Journal of Nematology (2005) 37, p. 385 (Noel et al.)

G. R. Noel and N. Atibalentja (2005)
Characterization of a bacterial endosymbiont of soybean cyst nematode, Heterodera glycines
Journal of Nematology 37 (3), 385-385
44th Annual Meeting, Society of Nematologists, Fort Lauderdale, Florida, 9-13 July, 2005
Abstract: The existence of bacterium-like endosymbionts of cyst nematodes has been known for almost 30 years, having been observed during TEM of Globodera rostochiensis from Bolivia, Heterodera goettingiana from the UK, and H. glycines from the US. These endosymbionts were studied in females of G. rostochiensis and H. goettingiana and in second-stage juveniles of H. glycines. Our TEM studies also found the endosymbiont in various tissues of adult H. glycines including oocytes and sperm cells. Attempts to culture the ensymbiont have not been successful. In order to identify the organism we extracted DNA from surface-sterilized second-stage juveniles and used universal bacterial primers to PCR-amplify, clone, and sequence the near full length of the 16S rRNA and gyrase B (gyrB) genes. A BLAST search of DNA databases revealed a 93% similarity to the 16S rDNA and an 81% similarity to gyrB of the `Bacteriodetes ' symbiont, `Canditatus Cardinium hertigii'. This endosymbiont, which parasitizes wasps of the genus Encarsia, was described in 2004. The bacterial endosymbiont of H. glycines has brush-like arrays of microfilament-like structures characteristic of the genus Candidatus Cardinium. However, a dissimilarity of 7% for the 16S rDNA and 19% for gyrB of the H. glycines-infecting bacterium with Candidatus C. hertigii indicate that the bacterial endosymbiont of H. glycines represents a new genus.
Database assignments for author(s): Gregory R. Noel

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Heterodera glycines	Soybean (Glycine max)
	Globodera rostochiensis
	Heterodera goettingiana