title: Origin, divergence, and phylogeny of epichloe endophytes of native Argentine grasses.
abstract: The epichloë endophytes are systemic, constitutive, and often vertically transmitted fungal symbionts of grass species in subfamily Poöideae. Prior studies indicate that several asexual epichloë endophytes (Neotyphodium species) have evolved directly from sexual (Epichloë) species, whereas others evolved by hybridization between two or more endophyte species. In this paper, we investigate the phylogenies of 27 Neotyphodium spp. isolates from 10 native grass species (in 4 tribes) in 22 populations throughout Argentina. Relationships among these fungi and a worldwide collection of epichloë endophytes were estimated by phylogenetic analysis of sequences from variable portions (mainly introns) of genes for beta-tubulin (tub2) and translation elongation factor 1-alpha (tef1). Most of the Argentine endophyte isolates were interspecific hybrids of Epichloë festucae and E. typhina. Only one isolate was a hybrid of a different ancestry, and three isolates were apparently non-hybrid endophytes. These results indicate that interspecific hybridization, which promotes genetic variation, was common during the evolution of the endophytes of Argentine grasses.
authors.affiliation: Laboratorio de Micología, PRHIDEB-CONICET, Depart. Biodiversidad y Biología Exp., Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
authors.forename: Agustina
authors.initials: A
authors.lastname: Gentile
authors.forename: María Susana
authors.initials: MS
authors.lastname: Rossi
authors.forename: Daniel
authors.initials: D
authors.lastname: Cabral
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Craven
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Schardl
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D014644:Genetic Variation; D010802:Phylogeny; D006109:Poaceae / Q000145:classification* / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers