Biocontrol Science and Technology (2002) 12, 267-276

S.A. Johnigk, S. Hollmer, O. Strauch, U. Wyss and R.-U. Ehlers (2002)
Heritability of the liquid culture mass production potential of the entomopathogenic nematode Heterorhabditis bacteriophora
Biocontrol Science and Technology 12 (2), 267-276
Abstract: The infective stage of entomopathogenic nematodes (Heterorhabditis spp.) is the mobile, but developmentally arrested dauer juvenile (DJ). For commercial application, nematodes are produced in liquid culture. Prior to the inoculation of the DJ, their symbiotic bacterium Photorhabdus luminescens is cultured. The DJ exit from the arrested stage (recovery) and develop to reproductive adults. Recovery is a response to bacterial food signals. In liquid culture the percentage of DJs recovering from the DJ stage is highly variable, which significantly influences the number of reproducing hermaphrodites and the final DJ yields. The liquid culture yield is defined by the number of DJ mL^-1 harvested from the medium. The heritability of the disposition to recover from the DJ stage and of the final DJ yield in liquid culture has been evaluated. From a hybrid strain of H. bacteriophora 30 homozygous inbred lines were established by inbreeding over seven generations. These inbred lines were propagated in liquid culture and DJ recovery and yields were recorded. The calculated heritability for the DJ recovery was low (h² = 0.38). No significant genetic variability could be detected for this trait. In contrast, a high heritability (h² = 0.90) was found for the total number of DJs produced in the liquid medium.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Urs Wyss, Ralf-Udo Ehlers

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
rearing/culturing/mass production
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Heterorhabditis bacteriophora/Photorhabdus (entomopathogen)