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Poster: Diseases of Plants: Disease Detection & Diagnosis


Morphological and Molecular Characterization of Plant-Parasitic Nematodes Populations from Corn Fields in Ohio
A. SIMON (1), T. Niblack (1), P. Paul (2), H. Lopez-Nicora (1) (1) OHIO STATE UNIVERSITY, U.S.A.; (2) Ohio State University, U.S.A.

Results from an Ohio survey in 2013 and 2014 showed that root-lesion nematode, among the most economically important plant-parasitic nematodes, was detected in more than 80% of the 425 fields sampled. Other plant-parasitic nematodes extracted were the lance, stunt, dagger, pin and spiral nematodes, found in 48, 37, 57, and 94% of fields, respectively; however, the impact of these nematodes on corn in Ohio remains unclear. Because damage caused by nematodes varies among genera and species within genera, it is necessary to characterize these nematodes to species. Nematodes were killed, fixed, and mounted before examination with a compound microscope, and identified to species based on quantitative and qualitative morphological characteristics with the aid of diagnostic keys. Three species with distinct morphological features of the genus Pratylenchus were identified as P. penetrans, P. neglectus, and P. thornei. Two species of Tylenchorhynchus were identified as T. silvaticus and T. nudus. Species of the lance, pin, spiral and dagger nematodes, namely Hoplolaimus galeatus, Paratylenchus neoamblycephalus and Helicotylenchus pseudorobustus were also identified based on morphology. Species identity will be further confirmed based on analyses of the D2-D3 regions of 28S rRNA gene and ITS rRNA gene. Findings from this study will be useful for establishing experiments to develop damage relationships and management programs for corn nematodes in Ohio.