RESUMEN
Euphorbia ingens trees have been dying in large numbers in the Limpopo Province of South Africa for approximately 15 years. The ambrosia beetle Cyrtogenius africus is often found infesting diseased and dying trees. The aim of this study was to identify the ophiostomatoid fungi occurring in the galleries of C. africus. Logs infested with this beetle were collected from the KwaZulu-Natal, Limpopo, Mpumalanga, and North West Provinces of South Africa. Fungi belonging to the Ophiostomatales were identified based on morphology and comparison of sequence data for the ß-tubulin, ITS1-5.8S-ITS2 and LSU gene regions. A novel species of Ophiostoma and a novel genus in the Ophiostomatales were identified. Inoculation studies with these fungi produced lesions in the branches of healthy E. ingens trees.
Asunto(s)
Euphorbia/parasitología , Ophiostomatales/clasificación , Ophiostomatales/aislamiento & purificación , Enfermedades de las Plantas/microbiología , Gorgojos/microbiología , Animales , Secuencia de Bases , ADN de Hongos/genética , Ophiostoma/clasificación , Ophiostoma/genética , Ophiostoma/aislamiento & purificación , Ophiostoma/patogenicidad , Ophiostomatales/genética , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADN , Sudáfrica , Árboles/microbiología , Tubulina (Proteína)/genéticaRESUMEN
Gondwanamyces and its Custingophora anamorphs were first described from Protea infructescences in South Africa. Subsequently these unusual fungi were also found on Cecropia in Central America. During an investigation into the decline and death of native Euphorbia trees in South Africa, several fungal isolates resembling the anamorph state of Gondwanamyces were obtained from diseased tissues. In this study these isolates are identified based on morphology and comparisons of DNA sequences. Two previously unknown Gondwanamyces species were identified, both were associated with damage caused by beetles (Cossonus sp.). Inoculation studies showed that the new species of Gondwanamyces are pathogenic on Euphorbia ingens and may contribute to the decline of these trees.