IFIBYNE   05513
INSTITUTO DE FISIOLOGIA, BIOLOGIA MOLECULAR Y NEUROCIENCIAS
Unidad Ejecutora - UE
artículos
Título:
Phylogenetic divergence, morphological and physiological differences distinguish a new Neotyphodium endophyte species in the grass Bromus auleticus from South America.
Autor/es:
LEOPOLDO JAVIER IANNONE; DANIEL CABRAL; CHRISTOPHER LEWIS SCHARDL; MARÍA SUSANA ROSSI
Revista:
MYCOLOGIA.
Editorial:
ALLEN PRESS INC
Referencias:
Año: 2009 vol. 101 p. 336 - 347
ISSN:
0027-5514
Resumen:
The fungi of the genus Neotyphodium are systemic, constitutive, symbionts of grasses species of the subfamily Pooideae. In the Southern hemisphere, most of these asexual endophytes are the result of the hybridization between two sexual species from Northern hemisphere, Epichloë festucae and E. typhina. However, the ancestral sexual species have not been detected in this region. Several grasses from Argentina are infected by Neotyphodium species. These endophytes are in general very similar at macro- and micro-morphological levels, and phylogenetically conform to the species N. tembladerae. However the Neotyphodium spp. endophytes of some hosts, as Bromus auleticus and Poa spicifomis var. spiciformis have not been included in this species. In this work we studied the incidence and characterized the diversity of Neotyphodium species in populations of the native grass Bromus auleticus from Argentina. The incidence of endophytes was 100% in all populations investigated. Two groups of endophytes were differentiated by their morphologies, growth rates, conidial onthogenies, and by relative resistance to the fungicide benomyl. Phylogenetic trees inferred from tefA and tubB intron sequences indicated that both N. tembladerae and the novel morphotype were hybrids of E. festucae and E. typhina, but the ancestral E. typhina genotype distinguished them. Isolates from plants that inhabit coastal dunes, xerophytic forest, savannahs and hills were morphologically and phylogenetically similar to N. tembladerae, whereas the endophytes from the humid pampa plains conformed to the novel group. We propose to consider the endophyte of Bromus auleticus from humid pampas as a new species: Neotyphodium pampeanum.