Submitted to: Journal of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2007
Publication Date: 3/30/2007
Citation: Bernard, E., Donald, P.A., Handoo, Z.A., Heinz, R., Powers, T. 2007. Characterization of a New Species of Cyst Nematode Parasitizing Corn. Journal of Nematology. Vol 39:74.
Technical Abstract: Examination of soil around unthrifty corn roots in northwestern Tennessee (Obion County) in 2006 revealed high population densities of juvenile nematodes and lemon-shaped cysts. This nematode resembles Cactodera spp. in possessing a circumfenestrate vulva but lacking bullae and an underbridge. These characters differentiate it from Heterodera spp., including H. zeae, the corn cyst nematode. Similar cyst specimens had previously been collected in 1978 from Lauderdale County, Tennessee, on goosegrass (Eleusine indica). Comparison of the 1978 specimens deposited in the USDA Nematode Collection at Beltsville, MD, and the 2006 specimens verified that they were identical. Infective juveniles are 320-400 micrometers long, have a short stylet (14-16 micrometers), and possess a short tail with a bluntly rounded terminus. Molecular comparison (18Sa, D2/3, ITS1) of the Tennessee nematode with a range of other Heteroderidae, including H. zeae, did not indicate any close relationships. This nematode reproduced well (RF > 5) on all tested hybrid corn cultivars. There was poor reproduction on other monocots and no dicot hosts have been found to date.