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United States Department of Agriculture

Agricultural Research Service

Title: Filling in the Gaps of the Lesion Nematode Family Tree with Old and New Molecular Characters

item Skantar, Andrea
item Carta, Lynn

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: April 8, 1999
Publication Date: N/A

Technical Abstract: Molecular identifications of parasitic nematodes may become increasingly useful when there is insufficient material for microscopic diagnosis, such as with some quarantine samples. We are looking at a standard phylogenetic gene sequence of 26S rDNA as well as two new molecules for which there may be a correlation between DNA sequence variation and survival functions. These include heat-tolerance and DNA from the hsp 90 gene, and toxin resistance from the pgp-3 gene, a Multi-Drug Resistance homologue. One group of parasitic nematodes suitable to these studies is the lesion nematodes. These are widespread, often damaging migratory endoparasites of many crop roots. A recent, partial 26S rDNA tree of lesion nematodes and relatives demonstrated the need to reassess morphological characters and include more taxa. We are adding more taxa that are pathogens to soybeans and their rotation crops. These include Pratylenchus agilis, zeae, and alleni. We are also testing P. teres, a warm-climate South African cotton pathogen (gift of Martie Botha-Greeff), a close morphological relative to temperate P. crenatus. We will be testing warm climate P. mediterranea from Israel (gift from Daniel Orion) and temperate P. thornei. Morphological sister species used as thermal "controls" include P. agilis and P. scribneri. PCR amplification and DNA sequence analysis of these genes in these nematodes are currently underway.

Last Modified: 4/21/2015