Globodera capensis: a new cyst nematode described from South Africa
During surveys of potato-production areas of South Africa carried out from 1999 to 2007, a new cyst nematode, Globodera capensis n. sp., was found on several farms in the Swartland and Sandveld areas. G. capensis was found to be morphologically very similar to potato cyst nematodes (G. rostochiensis and G. pallida), as well as from G. artemisiae, G. millifolii and G. tabacum tabacum. However, it could be distinguished from these species by molecular tests (PCR, sequencing). Phylogenetic analyses have indicated that G. capensis was closely related to Globodera species from Europe, Asia and New Zealand which parasitize non-solanaceous plants. At the time of its first description, the host plants of G. capensis were not known, as specimens had only been found in samples collected from cleared potato fields, as well as from the rhizosphere of wild plants (e.g. Conicosia pugioniformis (Aizoaceae) and Oncosiphon grandiflorum (Asteraceae)). The possible impacts of this new cyst nematode species on certification of seed potatoes and on potato exports prompted further studies about the reproductive ability of G. capensis on potatoes. These studies were carried out in the laboratory, as well as under glasshouse and field conditions, and showed that viable cysts of G. capensis were unable to reproduce on potato plants (Solanum tuberosum cvs. Avalanche, BP1, and VanderPlank).
Sources
Knoetze R (2014) New cyst nematode poses no threat to potatoes. CHIPS, 26-27.
Knoetze R, Swart A, Tiedt LR (2013) Description of Globodera capensis n. sp. (Nematoda: Heteroderidae) from South Africa. Nematology 15, 233-250.