Diffusion of the maize root signal ( E )-β-caryophyllene in soils of different textures and the effects on the migration of the entomopathogenic nematode Heterorhabditis megidis

Rhizosphere ◽  
2017 ◽  
Vol 3 ◽  
pp. 53-59 ◽  
Author(s):  
Xavier Chiriboga M. ◽  
Raquel Campos-Herrera ◽  
Geoffrey Jaffuel ◽  
Gregory Röder ◽  
Ted C.J. Turlings
Keyword(s):  
Entomopathogenic Nematode ◽  
Maize Root ◽  
Heterorhabditis Megidis ◽  
Root Signal

Comparison of metabolites produced in vitro and in vivo by Photorhabdus luminescens, a bacterial symbiont of the entomopathogenic nematode Heterorhabditis megidis

1998 ◽  
Vol 44 (11) ◽  
pp. 1072-1077 ◽  
Author(s):  
Kaiji Hu ◽  
Jianxiong Li ◽  
Wenjie Wang ◽  
Houming Wu ◽  
Hai Lin ◽  
...  
Keyword(s):  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Culture Broth ◽  
Bacterial Symbiont ◽  
Natural Source ◽  
Photorhabdus Luminescens ◽  
Heterorhabditis Megidis ◽  
Organic Extracts

The types of metabolites produced by Photorhabdus luminescens C9 when it is introduced by Heterorhabditis megidis 90 into Galleria mellonella larvae are different from those produced in tryptic soy broth. Only 3,5-dihydroxy-4-isopropylstilbene 1 was identified from the organic extracts of P. luminescens culture broth, but both 3,5-dihydroxy-4-isopropylstilbene 1 and 3,5-dihydroxy-4-ethylstilbene 3 were isolated from the organic extracts of nematode-bacterium infected G. mellonella larvae. In addition to two pigments, both of which had been previously reported from P. luminescens C9 culture broth, three pigments, 1,8-dihydroxy-3-methoxy-9,10-anthraquinone 2, 1-hydroxy-2,6,8-trimethoxy-9,10-anthraquinone 6, and 1,4-dihydroxy-2,5-dimethoxy-9,10-anthraquinone 7 were isolated from the organic extracts of G. mellonella larvae infected by the nematode-bacterium complex. Among these, compounds 6 and 7 are novel and isolated from a natural source for the first time.Key words: Photorhabdus luminescens, Heterorhabditis megidis, 1-hydroxy-2,6,8-trimethoxy-9,10-anthraquinone, 1,4-dihydroxy-2,5-dimethoxy-9,10-anthraquinone, pigment.

scholarly journals Density-dependent fecundity and infective juvenile production in the entomopathogenic nematode, Heterorhabditis megidis

Parasitology ◽  
2002 ◽  
Vol 125 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. J. RYDER ◽  
C. T. GRIFFIN
Keyword(s):  
First Generation ◽  
Entomopathogenic Nematode ◽  
Reproductive Investment ◽  
Host Population ◽  
Infective Juvenile ◽  
Density Dependent ◽  
Heterorhabditis Megidis ◽  
Single Host ◽  
Relative Production ◽  
Infection Density

The entomopathogenic nematode Heterorhabditis megidis may undergo several rounds of reproduction within a single host. Infective juveniles (IJs) are formed within each generation during a process referred to as endotokia matricida, which involves the progressive consumption of the parent hermaphrodite or female by the developing IJs prior to emergence from the host cadaver. The present study examines the extent to which within-host population dynamics exhibit density-dependent variation. Particular attention is paid to the effect of infection density on the relative production of IJs and ‘normal’, non-infective offspring within each generation and on the emergence of the IJs from the host. Fecundity was found to be negatively density dependent across generations. However, at high infection density the first generation hermaphrodites invested relatively more in IJs at the expense of producing non-infective offspring. It is suggested that this pattern resulted from an adaptive, phenotypically plastic allocation of reproductive investment between offspring types in response to increased competition. The F1 and F2 IJs were also shown to emerge from the host in relatively discrete pulses.

scholarly journals Restoring a maize root signal that attracts insect-killing nematodes to control a major pest

2009 ◽  
Vol 106 (32) ◽  
pp. 13213-13218 ◽  
Author(s):  
J. Degenhardt ◽  
I. Hiltpold ◽  
T. G. Kollner ◽  
M. Frey ◽  
A. Gierl ◽  
...  
Keyword(s):  
Maize Root ◽  
Major Pest ◽  
Root Signal

Development of the entomopathogenic nematode Heterorhabditis megidis strain NLH-E 87.3 in Galleria mellonella

Nematology ◽  
2000 ◽  
Vol 2 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Mari Boff ◽  
Peter Smits ◽  
Lonne Gerritsen ◽  
Gerrie Wiegers
Keyword(s):  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Heterorhabditis Megidis ◽  
Greater Wax Moth ◽  
Wax Moth

AbstractIncreasing densities of Heterorhabditis megidis strain NLH-E 87.3 infective juveniles (IJ) affected invasion, reproduction, length and time to first emergence of the nematodes in larvae of the greater wax moth, Galleria mellonella. Although the number of nematodes that invaded the host increased with increasing dose, percentage of invasion declined. The number of progeny produced per host initially increased with dose. The highest production of IJ per cadaver was reached at a dose of 300 IJ per host, at that dose 62 ± 3.4 IJ were established per cadaver. Production decreased again significantly at higher densities. The smallest IJ were produced at a dose of 1000 IJ per host and the largest at a dose of 300 IJ per host. Time to first emergence of juveniles was generally shorter when the number of IJ inoculated was large (300-3000 IJ/host).Des densités croissantes de juvéniles infestants (IJ) d'Heterorhabditis megidis souche NLH-E 87.3 ont affecté la pénétration, la reproduction, la longueur du corps et la date de la première émergence des nématodes des larves de Galleria mellonella. Bien que le nombre de nématodes ayant pénétré dans l'hôte ait augmenté avec l'inoculum, le pourcentage de pénétration a décru. L'importance de la descendance produite par hôte a initialement augmenté avec l'inoculum. La production la plus forte d'IJ par cadavre a été atteinte à un taux d'inoculum de 300 IJ par hôte; à ce taux d'inoculum, 62 ± 3.4 IJ par cadavre avaient pénétré. La production d'IJ a de nouveau diminué significativement aux taux d'inoculum plus élevés. Les IJ les plus petits ont été obtenus au taux d'inoculum de 1000 IJ par hôte. Le temps écoulé jusqu'à la première sortie des juvéniles hors de l'insecte a été généralement plus court lorsque le taux d'inoculum était élevé (300-3000 IJ/hôte).

Biophysical properties of the surface of desiccation-tolerant mutants and parental strain of the entomopathogenic nematode Heterorhabditis megidis (strain UK211)

Parasitology ◽  
1998 ◽  
Vol 117 (4) ◽  
pp. 337-345 ◽  
Author(s):  
S. A. O'LEARY ◽  
A. M. BURNELL ◽  
J. R. KUSEL
Keyword(s):  
Surface Properties ◽  
Desiccation Tolerance ◽  
Parental Strain ◽  
Insect Pests ◽  
Entomopathogenic Nematode ◽  
Infective Juvenile ◽  
Surface Coat ◽  
Binding Studies ◽  
Heterorhabditis Megidis ◽  
Mutant Lines

Entomopathogenic nematodes (EPN) are useful biological control agents of insect pests. However, the infective juvenile (IJ) stage which is the only stage to occur outside the host is susceptible to environmental extremes such as desiccation. We have isolated desiccation-tolerant strains of the EPN Heterorhabditis megidis. In this paper we describe the surface properties of these desiccation-tolerant mutants. Heterorhabditid IJs retain the sheath of the previous larval stage. The mutant lines possess alterations in the surface properties of the sheath. Differences were observed in fluorescent lipid analogue insertion into the surface of the sheath. Furthermore, cationized ferritin-binding studies demonstrated that the mutant lines possessed an increase in net negative surface charge. Removal of the surface layer of the sheath resulted in the loss of the mutant phenotype and in a reduction in the desiccation tolerance of the parental strain. Therefore, the negatively charged ‘surface coat’ appears to play an important role in the desiccation tolerance of Heterorhabditis species.

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