Nematodes comprise a large animal phylum with diverse free-living and parasitic species. While genetic and molecular studies are advanced for a few model free-living nematode species, progress has been limited for parasitic species. Root-knot nematodes cause major yield losses in many of the world's crops. These tiny animals invade the roots of their hosts causing the formation of galls or root-knots and compromising the health of the plant. Efforts to understand how these pests recognize and interact with their hosts have been hampered by their parasitic life cycle and small size. With previous funding from the NSF, a genetic cross was carried out between two root-knot nematode strains that differ in their ability to attack specific crop plants. Characterizing DNA markers in descendants of that cross led to the production of a genetic map. Meanwhile, a collaborating group determined the genome sequence of the same nematode species. The experiments in this project will utilize these genetic and genomic resources to produce an integrated map of the nematode. Traits that determine the ability of the nematode to infect and reproduce on particular plant species will be identified and cloned contributing to the understanding of how these animals are able to parasitize some host species, but not others. Current control measures against plant parasitic nematodes rely heavily on use of toxic chemicals. In depth understanding of the biology of these organisms is essential for the development of safer control measures. The experiments to be carried out will establish a knowledge base for investigations of plant parasites as well as for comparison to other nematode species. The research will provide a rich source of projects for training students in techniques in molecular genetics. Students ranging from high school to post graduate levels will participate in performing the experiments.
