Submitted to: Nematropica
Publication Type: Abstract Only
Publication Acceptance Date: 10/5/2004
Publication Date: 6/28/2005
Citation: Noel, G.R., Atibalentja, N. 2005. Preliminary description of a bacterial endosymbiont of soybean cyst nematode, heterodera glycines. Proceedings XXVI Annual Meeting Organization of Nematologists of Tropical America. Nematropica.p. 28.
Technical Abstract: Almost 25 years ago, transmission electron microscopy (TEM) revealed the occurrence of an intracellular "bacterium-like organism" in second-stage juveniles of Heterodera glycines. Additional TEM studies also found the bacterium in males and females. Since the bacterium cannot be cultured, we extracted DNA from surface-sterilized infected nematodes and used universal bacterial primers and to PCR amplify, clone, and sequence the near full length of the 16S rRNA gene of the bacterium. A BLAST search of DNA databases revealed a 93% similarity index to the 'Bacteriodetes' symbiont, 'Canditatus Cardinium hertigii'. This endosymbiont, which parastizes wasps of the genus Encarsia was described in 2004. The endosymbiont of H. glycines has brush-like arrays of microfilament-like structures characteristic of the genus Cardinium. However, a dissimilarity index of 7% with C. hertigii indicates that the endosymbiont of H. glycines is a new species.