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Irvine, Allister, Sharon A. Huws, Louise E. Atkinson, and Angela Mousley. "Exploring the antimicrobial peptidome of nematodes through phylum-spanning in silico analyses highlights novel opportunities for pathogen control." PLOS Neglected Tropical Diseases 17, no. 9 (September 6, 2023): e0011618. http://dx.doi.org/10.1371/journal.pntd.0011618.
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Antimicrobial Peptides (AMPs) are key constituents of the invertebrate innate immune system and provide critical protection against microbial threat. Nematodes display diverse life strategies where they are exposed to heterogenous, microbe rich, environments highlighting their need for an innate immune system. Within the Ecdysozoa, arthropod AMPs have been well characterised, however nematode-derived AMP knowledge is limited. In this study the distribution and abundance of putative AMP-encoding genes was examined in 134 nematode genomes providing the most comprehensive profile of AMP candidates within phylum Nematoda. Through genome and transcriptome analyses we reveal that phylum Nematoda is a rich source of putative AMP diversity and demonstrate (i) putative AMP group profiles that are influenced by nematode lifestyle where free-living nematodes appear to display enriched putative AMP profiles relative to parasitic species; (ii) major differences in the putative AMP profiles between nematode clades where Clade 9/V and 10/IV species possess expanded putative AMP repertoires; (iii) AMP groups with highly restricted profiles (e.g. Cecropins and Diapausins) and others [e.g. Nemapores and Glycine Rich Secreted Peptides (GRSPs)] which are more widely distributed; (iv) complexity in the distribution and abundance of CSαβ subgroup members; and (v) that putative AMPs are expressed in host-facing life stages and biofluids of key nematode parasites. These data indicate that phylum Nematoda displays diversity in putative AMPs and underscores the need for functional characterisation to reveal their role and importance to nematode biology and host-nematode-microbiome interactions.
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Haegeman, Annelies, John T. Jones, and Etienne G. J. Danchin. "Horizontal Gene Transfer in Nematodes: A Catalyst for Plant Parasitism?" Molecular Plant-Microbe Interactions® 24, no. 8 (August 2011): 879–87. http://dx.doi.org/10.1094/mpmi-03-11-0055.
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The origin of plant parasitism within the phylum Nematoda is intriguing. The ability to parasitize plants has originated independently at least three times during nematode evolution and, as more molecular data has emerged, it has become clear that multiple instances of horizontal gene transfer (HGT) from bacteria and fungi have played a crucial role in the nematode's adaptation to this new lifestyle. The first reported HGT cases in plant-parasitic nematodes were genes encoding plant cell wall–degrading enzymes. Other putative examples of HGT were subsequently described, including genes that may be involved in the modulation of the plant's defense system, the establishment of a nematode feeding site, and the synthesis or processing of nutrients. Although, in many cases, it is difficult to pinpoint the donor organism, candidate donors are usually soil dwelling and are either plant-pathogenic or plant-associated microorganisms, hence occupying the same ecological niche as the nematodes. The exact mechanisms of transfer are unknown, although close contacts with donor microorganisms, such as symbiotic or trophic interactions, are a possibility. The widespread occurrence of horizontally transferred genes in evolutionarily independent plant-parasitic nematode lineages suggests that HGT may be a prerequisite for successful plant parasitism in nematodes.
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Gdemakarti, Yoshua, Bainah Sari Dewi, I. Gede Swibawa, and Irwan Sukri Banuwa. "KOMUNITAS NEMATODA TANAH DI BLOK LINDUNG HUTAN PENDIDIKAN KONSERVASI TERPADU TAMAN HUTAN RAYA WAN ABDUL RACHMAN." Jurnal Hutan Tropis 9, no. 1 (April 18, 2021): 13. http://dx.doi.org/10.20527/jht.v9i1.10464.
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Hutan Pendidikan Konservasi Terpadu (HPKT) is part of Taman Hutan Raya Wan Abdul Rachman (Tahura WAR) enabled to support educational activities and research. The quality of the soil in this area is influenced by several factors, one of the factors i.e. nematodes. The aim of study to know the community of nematodes on the Protection Block, Hutan Pendidikan Konservasi Terpadu, Wan Abdul Rachman Forest Park. The research was conducted in April to May 2018. The soil samples were taken on arboretum seven, arboretum eight, arboretum nine and arboretum 10. Nematode observations were conducted in the laboratory of Plant Pests, Faculty of Agriculture, University of Lampung. Nematodes have been identified to genus level based on morphological traits. The result of study showed that there are 29 genus of nematode consists of 17 plant parasitic nematode genera, seven nematoda bacterial-feeding, three nematode fungal-feeding, one omnivore nematode and one predator nematode. The dominant nematode genera are Criconomella, Helycotylenchulus dan Rotylenchulus. The abundance of nematodes ranges from 251-613 individuals / 300cc soil. The diversity of soil nematodes based on the Shannon-Wienner index ranges from 2.33-2.62. The Shannon-Whienner Index criteria are classified as moderate. The Simpson Index ranges from 0.862-0.907. The highest similarity index genus in arboretum seven with arboretum nine and arboretum eight with arboretum nine with a value of 0.81. The lowest in arboretum seven and arboretum 10 that is 0.63.
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Grewal, Parwinder S., Edwin E. Lewis, and Sudha Venkatachari. "Allelopathy: a possible mechanism of suppression of plant-parasitic nematodes by entomopathogenic nematodes." Nematology 1, no. 7 (1999): 735–43. http://dx.doi.org/10.1163/156854199508766.
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Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.
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Indarti, Siwi, Arif Wibowo, Siti Subandiyah, and Miftahul Ajri. "First Record: A Stem and Bulb Plant Parasitic Nematode at Garlic Area Centre Temanggung, Central Java, Indonesia with Species Reference to Ditylenchus dipsaci." Jurnal Perlindungan Tanaman Indonesia 22, no. 2 (November 15, 2018): 233. http://dx.doi.org/10.22146/jpti.35321.
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A survey to investigate the stem and bulb plant parasitic nematode at one of garlic area centre, in Temanggung, Central Java, Indonesia was conducted from Januaryto February 2018. Infected plant with specific symptoms, morphological and morphometric characters both of female and male of adult nematodes were used to describe a A1 quarantine plant parasitic nematode Ditylenchus dipsaci. Seven from nine observed locations were postively infected with population in average 2.67 nematodes per 100 g of soil and 2.67–189.33 per bulb. This is the first report of D. dipsaci from Indonesia and consequently further investigations were needed to know their distribution and also to confirm the origin of the nematode. IntisariSurvei keberadaan nematoda parasit batang dan umbi dilakukan pada bulan Januari–Februari 2018 pada satu sentra penangkaran bawang putih di Temanggung, Jawa Tengah, Indonesia. Tanaman terinfeksi dengan gejala serangan yang spesifik, karakter morfologi dan morfometri nematoda betina dan jantan dewasa dipergunakan dalam identifikasi Ditylenchus dipsaci yang merupakan nematoda parasit tanaman yang termasuk OPTK A1 (Organisme Pengganggu Tanaman Karantina A1) di Indonesia. Sebanyak tujuh dari sembilan lokasi yang diamati mengindikasikan positif sebagai daerah sebaran nematoda tersebut dengan populasi rata-rata 2,67 ekor per 100 gram tanah dan 2,67–189,33 nematoda per umbi. Laporan pertama tentang nematoda D. dipsaci ini membawa konsekuensi perlunya penelitian lebih lanjut untuk mengetahui daerah sebaran dan juga konfirmasi dari mana nematoda tersebut berasal.
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Ono, Masaya, Yoichi Hayakawa, and Toyoshi Yoshiga. "Bacterial feeding nematodes ingest haemocytes in the haemocoel of the insect Galleria mellonella." Parasitology 147, no. 3 (November 18, 2019): 279–86. http://dx.doi.org/10.1017/s0031182019001550.
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AbstractInsect parasitic nematodes have acquired mechanisms to evade their host immune response for successful parasitism. Despite the importance of understanding of the evolution of evasion mechanisms from host immunity, insect immune response against non-parasitic nematodes has not been well studied. In our previous study, we demonstrated that a non-insect parasitic nematode Caenorhabditis elegans was not encapsulated by haemocytes in the larvae of the greater wax moth Galleria mellonella. To understand how nematodes influence insect haemocytes to escape encapsulation, we examined the effect of C. elegans on haemocytes in the haemocoel of G. mellonella larvae. Injection of nematodes resulted in the decrease of haemocyte density while mortality and spreading ability of haemocytes, the haematopoietic organs were not affected. In vitro co-incubation of haemocytes with nematodes resulted in a decrease of haemocyte density and we observed feeding on haemocytes by nematodes. Injection of C. elegans feeding-delay mutants into insects did not cause the decrease of haemocyte density. The decrease of haemocyte density was due to the nematode's ingestion of haemocytes. Furthermore, an entomopathogenic nematode and other bacterial feeding nematodes also showed similar feeding behaviour. The nematode's ability to feed on haemocytes may have played an important role in the evolution of nematode parasitism in bacterial-feeding nematodes.
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Reyes-Torres, Limarie Judith, Yazminne Meléndez-Torres, and Alonso Ramírez. "Ocurrencia de nemátodos en ninfas de Ephemeroptera en una quebrada de bosque tropical lluvioso." Intropica 11 (December 21, 2016): 67. http://dx.doi.org/10.21676/23897864.1863.
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Nematodes are common symbionts of aquatic insects. Here, we assessed the presence of nematodes in mayfly nymphs (Ephemeroptera), evaluated their prevalence in the population, and determined factors associated with nematode presence. Mayflies were collected (n = 130) from three stream habitats (riffles, pools, and boulders) using a D net, in Prieta stream, El Verde Field Station, Puerto Rico. Mayflies were dissected and nematode presence was determined under a light microscope (4 x and 10 x). Nematode prevalence was 50 %. Nematodes were not identified beyond Phylum level, but we were able to eliminate various groups as infective agents (Nematoda: Mermithidae and Nematomorpha: Gordiida). They were mostly found in the abdomen, head or thorax of mayflies. There were differences in infection among taxa, Neohagenulus was the group with the highest proportion of infection. Mayfly body shape, feeding strategy, or activity potentially explain differences in infection among taxa. There were no differences in infection among habitats, but mayflies were less abundant in riffles; and there was no relation between mayfly body length and the number of nematodes present. To our knowledge, this is the first report of a nematode present in mayfly nymphs in Puerto Rico.
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Panjerrino, Yoshua Gdemakarti, Bainah Sari Dewi, and I. Gede Swibawa. "Diversity of Soil Nematode in Utilization Block Integrated Educational Conservation Forest, Wan Abdul Rachman Great Forest Park." Jurnal Sylva Lestari 7, no. 2 (June 18, 2019): 214. http://dx.doi.org/10.23960/jsl27214-224.
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Change of land forest in Wan Abdul Rachman Forest Park became agroforestry, affect of cover condition and decrease the content of soil matter. Nematode was one of the soils biotas that can be used as an indicator of change in the soil status. The aim of study is to know the community and diversity of nematodes on the Utilization Block, Integrated Educational Conservation Forest, Wan Abdul Rachman Great Forest Park. The research was conducted in April to May 2018. The soil samples were taken on arboretum one, arboretum two, arboretum three and arboretum four in Integrated Educational Conservation Forest, Wan Abdul Rachman Great Forest Park. Nematode observations were conducted in the Plant Pests Laboratory, Faculty of Agriculture, University of Lampung. Nematodes was identified to genus level based on morphological traits. The analysis used were including the index of diversity, dominance and similarities between genus arboretum. The results showed that there were 30 genus of nematode consists of 19 plant parasitic nematode genera, six nematoda bacterial-feeding, three nematode fungal-feeding and two predator nematodes. The dominant nematode genera were Criconomella, Helycotylenchulus and Rotylenchulus. The abundance of nematodes ranges from 171-617 individuals/300cm3 soil. The diversity of soil nematodes based on the Shannon-Wienner index ranges from 2,47 – 2,80. The Shannon-Whienner Index criteria were classified as moderate. The Simpson Index ranges from 0,89 – 0,93. The highest similarity index genus in arboretum three and four with a value of 0,81 and the lowest in arboretum two and three which is 0,54. Key words: nematodes community, Integrated Educational Conservation Forest, Wan Abdul Rachman Great Forest Park
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Bird, A. F. "The influence of the actionmycete,Pasteuria penetrans, on the host–parasite relationship of the plant-parasitic nematode,Meloidogyne javanica." Parasitology 93, no. 3 (December 1986): 571–80. http://dx.doi.org/10.1017/s0031182000081270.
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SUMMARYThe actinomycete,Pasteuria penetrans, is a specific endoparasite of various plant-parasitic nematodes. When parasitizing the root-knot nematode (Meloidogyne javanical) the nematode's capacity to reproduce is destroyed and feeding on and stimulation of the plant host are unaffected even though the bulbous body of the female nematode becomes filled with spores. Parasitism by the actinomycete does not alter the rate of growth in the early stages of nematode development although the non-parasitized female grows more rapidly than the parasitized one for a short time immediately after the final moult.Pasteuriadid not invade or inactivate the anterior oesophageal region of the femaleMeloidogyneor influence the morphology of the giant cells induced by these nematodes in their hosts' roots. The influence of this parasite on the developmental physiology of its nematode host is discussed.
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Malyutina. "ABOUT EFFECTS OF SOME NEUROPEPTIDES ON LOCOMOTOR BEHAVIOR OF CYST-FORMING PLANT NEMATODES." THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL, no. 21 (May 29, 2020): 213–16. http://dx.doi.org/10.31016/978-5-9902341-5-4.2020.21.213-216.
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The article presents an analysis of world literature on the study of the physiological and functional significance of FMRFamide-like neuropeptides in the neurobiology of cyst-forming plant parasitic nematodes (by the example of larvae of the 2-yearold potato cyst nematode Globodera pallida and G. rostochiensis, and soybean cyst nematode Heterodera glycines). It was shown that the basic physiological and functional characteristics of FMRFamide-like neuropeptides were obtained from the effects that have some neuropeptides on the motor activity of intact nematode larvae, and molecular studies of flp-genes that encode FMRFamidelike neuropeptides. FMRFamide-like neuropeptides belong to the largest and most diverse family of signal neuropeptides found in invertebrate animals including numerous representatives of the Nematoda type which can significantly modulate the locomotor behavioral reactions of these animals. The work discusses a physiological function of FMRFamide-like neuropeptides and the identified putative receptor of one of the neuropeptides in locomotor behavioral reactions that ensure the vital activity of cyst-forming nematodes, and the possibility of using the data in developing new targeted anthelmintics. The fact of revealing the peptidergic nervous system in cyst-forming plant nematodes, parasitic nematodes of vertebrate animals and freeliving nematodes confirms the concept about the conservation of the peptidergic nervous system in representatives of the entire Nematoda type in general.
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Daramola, Fisayo Y., Rinus Knoetze, Antoinette Swart, and Antoinette P. Malan. "First report and molecular characterization of the dagger nematode, Xiphinema oxycaudatum (Nematoda, Dorylaimidae) from South Africa." ZooKeys 894 (December 3, 2019): 1–17. http://dx.doi.org/10.3897/zookeys.894.35281.
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Plant-parasitic nematodes of the genus Xiphinema Cobb, 1913 comprise a complex group of nematode species, some of which are important vectors of plant viruses. During a field survey to determine the soil health of an abandoned honeybush (Cyclopia genistoides) monoculture, a high density of the dagger nematode, Xiphinema oxycaudatum Lamberti & Bleve-Zacheo, 1979 (Nematoda, Dorylaimidae), was observed in soil around the roots of honeybush plants in an abandoned farmland at Bereaville, an old mission station in the Western Cape province of South Africa. Soil samples were taken from the rhizosphere of plants and nematodes were extracted from the soil using a modified extraction tray method. Specimen of the dagger nematodes were processed for scanning electron microscopy, morphological and molecular analysis. Molecular profiling of the nematode species was done in order to give an accurate diagnosis and to effectively discriminate the nematode from other species within the Xiphinema americanum group. Phylogenetic analysis based on the D2D3 expansion segment of the 28S gene supported a close relationship of species within the americanum group, however, the protein-coding cytochrome oxidase (coxI) of the mitochondrial gene provided a useful tool for distinguishing the nematode from other species within the group. This study represents the first report of X. oxycaudatum from South Africa.
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Nyaku, S. T., T. Amponsah-Awuku, E. Belbaar-Ib Guri, and S. Asare-Okai. "Parasitic nematode populations associated with developmental stages of mango in production regions of Ghana." African Crop Science Journal 32, no. 1 (March 28, 2024): 77–89. http://dx.doi.org/10.4314/acsj.v32i1.6.
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Nematode (Phylum nematoda) infestation is a major set back in mango (Mangifera indica) production world-wide. Control of nematodes requires understanding of their diversity, distribution and population densities. The objective of this study was to identify plant-parasitic nematodes associated with mangoes and their population densities at seedling and maturity stages in production regions of Ghana. The study was conducted in Greater Accra (Manya and Klagon) and the Eastern region (Somanya) during December 2016 to January 2018. Mango farmlands were surveyed for soil and root samples, from which nematodes were extracted, identified and quantified. Twenty-four nematode genera were identified in mango seedlings and matured trees from Somanya; and 14 genera dentified in seedlings and 22 in matured trees from Manya; while at Klagon, 15 nematode genera were identified in matured trees. Helicotylenchus spp. were the most populated in seedlings obtained from Somanya and Manya, with relative abundance of 23.29%. Tylenchus spp. had the highest population in mature trees, with relative abundance of 24.49% at Somanya and 38.86% at Manya; while Helicotylenchus spp. had the highest relative abundance of 43.96% at Klagon. Mature trees had higher nematode population densities, compared to seedlings. There were significant variation in nematode populations between seedlings and matured stages of mango.
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Yeates, Gregor W., Surinder Saggar, Carolyn B. Hedley, and Chris F. Mercer. "Increase in 14C-carbon translocation to the soil microbial biomass when five species of plant-parasitic nematodes infect roots of white clover." Nematology 1, no. 3 (1999): 295–300. http://dx.doi.org/10.1163/156854199508298.
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Abstract Clonal white clover growing in pots was inoculated with Heterodera trifolii, Meloidogyne hapla, Meloidogyne trifoliophila, Pratylenchus sp., or Xiphinema diversicaudatum, pulse-labelled with 14C and after 15 days the distribution of 14C in compartments of the soil: plant: nematode system determined. Nematode inoculation had no effect on shoot, root and soil microbial biomasses, but the nematode treatments significantly affected the distribution of 14C in these compartments. The greatest translocation of 14C to the soil was in pots with X. diversicaudatum, M. hapla or M. trifoliophila. The percentage of 14C in the microbial biomass varied significantly, being highest with X. diversicaudatum and Pratylenchus sp., and lowest in control pots. Nematodes of all species from the soil consistently had lower specific activity than those from roots. It has now been demonstrated for a range of nematodes and soils that nematode infection increases translocation of photosynthate to soil microbial biomass. As the soil microbial biomass plays a critical role in the availability of plant nutrients it appears that low infections of plant-parasitic nematodes may lead to greater availability of plant nutrients. Anstieg der Verlagerung von 14C-Kohlenstoff in die mikrobielle Biomasse, wenn funf Arten pflanzenschadigender Nematoden Wurzeln von Weissklee befallen - In Topfen gehaltene Weisskleeklone wurden mit Heterodera trifolii, Meloidogyne hapla, Meloidogyne trifoliophila, Pratylenchus sp. oder Xiphinema diversicaudatum infiziert. Die Nematoden waren mit 14C markiert, und nach 15 Tagen wurde die Verteilung des 14C in Abschnitten des Systems Boden: Pflanze: Nematode bestimmt. Nematodenbefall hatte zwar keine Wirkung auf die Biomassen von Spross, Wurzel und Mikroben, doch beeinflusste die Behandlung mit Nematoden signifikant die Verteilung von 14C in diesen Abschnitten. Die grosste Verlagerung von 14C in den Boden fand in den Topfen mit X. diversicaudatum, M. hapla oder M. trifoliophila statt. Der Anteil von 14C in der mikrobiellen Biomasse variierte stark. Er war am hochsten in Topfen mit X. diversicaudatum und Pratylenchus sp. und am gerigsten in den Kontrolltopfen. Bei allen Arten hatten die Nematoden aus dem Boden durchweg eine geringere spezifische Aktivitat als die aus den Wurzeln. Es wurde jetzt fur eine Reihe von Nematoden und Boden gezeigt, dass Nematodenbefall die Verlagerung von Photosyntheseprodukten in die mikrobielle Biomasse des Bodens steigert. Da die mikrobielle Biomasse im Boden eine kritische Rolle bei der Verfugbarkeit von Pflanzennahrstoffen spielt, scheint es, dass geringer Befall durch pflanzenschadigende Nematoden zu einer grosseren Verfugbarkeit von Pflanzennahrstoffen fuhren kann.
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Morais, Aprígio Mota, Melissa Querido Cárdenas, and José Celso de Oliveira Malta. "Nematofauna of red piranha Pygocentrus nattereri (Kner, 1958) (Characiformes: Serrasalmidae) from Amazonia, Brazil." Revista Brasileira de Parasitologia Veterinária 28, no. 3 (July 2019): 458–64. http://dx.doi.org/10.1590/s1984-29612019055.
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Abstract Between March and October 2008, 355 specimens of Pygocentrus nattereri were collected from the lowland lakes of Central Amazonia, Brazil, to study their nematode fauna. A total of 1.116 specimens of Nematoda were collected, belonging to six species. Procamallanus (Spirocamallanus) inopinatus was the species with the highest parasite indices. Larvae of Anisakis sp. have zoonotic potential and were found parasitizing the intestine and liver of Pygocentrus nattereri. Some of these nematode species were new records for the host P. nattereri. The diversity of nematodes that use P. nattereri as a host indicates the important role of this fish species in the maintenance of these six nematode species in the lowland lakes of Central Amazonia.
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Indrayati, Liestiana. "INVENTARISASI NEMATODA PARASIT PADA TANAMAN, HEWAN DAN MANUSIA." EnviroScienteae 13, no. 3 (December 20, 2017): 195. http://dx.doi.org/10.20527/es.v13i3.4306.
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Pathogenic nematodas are widespread in nature, it can attack plants, animals, and humans and cause disruption to their hosts, then effect to lower quantity of plantation, yields, and livestock production and also affect to degradation of human resource quality. This paper is a systematic review that uses literature method about the inventory of nematoda parasite that attacks plants, animals and human, some method of examination and the effects that occurred by the host. The major parasite nematodas that infect the plants are Meloidogyne sp, Pratylenchut sp, and Radopholus sp., nematode in animals are Strongyloides spp., Haemonchus spp., Oesophagosomum spp., and Trichostrongyloides spp. In the fish variant, Anisakis spp, and nematode in humans are Ascaris lumbricoides, Trichuris trichiura, and hookworm. Some animal nematodas were found to attack humans whereas plant nematodas have not been reported to be found in humans or animals. Nematoda control is by anthelmintic consumption, environmental modification, personal hygiene and the use of biological agents.
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HODDA, M. "Phylum Nematoda: trends in species descriptions, the documentation of diversity, systematics, and the species concept." Zootaxa 5114, no. 1 (March 10, 2022): 290–317. http://dx.doi.org/10.11646/zootaxa.5114.1.2.
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This paper summarizes the trends in nematode species description and systematics emerging from a comparison of the latest comprehensive classification and census of Phylum Nematoda (Hodda 2022a, b) with earlier classifications (listed in Hodda 2007). It also offers some general observations on trends in nematode systematics emerging from the review of the voluminous literature used to produce the classification. The trends in nematodes can be compared with developments in the systematics of other organisms to shed light on many of the general issues confronting systematists now and into the future.
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Togashi, Katsumi, and Shota Jikumaru. "Transmission of Bursaphelenchus mucronatus (Nematoda: Aphelenchoididae) through feeding wounds by Monochamus saltuarius (Coleoptera: Cerambycidae)." Nematology 3, no. 4 (2001): 325–33. http://dx.doi.org/10.1163/156854101317020240.
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AbstractThe transmission of Bursaphelenchus mucronatus by its vector beetle, Monochamus saltuarius, was investigated. Fortythree beetles were reared individually under outdoor conditions and characteristics of their complete transmission curves of B. mucronatus were determined. The averaged nematode-transmission curves exhibited by beetles carrying more than 10 000, 1000 to 9999, and 100 to 999 nematodes at their emergence had a peak of 568, 146 and 12 nematodes per 5 days, respectively. The peaks appeared during a period from 20 to 30 days after beetle emergence. Backward stepwise regression analysis showed that the initial nematode load, the nematode departure efficiency and the nematode transmission efficiency had significantly positive influences on the number of nematodes transmitted into pine twigs. Other statistical analysis showed that the initial nematode load was most important among the three factors to account for the among-beetle difference in the number of nematodes transmitted, followed by the nematode transmission efficiency and nematode departure efficiency in that order. There were significant, positive correlations between the nematode departure efficiency, the nematode transmission efficiency and the number of nematodes transmitted from beetle into pine twigs.
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Upadhyay, Devang, Rinu Kooliyottil, Sivanadane Mandjiny, Floyd L. Inman III, and Leonard D. Holmes. "Mass Production of the Beneficial Nematode Steinernema carpocapsae Utilizing a Fed-Batch Culturing Process." International Journal of Phytopathology 2, no. 1 (April 15, 2013): 52–58. http://dx.doi.org/10.33687/phytopath.002.01.0076.
Full textAbstract:
The present study deals with the batch and fed-batch mass production of Steinernema carpocapsae. S. carpocapsae is an entomoparasitic nematode that is used as a biological control agent of soil-borne crop insect pests. The ability and efficiency of fed-batch culture process was successful through the utilization of the nematode’s bacterial symbiont Xenorhabdus nematophila. Results from the fed-batch process were compared to those obtain from the standard batch process. The fed-batch process successively improved the mass production process of S. carpocapsae employing liquid medium technology. Within the first week of the fed-batch process (day six), the nematode density obtained was 202,000 nematodes mL−1; whereas on day six, batch culture mode resulted in a nematode density of 23,000 nematodes mL−1. The fed-batch process was superior to that of batch production with a yield approximately 8.8-fold higher. In fed-batch process, the nematode yield was improved 88.6 % higher within a short amount of time compared to the batch process. Fed-batch seems to make the process more efficient and possibly economically viable.
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Sikder, Md Maniruzzaman, Mette Vestergård, Rumakanta Sapkota, Tina Kyndt, and Mogens Nicolaisen. "Evaluation of Metabarcoding Primers for Analysis of Soil Nematode Communities." Diversity 12, no. 10 (October 9, 2020): 388. http://dx.doi.org/10.3390/d12100388.
Full textAbstract:
While recent advances in next-generation sequencing technologies have accelerated research in microbial ecology, the application of high throughput approaches to study the ecology of nematodes remains unresolved due to several issues, e.g., whether to include an initial nematode extraction step or not, the lack of consensus on the best performing primer combination, and the absence of a curated nematode reference database. The objective of this method development study was to compare different primer sets to identify the most suitable primer set for the metabarcoding of nematodes without initial nematode extraction. We tested four primer sets for amplicon sequencing: JB3/JB5 (mitochondrial, I3-M11 partition of COI gene), SSU_04F/SSU_22R (18S rRNA, V1-V2 regions), and Nemf/18Sr2b (18S rRNA, V6-V8 regions) from earlier studies, as well as MMSF/MMSR (18S rRNA, V4-V5 regions), a newly developed primer set. We used DNA from 22 nematode taxa, 10 mock communities, 20 soil samples, 4 root samples, and one bulk soil. We amplified the target regions from the DNA samples with the four different primer combinations and sequenced the amplicons on an Illumina MiSeq sequencing platform. We found that the Nemf/18Sr2b primer set was superior for detecting soil nematodes compared to the other primer sets based on our sequencing results and on the annotation of our sequence reads at the genus and species ranks. This primer set generated 74% reads of Nematoda origin in the soil samples. Additionally, this primer set did well with the mock communities, detecting all the included specimens. It also worked better in the root samples than the other primer set that was tested. Therefore, we suggest that the Nemf/18Sr2b primer set could be used to study rhizosphere soil and root associated nematodes, and this can be done without an initial nematode extraction step.
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Bhuyan, Prerana, Gitanjali Devi, Reecha T. Das, and Sailen Gogoi. "Prevalence of Plant-Parasitic Nematodes in Horticultural Fields of Assam Agricultural University: Jorhat Campus, India." Journal of Scientific Research and Reports 30, no. 6 (April 30, 2024): 245–51. http://dx.doi.org/10.9734/jsrr/2024/v30i62038.
Full textAbstract:
A random survey of the horticultural crops was conducted to assess the nematode community structure in the Experimental field of Department of Horticulture, AAU, Jorhat during Rabi and Kharif season, 2022-2023. Soil and root samples, representing 200 locations were examined. Analysis of 200 soil and root samples collected from the root rhizosphere of different vegetable, fruit and ornamental crops showed the presence of root-knot nematode(Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), root-lesion nematode (Pratylenchus spp.), lance nematode (Hoplolaimus spp.), spiral nematode (Helicotylenchus spp.), stunt nematode (Tylenchorhynchus spp.) along with Criconema spp., Xiphinema spp, Longidorus spp., free-living nematodes, mycophagous nematodes and predatory nematodes. Among all the isolated plant-parasitic nematodes, root-knot nematode (Meloidogyne incognita) was found to be more abundant with prominence value of 136.7, 81.3 and 76.3 in vegetable crops, fruit crops and ornamental crops, followed by Helicotylenchus spp. and Rotylenchulus reniformis. The prominence value of reniform nematode (Rotylenchulus reniformis) was found to be 90.5, 54.1 and 54.1 in vegetable crops, fruit crops and ornamental plants respectively.
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Zheng, Jinshui, Donghai Peng, Ling Chen, Hualin Liu, Feng Chen, Mengci Xu, Shouyong Ju, Lifang Ruan, and Ming Sun. "The Ditylenchus destructor genome provides new insights into the evolution of plant parasitic nematodes." Proceedings of the Royal Society B: Biological Sciences 283, no. 1835 (July 27, 2016): 20160942. http://dx.doi.org/10.1098/rspb.2016.0942.
Full textAbstract:
Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor . We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans , the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.
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Legaspi, Jesusa C., Benjamin C. Legaspi, and Robert R. Saldaña. "Evaluation of Steinernema riobravis (Nematoda: Steinernematidae) Against the Mexican Rice Borer (Lepidoptera: Pyralidae)." Journal of Entomological Science 35, no. 2 (April 1, 2000): 141–49. http://dx.doi.org/10.18474/0749-8004-35.2.141.
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The virulency of an endemic nematode, Steinernema riobravis Cabanillas, Poinar and Raulston (Nematoda: Steinernematidae), was tested against the Mexican rice borer, Eoreuma loftini(Dyar) (Lepidoptera: Pyralidae), in the laboratory and field. Steinernema riobravis caused 100% mortality in E. loftini larvae at all concentrations of 20 to 240 nematodes per larva 2 d post treatment. Numbers of juvenile progeny increased significantly with inoculum dosage of nematodes. Average juvenile progeny ranged from 2,000 per borer larva at 10 nematodes per larva to over 4,000 per larva at 120 per larva. A field experiment on sugarcane (Saccharum spp. cv ‘NCo 310’) was performed using three treatments: (1) control (no nematodes); (2) low application rate (1.24 × 109 nematodes/ha); and, (3) high application rate (2.47 × 109 nematodes/ha). At weekly intervals, the field was sampled for numbers of internodes per stalk, numbers of internodes damaged by borer larvae, and parasitoids reared from larvae collected. The field results showed the nematode treatments were ineffective in reducing borer incidence or damage. Percentage of bored internodes and numbers of borers collected significantly increased with time, but treatment effects were not significant. Numbers of parasitoids emerging from the larvae collected were too low to be analyzed statistically. Plant height, aboveground biomass, and juice quality were not significantly affected by treatment. The ineffectiveness of the nematode applications may be due to desiccation caused by exposure to sunlight and inadequate humidity, as well as poor contact with the target insect.
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Blair, B. L., and G. R. Stirling. "The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia." Australian Journal of Experimental Agriculture 47, no. 5 (2007): 620. http://dx.doi.org/10.1071/ea05287.
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Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.
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DAVIES, KERRIE A., WEIMIN YE, ROBIN M. GIBLIN-DAVIS, GARY S. TAYLOR, SONJA SCHEFFER, and W. KELLEY THOMAS. "The nematode genus Fergusobia (Nematoda: Neotylenchidae): molecular phylogeny, descriptions of clades and associated galls, host plants and Fergusonina fly larvae." Zootaxa 2633, no. 1 (October 1, 2010): 1. http://dx.doi.org/10.11646/zootaxa.2633.1.1.
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Collection data and biological information is presented on the genus Fergusobia (Nematoda: Neotylenchidae) from Australasia, India and The Philippines, an emended diagnosis of the genus is presented, and its putative phylogeny is discussed based on molecular and morphological evidence. About 20 clades have been found, and are outlined, including information on nematode and fly morphology; plant host species and distribution. Fly morphology, particularly the structure of the dorsal shield of third stage larvae, is congruent with the clades of nematodes, suggesting coevolution. However, little evidence of coevolution between the fly/nematode association and their host plants is apparent: host-switching appears to have been common, although host-specificity is stringent among most clades. A key to the species and morphospecies of nematodes collected from Corymbia, Angophora, Metrosideros, Syzygium, narrow-leaved Melaleuca, and Eucalyptus is presented.
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Ramdani, Souhila, Jean-Paul Trilles, and Zouhir Ramdane. "Histopathological changes from parasitic Nematoda infestation in the musculature of some marine teleost fishes from the Algerian coast." Fisheries & Aquatic Life 30, no. 4 (December 1, 2022): 209–16. http://dx.doi.org/10.2478/aopf-2022-0020.
Full textAbstract:
Abstract Numerous marine fishes from the Algerian coast were examined for nematode parasites. Our study revealed five species of nematodes that were identified according to morphological characteristics: Anisakis simplex, Hysterothylacium aduncum, Hysterothylacium reliquens, Hysterothylacium fabri, Dichelyne pleuronectidis. D. pleuronectidis was newly collected from the study region. Four new host species were recorded for A. simplex, six for H. aduncum, and three for H. fabri. The infection rates observed were higher for Hysterothylacium and Dichelyne than Anisakis. The highest infection rate by Nematoda parasites were recorded for Trachinus draco L., Pagellus acarne (Risso) and Mullus barbatus L. (P = 100%, P = 53.33%, P = 42.5%), respectively. Nematoda larvae were found in body cavity and musculature. Histological changes associated with nematode musculature infestation revealed myodegeneration of fibers with a loss of striated texture and skin damage.
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Townsend, Monica L., Don C. Steinkraus, and Donn T. Johnson. "Mortality Response of Green June Beetle (Coleoptera: Scarabaeidae) to Four Species of Entomopathogenic Nematodes." Journal of Entomological Science 29, no. 2 (April 1, 1994): 268–75. http://dx.doi.org/10.18474/0749-8004-29.2.268.
Full textAbstract:
Four species of entomopathogenic nematodes, Steinernema carpocapsae (Weiser) (All strain), S. feltiae (Filipjev) (NC strain), S. glaseri (Steiner), and Heterorhabditis bacteriophora Poinar, were tested in the laboratory for their effect on larvae of the green June beetle, Cotinus nitida L. When nematodes were injected into the foregut of larvae (ca. 1,000 nematodes per larva), S. carpocapsae, S. feltiae, S. glaseri, and H. bacteriophora caused similar mortality (65, 45, 65, and 63%, respectively). At a concentration of 10 nematodes per larva, S. carpocapsae produced significantly higher mortality (51%) than the other three nematode species. Increasing nematode concentrations resulted in only a slight increase in mortality of larvae injected perorally with any of the four nematode species. Water filtrates from whole nematodes or ground nematode tissue supernatants from S. carpocapsae and H. bacteriophora injected perorally into the alimentary tract did not kill green June beetle larvae. Thus, live nematodes appeared to be necessary to cause mortality. Subcuticular or peroral injections of S. carpocapsae or H. bacteriophora (1,000 nematodes per larva) produced similar mortality of green June beetle larvae ranging from 60 to 70%. Nematode-killed larvae were dissected (n=277) but only two cadavers contained live nematodes and nematodes did not successfully reproduce in any nematode-killed green June beetle larvae. Possible explanations for the failure of cadavers to produce nematode progeny are discussed.
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Hai, Tang, and Ji Ya Qi Du. "The Response of the Free-Living Nematodes Species and Quantity to Grazing Intensity of Meadow Grassland." Advanced Materials Research 518-523 (May 2012): 5185–88. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.5185.
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Abstract. To study of meadow grassland soil free lifing nematodes types and quantities under the grazing intensity, the results show that we captured 13 species free lifing nematodes in different grazing area.With the increase of the grazing intensity the total number of Free life nematodes gradually reduce, among them Bacterial feeding nematode and Omnivorous predator nematode gradually reduced with the increase of nematode grazing intensity and the Fungal-feeding nematodes quantities gradually increased . the number of the Bacterial feeding nematode and Fungal-feeding nematodes gradually decrease with the deepening of the soil layer under the different grazing intensity and Omnivorous predator nematodegradually increased
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ÇAKMAK, Taylan. "The nematode assemblages of a lake ecosystem (Lake Korugöl Natural Park, Düzce, West Black Sea Cost of Türkiye): ecology and biodiversity patterns with first reports of 10 genera to the Türkiye nematofauna." Turkish Journal of Entomology 47, no. 3 (September 25, 2023): 283–94. http://dx.doi.org/10.16970/entoted.1273242.
Full textAbstract:
This research was conducted to reveal the soil nematode fauna of Korugöl, Düzce and to contribute to the nematode diversity of the Western Black Sea Region of Türkiye. Field studies within the scope of the study were implemented in 2021. As a result of the study, 29 families, 45 genera and 46 nematode taxa were identified. 10 nematode taxon, namely Aporcelinus, Baladorylaimus, Dorylaimoides, Euteratocephalus, Labronemella, Laimydorus, Lindseyus, Metateratocephalus, Paractinolaimus and Tripylella are the first report for Türkiye's nematofauna. Classification of nematodes according to their feeding types were: 27.27% bacterivorous nematodes, 2.10% fungivoresnematodes, 1.51% herbivorous nematodes, 16.35% predator nematodes and 52.77% omnivorous nematodes.
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Potter, J. W., and A. W. McKeown. "Nematode biodiversity in Canadian agricultural soils." Canadian Journal of Soil Science 83, Special Issue (August 1, 2003): 289–302. http://dx.doi.org/10.4141/s01-064.
Full textAbstract:
The biodiversity of soil-inhabiting nematodes in Canada is incompletely known, as large areas of Canada’s landmass have not been surveyed for nematode fauna. Nematodes considered as indigenous are generally well adapted to a variety of ecological niches and climatic zones. Much of the available information is based on agricultural ecosystems and agricultural species, and thus is biased toward conditions in disturbed ecosystems and away from “primeval” ecology. Introduced nematode species are frequently quite pathogenic, even to exotic host plants from the same geographic point of origin. Estimates of crop loss due to single species infestations of pathogenic nematodes and the costs of nematode control using chemicals are reasonably well known, averaging about 10% of crop value, but ranging to 100% depending on the situation; the cost of damage by multiple-species infestations is less defined. Nematode-suppressive mechanisms are understood in only a few plant species; sulfur appears to be important as a constituent of active compounds in suppressive plants of agricultural origin. Similarly, some native plants are equally adapted with allelopathic chemicals that suppress nematodes. Management of nematode populations in agricultural soils by integrated crop management methods is at an early stage, requiring research to quantify effects of nematode-suppressive plants and soil amendments containing nitrogen. An integrated program could include nematode-suppressive plants, appropriate soil amendments, and the promotion of microbial antagonists. Different mathematical methods may be required to analyze and explain multi-factor nematode control systems. Less-toxic management systems could benefit the soil-inhabiting nematodes that predate arthropod soil pests. Further research on soil-borne nematodes may demonstrate the value of nematodes as indicators of agroecosystem health and environmental pollutants. Key words: Biocontrol, biodiversity, nematode distribution, nematode management, soil ecology
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Schroeder, Jill, Stephen H. Thomas, and Leigh Murray. "Yellow and Purple Nutsedge and Chile Peppers Host Southern Root-Knot Nematode." Weed Science 41, no. 1 (March 1993): 150–56. http://dx.doi.org/10.1017/s0043174500057738.
Full textAbstract:
Yellow and purple nutsedge and southern root-knot nematode are common pests in intensively managed chile pepper production. Greenhouse studies were conducted to identify relationships among nutsedge species, chile peppers, and root-knot nematode. All practical combinations of the plant species and nematodes were grown together in pots for 14 wk. Both nutsedges and root-knot nematode reduced chile pepper height over time with no interaction. Competition from purple nutsedge or either nutsedge species plus nematodes reduced chile pepper top weight more than yellow nutsedge or nematodes alone. All pest combinations reduced chile pepper root weight. Chile pepper and nematodes individually reduced rates of shoot production, as well as top and belowground weights of yellow and purple nutsedge. Chile pepper and purple and yellow nutsedge hosted root-knot nematode host race 3. Nematode egg production was greater on chile pepper roots than on either nutsedge species. Purple nutsedge growing with chile pepper increased nematode production g−1 of chile pepper root. Purple nutsedge grown with chile pepper was the most detrimental for chile pepper growth, but most efficient for maintaining the root-knot nematode population on the least amount of root biomass. Since root-knot nematode infests yellow and purple nutsedge, and few nematicides are available for nematode control, root-knot nematode cannot be managed with crop rotation if nutsedge is not controlled.
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Severns, Paul M., Ganpati B. Jagdale, Ted Holladay, Phillip M. Brannen, Jim P. Noe, and William O. Cline. "Potential for the Pathogenicity of Plant-Parasitic Nematodes Associated with Blueberries in Georgia and North Carolina." Plant Health Progress 21, no. 1 (January 1, 2020): 9–12. http://dx.doi.org/10.1094/php-09-19-0069-s.
Full textAbstract:
Ring (Mesocriconema ornatum) nematode in Georgia (GA) has been associated with blueberry replant disease. A survey of plant-parasitic nematodes (PPNs) from production blueberry fields in GA and North Carolina (NC) was previously presented and evaluated from an abundance perspective. However, PPNs are often patchily distributed, occurring in close physical association with infected plant roots. Soil cores may or may not sample the areas of high nematode abundance, and nematode counts tend to be highly variable because of this patchiness. To evaluate the survey data for potentially unrecognized blueberry PPNs, we reanalyzed nematode survey data from NC and GA using multivariate analyses that integrate both patterns of occurrence and patterns in relative abundance. Indicator species analysis identified ring nematode in GA as a potentially pathogenic nematode, consistent with previous confirmation of pathogenicity through a container study. Indicator species analysis also identified two potentially pathogenic nematodes in NC blueberries: awl (Dolichodorus spp.) and sheath (Hemicycliophora spp.) nematodes. Of the two nematodes, awl shared a similar position in the NC blueberry nematode community when compared with ring nematode in GA. However, awl nematode relative abundance was low enough, when compared with ring nematode in GA, to suggest that although it is likely parasitic on NC blueberries, it may not be pathogenic. Our analysis from a previous survey suggests that PPNs are unlikely to be a threat to NC blueberry production. However, if blueberry replant disease emerges in NC, then ring, awl, and sheath nematodes should be considered as potential causal agents.
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Min, Yu Yu, Koki Toyota, and Erika Sato. "A novel nematode diagnostic method using the direct quantification of major plant-parasitic nematodes in soil by real-time PCR." Nematology 14, no. 3 (2012): 265–76. http://dx.doi.org/10.1163/156854111x601678.
Full textAbstract:
We have developed a direct quantification method using real-time PCR for various plant-parasitic nematodes. Firstly, specific primers were designed for the root-knot nematode Meloidogyne incognita, the root-lesion nematode Pratylenchus penetrans, the potato cyst nematode Globodera rostochiensis and the soybean cyst nematode Heterodera glycines. A DNA extraction method was then developed beginning with 20 g of soil, a relatively large amount of soil but a necessary amount in the consideration of heterogeneous distribution of nematodes in soil. To estimate the density of the target nematode in soil, calibration curves for each plant-parasitic nematode were obtained by inoculating different numbers of the target nematode and then extracting DNA from the soils. The detection limit was 4-5 nematodes (20 g soil)−1. This method was applied to nematode diagnostics. Soil sampling was done when transplanting of radish and sweet potato in fields was taking place, and the density of plant-parasitic nematodes was measured using both the Baermann funnel extraction method and real-time PCR methods. In some soils, P. penetrans and M. incognita were not found with the Baermann method but were detected with the real-time PCR method. At harvest, damage to crops was evaluated and its relationship with initial densities was investigated. The real-time PCR method more precisely predicted damage to radish and sweet potato by nematodes and was considered to be a powerful tool in the diagnosis of nematode diseases.
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Ryss, A. Yu. "Evolution of life cycles of nematodes parasitizing woody plants as a result of ecological and phylogenetic co-adaptations with hosts and vectors." Паразитология 57, no. 6 (December 15, 2023): 450–80. http://dx.doi.org/10.31857/s0031184723060029.
Full textAbstract:
Fundamental aspects in the evolution of nematodes parasitizing woody plants are reviewed. 1) Nematode faunal lists of natural refigia are useful to predict the risks of opportunistic pathogens becoming true pathogens in the forest and park communities. 2) Nematode composition in natural refugia gives a chance to identify nematode antagonists of insect vectors of dangerous fungal and nematode infections, which can be potentially used as of the biological agents for woody plants’ protection. 3) Dauers of the ancestors of wood-inhabiting nematodes played a role as a survival stage in the detritus decomposition succession, and they later acquired the functions of dispersion and adaptations for transmission using insect vectors. 4) When inspecting wilted trees, it is necessary to use dauers for diagnostics, as sexually mature nematodes may absent in tree tissues. 5) Plant parasitic nematodes originated from members of the detritus food web and retained a detritivorous phase in the life cycle as a part of the propagative generation. 6) Vectors in the life cycles of plant parasitic nematodes are inherited from the ancestral detritivorous nematode associations, rather than inserted in the dixenic life cycle of the ‘nematode-fungus-plant’ association. 7) Despite the significant difference in the duration of the nematode-tree and nematode-vector phases of the life cycle, the actual parasitic nematode specificity is twofold: firstly to the vector and secondly to the natural host plant (as demonstrated in phytotests excluding a vector).
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Bekal, Sadia, Terry L. Niblack, and Kris N. Lambert. "A Chorismate Mutase from the Soybean Cyst Nematode Heterodera glycines Shows Polymorphisms that Correlate with Virulence." Molecular Plant-Microbe Interactions® 16, no. 5 (May 2003): 439–46. http://dx.doi.org/10.1094/mpmi.2003.16.5.439.
Full textAbstract:
Parasitism genes from phytoparasitic nematodes are thought to be essential for nematode invasion of the host plant, to help the nematode establish feeding sites, and to aid nematodes in the suppression of host plant defenses. One gene that may play several roles in nematode parasitism is chorismate mutase (CM). This secreted enzyme is produced in the nematode's esophageal glands and appears to function within the plant cell to manipulate the plant's shikimate pathway, which controls plant cell growth, development, structure, and pathogen defense. Using degenerate polymerase chain reaction primers, we amplified and cloned a chorismate mutase (Hg-cm-1) from Heterodera glycines, the soybean cyst nematode (SCN), and showed it had CM activity. RNA in situ hybridization of Hg-cm-1 cDNA to SCN sections confirms that it is specifically expressed in the nematodes' esophageal glands. DNA gel blots of genomic DNA isolated from SCN inbred lines that have differing virulence on SCN resistant soybean show Hg-cm-1 is a member of a polymorphic gene family. Some Hg-cm family members predominate in SCN inbred lines that are virulent on certain SCN resistant soybean cultivars. The same polymorphisms and correlation with virulence are seen in the Hg-cm-1 expressed in the SCN second-stage juveniles. Based on the enzymatic activity of Hg-cm-1 and the observation that different forms of the mutase are expressed in virulent nematodes, we hypothesize that the Hg-cm-1 is a virulence gene, some forms of which allow SCN to parasitize certain resistant soybean plants.
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Eleftherianos, Ioannis, and Christa Heryanto. "Transcriptomic Insights into the Insect Immune Response to Nematode Infection." Genes 12, no. 2 (January 30, 2021): 202. http://dx.doi.org/10.3390/genes12020202.
Full textAbstract:
Insects in nature interact with a wide variety of microbial enemies including nematodes. These include entomopathogenic nematodes that contain mutualistic bacteria and together are able to infect a broad range of insects in order to complete their life cycle and multiply, filarial nematodes which are vectored by mosquitoes, and other parasitic nematodes. Entomopathogenic nematodes are commonly used in biological control practices and they form excellent research tools for understanding the genetic and functional bases of nematode pathogenicity and insect anti-nematode immunity. In addition, clarifying the mechanism of transmission of filarial nematodes by mosquitoes is critical for devising strategies to reduce disease transmission in humans. In all cases and in order to achieve these goals, it is vital to determine the number and type of insect host genes which are differentially regulated during infection and encode factors with anti-nematode properties. In this respect, the use of transcriptomic approaches has proven a key step for the identification of insect molecules with anti-nematode activity. Here, we review the progress in the field of transcriptomics that deals with the insect response to nematode infection. This information is important because it will expose conserved pathways of anti-nematode immunity in humans.
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Khaithong, Tridate, Brent S. Sipes, and Adelheid R. Kuehnle. "(287) Chloroplast Small Subunit Rubisco Protein Is Ingested by Migratory Endoparasitic Nematodes." HortScience 40, no. 4 (July 2005): 1080D—1080. http://dx.doi.org/10.21273/hortsci.40.4.1080d.
Full textAbstract:
Lack of a conclusive evidence of ingestion of plastid components by plant-parasitic nematodes cautions the use of plastid transformation technology for nematode resistance. Nematode-resistant effector proteins generally require ingestion by the nematode to be effective. Transgene-encoded proteins produced in plastids are not known to be exported into the cytoplasm. Disintegration of plant cell organelles after nematode feeding suggests that nematodes possibly ingest plastid components. Proof of ingestion will validate the development of plastid transformation for nematode resistance. Small subunit ribulose-1,5-bisphosphate carboxylase/oxygenase (SSRubisco) protein is prevalent in chloroplasts and thus chosen as a study molecule. The migratory endoparasitic nematodes Pratylenchus penetrans and Radopholus similis were cultured on green carrot callus containing chloroplasts. Total nematode proteins were extracted and subjected to western blot analysis using cross-reactive polyclonal antibody raised against spinach SSRubisco. Positive detection of SSRubisco occurred in protein extracts from nematodes fed on green carrot callus, but not in extracts from nematodes cultured on non-green alfalfa root callus as negative control. These results confirm the ingestion of plastid components of MW 14 kDA by migratory endoparasitic nematodes.
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Trambadiya, Krishna, Riddhi Kanabar, and Manish Visavadia. "Comparison Between Agriculture Soil and Common Land Soil in Relation to Soil Edaphic Factors and Nematode Community." International Journal for Research in Applied Science and Engineering Technology 10, no. 3 (March 31, 2022): 2357–62. http://dx.doi.org/10.22214/ijraset.2022.41130.
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Abstract: Plant-parasitic nematodes may cause mechanical damage to the roots, stems, leaves, and flower structures of many plants. The host plant is more important in the nematode population. The control of these nematodes is more difficult than that of other pests because they mostly inhabit the inner part of the crops. Some Edaphic factors and secondary metabolites of plants play an important role in nematode control. The present study aims to analyze the comparision between agriculture soil and common land soil in relation to soil edaphic factors and nematode community. For testing nematode infection in crops, different agricultural fields were selected from different areas in and around Junagadh District. We have selected some agriculture sites in which nematode population were widely found. On the other hand, common land soil were no nematode population found. Edaphic factors like soil pH, Temperature, Moisture, Organic Carbon, Electrical Conductivity, Phosphorus, and Potassium were effective in the nematode growth. Results indicate that Soil temperature and Moisture were more affected in the nematode community. Further studies for the control of these nematodes are underway. Keywords: Nematode, Edaphic factors, Temperature, Moisture, Organic Carbon
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Sikder, Md Maniruzzaman, Mette Vestergård, Tina Kyndt, Inge S. Fomsgaard, Enoch Narh Kudjordjie, and Mogens Nicolaisen. "Benzoxazinoids selectively affect maize root-associated nematode taxa." Journal of Experimental Botany 72, no. 10 (March 13, 2021): 3835–45. http://dx.doi.org/10.1093/jxb/erab104.
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Abstract Although the effects of plant secondary metabolites on plant defence have been studied for decades, the exact roles of secondary metabolites in shaping plant-associated microbial and nematode communities remain elusive. We evaluated the effects of benzoxazinoids, a group of secondary metabolites present in several cereals, on root-associated nematodes. We employed 18S rRNA metabarcoding to compare maize root-associated nematode communities in a bx1 knockout maize line impaired in benzoxazinoid synthesis and in its parental wild type. Both genotype and plant age affected the composition of the nematode community in the roots, and the effects of benzoxazinoids on nematode communities were stronger in the roots than in the rhizosphere. Differential abundance analysis and quantitative PCR showed that the root lesion nematode Pratylenchus neglectus was enriched in the bx1 mutant line, while another root lesion nematode, Pratylenchus crenatus, was reduced. Correlation analysis showed that benzoxazinoid concentrations in maize roots mostly correlated negatively with the relative abundance of nematode sequence reads. However, positive correlations between benzoxazinoids and nematode taxa, including several plant-parasitic nematodes, were also identified. Our detailed nematode community analysis suggests differential and selective effects of benzoxazinoids on soil nematodes depending on both the nematode species and the benzoxazinoid compound.
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Renčo, Marek, Václav Čermák, and Andrea Čerevková. "Composition of soil nematode communities in native birch forests in Central Europe." Nematology 14, no. 1 (2012): 15–25. http://dx.doi.org/10.1163/138855411x575430.
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Soil nematodes were studied in 27 birch forests in the Slovak and Czech Republics. A total of 66 nematode genera were found. The eudominant nematode genera were Rhabditis and Aphelenchoides, followed by dominant genera Cephalobus, Paratylenchus, Plectus, Helicotylenchus and Aglenchus. Nevertheless, only Rhabditis, Cephalobus, Plectus and Aphelenchoides were recorded in all investigated birch stands. The highest nematode abundance was recorded in the birch forest situated in the Drahanská Highland (the Czech Republic). All nematode trophic groups were present in the investigated birch forests, with bacteriovores being the dominant group, followed by plant-parasitic nematodes, fungal feeders, root-fungal feeders, omnivores and predators. Ecological evaluation of nematode communities based on ecological indices demonstrated that the conditions of the nematode communities in birch forests were rather stable with prevailing bacterial decomposition pathways, which reflects the dominance of bacteriovorous nematodes.
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Mokrini, Fouad, Salah-Eddine Laasli, Youssef Karra, Aicha El Aissami, and Abdelfattah A. Dababat. "Diversity and incidence of plant-parasitic nematodes associated with saffron (Crocus sativus L.) in Morocco and their relationship with soil physicochemical properties." Nematology 22, no. 1 (September 4, 2019): 87–102. http://dx.doi.org/10.1163/15685411-00003286.
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Summary Saffron (Crocus sativus) fields in Morocco’s Taliouine and Taznakht regions were surveyed between January and April 2018 to study the diversity and incidence of plant-parasitic nematodes and assess the effects of soil physicochemical properties on the nematodes. Fourteen nematode genera were identified in soil and root samples collected from 66 saffron fields. The most common plant-parasitic nematodes in the Taliouine region were Pratylenchus spp. and Helicotylenchus spp. In the Taznakht region, the most common nematodes were Pratylenchus spp., Tylenchorhynchus spp. and Ditylenchus dipsaci. Nematodes, particularly Pratylenchus spp. and Ditylenchus spp., were abundant and frequent throughout the region. Several nematode genera were significantly associated with soil texture and mineral content, indicating that soil properties play an important role in plant-parasitic nematode communities. This description of plant-parasitic nematode assemblages associated with saffron fields in Morocco and their relationship with soil physicochemical properties provides a starting point from which appropriate nematode management strategies can be implemented.
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BLAXTER, MARK, and GEORGIOS KOUTSOVOULOS. "The evolution of parasitism in Nematoda." Parasitology 142, S1 (June 25, 2014): S26—S39. http://dx.doi.org/10.1017/s0031182014000791.
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SUMMARYNematodes are abundant and diverse, and include many parasitic species. Molecular phylogenetic analyses have shown that parasitism of plants and animals has arisen at least 15 times independently. Extant nematode species also display lifestyles that are proposed to be on the evolutionary trajectory to parasitism. Recent advances have permitted the determination of the genomes and transcriptomes of many nematode species. These new data can be used to further resolve the phylogeny of Nematoda, and identify possible genetic patterns associated with parasitism. Plant-parasitic nematode genomes show evidence of horizontal gene transfer from other members of the rhizosphere, and these genes play important roles in the parasite-host interface. Similar horizontal transfer is not evident in animal parasitic groups. Many nematodes have bacterial symbionts that can be essential for survival. Horizontal transfer from symbionts to the nematode is also common, but its biological importance is unclear. Over 100 nematode species are currently targeted for sequencing, and these data will yield important insights into the biology and evolutionary history of parasitism. It is important that these new technologies are also applied to free-living taxa, so that the pre-parasitic ground state can be inferred, and the novelties associated with parasitism isolated.
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Kaplan, M., E. P. Caswell-Chen, and V. M. Williamson. "Assessment of Host-Induced Selection on Three Geographic Isolates of Heterodera schachtii Using RAPD and AFLP Markers." Phytopathology® 89, no. 1 (January 1999): 68–73. http://dx.doi.org/10.1094/phyto.1999.89.1.68.
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The hypothesis that host plants exert selection pressure on Heterodera schachtii populations was tested. Host selection of genotypes from three genetically distinct isolates of H. schachtii was assessed using cabbage, sugar beet, oilseed radish (Raphanus sativus), and white mustard (Sinapis alba). The plants represent a range of susceptibility to H. schachtii and included R. sativus and S. alba, because cultivars of those species have been used as trap crops for H. schachtii in Europe. Genotypic differences in amplified fragment length polymorphism (AFLP) and random amplified polymorphic DNA (RAPD) markers were detected among the isolates after they reproduced on the different hosts. The poorest host plant, R. sativus, resulted in the greatest number of changes in both AFLP and RAPD markers. Oilseed radish selected nematode genotypes in less than four nematode generations. The nematode population genotypes detected by RAPD analyses after selection on oilseed radish were observed even after nematode populations were transferred back to the other three hosts. The genetic markers that were detected after selection were influenced by the genotypes of the original nematode isolates. The results indicate the utility of RAPDs and AFLPs for identifying and monitoring intraspecific genetic variability in nematodes and for understanding nematode population responses to host plants. Nematode management practices such as using resistant cultivars may alter gene frequencies, thereby reducing the efficacy of the tactic and exacerbating the nematode's potential to damage subsequent crops.
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Bhuiyan, Shamsul A., Kylie Garlick, and George Piperidis. "Saccharum spontaneum, a Novel Source of Resistance to Root-Lesion and Root-Knot Nematodes in Sugarcane." Plant Disease 103, no. 9 (September 2019): 2288–94. http://dx.doi.org/10.1094/pdis-02-19-0385-re.
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Root-lesion nematode (Pratylenchus zeae) and root-knot nematode (Meloidogyne javanica) are two important pathogens of sugarcane (Saccharum hybrid). No commercial cultivars are resistant to these nematodes in Australia. Twenty accession lines of S. spontaneum, a wild relative of sugarcane, were tested against these two nematode species. S. spontaneum lines were tested twice for resistance to root-lesion nematode and three times for root-knot nematode. Reproduction (final population/starting population) of root-lesion nematodes was significantly lower in 17 of the 20 S. spontaneum accession lines tested in two experiments compared with two commercial cultivars. Four S. spontaneum lines supported a significantly lower number of root-lesion nematodes per gram of root than that of two commercial sugarcane cultivars. Reproduction of root-knot nematodes was significantly lower in 16 S. spontaneum lines compared with two commercial cultivars. Fourteen of the S. spontaneum lines tested supported significantly fewer eggs per gram of root compared with two commercial cultivars. This study showed that S. spontaneum lines possessed resistance for root-lesion and root-knot nematodes. Targeted crossing with commercial hybrid parental lines should be conducted to introduce nematode resistance into sugarcane cultivars for the Australian sugar industry.
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Michiels, Iris, and Walter Traunspurger. "A three year study of seasonal dynamics of a zoobenthos community in a eutrophic lake." Nematology 6, no. 5 (2004): 655–69. http://dx.doi.org/10.1163/1568541042843568.
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AbstractThe meiofauna community in the eutrophic Lake Obersee was investigated, with special emphasis on nematodes, from March 2001 to December 2003. Meiobenthos showed a stable annual and seasonal pattern with oligochaetes contributing most to benthic biomass and nematodes to benthic abundance. With 152 nematode species, Lake Obersee is the most nematode species-rich lentic habitat described so far. The nematode community was dominated by the family Monhysteridae. Bacterial feeders were the most abundant feeding type; omnivorous nematodes contributed most to total nematode biomass. Reproduction occurred throughout the year, with most species reproducing parthenogenetically. No seasonal pattern in reproductive strategies was found.
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Garcia, Orlando, Dana Garibaldi, Krissa Jhaveri, Jake Lanoue, and Pushpa Soti. "Soil Nematode Trophic Group Composition and Influence on Growth of Amaranthus palmeri and Parthenium hysterophorus." Journal of Agricultural Science 14, no. 11 (October 15, 2022): 19. http://dx.doi.org/10.5539/jas.v14n11p19.
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Weeds have a significant impact on agricultural systems. They not only cause a loss in crop yield by competing with them for resources, but they can also serve hosts for several pests and parasties such as plant parasitic nematodes casusing additional crop loss. The aim of this study was to analyze plant-nematode feedback in two major weeds, Amaranthus palmeri S Watson and Parthenium hysterophorus L. First, a field survey was conducted to determine the rhizosphere nematode trophic groups associated with these two plants in the summer of 2020 and 2021. Then a 6-week greenhouse study was conducted where the two weed species were treated with nematode communities extracted from their respective rhizospheres. Results from this study show that both weeds harbored a high number of herbivore nematodes, followed by fungivore and bacterivore nematodes. Total number of these nematodes were highly influenced by total sol carbon, pH and salinity. Under greenhouse conditions, the nematode treatment did not have any impact on the growth of P. hysterophorus but A. palmeri plants treated with nematodes had significantly higher above ground biomass. In conclusion, plant-nematode relationships are complex. Given the extent of direct damage caused by these weeds and plant parasitic nematodes in global crop production, the weeds-nematode feedback warrants further detailed studies.
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McSorley, Robert. "Alternative practices for managing plant-parasitic nematodes." American Journal of Alternative Agriculture 13, no. 3 (September 1998): 98–104. http://dx.doi.org/10.1017/s0889189300007761.
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AbstractThe most widely used and successful cultural practices for managing plantparasitic nematodes are resistant cultivars and some elements of cropping systems, such as rotation crops, cover crops, or nematode-antagonistic crops. Exclusion and sanitation practices, such as use of nematode-free planting material, site selection, and weed management, are useful in limiting infestations. Soil solarization, organic amendments, biological control, fallow, flooding, timing of planting dates, or tillage practices may be helpful in some areas, but additional research is needed to optimize their use. Most management methods emphasize reduction of nematode populations, but improvement of crop tolerance to nematodes should not be overlooked. For their successful use, most of these alternative methods require detailed knowledge of nematode and plant biology and ecology, and it may be necessary to integrate several practices for maximum nematode suppression. Although the basic principles of nematode management are generally known, detailed data often are lacking on specific combinations of nematodes and host crop cultivars. Consequently, the availability of such data will likely determine whether nematodes can be managed successfully in a particular situation.
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Fitzpatrick, David A., and Damien M. O'Halloran. "Investigating the Relationship between Topology and Evolution in a Dynamic Nematode Odor Genetic Network." International Journal of Evolutionary Biology 2012 (September 28, 2012): 1–8. http://dx.doi.org/10.1155/2012/548081.
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The relationship between biological network architectures and evolution is unclear. Within the phylum nematoda olfaction represents a critical survival tool. For nematodes, olfaction contributes to multiple processes including the finding of food, hosts, and reproductive partners, making developmental decisions, and evading predators. Here we examine a dynamic nematode odor genetic network to investigate how divergence, diversity, and contribution are shaped by network topology. Our findings describe connectivity frameworks and characteristics that correlate with molecular evolution and contribution across the olfactory network. Our data helps guide the development of a robust evolutionary description of the nematode odor network that may eventually aid in the prediction of interactive and functional qualities of novel nodes.
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Rzeznik-Orignac, Jadwiga, Denis Fichet, and Guy Boucher. "Extracting massive numbers of nematodes from muddy marine deposits: efficiency and selectivity." Nematology 6, no. 4 (2004): 605–16. http://dx.doi.org/10.1163/1568541042665287.
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Abstract Extraction of large numbers of living and debris-free nematodes is based on the active downward migration of nematodes through muddy sediments. This study is an assessment of how representative the extracted nematode population is in comparison to the in situ population. Nematode extraction efficiencies ranged from 20-29%; however, the method yielded 153 000 and 223 000 debris-free nematodes in 48 h (per m2 of mud with nematode population density of 776 000 individuals m–2). Sieve mesh size, migration device mesh size, and size distribution and behaviour of nematode species all influenced the extraction results. The species composition of the extracted nematode populations was significantly different from the in situ population assemblage. Metachromadora remanei and M. vivipara migrated less efficiently than Ptycholaimellus jacobi, Chromadora macrolaima and Daptonema oxycerca. This bias should be monitored in experimental studies using nematode populations extracted by means of sieving and downward migration.
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DJIWANTI, SETYOWATI RETNO, and SUPRIADI SUPRIADI. "EKOBIOLOGI NEMATODA HAWAR DAUN (Aphelenchoides fragariae) PADA TANAMAN SAMBILOTO (Andrographis paniculata)." Jurnal Penelitian Tanaman Industri 17, no. 3 (June 19, 2020): 95. http://dx.doi.org/10.21082/jlittri.v17n3.2011.95-101.
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<p>ABSTRAK</p><p>Nematoda hawar daun (Aphelenchoides fragariae) merupakan salahsatu kendala dalam budidaya tanaman obat sambiloto (Andrographispaniculata). Informasi tentang perilaku dan cara pengendalian nematodapada tanaman sambiloto masih sangat terbatas. Dalam rangka mencari carapengendalian nematoda yang efektif, maka penelitian ini bertujuan untukmengetahui ekobiologi nematoda tersebut seperti kisaran inang, sumberinokulum, dan pestisida. Penelitian dilakukan di laboratorium, rumah kaca,dan kebun percobaan Balittro pada tahun 2006-2008. Studi kisaran inangalami dilakukan dengan mengamati karakteristik gejala khas penyakit,ekstraksi, dan karakterisasi morfologi nematoda dari sampel daun-daungulma yang tumbuh di pembibitan dan pertanaman sambiloto. Studi sum-ber penularan nematoda dilakukan dengan metode bioassay, yaitu denganmengamati gejala hawar daun dan jenis nematoda pada bibit sambilotoyang ditanam pada beberapa macam media tumbuh (tanah steril dicampurdengan beberapa macam jenis bahan organik seperti pupuk kandang,kompos, pupuk organik, dan potongan daun-daun sambiloto sakit).Sedangkan studi sensitivitas nematoda terhadap pestisida sintetik dannabati dilakukan di rumah kaca dan di lapang. Hasil penelitian menun-jukkan bahwa 6 jenis gulma, yaitu babadotan (Ageratum conyzoides),pulus hayam (Acalypha lanceolata), calincing (Oxalys sepium), gulmaBorreria sp., gulma daun sirih (Lindernia sp.), dan paku (Pleocnemia sp.)merupakan inang pengganti nematoda A. fragariae. Bahan organik sepertipupuk kandang dan serasah daun sambiloto sakit dalam tanah merupakansumber penting inokulum A. fragariae, tetapi penyebaran utama penyakitterjadi melalui bibit terinfeksi dan kontak fisik antara daun sakit dengandaun sehat. Perkembangan penyakit hawar daun berlangsung selama 2-4minggu setelah infeksi pertama. Senyawa karbofuran (2-5 g/tanaman),CNSL (cashew nut shell liquid) (0,5-1,0%), tepung (10,0-15,0 g/tanaman),dan ekstrak biji mimba (0,5-1,0%) efektif menekan populasi A. fragariae.Penanaman bibit sehat, sanitasi kebun, penggunaan pupuk kandang yangbenar-benar matang, dan aplikasi pestisida merupakan faktor pentingdalam pengendalian penyakit hawar daun nematoda pada sambiloto.</p><p>Kata kunci: Andrographis paniculata, sambiloto, nematoda hawar daun,Aphelenchoides fragariae, ekobiologi</p><p>ABSTRACT</p><p>Bioecology of Leaf Blotch Nematode (Aphelenchoidesfragariae) on King of Bitter Plant (Andrographispaniculata)</p><p>Leaf blotch nematode (Aphelenchoides fragariae) is one of the mostimportant constrains on cultivation of king of bitter plant (Andrographispaniculata). Information on the bioecology and control method of thenematode is still limited. In relation to finding an effective control methodof the nematode, this study aimed to evaluate several bioecological factorsof the nematode, such as its host range, inoculums source, and sensitivityof the nematode to several chemicals. The studies were conducted inlaboratory, green house, and experimental station of the IndonesianMedicinal and Aromatic Crops Research Institute in 2006-2008. Naturalhost range of the nematode was studied by examining the typical diseasesymptoms on leaves of several weeds grown in the nursery and field of theking of bitter plants, followed with extraction and morphologicalexamination of nematodes. Infection source of the nematode was carriedout by bioassay method using healthy king of bitter seedlings grown onsoil planting medium incorporated with suspected infection sources suchas animal manure, compost, organic fertilizer, and diseased leaf cutting ofthe plants. Sensitivity of the nematode to several pesticides (carbofuran,neem seed powder, neem seed extract, and cashew nut shell liquid) wasconducted in the green house and field. The results showed that six weedssuch as Ageratum conyzoides, Acalypha lanceolata, Oxalys sepium,Borreria sp., Lindernia sp., and Pleocnemia sp. grown in the nursery andfield of king of bitter plantation were infected with the nematode; thereforethese plants are natural alternate hosts of A. fragariae. Organic animalmanure and infected fallen leaves of the king of bitter were importantsources of inoculums of A. fragariae, however, main spread of the diseasewas through infected seedlings and direct contact between healthy andinfected leaves. Leaf blotch disease development occurred 2-4 weeks afterfirst infection. Chemicals such as carbofuran (2-5 g/plant), cashew nutshell liquid (0.5-1.0%), neem seed powder (10.0-15.0 g/plant) and extract(0.5-1.0%) were effectively suppressed the nematode. Planting disease-free seedlings, sanitation, and application of well-decomposed animalmanure and certain chemical pesticides are important factors to control theleaf blotch nematode on king of bitter plant.</p><p>Key words: Andrographis paniculata, king of bitter, leaf blotchnematode, Aphelenchoides fragariae, bioecology.</p>
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Davies, Kerrie A., Weimin Ye, Gary S. Taylor, Sonja Scheffer, and Robin M. Giblin-Davis. "Galling problems – the Fergusobia nematode/Fergusonina fly mutualism on myrtaceous hosts." Nematology 18, no. 6 (2016): 629–49. http://dx.doi.org/10.1163/15685411-00003002.
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Fergusobia (Sphaerularioidea, Tylenchida) is the only known nematode to have a dicyclic life cycle with a generation in a plant (a myrtaceous host) followed by one in an insect (a Fergusonina fly: Diptera, Fergusoninidae). The nematode and fly have a mutualistic association, with the nematode inducing a plant gall on which the fly feeds and develops, and the fly providing transport for the nematode. The life cycle, specificity, diversity and distribution of the nematode are described, and the nematode phylogeny is discussed. Fergusobia is monophyletic but its origins are unclear. This paper raises questions about Fergusobia, including: what model best accounts for evolution of the known diversity of the nematode/fly mutualism?; how are the nematode/fly life cycles coordinated?; how do the nematodes avoid resistance mechanisms of both flies and plants?; what cecidogenic processes does the nematode use?; and what is the form of parthenogenesis occurring in Fergusobia and how does it relate to the inheritance of variability? Given the models of genomes and transcriptomes now available for other plant-parasitic nematodes and the availability of technologies to examine Fergusobia, it should be possible to answer some of these questions and begin to understand how Fergusobia nematodes might have evolved.