Neocosmospora caricae sp. nov. and N. metavorans, two new stem and trunk canker pathogens on Ficus carica in Iran

During 2018-2021, a survey was conducted in rainfed fig (Ficus carica L.) orchards throughout the Fars Province of Iran to investigate the occurrence of canker diseases, and to identify the causal organisms. Morphological and cultural characteristics, as well as multilocus phylogenetic analyses of the internal transcribed spacer (ITS) region of rDNA, RNA polymerase II second largest subunit (RPB2), and the translation elongation factor 1-alpha (TEF1), revealed that the recovered isolates from the infected fig trees clustered in clade 3 of Neocosmospora (Nectriaceae), including N. metavorans, and a new taxon described here as N. caricae sp. nov. Neocosmospora caricae is characterised by falcate, multiseptate, gently dorsoventrally curved macroconidia with poorly developed foot-shaped basal cells, ovoid, aseptate microconidia that cluster in false heads, and abundant terminal or intercalary chlamydospores. Pathogenicity tests indicated that isolates of both Neocosmospora species were pathogenic, causing stem canker and wood discolouration on fig saplings of Sabz and Shah Anjeer cultivars. The present study adds to existing knowledge on the aetiology of fig stem and trunk canker, and may provide essential information for developing effective integrated management strategies against canker diseases affecting fig orchards in Iran.

Automated summary

A survey conducted in rainfed fig orchards in the Fars Province of Iran from 2018 to 2021 identified the occurrence and causal organisms of canker diseases. The study identified a new species, N. caricae sp. nov., as a cause of canker diseases and provided essential information for management strategies against these diseases in fig orchards in Iran.