CONICET | Buscador de Institutos y Recursos Humanos

Arambarria (Hymenochaetales, Basidiomycota) is a monotypic genus recently described to accommodatespecimens from the Patagonian forests of Argentina wrongly assigned in the past to Inocutis jamaicensis. Onthe basis of a wide sampling of strains and phylogenetic analysis inferred from combined sequences includingthe nuc rDNA ITS1-5.8-ITS2 region, 28S rDNA D1-D2 domains and partial sequences of translation elongationfactor 1-a (tef1-α) we demonstrate that this genus is associated to an important canker-rot of eucalyptplantations in Uruguay, to wood-rots of many native and exotic hosts, and to ?hoja de malvón? and chloroticleafroll of grapevines diseases in Central Chile, Central Argentina and Uruguay, formerly assigned to I.jamaicensis and/or Fomitiporella sp. The combined phylogenetic analysis showed the existence of three,closely related clades that corresponded to (1) the Pampas of Uruguay and Argentina (?uruguay? clade), (2) theMonte, Chaco Serrano and Yungas forests of Argentina (?cognata? clade), and (3) the Patagonian Andes forestsand Chilean Province (?destruens? clade). Lack of morphological differences between taxa from the threeclades, their occurrence in both native and exotic hosts, previous results showing interfertility between isolatesfrom Uruguay and Argentina, and the lack of full support in the concatenated ITS + 28S + tef1-α analysis,prevents us to distinguish and describe three different taxa; the proper name of the taxon being Arambarria cognata comb. nov. A fourth, distinctly separated clade corresponded to South African strains isolated fromvineyards representing an undescribed taxon associated to Esca grapevine disease in that country. Arambarriais shown to be unrelated to Inocutis, with which it was confused in the past and, so far, remains restricted tothe Northern Hemisphere in America (Mexico, Jamaica and the USA).