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Parwinder S. Grewal - One of the best experts on this subject based on the ideXlab platform.
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susceptibility of the adult japanese beetle popillia japonica to entomopathogenic nematodes
Journal of Nematology, 2011Co-Authors: Erin E Morris, Parwinder S. GrewalAbstract:To build upon prior research demonstrating the potential of entomopathogenic nematode dissemination by infected adult Japanese beetle, Popillia japonica, we evaluated susceptibility of the adult beetles to 20 strains of Steinernema and Heterorhabditis under laboratory conditions. The nematodes were applied at a rate of 10,000 infective juveniles per 10 adult beetles in 148 mL plastic cups containing autoclaved sand and sassafras leaves as a source of food for the beetles. All strains infected the beetles and caused 55% to 95% mortality. The most virulent strains that caused 50% beetle mortality in less than 5 days included a strain of H. georgiana (D61), three strains of Steinernema sp. (R54, R45, and FC48), and two strains of S. carpocapsae (All and D60). The ability of two strains of Steinernema sp. (R45 and R54) and two strains of Heterorhabditis bacteriophora (D98 and GPS11) to infect and reproduce in the beetle was further examined to assess the potential of infected beetles to disseminate nematodes upon their death. All four strains infected and killed the beetles, but only Steinernema strains reproduced in the cadavers. We conclude that both Heterorhabditis and Steinernema strains are able to cause mortality to adult Japanese beetle, but Steinernema strains may be effectively disseminated due to their reproduction in the beetle.
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Erratum to: Photorhabdus luminescens subsp. kleinii subsp. nov. (Enterobacteriales: Enterobacteriaceae)
Current Microbiology, 2011Co-Authors: Parwinder S. GrewalAbstract:The original version of the article entitled ‘‘Photorhabdus luminescens subsp. kleinii subsp. Nov. (Enterobacteriales: Enterobacteriaceae)’’ (Current Microbiology, 2011, 62: 539–543) contained a statement in the first line of the last paragraph in Introduction section ‘‘In this study, symbiotic bacteria associated with Heterorhabditis georgiana strains were isolated for the first time’’. The correct statement should read as ‘‘In this study, symbiotic bacteria associated with three Heterorhabditis georgiana strains were isolated’’. Also the statement ‘‘This is also the first description of the bacteria associated with the nematode H. georgiana’’ in the last paragraph of Discussion section should be removed. This erratum is made due to an unintentional omission of a paper by Shapiro-Ilan et al. (2009): Characterization of biocontrol traits in the entomopathogenic nematode Heterorhabditis georgiana (Kesha strain) and phylogenetic analysis of the nematode’s symbiotic bacteria (Biological Control 51: 377–387). Interestingly, the two papers report completely different subspecies of Photorhabdus luminescens to be associated with the two different strains of the same nematode species.
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Phylogenetic and cophylogenetic relationships of entomopathogenic nematodes (Heterorhabditis: Rhabditida) and their symbiotic bacteria (Photorhabdus: Enterobacteriaceae)
Molecular phylogenetics and evolution, 2011Co-Authors: Patchareewan Maneesakorn, Parwinder S. Grewal, Hannah Daneshvar, Kara J.m. Taylor, Xiaodong Bai, Byron J. Adams, Angsumarn ChandrapatyaAbstract:Mutualistic association between entomopathogenic Photorhabdus bacteria and Heterorhabditis nematodes represents one of the emerging model systems in symbiosis studies, yet little is known about this partnership from a coevolutionary perspective. Herein, we investigated phylogenetic and cophylogenetic relationships of Heterorhabditis and Photorhabdus strains using molecular markers Internal Transcribed Spacer and gyrase B gene sequences, respectively. The phylogenies presented consistent, well supported, monophyletic groups in the parsimonious and likelihood analyses for both the nematode and bacterial strains and supported the placement of currently recognized taxa, from which a potentially new Heterorhabditis species represented by a Thailand strain MP68 was identified. While the nematode strains with distant geographic distributions showed no detectable phylogenetic divergence within H. bacteriophora or H. georgiana monophyletic groups, their respective symbiotic bacteria speciated into two Photorhabdus species: P. luminescens and P. temperata, indicating the occurrence of duplication. Although such evolutionary process reduces the phylogenetic congruence between Heterorhabditis nematodes and Photorhabdus bacteria, global cophylogenetic tests using ParaFit detected a highly significant correlation between the two phylogenies (ParaFitGlobal = 0.001). Further, the associations between H. zealandica, H. indica and H. megidis strains and their symbiotic bacteria exhibited significant contribution to the overall cophylogenetic structure. Overall, this study reveals evidence of coevolution between Photorhabdus bacteria and Heterorhabditis nematodes and provides a framework for further examination of the evolution of these associations.
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Photorhabdus temperata subsp. stackebrandtii subsp. nov. (Enterobacteriales: Enterobacteriaceae)
Current Microbiology, 2010Co-Authors: Parwinder S. GrewalAbstract:The bacterial symbiont of the entomopathogenic nematode Heterorhabditis bacteriophora strain GPS11 was characterized by 16S rRNA gene sequence and physiological traits. The phylogenetic tree built upon 16S rRNA gene sequences clustered the GPS11 bacterial isolate with Photorhabdus temperata strains which have been previously isolated from Heterorhabditis species. The phylogenetic tree further identified four subgroups in P. temperata , and the relationships among these subgroups were confirmed by gyrase subunit B ( gyrB ) gene sequence analysis. The subgroup containing the GPS11 bacterial isolate differs from other subgroups in sequences of 16S rRNA and gyrB gene, physiological traits, nematode host species, and geographic origin. Therefore, the subgroup comprising the GPS11 bacterial isolate is proposed here as a new subspecies: Photorhabdus temperata subsp. stackebrandtii subsp. nov. (type strain GPS11). The type strain has been deposited in ATCC and DSMZ collections.
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Photorhabdus luminescens subsp. kleinii subsp. nov. (Enterobacteriales: Enterobacteriaceae)
Current microbiology, 2010Co-Authors: Parwinder S. GrewalAbstract:Association between bacteria Photorhabdus and their nematode hosts Heterorhabditis represents one of the emerging models in symbiosis studies. In this study, we isolated the bacterial symbionts of the nematode Heterorhabditis georgiana. Using gyrB sequences for phylogenetic analysis, these strains were shown to be part of the species of Photorhbdus luminescens but with clear separation from currently recognized subspecies. Physiological properties and DNA–DNA hybridization profiles also supported the phylogenetic relationship of these strains. Therefore, a new subspecies, Photorhabdus luminescens subsp. kleinii subsp. nov., is proposed with the type strain KMD37T (=DSM 23513 =ATCC =NRRL B-59419).
Raquel Camposherrera - One of the best experts on this subject based on the ideXlab platform.
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cutaneous excreta of the earthworm eisenia fetida haplotaxida lumbricidae might hinder the biological control performance of entomopathogenic nematodes
Soil Biology & Biochemistry, 2020Co-Authors: Maryam Chelkha, Ruben Blancoperez, Francisco Angel Buenopallero, S Amghar, Abdellatif El Harti, Raquel CamposherreraAbstract:Abstract Earthworms enhance soil structure, the decomposition of organic matter and the dissemination of beneficial soil organisms such as the entomopathogenic nematodes (EPNs). Nevertheless, the effects of earthworm feeding behavior or cutaneous excreta (CEx) on the performance of EPNs as biological control agents is poorly understood. We hypothesized that the presence of earthworms or their excreta reduces EPN fitness, measured in terms of pathogenicity and reproductive success. In laboratory experiments we first evaluated the killing ability of EPNs against Galleria mellonella (Lepidoptera: Pyralidae) larvae when inoculated in autoclaved soil alone or in combination with the earthworm Eisenia fetida (Haplotaxida: Lumbricidae) or their excreta. We also evaluated EPN efficacy and reproduction when exposed to CEx derived from E. fetida at two nematode concentrations (1.5 and 10 IJs/cm2). For both experiments, we tested four steinernematids (Steinernema carpocapsae, S. feltiae, S. glaseri, and S. khuongi) and two heterorhabditids (Heterorhabditis bacteriophora and H. zealandica). The presence of earthworms or their excreta resulted in significant reduction of the larval mortality caused by some of the steinernematids at certain timings depending of the species (P
Maryam Chelkha - One of the best experts on this subject based on the ideXlab platform.
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cutaneous excreta of the earthworm eisenia fetida haplotaxida lumbricidae might hinder the biological control performance of entomopathogenic nematodes
Soil Biology & Biochemistry, 2020Co-Authors: Maryam Chelkha, Ruben Blancoperez, Francisco Angel Buenopallero, S Amghar, Abdellatif El Harti, Raquel CamposherreraAbstract:Abstract Earthworms enhance soil structure, the decomposition of organic matter and the dissemination of beneficial soil organisms such as the entomopathogenic nematodes (EPNs). Nevertheless, the effects of earthworm feeding behavior or cutaneous excreta (CEx) on the performance of EPNs as biological control agents is poorly understood. We hypothesized that the presence of earthworms or their excreta reduces EPN fitness, measured in terms of pathogenicity and reproductive success. In laboratory experiments we first evaluated the killing ability of EPNs against Galleria mellonella (Lepidoptera: Pyralidae) larvae when inoculated in autoclaved soil alone or in combination with the earthworm Eisenia fetida (Haplotaxida: Lumbricidae) or their excreta. We also evaluated EPN efficacy and reproduction when exposed to CEx derived from E. fetida at two nematode concentrations (1.5 and 10 IJs/cm2). For both experiments, we tested four steinernematids (Steinernema carpocapsae, S. feltiae, S. glaseri, and S. khuongi) and two heterorhabditids (Heterorhabditis bacteriophora and H. zealandica). The presence of earthworms or their excreta resulted in significant reduction of the larval mortality caused by some of the steinernematids at certain timings depending of the species (P
Ralfudo Ehlers - One of the best experts on this subject based on the ideXlab platform.
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selective breeding for desiccation tolerance in liquid culture provides genetically stable inbred lines of the entomopathogenic nematode Heterorhabditis bacteriophora
Applied Microbiology and Biotechnology, 2013Co-Authors: Samuel Anbesse, Nanette Hope Sumaya, Olaf Strauch, Anna Verena Dorfler, Ralfudo EhlersAbstract:The entomopathogenic nematode (EPN) Heterorhabditis bacteriophora is used in biological plant protection to control pest insects. In the past, several attempts targeted at an enhancement of the desiccation tolerance of EPN by genetic selection in order to improve their storage stability. The subsequent loss of improved beneficial traits after release of selection pressure has often been reported. In order to stabilize progress of selective breeding, selection during liquid culturing was tested against propagation in host insects. After release of the selection pressure, the tolerance was monitored over additional reproductive cycles in vivo and in vitro to compare the stability of the trait. Furthermore, it was tested whether the virulence of the selected strains would be impaired. Exposure to desiccation stress prior to propagation, in vivo or in vitro, both resulted in increasing desiccation tolerance. When selection pressure was released, the gained tolerance was lost again during in vivo production, whereas the tolerance was maintained at a high level when EPNs were cultured in liquid culture. In Heterorhabditis sp., liquid culture conditions produce highly homozygous, genetically stable inbred lines. The investigation provides easily applicable methods to improve and stabilize beneficial traits of heterorhabditid EPNs through selective breeding in liquid culture. Compared to nematodes from in vivo propagation, production in liquid media yielded EPN of higher virulence.
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sustainable control of black vine weevil larvae otiorhynchus sulcatus coleoptera curculionidae with Heterorhabditis bacteriophora in strawberry
Biocontrol Science and Technology, 2008Co-Authors: Alper Susurluk, Ralfudo EhlersAbstract:Abstract Efficacy, persistence and recovery of the nematode Heterorhabditis bacteriophora was tested in the laboratory after application of the nematode to strawberry roots by dipping. To mitigate nematode sedimentation and improve attachment to strawberry roots, carboxy-methyl-cellulose was added to the nematode solution. Mortality of black vine weevil Otiorhynchus sulcatus varied between 90 and 96% in the pot trials.
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effect of photorhabdus luminescens phase variants on the in vivo and in vitro development and reproduction of the entomopathogenic nematodes Heterorhabditis bacteriophora and steinernema carpocapsae
FEMS Microbiology Ecology, 2001Co-Authors: Richou Han, Ralfudo EhlersAbstract:Photorhabdus luminescens (Enterobacteriaceae) is a symbiont of entomopathogenic nematodes Heterorhabditis spp. (Nematoda: Rhabditida) used for biological control of insect pests. For industrial mass production, the nematodes are produced in liquid media, pre-incubated with their bacterial symbiont, which provides nutrients essential for the nematode's development and reproduction. Particularly under in vitro conditions, P. luminescens produces phase variants, which do not allow normal nematode development. The phase variants were distinguished based on dye absorption, pigmentation, production of antibiotic substances, occurrence of crystalline inclusion proteins and bioluminescence. To understand the significance of the phase shift for the symbiotic interaction between the bacterium and the nematode, feeding experiments tested the effect of homologous and heterologous P. luminescens phase variants isolated from a Chinese Heterorhabditis bacteriophora (HO6), the Heterorhabditis megidis type strain from Ohio (HNA) and the type strain of Heterorhabditis indica (LN2) on the in vivo and in vitro development and reproduction of the nematode species H. bacteriophora (strain HO6) and another rhabditid and entomopathogenic nematode, Steinernema carpocapsae (A24). In axenically cultured insect larvae (Galleria mellonella) and in vitro in liquid media, H. bacteriophora produced offspring on phase I of its homologous symbiont and on the heterologous symbiont of H. megidis, but not on the two corresponding phase II variants. In solid media, nematode yields were much lower on phase II than on phase I variants. On the heterologous phase I symbiont isolated from H. indica the development of H. bacteriophora was not beyond the fourth juvenile stage of the nematode in any of the media tested, but further progressed on phase II with even a small amount of offspring recorded in solid media. Infective juveniles of S. carpocapsae did not develop beyond the J3 stage on all phase I P. luminescens. They died in phase I P. luminescens isolated from H. bacteriophora. Development to adults was recorded for S. carpocapsae on all phase II symbionts and offspring were produced in all media except in liquid. It is concluded that a lack of essential nutrients or the production of toxins is not responsible for the negative impact of homologous phase II symbiont cells on the development and reproduction of H. bacteriophora. The infective juveniles of H. bacteriophora retained cells of the homologous phase I symbiont, but not phase II cells and cells from heterologous symbionts, indicating that the transmission of the symbiont by the infective juvenile is selective for phase I cells and the homologous bacterial associate.
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identification and ecological characterisation of three entomopathogenic nematode bacterium complexes from turkey
Nematology, 2001Co-Authors: Alper Susurluk, Olaf Strauch, Ilona Dix, Erko Stackebrandt, Urs Wyss, Ralfudo EhlersAbstract:Two heterorhabditid nematode strains (TUR-H1 and TUR-H2), and their bacterial symbionts isolated from soil samples taken at the campus of the Agriculture Faculty of the University of Ankara, Turkey, were identified by molecular methods and by cross-breeding with Heterorhabditis bacteriophora . The bacterial symbionts shared >99% similarity in the 16S rDNA sequence with Photorhabdus luminescens subsp. laumondii . Results of the restriction fragment length analysis of the ITS region assigned both nematode strains to the species H. bacteriophora . Cross-breeding confirmed the species designation for strain TUR-H2. Crosses of TUR-H1 with a hybrid strain of H. bacteriophora or with TUR-H2 resulted in infertile offspring. Both strains reproduced in monoxenic cultures of the symbionts P.luminescens isolated from H. bacteriophora and H. megidis and the resulting dauer juveniles retained cells of the bacteria. Reproduction on the symbionts isolated from H. indica failed. Infectivity at variable soil moisture and heat tolerance of the two heterorhabditid strains was compared with a Turkish isolate of Steinernema feltiae . Significantly more nematodes invaded the insect Galleria mellonella in a sandy soil assay at 10% water content than at lower values. A higher water content significantly reduced the invasion rate. Steinernema feltiae was better adapted to a temperature of 32°C than the heterorhabditid strains. Hardly any nematodes of all strains survived for longer than 4 h at 36°C.
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endotokia matricida in hermaphrodites of Heterorhabditis spp and the effect of the food supply
Nematology, 1999Co-Authors: Stefanandreas Johnigk, Ralfudo EhlersAbstract:Intra-uterine birth causing maternal death ( endotokia matricida ) is relatively common in rhabditid nematodes and typical for entomopathogenic nematodes of the genus Heterorhabditis . A detailed description of this phenomenon is given, including a summary of embryo development, egg-laying, juvenile hatching and development. It is demonstrated that low food supply significantly promotes the beginning of endotokia matricida but has no influence on the time scale of the process. The biological function of endotokia matricida and the intra-uterine induction of the dauer formation is discussed. Endotokia matricida in Heterorhabditis spp. is a well synchronised process of the destruction of the maternal tissues correlated with the juvenile development including the uptake of the symbiotic bacteria by the late pre-dauer stage. It secures the development of dauer juveniles at a moment when the external food supply is reducing and provides offspring which are well equipped with energy reserves and symbiotic bacteria for long term survival and subsequent infection of insects in the soil. Endotokia matricida bei Hermaphroditen von Heterorhabditis spp. und der Einfluss der Nahrungsversorgung . - Der Schlupf juveniler Nematoden im mutterlichen Uterus mit anschliessender Totung des Muttertieres ( endotokia matricida ) ist relativ weit verbreitet bei rhabditiden Nematoden und typisch fur entomopathogene Nematoden der Gattung Heterorhabditis . Die Endotokia matricida wird beschrieben sowie die Embryonalentwicklung, das Eilegeverhalten, der Schlupf und die Entwicklung der Juvenilen. Der Beginn der endotokia matricida wird durch eine niedrige Nahrungsverfugbarkeit in der Kultur signifikant gefordert, diese hat jedoch keinen Einfluss auf den zeitlichen Ablauf der endotokia matricida . Die biologische Funktion der endotokia matricida und die intra-uterine Induktion der Dauerlarvenbildung werden diskutiert. Die endotokia matricida bei Heterorhabditis spp. ist ein gut synchronisierter Prozess, bei dem die Zerstorung des Muttertiers korreliert mit der Entwicklung der Juvenilstadien, einschliesslich der Aufnahme der symbiotischen Bakterien durch das Pra-Dauer Stadium. Sie sichert die Entwicklung von Dauerlarven zu einem Zeitpunkt, wenn die externe Nahrungsversorgung sich verschlechtert und bringt so Nachkommen hervor, die gut mit Energiereserven und symbiotischen Bakterien ausgestattet sind, um im Boden lange zu uberdauern und Insekten zu befallen.
Ruben Blancoperez - One of the best experts on this subject based on the ideXlab platform.
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cutaneous excreta of the earthworm eisenia fetida haplotaxida lumbricidae might hinder the biological control performance of entomopathogenic nematodes
Soil Biology & Biochemistry, 2020Co-Authors: Maryam Chelkha, Ruben Blancoperez, Francisco Angel Buenopallero, S Amghar, Abdellatif El Harti, Raquel CamposherreraAbstract:Abstract Earthworms enhance soil structure, the decomposition of organic matter and the dissemination of beneficial soil organisms such as the entomopathogenic nematodes (EPNs). Nevertheless, the effects of earthworm feeding behavior or cutaneous excreta (CEx) on the performance of EPNs as biological control agents is poorly understood. We hypothesized that the presence of earthworms or their excreta reduces EPN fitness, measured in terms of pathogenicity and reproductive success. In laboratory experiments we first evaluated the killing ability of EPNs against Galleria mellonella (Lepidoptera: Pyralidae) larvae when inoculated in autoclaved soil alone or in combination with the earthworm Eisenia fetida (Haplotaxida: Lumbricidae) or their excreta. We also evaluated EPN efficacy and reproduction when exposed to CEx derived from E. fetida at two nematode concentrations (1.5 and 10 IJs/cm2). For both experiments, we tested four steinernematids (Steinernema carpocapsae, S. feltiae, S. glaseri, and S. khuongi) and two heterorhabditids (Heterorhabditis bacteriophora and H. zealandica). The presence of earthworms or their excreta resulted in significant reduction of the larval mortality caused by some of the steinernematids at certain timings depending of the species (P