Journal articles on the topic 'Nematodes'
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1
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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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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Xu, Zhen, Yong-Qiang Zhao, Dong-Jing Yang, Hou-Jun Sun, Cheng-Ling Zhang, and Yi-Ping Xie. "Attractant and repellent effects of sweet potato root exudates on the potato rot nematode, Ditylenchus destructor." Nematology 17, no. 1 (2015): 117–24. http://dx.doi.org/10.1163/15685411-00002856.
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Potato rot nematode (Ditylenchus destructor) is one of the most damaging pests of sweet potato in the northern region of China. Glasshouse and field experiments were conducted to explore the main invasion route used by potato rot nematodes during infection of sweet potato plants. The nematode’s host location behaviour was also investigated. Results suggested that substantial yield losses of sweet potato caused by D. destructor parasitism depend upon the existence of wounds on seedling roots. Therefore, reducing the number of nematodes that invade through such wounds would be an effective control method. We found that root exudates and extracts from underground stems of both resistant (cv. Zhenghong 22) and susceptible (cv. Lizixiang) sweet potato cultivars attracted potato rot nematodes. In addition, a strong repellent effect of latex against these nematodes was observed in both cultivars. Interestingly, octadecyl-(Z)-p-coumarate, a component of sweet potato latex, acted as a repellent for potato rot nematodes, while hexadecyl- and eicosyl-(Z)-p-coumarates did not. These findings provide a basis for understanding the mechanism underlying the host location behaviour of potato rot nematodes and can help in designing new nematode control methods.
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Yeates, G. W. "Abundance, diversity, and resilience of nematode assemblages in forest soilsThis article is one of a selection of papers published in the Special Forum on Towards Sustainable Forestry — The Living Soil: Soil Biodiversity and Ecosystem Function." Canadian Journal of Forest Research 37, no. 2 (February 2007): 216–25. http://dx.doi.org/10.1139/x06-172.
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Forest litter and soil may contain >10 × 106 individual nematodes·m–2 and, regionally, >400 species. Root-feeding nematodes may be pathogenic to young plants; microbial-feeding nematodes may increase turnover of the microbial pool; predacious and omnivorous nematodes represent higher trophic levels. The spatial distribution and abundance of nematode species in forests reflect soil type, soil fertility, climate, canopy and understorey plant species, litter depth, forest age, and management. Nematodes may be important in forest nurseries; they occur throughout the rooting depth of forest trees; hyphal-feeding species may influence mycorrhizae; and insect-vectored Bursaphelenchus species are a quarantine risk. Nematode populations interact with those of other soil animals (e.g., mites, tardigrades, enchytraeids, and protozoa). The diversity and abundance of the nematode assemblage make nematodes a useful indicator of soil condition and soil processes. Information available from forest systems suggests that, as long as physical disturbance is minimized and remaining trees or herb layer moderate the microclimate, logging and other forestry operations have only transitory effects on nematode populations. Extreme disturbance, such as bulldozing and slash-and-burn management, can significantly reduce nematode abundance and diversity. In contrast, management that enhances growth of understorey or herb layer can stimulate nematode populations. Each of these changes can be related to changes in food resource availability and environmental conditions, such as soil temperature and moisture. Although details of soil nematode contributions to nutrient processes in forest soils are sparse, that their populations are maintained through cycles of moderate management practices suggest that their beneficial contributions will also be maintained.
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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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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.
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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.
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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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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.
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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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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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Gede Swibawa, I., and Titik Nur Aeny. "KARAKTERISTIK KOMUNITAS NEMATODA DI PADANG GOLF SUKARAME (PGS) BANDAR LAMPUNG." Jurnal Hama dan Penyakit Tumbuhan Tropika 7, no. 2 (September 13, 2007): 80–90. http://dx.doi.org/10.23960/j.hptt.2780-90.
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ABSTRACTCharacteristic of Nematodes Community at PGS Golf Course Bandar Lampung. Golf course is a unique ecosystem where plant parasitic nematodes inhabit and become important pest because they reduce the quality of the grass. The pest problems on golf course can be indicated by its characteristics of nematode community. Survey on nematodes community at PGS Golf Course Bandar Lampung was conducted from March to December 2004. The objective was to study the characteristics of nematode community in the part of golf courses hole (green, collar, apron, and fairway). Soil samples were taken from five holes each of it consists of green, collar, apron, and fairway, respectiveley. Nematodes extraction was done in Laboratory of Arthropod Pest, Department of Plant Protection University of Lampung. The result showed that at least 50 nematodes genera of 28 families inhabit PGS. The number of plant parasitic nematode genera was higher than the free-living one. The characteristic of nematodes community on green and collar was different than on faiway. Nematode abundance and diversity on green and collar were higher than on fairway. Based on abundance of nematode feeding group, maturity index of free-living nematodes (MI) and that of plant parasitic nematodes (PPI), green and collar part seemed to be more favorable to plant parasitic nematodes than free-living nematodes. The contrary happened for fairway. Four most dominant genera of plant parasitic nematodes on PGS golf course were Helicotylenchus, Hoplolaimus, Criconemella, and Xiphinema.
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Kimpinski, J., Y. A. Papadopoulos, B. R. Christie, K. B. McRae, and C. E. Gallant. "Invasion and reproduction of Pratylenchus penetrans in birdsfoot trefoil cultivars." Phytoprotection 80, no. 3 (April 12, 2005): 179–84. http://dx.doi.org/10.7202/706191ar.
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Greenhouse trials were conducted to determine the levels of invasion of birdsfoot trefoil(Lotus corniculatus) cultivars and lines by the root-lesion nematode (Pratylenchuspenetrans). Numbersof nematodesin roots grown in 50-cm3 polystyrene starter pots were determined 6 weeks after planting. Nematodes were detected in the roots of all cultivars and lines, though the degree of invasion varied significantly. In the first screening trial, carried out in 1994 on 23 cultivars and lines, NB90-104, Upstart, and Viking harbored the lowest population densities of nematodes with levels below 1 000 g-1 of dry root, while Fergus and EPF had population densities over 30 000 g-1 of dry root. In the second screening trial conducted in 1995, all nine cultivars and lines tested, including NB90-104, Upstart, and Viking, had nematode levels greater than 7 900 g-1 of dry root. The results indicated that the cultivars and lines tested in this study exhibited wide genetic variability for invasion by root-lesion nematodes.
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STEPEK, G., A. E. LOWE, D. J. BUTTLE, I. R. DUCE, and J. M. BEHNKE. "Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode,Protospirura muricola,in vitroandin vivo." Parasitology 134, no. 1 (October 11, 2006): 103–12. http://dx.doi.org/10.1017/s0031182006001302.
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Cysteine proteinases from the fruit and latex of plants, including papaya, pineapple and fig, were previously shown to have a rapid detrimental effect,in vitro, against the rodent gastrointestinal nematodes,Heligmosomoides polygyrus(which is found in the anterior small intestine) andTrichuris muris(which resides in the caecum). Proteinases in the crude latex of papaya also showed anthelmintic efficacy against both nematodesin vivo. In this paper, we describe thein vitroandin vivoeffects of these plant extracts against the rodent nematode,Protospirura muricola, which is found in the stomach. As in earlier work, all the plant cysteine proteinases examined, with the exception of actinidain from the juice of kiwi fruit, caused rapid loss of motility and digestion of the cuticle, leading to death of the nematodein vitro. In vivo, in contrast to the efficacy againstH. polygyrusandT. muris, papaya latex only showed efficacy againstP. muricolaadult female worms when the stomach acidity had been neutralized prior to administration of papaya latex. Therefore, collectively, our studies have demonstrated that, with the appropriate formulation, plant cysteine proteinases have efficacy against nematodes residing throughout the rodent gastrointestinal tract.
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Kang, Heonil, Hwanseok Je, and Insoo Choi. "Occurrence and Distribution of Root-Knot Nematodes in Kiwifruit Orchard." Research in Plant Disease 29, no. 1 (March 31, 2023): 45–51. http://dx.doi.org/10.5423/rpd.2023.29.1.45.
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The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on kiwi orchards in Korea. Plant parasitic nematodes genus and densities were investigated at a total of 102 sites in Jeollanam-do, Gyeongsangnam-do, and Jeju-do, which are the main production areas of domestic kiwi orchards. Plant parasitic nematodes detected were of 9 genera, including root-knot nematodes (Meloidogyne spp.), spiral nematodes (Helicotylenchus spp.), and needle nematodes (Paratylenchus spp.), and 56% of the 102 plantations were infected with root-knot nematodes. Root-knot nematodes were found to be the most important plant parasitic nematode in domestic kiwi orchards. The average density of root-knot nematodes is 97 per 300 cm<sup>3</sup> soil, and there is concern about the kiwi yield reduction. As a result of identifying the root-knot nematode species: M. arenaria, M. hapla, M. incognita, and M. javanica. Among them, M. arenaria is the most dominant. As the plant parasitic nematode infection route in fruit trees is often spread through the transplantation of infected seedlings, attention should be paid to the production of nematode-free plants during the production and supply of kiwifruit plants.
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Wu, Wentao. "Marigold (Tagete erecta): An Effective Meloidogyne incognita Trap Plant." International Journal of Agriculture and Biology 25, no. 02 (February 1, 2021): 271–76. http://dx.doi.org/10.17957/ijab/15.1666.
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Root-knot nematodes (Meloidogyne spp.) are soil-borne pathogens that can cause severe damage to agricultural production. The most common approaches to prevent root-knot nematode infections are based on crop rotation with non-host plants, use of chemical insecticides, biological control methods, and use of nematode-antagonistic or trap plants. Marigolds (Tagetes erecta) are used as nematode-killing plants, but there is controversy over the mechanism through which they control root-knot nematodes. This study confirmed that marigold root-exudates are lethal to root-knot nematodes, illustrated that marigolds act as trap plants for root-knot nematodes when planted close to nematode host plants such as tomato. We investigated the rates of infection and development of nematode larvae injected into the marigold root system to evaluate whether marigolds could act as a non-host plant for root-knot nematodes. We found that aqueous solutions of marigold root-exudates showed strong lethal and inhibitory effects on sec-stage juveniles and eggs of root-knot nematodes. Marigold roots secreted substances that attracted nematodes from the surrounding environment. Furthermore, marigold root cells contained substances that had a strong inhibitory effect on the development of root-knot nematodes, resulting in diapause in nematodes, and inhibition of further infection. Herein we report a preliminary exploration of the antagonistic mechanism in marigolds for controlling the growth and development of root-knot nematodes. Our research provides basis for promoting the use of marigold for the control of nematodes as an important part of sustainable cropping strategies that rely on biological pest control. © 2021 Friends Science Publishers
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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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Karabörklü, Salih, Abdurrahman Ayvaz, Semih Yilmaz, and Ugur Azizoglu. "Fungi associated with free-living soil nematodes in Turkey." Archives of Biological Sciences 67, no. 4 (2015): 1173–83. http://dx.doi.org/10.2298/abs150204093k.
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Free-living soil nematodes have successfully adapted world-wide to nearly all soil types from the highest to the lowest of elevations. In the current study, nematodes were isolated from soil samples and fungi associated with these free-living soil nematodes were determined. Large subunit (LSU) rDNAs of nematode-associated fungi were amplified and sequenced to construct phylogenetic trees. Nematode-associated fungi were observed in six nematode strains belonging to Acrobeloides, Steinernema and Cephalobus genera in different habitats. Malassezia and Cladosporium fungal strains indicated an association with Acrobeloides and Cephalobus nematodes, while Alternaria strains demonstrated an association with the Steinernema strain. Interactions between fungi and free-living nematodes in soil are discussed. We suggest that nematodes act as vectors for fungi.
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Lubis, Khairunnisa, Siwi Indarti, and Nugroho Susetya Putra. "Plant Parasitic Nematode Abundance and Diversity in Potato (Solanum tuberosum) Cultivation at Various Altitudes in Wonosobo and Banjarnegara." Jurnal Perlindungan Tanaman Indonesia 25, no. 2 (August 12, 2021): 99. http://dx.doi.org/10.22146/jpti.26018.
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Plant-parasitic nematodes are one of the causes of yield loss in potato cultivation. Currently, information on the diversity, abundance, and dominance of potato parasitic nematode genera is not available. This research aimed to determine the pattern of distribution, abundance, and dominance of parasitic nematode genera on potato plant (Solanum tuberosum) in Wonosobo and Banjarnegara Districts at various altitudes i.e.: 1,250--1,500; 1,500--1,750; 1,750--2,000; and 2,000--2,250 meters above sea level (m.a.s.l.). Soil rhizosphere and root samples were collected, and nematodes were extracted using the Whitehead tray modification technique. The nematodes were adjusted with Formalin Acetic acid Alchohol (FAA), mounted, and identified based on morphological characters. The diversity index was determined to distinguish plant-parasitic nematode diversity. Six genera of potato plant-parasitic nematodes were found, namely Meloidogyne, Hirschmanniella, Globodera, Criconemoides, Helicotylenchus, and Xiphinema. The highest population of plant-parasitic nematodes was found at 1,250–1,500 m.a.s.l. from both root and soil samples. The nematode populations were 56.67 nematodes/5 g root and 103.33 nematodes/100 g of soil. The abundance of parasitic nematodes did not differ significantly among different altitudes in both districts. The dominant parasitic nematodes in soil samples were Meloidogyne with 16.78%, while Globodera was 13.98%. The Shannon-Wiener index implied that the diversity of parasitic nematodes of potato plants and stability of community in Wonosobo and Banjarnegara Districts were categorized as low.
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Liang, Lian-Ming, Cheng-Gang Zou, Jianping Xu, and Ke-Qin Zhang. "Signal pathways involved in microbe–nematode interactions provide new insights into the biocontrol of plant-parasitic nematodes." Philosophical Transactions of the Royal Society B: Biological Sciences 374, no. 1767 (January 14, 2019): 20180317. http://dx.doi.org/10.1098/rstb.2018.0317.
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Plant-parasitic nematodes (PPNs) cause severe damage to agricultural crops worldwide. As most chemical nematicides have negative environmental side effects, there is a pressing need for developing efficient biocontrol methods. Nematophagous microbes, the natural enemies of nematodes, are potential biocontrol agents against PPNs. These natural enemies include both bacteria and fungi and they use diverse methods to infect and kill nematodes. For instance, nematode-trapping fungi can sense host signals and produce special trapping devices to capture nematodes, whereas endo-parasitic fungi can kill nematodes by spore adhesion and invasive growth to break the nematode cuticle. By contrast, nematophagous bacteria can secrete virulence factors to kill nematodes. In addition, some bacteria can mobilize nematode-trapping fungi to kill nematodes. In response, nematodes can also sense and defend against the microbial pathogens using strategies such as producing anti-microbial peptides regulated by the innate immunity system. Recent progresses in our understanding of the signal pathways involved in microbe–nematode interactions are providing new insights in developing efficient biological control strategies against PPNs. This article is part of the theme issue ‘Biotic signalling sheds light on smart pest management'.
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Togashi, Katsumi, and Ichirow Kaihotsu. "Unilateral to bilateral distribution pattern of the pine wood nematode Bursaphelenchus xylophilus within bodies of the insect vector Monochamus alternatus depends on nematode load." Nematology 17, no. 5 (2015): 601–6. http://dx.doi.org/10.1163/15685411-00002894.
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Monochamus alternatusadults carry the pine wood nematodeBursaphelenchus xylophilus. The nematodes are present in the tracheal system of vector beetles. It is known that carrying more than 10 000 nematodes causes drastic reduction in the lifespan and flight activity of beetles. To understand the effects of heavy nematode loads, 41 newly emergedM. alternatusadults were examined for lateral distribution of nematodes within the insect body. The nematodes were distributed unevenly between right and left sides of the beetle body at small nematode loads, whereas they were distributed evenly between them at heavy nematode loads. An analysis using Hagen-Poiseuille flow in a thin tube suggested that the rate of air flow decreased exponentially as the number of nematodes increased in a trachea. Thus, even distribution of nematodes between right and left sides of the vector body was considered to be responsible in part for the effects of heavy nematode loads on beetle activity.
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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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Rosenzweig, W. D., D. Premachandran, and D. Pramer. "Role of trap lectins in the specificity of nematode capture by fungi." Canadian Journal of Microbiology 31, no. 8 (August 1, 1985): 693–95. http://dx.doi.org/10.1139/m85-131.
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Seven adhesive-producing nematode-trapping fungi were tested for their ability to capture nine different nematodes. The nematodes included species that are free living as well as plant and insect parasites. The fungi displayed no selectivity. Each fungus was able to trap and consume all of the different nematodes tested. A study of cuticle surface saccharides of five of the nematodes revealed the presence on all the nematodes of glucose–mannose and N-acetylgalactosamine residues. L-Fucose residues were not found on any of the nematodes. The involvement of lectins in the capture of prey by nematode-trapping fungi is discussed.
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Bartlett, Cheryl M. "A new hypothesis concerning attachment of parasitic nematodes (Spirurida: Acuarioidea) to the upper alimentary tract of birds." Canadian Journal of Zoology 69, no. 7 (July 1, 1991): 1829–33. http://dx.doi.org/10.1139/z91-252.
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A gelatinous caplike structure found in vivo around the anterior end of two species of acuarioid nematode parasites (Skrjabinocerca prima Shikhobalova, 1930 and Skrjabinoclava inornatae Wong and Anderson, 1988) is described, termed a "pileus," and suggested as the means by which the nematodes attach to the oesophageal and proventricular mucosa of their bird hosts (Recurvirostra americana and Catoptrophorus semipalmatus inornatus, respectively). Nematodes were embedded in host tissues to the depth of the posteriormost extent of the pileus, which corresponded to the posteriormost extent of the cuticular cordons on the external surface of the anterior end of the nematode. Each cordon, C-shaped in cross section, may serve as a conduit that allows liquid nutrients in the lumen of the alimentary tract to seep into the nematode's mouth, thus enabling the parasite to feed when tightly sealed by the pileus into host tissues.
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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.
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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.
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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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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.
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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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Hussein, Hany, Manal Adel, and Ivan Gelbič. "Effectiveness of the entomopathogenic nematode Steinernema feltiae in agar gel formulations against larvae of the Colarado potato beetle, Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae)." Open Life Sciences 7, no. 1 (February 1, 2012): 77–82. http://dx.doi.org/10.2478/s11535-011-0090-0.
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AbstractThe entomopathogenic nematode Steinernema feltiae strain Ustinov Russia was used on potato foliage to control larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae). Nematodes were applied in formulations of agar at 4%, 2%, 1% and 0.5% concentrations and compared to a control application of nematodes in water for nematode survival. Agar formulation significantly improved efficacy by increasing nematode survival through reduction in desiccation when compared to water-based formulation. More than 70% of infective juvenile nematodes (IJs) died after being incubated in the highest concentration of agar for 12 h, while only 8% mortality was recorded at the 1% concentration. Suspension of nematodes in 1% agar gel was shown to be efficacious in both laboratory and greenhouse tests for extension of the nematodes’ survival. Agar formulation droplets dried slower than control droplets by 127.8 min. Leptinotarsa decemlineata mortality significantly increased when insects were exposed to infective juvenile nematodes for four hours after application. In conclusion, the agar formulation enhanced nematode survival by providing a suitable environment thereby delaying dryingand increasing the possibility for nematodes to invade their host on the foliage.
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Schroeder, Jill, Stephen H. Thomas, and Leigh W. Murray. "Yellow (Cyperus esculentus) and purple nutsedge (Cyperus rotundus) are not injured by increasing root-knot nematode (Meloidogyne incognita) population density." Weed Science 47, no. 2 (April 1999): 201–7. http://dx.doi.org/10.1017/s0043174500091621.
Full textAbstract:
Greenhouse studies in 1995 and 1996 examined the response of yellow and purple nutsedge to inoculation with increasing densities of southern root-knot nematodes. Yellow and purple nutsedge root and shoot weight, numbers of leaves and tubers produced, and tuber weight were unaffected across 17 nematode inoculum densities that ranged from 0 to 20,000 eggs per 15-cm pot, four times the maximum nematode density recorded under field conditions in New Mexico. Hence, yellow and purple nutsedge do not exhibit a classic threshold response to root-knot nematodes. Moreover, the results suggest that the relationship between these nematodes and perennial nutsedges is an example of a positive biological interaction. The relationship between root-knot nematodes and purple nutsedge appears to be one of commensalism, because while the nematodes reproduced effectively, purple nutsedge reproduction was not related to final nematode populations. The relationship between yellow nutsedge and root-knot nematodes appears to be a mutually beneficial one, because yellow nutsedge tuber number and weight and root weight increased as final nematode populations increased. However, while both nutsedges were unaffected in the absence of the association, root-knot nematodes cannot survive without a host plant.
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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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Hauri, Kayleigh C., and Zsofia Szendrei. "A Meta-analysis of Interactions Between Insect Herbivores and Plant-Parasitic Nematodes." Environmental Entomology 51, no. 1 (November 19, 2021): 1–10. http://dx.doi.org/10.1093/ee/nvab131.
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Abstract Insect herbivores and plant-parasitic nematodes are global, economically devastating pests that are present in nearly every crop and natural system worldwide. Although they may be spatially separated, they indirectly interact with each other by altering both plant chemical defense and nutrition. However, the outcome of these interactions is highly variable across different focal species. We performed a meta-analysis to determine how plant and nematode traits influence insect herbivore growth and reproduction, as well as nematode abundance and reproduction. We investigated how interactions between plant-parasitic nematodes and insect herbivores influence plant biomass, carbon, and nitrogen in the roots and shoots. We found no overall effect of nematodes on insect herbivores or insect herbivores on nematodes. However, while phloem-feeding insect reproduction was not affected by nematode feeding guild or plant family, chewing insect growth increased in the presence of cyst nematodes and decreased in the presence of gall nematodes. The effect of nematodes on chewing insect herbivore growth was also affected by the focal plant family. Nematode presence did not alter plant biomass when plants were exposed to aboveground insect herbivory, but carbon and nitrogen were higher in roots and nitrogen was higher in shoots of plants with nematodes and insects compared to plants with insects alone. Our results indicate that the mechanisms driving the outcome of aboveground–belowground interactions are still unclear, but those chewing insects may have more variable responses to nematode damage than phloem-feeders.
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Hallmann, Johannes, and Björn Niere. "Efficacy of sedimentation basins of a nematology laboratory in retaining plant-parasitic nematodes." Nematology 16, no. 1 (2014): 9–18. http://dx.doi.org/10.1163/15685411-00002739.
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Laboratories working with regulated plant-parasitic nematodes need to ensure that those nematodes are contained within the quarantine facility. Solid or liquid waste produced during the nematode extraction process has to be deposited in such a way that there is no risk of nematodes spreading. Autoclaving works well for solid waste but uses substantial amounts of energy and thus is often considered too expensive for the enormous amount of wastewater accumulating during nematode extraction. Therefore, there is considerable interest in using less energy-consuming alternatives, such as sedimentation basins. However, published information on the efficacy of sedimentation basins in retaining plant-parasitic nematodes is almost non-existent. In this study, the efficacy of a three-step sedimentation system under routine and artificially nematode-enriched conditions was investigated. Under all experimental conditions, nematode cysts or part of cysts were never found to escape the sedimentation system. This also accounts for plant-parasitic nematodes (eggs and vermiform stages) during routine operation. However, under artificially nematode-enriched conditions (supply of up to several million nematodes) and maximum water flow rates, single specimens of plant-parasitic nematodes were detected in the effluent of the last sedimentation basin that feeds into the closed municipal sewage system. Although wastewater treatment was not investigated in this study, the combination of a system of sedimentation basins plus subsequent wastewater treatment in sewage plants is considered a cost-effective method to contain plant-parasitic nematodes during routine operation.
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DEWI, KARTIKA, and ENDANG PURWANINGSIH. "A checklist of nematode parasites from Indonesian murids." Zootaxa 3608, no. 7 (January 24, 2013): 531–46. http://dx.doi.org/10.11646/zootaxa.3608.7.1.
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A checklist of nematode parasites from Indonesian murids with their geographic distribution is presented. This checklist is compiled from three sources: the catalogue of nematode parasites of Museum Zoologicum Bogoriense (unpublished specimens in the collection), data from our previous research and articles on nematodes of Indonesian murids. This checklist is presented as a list of nematode parasites with host information, and a host list with information on their nematodes. This paper reports 38 nominal species of nematodes and 13 species identified to the generic level only. The nematodes reported comprise 32 genera and 17 families parasitizing 32 species of Indonesian murids.
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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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Edwards, M. "Resistance and tolerance of grapevine rootstocks to plant parasitic nematodes in vineyards in north-east Victoria." Australian Journal of Experimental Agriculture 29, no. 1 (1989): 129. http://dx.doi.org/10.1071/ea9890129.
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Three grapevine rootstock trials in North-East Victoria, Australia, were sampled over several summers to determine nematode populations and the resistance or the tolerance of some commonly used winegrape varieties and rootstocks to plant parasitic nematodes. Rootstocks on which nematodes failed to reproduce or reproduced poorly were considered resistant, rootstocks which supported high populations of nematodes with no apparent effect on yield were considered tolerant. Susceptible rootstocks supported high numbers of nematodes and yielded poorly. The varieties studied were: Shiraz, Chardonnay, Cabernet Sauvignon; and the rootstocks were: Harmony, Richter 110, Schwarzmann, ARG No. 1, 5A Teleki, Rupestris du Lot, 5BB Kober, SO4, Ramsey, K5 1-32 and 1202. The plant parasitic nematodes found on the trial sites were root-knot (Meloidogyne javanica (Treub) Chitwood) and citrus (Tylenchulus semipenetrans Cobb) nematodes. Cabernet Sauvignon, Chardonnay, Shiraz and ARG No. 1 were susceptible to the root-knot nematode. Harmony exhibited tolerance to the citrus nematode and was a good host, allowing a large population to build up. Ramsey appeared to be resistant to the citrus nematode, at least in the Cabernet Sauvignon rootstock trial at Wahgunyah.
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McLeish, L. J., G. N. Berg, J. M. Hinch, L. V. Nambiar, and M. R. Norton. "Plant parasitic nematodes in white clover and soil from white clover pastures in Australia." Australian Journal of Experimental Agriculture 37, no. 1 (1997): 75. http://dx.doi.org/10.1071/ea96046.
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Summary. Seventeen sites, including locations in all the major white clover growing regions of Australia, were surveyed for the presence of plant parasitic nematodes in autumn and spring 1993. Trifolium repens L. cvv. Haifa and Irrigation, plus 1 other cultivar, were sampled at each site and nematodes extracted from roots, stems and soil. Thirteen genera of plant parasitic nematodes were detected. The clover cyst nematode, Heterodera trifolii, and root knot nematodes, Meloidogyne spp., were each recorded at over 75% of the sites. The most common genera of plant parasitic nematodes detected were Tylenchus, which was present at all sites, and Pratylenchus (root lesion nematode), which was present at all but 1 site. Other plant parasitic nematode genera found included Ditylenchus, Helicotylenchus and Paratylenchus. The widespread presence of nematodes in white clover pastures, and the high populations at some sites, suggest that they may be economically important to the Australian dairy industry.
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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.
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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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Nabilah, Nabilah, I. Gede Swibawa, Radix Suharjo, and Yuyun Fitriana. "DIVERSITY AND ABUNDANCE OF NEMATODES IN GUAVA (Psidium guajava L.) CULTIVATION IN LAMPUNG." JURNAL HAMA DAN PENYAKIT TUMBUHAN TROPIKA 21, no. 2 (July 28, 2021): 134–43. http://dx.doi.org/10.23960/jhptt.221134-143.
Full textAbstract:
Diversity and abundance of nematodes in guava (Psidium guajava L.) cultivation in Lampung. Crystal guava agroecosystem is inhabited by many species of plant parasitic nematodes. However, information regarding this topic was still limited. This study aimed to understand the species dominancy of nematodes in crystal guava cultivation in Lampung. Sampling was carried out in three locations of guava crystal plantations: Lampung Timur, Lampung Tengah, and Tanggamus. The laboratory analysis was done at the Plant Pest Science Laboratory and Agricultural Biotechnology Laboratory, Universitas Lampung. The study was conducted in December 2019 – July 2020. Nematodes were identified to the level of the genus. The Prominance value (PV) was used to assess the nematodes genus dominancy. The results showed that the nematodes inhabiting the crystal guava agro-ecosystem in Lampung was both plant parasitic and free-living nematodes. The plant parasitic nematodes were identified as Meloidogyne, Aphelenchus, Hemicriconemoides, Tylenchus, Aphelenchoides, and Xiphinema, while free-living nematodes was Rhabditis, Dorylaimine, Dorylaimus, and Mononchus. The dominant plant parasitic nematode was Meloidogyne and the dominant free-living nematode was Rhabditis. The abundance of Meloidogyne /300 mL of soil was 351.47 individuals in Lampung Timur, 124.27 individuals in Lampung Tengah, and 82.18 individuals in Tanggamus. The dominant free-living nematode in the three locations was Rhabditis.
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Kawanobe, Masanori, Soh Sugihara, Naoko Miyamaru, Koichi Yoshida, Eito Nonomura, Hiroaki Oshiro, and Koki Toyota. "Distribution of Root-Lesion and Stunt Nematodes, and Their Relationship with Soil Properties and Nematode Fauna in Sugarcane Fields in Okinawa, Japan." Agronomy 10, no. 6 (May 27, 2020): 762. http://dx.doi.org/10.3390/agronomy10060762.
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Sugarcane cultivation in Japan has not yet focused on suppressing plant-parasitic nematodes. For proper nematode management, it is essential to know the spatial distribution of economically important plant-parasitic nematodes and free-living nematodes that play important roles in terrestrial ecosystems. We aimed to reveal nematode fauna and soil properties in 85 sugarcane fields of three major sugarcane producing islands in Japan, and to examine their relationship by using the mixed-effect model and by visualizing the spatial distributions using the inverse distance weighting (IDW) approach. The nematode community structures were analyzed by non-metric multidimensional scaling (NMDS). Among plant-parasitic nematodes in sugarcane, the root-lesion nematodes (Pratylenchus sp.) and the stunt nematodes (Tylenchorhynchus sp.) were widely distributed in these islands, yet the abundance and the species varied geospatially. Soil pH was significantly correlated with the abundance of Pratylenchus and Tylenchorhynchus species. The abundance of Pratylenchus and Tylenchorhynchus species were significantly correlated with soil pH. The abundance of Pratylenchus was significantly correlated with the abundance of free-living nematodes, the number of free-living nematode species, and exchangeable cation K+, as were the abundance of Tylenchorhynchus to the clay content and that of non-Tylenchorhynchus. This study also revealed that the three islands had different nematode faunas, which were explained especially by soil pH, texture, and exchangeable basic cations.
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Rahman, Mati Ur, Peng Chen, Xiuyu Zhang, and Ben Fan. "Predacious Strategies of Nematophagous Fungi as Bio-Control Agents." Agronomy 13, no. 11 (October 25, 2023): 2685. http://dx.doi.org/10.3390/agronomy13112685.
Full textAbstract:
Plant-parasitic nematodes significantly threaten agriculture and forestry, causing various diseases. They cause annual losses of up to 178 billion dollars worldwide due to their parasitism. Nematophagous fungi (NF) are valuable in controlling or reducing parasitic nematode diseases by killing nematodes through predatory behavior. This article summarizes the strategic approaches adopted by NF to capture, poison, or consume nematodes for food. NF are classified based on their attacking strategies, including nematode trapping, endoparasitism, toxin production, and egg and female parasitism. Moreover, extracellular enzymes such as serine proteases and chitinases also play an important role in the fungal infection of nematodes by disrupting nematode cuticles, which act as essential virulence factors to target the chemical constituents comprising the nematode cuticle and eggshell. Based on the mentioned approaches, it is crucial to consider the mechanisms employed by NF to control nematodes focused on the use of NF as biocontrol agents.
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Diakhate, Sidy, Florence Khady Ngom, and Saïdou Nourou Sall. "Controlling plant-parasitic nematodes in sandy soil in the Senegal River Valley using composts based on potentially nematicidal plants." Journal of Applied Biosciences 145 (January 31, 2020): 14892–901. http://dx.doi.org/10.35759/jabs.145.5.
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Objective: This study in the Senegal River Basin evaluated the effect of three types of compost, made from manure combined with straw, Calotropis procera (Sodom Apple) or Crotalaria juncea (Indian Hemp) , on plant-parasitic as well as free-living nematodes and on the growth of tomato plants. Methodology and results: This study was performed in a greenhouse where a Mongal tomato was grown during 3 months in a soil that had been abandoned due to infestation by nematodes. The treatments were composts of straw, Calotropis procera Crotalaria juncea and control without compost. The soils amended with compost had significantly higher nematode abundances than the unamended. The compost with Crotalaria juncea gave the highest abundance. The soils with compost also had a much lower proportion of plant-parasitic nematodes than the control soil and much higher proportion of bacterivorous nematodes. The height of the plants was positively correlated with the proportion of bacterivorous nematodes and negatively correlated with the proportion of plant-parasitic nematodes. Conclusions and application of the results: The influence on the soil nematode community of compost materials is associated more with their phenol content than the total organic carbon. The Calotropis procera and Crotalaria juncea encourage the growth of the bacterivorous nematode community, which plays an important role in maintaining soil fertility, and the growth of omnivorous and predatory nematodes while limiting the growth of the plant-parasitic nematode community. The results suggested that the compost with Crotalaria juncea seems to be worthwhile pursuing as it maintained the equilibrium between nematode feeding guilds while suppressing plant-parasitic nematodes. Keywords: Compost, Crotalaria, Calotropis, Straw, Nematode, sandy soil.
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Lambert, Kris N., Keith D. Allen, and Ian M. Sussex. "Cloning and Characterization of an Esophageal-Gland-Specific Chorismate Mutase from the Phytoparasitic Nematode Meloidogyne javanica." Molecular Plant-Microbe Interactions® 12, no. 4 (April 1999): 328–36. http://dx.doi.org/10.1094/mpmi.1999.12.4.328.
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Root-knot nematodes are obligate plant parasites that alter plant cell growth and development by inducing the formation of giant feeder cells. It is thought that nematodes inject secretions from their esophageal glands into plant cells while feeding, and that these secretions cause giant cell formation. To elucidate the mechanisms underlying the formation of giant cells, a strategy was developed to clone esophageal gland genes from the root-knot nematode Meloidogyne javanica. One clone, shown to be expressed in the nematode's esophageal gland, codes for a potentially secreted chorismate mutase (CM). CM is a key branch-point regulatory enzyme in the shikimate pathway and converts chorismate to prephenate, a precursor of phenylalanine and tyrosine. The shikimate pathway is not found in animals, but in plants, where it produces aromatic amino acids and derivative compounds that play critical roles in growth and defense. Therefore, we hypothesize that this CM is involved in allowing nematodes to parasitize plants.
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Ekine, Emmanuel Green, and Chinonye Oluchi Ezenwaka. "Phyto-parasitic nematodes of bell pepper plant and farm soil in Abua, Rivers State, Nigeria." Science World Journal 19, no. 1 (May 2, 2024): 275–78. http://dx.doi.org/10.4314/swj.v19i1.38.
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Bell pepper farming significantly contributes to economic development in Abua. However, phyto-parasitic nematodes are endemic in the area and affect quality of crop yield. Hence, this study was undertaken to investigate the dynamics of occurrence of nematodes in bell pepper roots and soil samples of the farms in Abua. Roots and soil from the root rhizosphere were simultaneously collected at 0-20 cm depth using an improvised soil auger and knife. Modified sieve plate technique was employed for nematode detection and a pictorial key was used for nematode identification at the genera level. An overall nematode abundance of 746 nematodes in the soil around the root region and 216 nematodes in the root tissues of the bell peppers were recorded. Gracilachus species (10.6 %) was more prevalent in the soil, and Meloidogyne species (35.2 %) exhibited the highest population in roots. The study found that Abua's cultivated soil is susceptible to nematode infestation, limiting crop performance. The nematodes showcased root burrowing which is an inherent pattern for survival. The result on root nematodes across the five bell farms surveyed was not significant (p > 0.05). The result opined that farmers in Abua, Rivers State, should understand the role of the soil nematodes and implement soil improvement strategies for improved crop performance and rural economic development.
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Tanney, Joey B., and Leonard J. Hutchison. "Encapsulation and immobilization of a mycophagous nematode by two Sphaerobolus species." Botany 89, no. 11 (November 2011): 745–51. http://dx.doi.org/10.1139/b11-060.
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A defence mechanism against nematodes produced by Sphaerobolus stellatus Tode and Sphaerobolus iowensis L.B. Walker is described for the first time. Within 24 h of introduction, some individuals of a mycophagous nematode ( Aphelenchoides sp.) exhibited lethargic behaviour marked by the cessation of feeding and a reduction in movement. The anterior portion of the affected nematodes appeared swollen and was encapsulated with an amorphous material of unknown composition. The nematode stylet could not penetrate this encapsulating matrix, preventing further hyphal grazing and subsequently leading to death of the nematodes, possibly due to starvation. Immobilized nematodes were not consumed by the fungi. It is hypothesized that when the feeding nematodes pierce a specialized structure found in Sphaerobolus cultures, referred to as a gloeocystidium, the contents are released and solidify on the nematode heads. It is proposed that the gloeocystidia function to protect the hyphal system and act as a general antifeedant mechanism against mycophagous nematodes and possibly other fungus-feeding microfauna.
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Varodi, E. I., A. M. Malega, Y. I. Kuzmin, and V. V. Kornyushin. "Helminths of Wild Predatory Mammals of Ukraine. Nematodes." Vestnik Zoologii 51, no. 3 (June 27, 2017): 187–202. http://dx.doi.org/10.1515/vzoo-2017-0026.
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Abstract The article summarizes information on the nematodes parasitic in wild Carnivora of Ukraine. Totally, 50 species of nematodes are known to parasitise carnivorans in the country, 30 species were registered in the present study. Nematodes were found in 14 species of examined hosts from the families Canidae, Mustelidae and Felidae. Maximum diversity of nematodes of carnivorans was observed in Polissia (forest zone in the north of the country) and in Kherson Region in the south. Hosts from the family Canidae harboured 19 nematode species; studied species of the Mustelidae were infected with 15 nematode species, 6 of them were also found in Canidae. The wildcat (Felis silvestris Schreber) and the lynx (Lynx lynx Linnaeus) harboured only two species of nematodes, both are specific parasites of these hosts. The most comprehensive information concerns the nematode communities of the red fox (Vulpes vulpes Linnaeus) and the wolf (Canis lupus Linnaeus), with 19 and 9 nematode species found, correspondingly. From 1 to 6 nematode species were found in other species of carnivorans.
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Prasad, N., and R. Kant. "Dynamics of plant parasitic and free living nematode populations in sugarcane Saccharum officinarum in Fiji." New Zealand Plant Protection 70 (July 31, 2017): 321. http://dx.doi.org/10.30843/nzpp.2017.70.85.
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Parasitic nematodes are one of the main constraints in the production of sugarcane, Saccharum officinarum, in Fiji and other sugarcane-growing countries. Both plant parasitic and free-living nematodes are associated with roots of the plant, and the level of infestation affects both soil health and cane yield. This study examined the dynamics of plant parasitic and free-living nematode populations in sugarcane crops in Drasa Estate, Lautoka, Fiji. Soil samples to quantify nematode populations were collected ve times during the crop cycle. There was an exponential increase in the plant parasitic nematode population with time after planting (nematode population=64.316e0.0112x; R2=0.56, x=days after planting). However, the increase was not consistent among the different nematode groups. Significant increases in Lesion (P<0.05), Rootknot (P<0.05), Spiral (P<0.01), and Ring (P<0.03) nematode populations were found but not for Reniforms (P>0.05). Populations of free-living nematodes built up 90 days after planting and remained elevated in the ratoon crop. Populations of parasitic nematodes increased with the growth of cane (as measured by cane height) with increases occurring faster in the ratoon than in the plant crop (P=0.001). The number of free-living nematodes may have affected population growth of parasitic nematodes.
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ROHDE, CRISTHIANE, NATÁLIA RAMOS MERTZ, and ALCIDES MOINO JUNIOR. "ENTOMOPATHOGENIC NEMATODES ON CONTROL OF MEDITERRANEAN FRUIT FLY (DIPTERA: TEPHRITIDAE)." Revista Caatinga 33, no. 4 (October 2020): 974–84. http://dx.doi.org/10.1590/1983-21252020v33n412rc.
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ABSTRACT Mediterranean fruit fly (Ceratitis capitata) is one of the world's major pests infesting fruit crops, causing significant losses. However, this insect has a soil phase and is a potential target for entomopathogenic nematodes. The objective of this work was to test the efficiency of the nematodes Steinernema carpocapsae ALL and Heterorhabditis amazonensis JPM4 in controlling larvae and pupae of Ceratitis capitata. Petri dishes with filter paper or pots with 200 g of soil were used to assess different nematode concentrations; 20 individuals (larvae or pupae) were placed in each container and the nematode suspension was applied at concentrations of 0, 140, 180, 220, 260, and 300 IJs (infective juveniles) cm-2. The nematode horizontal movement was tested using pots with soil and a metal screen at every 10 cm to define different distances (0, 10, 20, and 30 cm from the application site). Ten larvae and ten pupae were transferred to every distance; 10 mL of the nematode suspension (220 IJs cm-2) were applied at the distance zero; 10 mL of the nematode suspension with 220 IJs cm-2 was applied to each pot, using ten larvae and ten pupae for each evaluation time (0, 10, 20, and 30 days after application of nematodes) to study the effectiveness of these nematodes over time. Both nematodes killed C. capitata larvae and pupae, but S. carpocapsae ALL was the most effective. However, this nematode showed no ability for horizontal movement, which was found in H. amazonensis JPM4 nematodes. Both nematodes showed decreasing efficiency over time.
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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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Moens, Maurice, and Yunliang Peng. "Host resistance and tolerance to migratory plant-parasitic nematodes." Nematology 5, no. 2 (2003): 145–77. http://dx.doi.org/10.1163/156854103767139653.
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AbstractPlant-parasitic nematodes are divided according to their feeding strategy into three major groups: sedentary endoparasites, migratory endoparasites and ectoparasites. Compared to what is known about sedentary endoparasitic nematode species, resistant and tolerant relationships between the nematodes from the latter two groups and their hosts are much less documented. However, methods for screening and evaluation of the resistance and tolerance of plants to migratory plant-parasitic nematodes have been well developed and sources of resistance and tolerance to these nematodes have been found. Advances have been made in breeding resistance to migratory plant-parasitic nematodes in rice, alfalfa, banana, pine trees, grape, woody fruits and other crops. Although accessions immune to stem, leaf and bud nematodes are found quite frequently, host resistance to migratory root-parasitic nematodes has been detected less frequently and generally only partly reduces nematode multiplication. Host tolerance to migratory nematodes is important even for resistant varieties and therefore is gaining attention. An insufficient degree of resistance and tolerance, their variability with the environment, and their linkage to undesired agricultural or horticultural characters are commonly observed. Polygenic bases for plant resistance and tolerance to migratory nematodes have been demonstrated by genetic and biochemical observations and make breeding even more complicated than that for resistance to sedentary plant-parasitic nematodes. These factors, with the presence of different nematode species in the field and community and population differences in pathogenicity, hinder the availability of host resistance and tolerance and offer a big challenge.
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Everard, A., C. T. Griffin, and A. B. Dillon. "Competition and intraguild predation between the braconid parasitoidBracon hylobiiand the entomopathogenic nematodeHeterorhabditis downesi, natural enemies of the large pine weevil,Hylobius abietis." Bulletin of Entomological Research 99, no. 2 (November 12, 2008): 151–61. http://dx.doi.org/10.1017/s0007485308006287.
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AbstractIn biological control programmes introduced natural enemies compete with indigenous enemies for hosts and may also engage in intraguild predation when two species competing for the same prey attack and consume one another. The large pine weevil,Hylobius abietisL. (Coleoptera: Curculionidae), is an important pest of coniferous reforestation in Europe. Among its natural enemies, the parasitoidBracon hylobiiRatz. (Hymenoptera: Braconidae) and entomopathogenic nematodes have potential as biological control agents. Both parasitoid and nematodes target the weevil larvae and, hence, there is potential for competition or intraguild predation.In this study, we examine the interaction ofB. hylobiiwith the nematodeHeterorhabditis downesiStock, Griffin and Burnell (Nematode: Heterorhabditidae), testing the susceptibility of larvae, pupae and adults ofB. hylobiitoH. downesiand whether female parasitoids discriminate between nematode-infected and uninfected weevils for oviposition. In choice tests, when weevils were exposed to nematodes 1–7 days previously, noB. hylobiioviposited on nematode-infected weevil larvae. Up to 24 h, healthy weevils were twice as likely as nematode-infected ones to be used for oviposition.Bracon hylobiifemales did not adjust clutch size; nematode-infected hosts were either rejected or the parasitoid laid a full clutch of eggs on them.When nematodes were applied to the parasitoid feeding on weevil larvae, the nematodes parasitized the parasitoid larvae, there was a reduction in cocoon formation and fewer cocoons eclosed. Eclosion rate was not reduced when nematodes were applied to fully formed cocoons, but nearly all of the emerging adults were killed by nematodes.
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Al-Ghamdi, Amal Ahmed Mohammed. "Relationship between Nematodes and some Soil Properties in the Rhizosphere of Banana Plants." International Letters of Natural Sciences 82 (April 2021): 1–12. http://dx.doi.org/10.18052/www.scipress.com/ilns.82.1.
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Nematodes are plant-parasitic organisms that cause alterations in the chemical and physical environment of soils. This study investigates the relationship between nematode occurrence and some soil parameters. The results showed that the proportion of nematodes in soil was negatively correlated with soil pH (r2= 0.89); however, it increased with increasing electrical conductivity (EC) (r2 = 0.95), soil moisture (SM) (r2 = 0.60), and organic matter (OM) content (r2= 0.78). A positive correlation was found between the proportion of nematodes in the roots and the amount of coarse sand, while a negative correlation existed between the proportion of nematodes and the amount of fine sand, clay, and silt. The degree of colonization by nematodes increased with increasing coarse sand content (r2= 0.91). Conversely, the soil nematode population decreased with increasing fine sand content (r2= 0.83), clay (r2= 0.80), and silt content (r2= 0.97). The nematode population in banana roots correlated with soil phosphorus (r2 = 0.88), potassium (r2 = 69), calcium (r2 = 0.78), and magnesium levels (r2=0.78). Conversely, a negative correlation was found between nitrogen concentration and the nematode population in banana roots (r2=0.76). Overall, the population of nematodes in soil affects its pH, EC, SM, and OM content.