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Title: The true identity of Nectria haematococca

item Samuels, Gary
item NALIM, AMEENA - New Mexico State University
item GEISER, DAVID - Pennsylvania State University

Submitted to: Inoculum
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2009
Publication Date: 6/8/2009
Citation: Samuels, G.J., Nalim, A., Geiser, D. 2009. The true identity of Nectria haematococca. Inoculum. 60(3):39

Interpretive Summary:

Technical Abstract: Nectria haematococca is usually identified as the teleomorph of Fusarium solani, a common plant pathogen and cause of opportunistic infections in animals, including man. Nectria haematococca and F. solani belong to the Fusarium solani species complex (FSSC). Nectria haematococca includes seven phylogenetically distinct mating populations and at least two ‘varieties.’ In addition, unnamed perithecial species are common in the FSSC. Perithecial morphology is conserved in the FSSC; with species differences manifested in the anamorph. What is true Nectria haematococca? It was originally described from a 19th century collection made on wood in Sri Lanka. Because there is no culture from this specimen, and no anamorph remains on the type collection, an epitype is required to stabilize taxonomy of N. haematococca. We epitypify the species and document phylogenetic and phenotypic diversity among teleomorph and anamorph collections made in Sri Lanka. The FSSC comprises three clades based to some extent on biogeographic structure. Five of the seven Sri Lankan perithecial populations cluster in Clade 2, which was formerly thought to be South American. One of these collections made near the type locality of N. haematococca is designated as epitype. Two of the perithecial strains and all of the F. solani isolates from soil samples cluster in the cosmopolitan Clade 3. Soil strains rarely clustered with ascospore-derived strains, suggesting a clonal structure in the soil populations. Nectria haematococca is not the teleomorph of F. solani, a species originally isolated from potato in Europe, nor is N. haematococca a species of Nectria. It has been placed in its own genus, Haematonectria. Neocosmospora vasinfecta, the type species of Neocosmospora, is derived from within the FSSC. On nomenclatural and phylogenetic grounds, Neocosmospora should be adopted as the teleomorph name but we argue against adopting any name for the teleomorph of these Fusarium species at this time.