Poster Session: Detection and Diagnosis-Nematodes

353-P

Extraction of Pratylenchus sp. and Hoplolaimus sp. from corn roots using two methods and two extraction solutions.
M. BATISTA DA SILVA (1), G. L. Tylka (1)
(1) Iowa State University, Ames, IA, U.S.A.

Plant-parasitic nematodes occur in most fields where corn is grown in Iowa, although most are not thought to be damaging to the crop at low population densities. The types and numbers of nematodes present must be known to assess if yield loss is occurring and management is necessary. Some of these nematodes exist within roots as well as in soil and must be extracted from the roots to identify and count. The recovery of root-lesion (Pratylenchus sp.) and lance (Hoplolaimus sp.) nematodes from corn root tissue using two extraction methods and two solutions were compared in laboratory experiments. Corn plants were grown in soil infested with both nematodes. After 60 days, roots were washed of soil and cut into 1-cm-long fragments. A 3-g root sample from each plant was assigned to an extraction solution and method combination. Treatment combinations were replicated six times, and the experiment was conducted twice with consistent results. More root-lesion nematodes were extracted from roots after seven days on a platform shaker than in a Baermann funnel. Also, more were extracted from roots in water than in a dihydrostreptomycin sulfate-mercuric chloride (strep-HgCl) solution with the platform shaker, but not with Baermann funnels. More lance nematodes were recovered using the platform shaker than the Baermann funnel, and more were recovered using water than the strep-HgCl solution. There was no interaction between extraction method and solution for lance nematode.
Keywords: Nematode, Cereals-Grains, Corn