MOLECULAR SYSTEMATICS OF CLAVICIPITACEAE SUPPORTING MONOPHYLY OF GENUS EPICHLOE AND FORM GENUS EPHELIS

The family Clavicipitaceae (Ascomycota) is comprised of fungi with per ithecia borne on stromata, unitunicate asci, and filamentous, multisep tate ascospores. All are biotrophic symbionts, either mutualistic with plant hosts or pathogenic to plants, invertebrate animals or other fu ngi. Genera of plant-associated Clavicipitaceae (tribes Balansieae and Clavicipieae) are distinguished, in part, by stromal and ascus morpho logy, ascospore germination patterns, whether sclerotia are formed, an d host interactions. Their anamorphs include enteroblastic microconidi al states, classified in anamorphic genera Neotyphodium and Sphacelia (for teleomorphs Atkinsonella, Claviceps, Echinodothis, and Epichloe), and holoblastic macroconidia, classified in the anamorphic genus Ephe lis (teleomorphs Atkinsonella, Balansia, and Myriogenospora). Epichloe species often are mutualistic with grass hosts, and are ancestral to asexual, seed transmitted endophytes symbiotic with many cool-season g rasses. Partial 28S nuclear rDNA sequences were determined from isolat es of five species and two undescribed mating populations of Epichloe, one asexual Epichloe hybrid (Neotyphodium coenophialum), and represen tatives of six other genera in the family. Results from phylogenetic a nalysis of the sequences supported monophyly of plant-associated Clavi cipitaceae, with insect-pathogenic Cordyceps species more deeply roote d. Four clades were distinguished among plant-associated Clavicipitace ae: a monophyletic genus Epichloe (including N. coenophialum), a monop hyletic genus Claviceps, a clade represented only by Echinodothis tube riformis, and a clade including all sampled strains with Ephelis anamo rphs. Morphological relationships of anamorphs and ascospore developme nt better fit the molecular phylogenetic relationships than did host r elationships or host tissue specificity.