Identification of the causal agent of Armillaria root rot of Pinus speciesin South Africa

Armillaria root rot was reported on economically important Pinus and Eucaly ptus species grown in plantations in South Africa since the early 1900s. Ar millaria species have been well studied in North America and Europe, but ha ve received minimal attention in South Africa. Most reports of Armillaria r oot rot in South Africa suggest that A. mellea is the causal agent. The nam e A. heimii has also been used in more recent reports, although these have not been based on mycological studies. The taxonomic disposition of Armilla ria in South Africa, therefore, remains unknown. The aim of this study was to identify and characterize Armillaria isolates from forest plantations in South Africa based on morphology, PCR-RFLP profiles and sequence data. Ana lysis of these characters revealed that the isolates originating from the p lantations in South Africa are distinct from A. mellea and A. heimii. We be lieve that they represent A. fuscipes.