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United States Department of Agriculture

Agricultural Research Service

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2009 Annual Report

1a. Objectives (from AD-416)
1) Discover, refine, and implement improved microscopic, molecular, and software tools to modernize classification and improve predictive features for plant-parasitic and other agriculturally important nematodes; and 2) Discover new nematode species, new host associations, and new geographic occurrences among the many nematodes sent to the Nematology Laboratory for identification by various customers.

1b. Approach (from AD-416)
1) Adapt and test recently discovered and potentially promising light and scanning electron microscopic methods to determine if visualization of diagnostically important critical features can be improved in resolution and consistency. Characterize new agriculturally important nematodes with expanded or novel morphological and molecular diagnostic characters for the development of improved diagnostic keys and phylogenetic trees. Identify and prioritize, using phylogenetic methods, potential molecular control targets based on physiologically important peptides within diverse nematodes having analogous phenotypes; and 2) Characterize unknown or important nematodes by morphology, molecular biology and host range; and continue to computerize and curate the USDA Nematode Collection.

3. Progress Report
New nematode identification methods and phylogenies. The identification of new species of nematodes and the development of new methods to rapidly and accurately identify plant-parasitic nematodes are urgently needed by researchers, regulators, diagnosticians and growers to deliver the safest, most effective possible plant disease controls. To this end ARS researchers are describing new species of root-knot, cyst, lesion and insect-associated nematodes. New methods for improving the orientation of nematodes under the low-temperature scanning electron microscope, and for distinguishing nematodes by microscopic spectroscopy are being studied in the laboratory. Nematode DNA sequences are being generated for use in building family trees, and DNA sequences from new genes are being evaluated for possible use in family trees. These descriptions, methods, and tools will be used by diagnosticians and extension personnel throughout the world to accurately diagnose and select appropriate controls for a wide variety of crops. Building the USDA Nematode Collection. The researchers and extension personnel that identify nematodes need a source of nematode reference specimens to assure that identifications are accurate. The USDA Nematode Collection at Beltsville, Maryland, is the most important repository of nematode reference specimens in the world. Curatorial services and maintenance are constantly needed to improve the quality and breadth of the Collection. Therefore, scientists at the Nematology Laboratory in Beltsville added 285 slides and vials from worldwide sources to create a total collection of 43,041 slides and vials, loaned 155 slides and vials containing valuable nematode specimens to scientists around the world to enable them to perform accurate nematode identifications, and entered 153 records of specimens into the computerized database, bringing it to a total of 36,412 records. Nematologists throughout the world are using the specimens and related information in the Collection as essential aids in nematode identification and research.

4. Accomplishments
1. New nematode species discovered in wheat fields. New, comprehensive information to rapidly and accurately identify plant-parasitic nematodes are urgently needed by researchers, regulators, diagnosticians and growers to deliver the safest, most effective possible plant disease controls. To this end, ARS researchers described two new nematode species from wheat soil; additionally, they developed a key and diagnostic compendium to the species of the genus with international collaborators to better explain their interactions with plants and pests. The results are significant because they provide valuable details that allow these species to be identified. This research will be used by scientists, action agencies, and extension agencies engaged in nematode research and control.

Review Publications
Ramzan, M., Handoo, Z.A., Fayyaz, S. 2008. Description of Tylenchorhynchus qasimii sp. n with a new report of T. kegasawai Minagawa, 1995 from Pakistan. Journal of Nematology. 40(1):20-25.

Troccoli, A., De Luca, F., Handoo, Z.A., Di Vito, M. 2008. Morphological and molecular characterization of Pratylenchus lentis n. sp. (Nematoda: Pratylenchidae) from Sicily. Journal of Nematology. 40:190-196.

Walters, S.A., Bond, J., Russell, J., Taylor, B., Handoo, Z.A. 2008. Incidence and influence of plant-parasitic nematodes in southern Illinois peach orchards. Nematropica. 38(1):63-74.

Khan, A., Sayed, M., Shaukat, S., Handoo, Z.A. 2008. Efficacy of four plant extracts on nematodes associated with papaya in Sindh, Pakistan. Nematologia Mediterranea. 36:93-98.

Van Den Berg, E., Subbotin, S.A., Handoo, Z.A., Tiedt, L.R. 2009. Hirschmanniella kwazuna sp. n. from South Africa with notes on a new record of H. spinicaudata, Schuurmans Stekhoven,1944, Luc & Goodey, 1964 (Nematoda: Pratylenchidae) and on the molecular phylogeny of Hirschmanniella Luc & Goodey, 1964. Nematology. 11(4):523-540.

Handoo, Z.A., Carta, L.K., Skantar, A.M. 2008. Taxonomy, morphology and phylogenetics of coffee-associated root-lesion nematodes, Pratylenchus spp. In: Souza, R.M., editor. Plant-parasitic nematodes of coffee. Springer Science + Business Media B.V. p. 29-50.

Last Modified: 2/23/2016
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