Meloidogyne fallax Karssen, 1996
First record of the root-knot nematode, Meloidogyne fallax, in Australia.
Name: Meloidogyne fallax Karssen, 1996
Animalia: Nematoda: Secernentea: Tylenchida: Meloidogynidae
Common Names: False Columbia root-knot nematode
Previously known only from a small area in Europe, M. fallax has now been detected on potato tubers and in soil collected from southeast Australia, though how long it has been present in that country is unknown. Meloidogyne fallax is closely related to M. chitwoodi, a significant pest of potato, though M. fallax is also known to favor species of Hemerocallis cv. Rajah and could travel to North America via established pathways from Europe.
Issues of Concern: Meloidogyne fallax and M. chitwoodi have similar, but not identical, host ranges, though both damage economically valuable species such as potato, black salsify (oyster plant), and carrot, causing blister-like swelling (galls) and internal necrosis just below the skin. However, recent evidence suggests that M. fallax may be more aggressive on potato and have a shorter life cycle than its sister species, though these observations have yet to be thoroughly investigated.
This species can be spread via movement of infected or contaminated planting material, such as daylily bulbs or seed potato tubers. In addition, the movement of non-host seedling transplants, nursery stock, machinery or other products which are contaminated with M. fallax infested soil have the potential to spread this pest.
Hosts: Primary hosts for this species include Solanum tuberosum (potato), Scorzonera hispanica (oyster plant), and Daucus carota (carrot), as well as the perennials Oenothera erythrosepala (primrose) Dicentra spectabilis (bleeding heart) and Hemerocallis cv. Rajah spp (daylily). Secondary hosts include Lycopersicon esculentum (tomato), Lactuca sativa (lettuce) and Cynara scolymus(artichoke).
Australia; Europe (Belgium, France, Germany, Netherlands); New Zealand
Quarantines: The European Plant Protection Organization considers this species an A2 pest.
On potato, M. fallax infestations result in small, raised swellings on the tuber surface above the developing nematodes. Adult females, when alive, appear as glistening, white, pear-shaped bodies surrounded by a brownish layer of host tissue, and are visible just below the surface. Lightly infested tubers may not show obvious contamination, though storage may lead to the development of the characteristic external symptoms mentioned above.
Meloidogyne fallax was initially proposed as a new race of Meloidogyne chitwoodi after being detected for the first time in 1992, and named M. chitwoodi (Baexem)B-type van Meggelen et al.
Source: Nobbs, J.M., Q. Liu, D. Hartley, Z. Handoo, V.M. Williamson, S. Taylor, G. Walker and J. Curran, 2001. First record of Meloidogyne fallax in Australia. Australasian Plant Pathology 30: 373
Karssen G. 1996. Description of Meloidogyne fallax n. sp. (Nematoda: Heteroderidae), a root-knot nematode from the Netherlands. Fundamental and Applied Nematology 19, 593-599.
Van der Beek, JG; Vereijken, PF; Poleij, LM; Van Silfhout, CH. 1998. Isolate-by-cultivar interaction in root-knot nematodes Meloidogyne hapla, M chitwoodi and M fallax on potato. Canadian Journal of Botany 76(1), 75-82.
Warning: The information in this archived item was not confirmed with the appropriate National Plant Protection Organization and is provided solely for informational purposes. Please use this information with caution.