Abstract:
Cysts from nematode-infested plots on eight potato farms in the Sandveld and Ceres regions of South Africa were analysed by means of rDNA-RFLP. The size of the PCR amplification products for all populations was typical for the genus Globodera. Restriction digestion of the amplified products with MspI and HinfI confirmed Globodera rostochiensisto be present in both the Sandveld and Ceres regions and Globodera pallidato be absent from South African potato cyst nematode populations. However, several populations from the Sandveld region showed no recognition of the HinfI restriction site and no digestion took place, indicating them to be a distinct Globodera species. Sequencing of the ITS1 region confirmed the presence of G. rostochiensis and an unknown Globodera species, and the absence of G. pallida in South Africa. Species-specific primers for the identification of G. rostochiensis and G. pallida were optimised.