive pest, threatening the biodiversity of native ladybirds globally, in part because of its superior immune system. H. axyridis is infected and killed by the parasitic nematode Parasitylenchus bifurcatus, which could therefore be developed as a biological strategy to counter the spread of this insect pest. However, effective control requires an understanding of the tripartite relationship between H. axyridis, P. bifurcatus and their potential bacterial mutualists. Here we describe the isolation of two species of nematode-associated bacteria (Serratia marcescens and Providencia rettgeri) which were highly virulent against H. axyridis in survival experiments. In addition, contact between the nematodes and beetles led to the sex-specific modulation of multiple host immunity-related genes after 24 and 48 h, with many genes encoding antimicrobial peptides rapidly and stably repressed in females whereas the same genes were initially induced in males before suppression at the later time point. These data provide evidence that the female immune system responds much more strongly to the nematodes and provokes, in turn, a more robust invasion strategy involving the bacterial mutualists.


Subject(s)
Coleoptera/parasitology , Enterobacteriaceae/pathogenicity , Immune System/metabolism , Tylenchida/microbiology , Animals , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/metabolism , Coleoptera/immunology , Coleoptera/metabolism , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Female , Gene Expression , Larva/microbiology , Male , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/metabolism , Symbiosis , Tylenchida/growth & development , Tylenchida/isolation & purification , Virulence
9.
Pest Manag Sci ; 73(5): 888-895, 2017 May.
Article in English | MEDLINE | ID: mdl-27414986

ABSTRACT

BACKGROUND: Bursaphelenchus xylophilus is a serious quarantined pest that causes severe damage and major economic losses to pine forests. Because of the adverse effects of some traditional nematicides on humans and the environment, the search for new plant toxicants against these nematodes has intensified. Nematicidal activity of trans-2-hexenal, which is a six-carbon aldehyde present in many plants, was tested against the nematode. RESULTS: trans-2-Hexenal showed significant efficacy against B. xylophilus in a dose range of 349.5-699 g m-3 by fumigation of pinewood logs. Additionally, it had significant nematicidal activity against different life stages of B. xylophilus in an in vitro test, with second-stage larvae (L2s) being the most sensitive, with an LC50 value of 9.87 µg mL-1 at 48 h. Egg hatch was also significantly inhibited. Further studies revealed that trans-2-hexenal inhibited the reproductive activity of B. xylophilus, with negative effects on reproduction rate and egg numbers. Moreover, trans-2-hexenal reduced the body length of B. xylophilus. Respiratory rate and thrashing behaviour of B. xylophilus also decreased following treatment with this compound. CONCLUSION: trans-2-Hexenal had significant nematicidal activity against B. xylophilus, providing a basis for elucidation of the mode of action of trans-2-hexenal against plant-parasitic nematodes in future studies. © 2016 Society of Chemical Industry.


Subject(s)
Aldehydes/pharmacology , Behavior, Animal/drug effects , Tylenchida/drug effects , Tylenchida/physiology , Animals , Female , Fumigation , Locomotion/drug effects , Male , Oviposition/drug effects , Pinus/parasitology , Reproduction/drug effects , Respiration/drug effects , Tylenchida/growth & development , Tylenchida/metabolism
10.
Zootaxa ; 4168(3): 541-556, 2016 Sep 16.
Article in English | MEDLINE | ID: mdl-27701326

ABSTRACT

Two new species of Seinura are described and illustrated using both morphological and molecular characters. Seinura persica n. sp. is characterized by having females with a distinct cephalic region, stylet 19.5 (18-20) µm long, four incisures in the lateral fields, position of excretory pore anterior to the base of metacorpus, post-uterine sac 54.8 (50-60) µm long, and an elongate-conoid tail with a shallow depression on the dorsal side ending in a sharply pointed tip. Males have body length of 467 and 592 µm, spicules 15 and 16 µm long with a prominent triangular-shaped rostrum, developed condylus and no cucullus. Seinura hyrcania n. sp. is characterized by having an offset lip region, stylet 21.5 (18-24) µm long, three incisures in the lateral fields, excretory pore anterior to the base of the metacorpus, post-uterine sac 19 (12-25) µm long and conical tail ending in a filiform terminus. Morphological and morphometric diagnostic characters together with molecular data based on partial sequences of SSU and LSU of the ribosomal DNA gene are provided for these new species.


Subject(s)
Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , DNA, Ribosomal/genetics , Ecosystem , Female , Iran , Male , Organ Size , Phylogeny , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development , Wood/parasitology
11.
Zootaxa ; 4083(2): 297-300, 2016 Feb 19.
Article in English | MEDLINE | ID: mdl-27394233

ABSTRACT

Identification of nematode species by using conventional methods requires fixation of the isolated material and a suitable preparation for further analyses. Tentative identification using microscopic methods should also be performed prior to initiating molecular studies. In the literature, various methods are described for the preparation of nematodes from the genus Aphelenchoides for identification and microscopic studies. The most commonly used fixatives are formalin (Timm 1969; Szczygiel & Cid del Prado Vera 1981, Crozzoli et al. 2008, Khan et al. 2008), FAA (Wasilewska 1969; Vovlas et al. 2005, Khan et al. 2007) and TAF (Hooper 1958, Chizhov et al. 2006, Jagdale & Grewal 2006).


Subject(s)
Fixatives/chemistry , Tissue Fixation/instrumentation , Tylenchida/anatomy & histology , Tylenchida/chemistry , Animal Structures/anatomy & histology , Animal Structures/chemistry , Animal Structures/growth & development , Animals , Body Size , Female , Organ Size , Tissue Fixation/methods , Tylenchida/growth & development
12.
J Invertebr Pathol ; 134: 12-14, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26724378

ABSTRACT

The Kamona strain of the nematode Deladenus siricidicola has been extensively used as a biological control agent against invasive Sirex noctilio woodwasps in the Southern Hemisphere, where it sterilizes female hosts. In North America, a non-sterilizing (NS) strain of D. siricidicola, thought to have been introduced with S. noctilio, is commonly found parasitizing this invasive woodwasp. Species of Deladenus that parasitize Sirex have a parasitic form, as well as a mycophagous form. The mycophagous form feeds on Sirex fungal symbionts in the genus Amylostereum. The goal of this study was to compare reproduction of NS and Kamona D. siricidicola when feeding on four isolates of Amylostereum areolatum (three introduced and one native in North America) and one native strain of Amylostereum chailletii isolated from Sirex nigricornis. Mycophagous forms of the two D. siricidicola strains displayed relatively similar production of offspring when feeding on most of the A. areolatum found associated with S. noctilio in this continent, except for strain BD on which NS produced more offspring than the biological control strain Kamona. Growth of both nematodes was greater on the introduced versus the native A. areolatum isolates.


Subject(s)
Basidiomycota/physiology , Tylenchida/growth & development , Wasps/parasitology , Animals , Biological Assay , Feeding Behavior , Female , Pest Control, Biological , Symbiosis , Tylenchida/physiology , Wasps/microbiology
13.
Zootaxa ; 4013(2): 207-24, 2015 Sep 08.
Article in English | MEDLINE | ID: mdl-26623893

ABSTRACT

Few Aphelenchoides spp. are facultative plant-parasites (foliar and bulb nematodes); three of them are well known in agricultural systems, namely Aphelenchoides besseyi, A. fragariae and A. ritzemabosi. Ten other plant-parasitic species, A. arachidis, A. bicaudatus, A. blastophthorus, A. dalianensis, A. ensete, A. nechaleos, A. paranechaleos, A. saprophilus, A. sphaerocephalus and A. subtenuis, have been reported from a limited number of plant species. We compiled a new database of the associated plants for these thirteen species, a comprehensive list that includes 1104 reports from 126 botanical families. A. besseyi, A. fragariae and A. ritzemabosi represent 94% of the reports, circa 83% and 16% of the total reports correspond to flowering plants and ferns, respectively, with three records on conifers and two from other botanical groups also listed. Most plant-parasitic Aphelenchoides show a remarkably broad diversity of associated plants. Most species appear to have no specific plant hosts (i.e. are generalists). The broad host ranges of these species and absence of more intimate interactions with the associated plants highlights the primitive mode of parasitism in Aphelenchoides species, making them potentially interesting in the study of the evolution of plant parasitism. Even though the compiled list of associated plants is long, it probably only represents a fraction of the potential range. The complete compilation has been uploaded to http://nematodes.myspecies.info/.


Subject(s)
Plant Diseases/parasitology , Tylenchida/classification , Animal Distribution , Animals , Ecosystem , Phylogeny , Plants/classification , Plants/parasitology , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development
14.
Zootaxa ; 3915(4): 591-600, 2015 Feb 05.
Article in English | MEDLINE | ID: mdl-25662146

ABSTRACT

Laimaphalenchus hyrcanus n. sp., from bark samples of cypress (Cupressus sp.) and jujube (Ziziphus jujube Miller) from Gorgan, Golestan province in northern Iran, is described and illustrated based on morphological and molecular characters. The new species is characterized by females with 670-870 µm body length, slender stylet of 11-12 µm, six-lobed cephalic region not divided by ribs, three incisures in the lateral field with slightly areolated outer lines in the posterior region, cuticular vulval flap, males with two pairs of caudal papillae, and subcylindrical tail in both sexes ending in a single stalk-like terminus with four pedunculate tubercles bearing 9-10 finger-like projections. The new species most closely resembles L. persicus and L. penardi but it can be differentiated by its having three incisures in the lateral field and two pairs of caudal papillae in males. Molecular analysis of the D2/D3 region of the 28S ribosomal RNA gene indicates a sister-taxon relationship with L. penardi (Steiner, 1914) Filipjev & Schuurmans Stekhoven, 1941 and L. deconincki Elmiligy & Geraert, 1972. 


Subject(s)
Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Ecosystem , Female , Iran , Male , Organ Size , Phylogeny , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development
15.
Zootaxa ; 3889(2): 214-36, 2014 Dec 01.
Article in English | MEDLINE | ID: mdl-25544140

ABSTRACT

Two new species of Fergusobia, collected from 'rosette' shoot bud galls on Melaleuca quinquenervia, and from leaf, stem, leaf and flower bud galls on Syzygium luehmannii, both from the Cairns region of Queensland, Australia, are described. Fergusobia rosettae Davies n. sp. is characterised by the combination of a small, arcuate parthenogenetic female having a short conoid tail with a bluntly rounded tip, an arcuate, relatively slender, infective female with an almost hemispherical tail tip, and arcuate males with arcuate to angular (not heavily sclerotised) spicules and leptoderan bursa arising at 40-50% of body length from tail tip. Fergusobia tolgaensis Davies n. sp. is characterised by the combination of a small open C-shaped parthenogenetic female with a broadly conoid tail, an arcuate infective female with a broadly rounded tail tip, and arcuate males with angular (not heavily sclerotised) spicules and short to mid-length leptoderan bursa. These two species of nematodes are associated with fly larvae that have dorsal shields comprising bars of raised cuticular ridges and spicules, similar to that of fly larvae from the M. leucadendra species group. The shield morphologies of these fly larvae and their possible genetic relationships are discussed. Possible evolutionary relationships of the Fergusobia nematodes from these galls are discussed, considering their morphology, DNA sequences, and the relationships of the associated Fergusonina flies and host plants.


Subject(s)
Melaleuca/parasitology , Plant Tumors/parasitology , Syzygium/parasitology , Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Female , Male , Organ Size , Phylogeny , Queensland , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development
16.
Zootaxa ; 3889(2): 237-58, 2014 Dec 01.
Article in English | MEDLINE | ID: mdl-25544141

ABSTRACT

Three new species of Fergusobia, respectively collected from shoot bud galls on narrow-leaved Melaleuca spp. in Australia, are described. Fergusobia armillarisae n. sp. Davies is characterised by the combination of an arcuate to open C-shaped parthenogenetic female with an extensile uterus and a short, conoid tail, an arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 50-80% of body length. Fergusobia decorae n. sp. Davies has an arcuate parthenogenetic female with a non-extensile uterus and a broadly conoid tail, an arcuate infective female with most curvature behind the vulva and a short tail with a broadly rounded tip, and an arcuate male with an arcuate spicule and bursa arising at 40-50% of body length. Fergusobia linariifoliae n. sp. Davies is characterised by the combination of an arcuate parthenogenetic female with an extensile uterus and a short, conoid tail with a bluntly rounded tip, a barely arcuate infective female with a broadly rounded tail tip, and an arcuate male with an angular spicule and bursa arising at 40-50% of body length. Earlier molecular analyses inferred from DNA sequencing of 28S rDNA D2/D3 domains and a portion of mitochondrial DNA cytochrome oxidase subunit I (mtCOI) are further discussed. 


Subject(s)
Melaleuca/parasitology , Plant Tumors/parasitology , Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Australia , Body Size , Female , Male , Organ Size , Phylogeny , Plant Leaves/parasitology , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development
17.
Zootaxa ; 3856(3): 326-48, 2014 Aug 25.
Article in English | MEDLINE | ID: mdl-25284662

ABSTRACT

Collection data and biological information is presented on the Fergusobia (Nematoda: Neotylenchidae)/ Fergusonina (Diptera: Fergusoninidae) mutualism inducing galls on Angophora in Australia. Three species and two morphospecies have been recognised. Fergusobia colbrani Davies n. sp. is described from soft spheroid leaf galls on Angophora floribunda. It is characterised by a combination of morphological characters including a small C-shaped parthenogenetic female with a short broadly conoid tail, an arcuate infective female with an almost hemispherical tail tip, and an arcuate to barely J-shaped male with an angular spicule having a notched tip and mid-length leptoderan bursa. A key to the species and morphospecies of nematodes collected from Angophora is presented. Possible relationships of these organisms are discussed based on evidence from the nematode morphology, gall forms, and the morphology of the dorsal shield of the associated Fergusonina fly larvae. 


Subject(s)
Myrtaceae/parasitology , Plant Tumors/parasitology , Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Australia , Body Size , Female , Male , Organ Size , Tylenchida/anatomy & histology , Tylenchida/growth & development , Tylenchida/isolation & purification
18.
Zootaxa ; 3856(4): 529-54, 2014 Aug 26.
Article in English | MEDLINE | ID: mdl-25284673

ABSTRACT

Fergusobia tumifaciens (Currie 1937) Wachek 1955, the type species for the genus Fergusobia, is re-described from specimens collected from 'leafy' leaf bud galls on Eucalyptus bridgesiana near Albury in New South Wales, Australia. It is morphologically characterized by the combination of an open C-shaped parthenogenetic female with a small broadly conoid tail, a C-shaped infective female with a bluntly rounded tail tip, and an arcuate to J-shaped male with angular spicules, not heavily sclerotised, and short to mid-length peloderan bursa. Two new species of Fergusobia, collected from 'leafy' leaf bud galls on, respectively, Eucalyptus planchoniana in Queensland, and E. viminalis in South Australia, Australia, are described. Fergusobia planchonianae Davies n. sp. is characterised by the combination of a C-shaped parthenogenetic female with a conoid tail, an arcuate infective female with an hemispherical tail tip, and an almost straight to arcuate to C-shaped male with an angular spicule, a long peloderan bursa and a narrow tail. Fergusobia viminalisae Davies n. sp. is characterised by the combination of an open C-shaped parthenogenetic female with a broadly conoid tail, a C-shaped infective female with a bluntly rounded tail tip, and an arcuate to J-shaped male with an angular (not heavily sclerotised) spicule and short to mid-length peloderan bursa. The shield morphologies of the fly larvae associated with the 'leafy' leaf bud galls and their possible relationships are outlined. Possible evolutionary relationships of the Fergusobia nematodes from these galls are discussed, considering their morphology, DNA sequences, and the relationships of the associated Fergusonina flies and host plants. 


Subject(s)
Myrtaceae/parasitology , Plant Leaves/parasitology , Plant Tumors/parasitology , Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Australia , Body Size , Female , Male , Molecular Sequence Data , Organ Size , Phylogeny , Tylenchida/anatomy & histology , Tylenchida/genetics , Tylenchida/growth & development
19.
Zootaxa ; 3841(2): 151-87, 2014 Jul 25.
Article in English | MEDLINE | ID: mdl-25082035

ABSTRACT

Morphological and morphometric analyses were conducted on the genus Paratylenchus, based on documented data in the literature and characters of Iranian populations of twelve species, including P. arculatus, P. colinus, P. conicephalus, P. coronatus, P. neoamblycephalus, P. neoprojectus, P. obtusicaudatus, P. paraperaticus, P. similis, P. straeleni, P. variabilis and P. veruculatus. Moreover, males of P. obtusicaudatus are described for the first time and additional data provided for males of P. paraperaticus. The variability of the most important taxonomic characters for species identification in the genus was estimated by calculation of coefficient of variation (CV) for 49 species and the ratio of extremes in the range of measured females (max/min ratios) for 82 species of the genus, based on 66 and 170 populations, respectively. A list of 117 valid species of Paratylenchus is provided, along with a dichotomous identification key and a diagnostic compendium. 


Subject(s)
Tylenchida/classification , Animal Distribution , Animal Structures/anatomy & histology , Animal Structures/growth & development , Animals , Body Size , Female , Male , Organ Size , Plant Diseases/parasitology , Tylenchida/anatomy & histology , Tylenchida/growth & development , Tylenchida/isolation & purification
20.
Dongwuxue Yanjiu ; 34(E4-5): E140-2, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24115672

ABSTRACT

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.


Subject(s)
Plant Diseases/parasitology , Tylenchida/isolation & purification , Zea mays/parasitology , Animals , China , Female , Male , Soil/parasitology , Tylenchida/classification , Tylenchida/growth & development
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