Submitted to: Australasian Plant Pathlogy Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2001
Publication Date: 12/1/2001
Citation: Nobbs, J.M., Liu, Q., Hartley, D., Handoo, Z.A., Williamson, V., Santo, G., Curran, J., Walker, G., Taylor, S. 2001. First record of meloidogyne fallax in australia. Australasian Plant Pathlogy Society 30: 373. Interpretive Summary: Nematodes are microscopic worms that attack plant roots and cause ten billion dollars of crop loss each year in the United States. Root-knot nematodes are important root parasites that seriously damage many economic plants worldwide. One problem with determining the extent of crop loss due to plant-parasitic nematodes is that the nematodes present in many areas are unknown. The objective of this work was to identify the nematodes that are causing blister-like swellings on potato tubers in Australia. A collaboration of ARS, Australian scientists and personnel at the University of California and Washington State University used both anatomical and DNA sequence data to reveal that the nematode is the root- knot nematode Meloidogyne fallax. This discovery is significant because it is the first report of this nematode in Australia and thus is of quarantine interest. This report will serve as a useful guide to researchers in planning future research, revising quarantine strategies, and identifying economically important species.
Technical Abstract: A root-knot nematode was discovered on potato tubers and soil collected in the south east of South Australia and at other sites around Mt. Gambier and at Mt. Barker in the Adelaide Hills and was identified as Meloidogyne fallax Karssen, based on morphological observations and DNA sequencing. A paddock whose history was of a pasture dominated by Trifolium repens was sampled as a pre-planting measure for plant- parasitic nematodes and Meloidogyne juveniles were recovered. Potatoes were planted and when harvested the tubers were found to have blister- like swellings suggesting infection of the tubers by root-knot nematodes later identified as M. fallax. Its close resemblence with two other closely related species (M. Chitwoodi and M. hapla)is discussed. A molecular DNA character indicated a close relationship of this nematode to Columbia root-knot nematode. However, using restriction enzymes this was eliminated and confirmed its identification as M. fallax. The distribution of this nematode in potato fields throughout Australia needs to be determined.