RESUMEN
The genus Fraxinus (Oleaceae), known as ash trees, currently comprises 43 recognized species that are distributed in temperate and subtropical regions of the Northern Hemisphere. Two Phyllactinia species, P. fraxini and P. fraxinicola, have been known on Fraxinus spp. so far. In this study, powdery mildews belonging to Phyllactinia were collected on Fraxinus spp. from different areas of the world to make molecular and morphological analyses. These specimens are divided into four distinct molecular phylogenetic groups, which are distinguishable by their morphology and/or host preference. Two new species, viz. P. japonica occurring on F. sieboldina and F. lanuginosa f. serrata, and P. fraxini-longicuspidis on F. longicuspis, are proposed in this study. An epitype is designated for P. fraxini. This study indicates very high host specificity among the four Phyllactinia species on Fraxinus, suggesting that genetic isolation by host specificity played a more important role than geographic segregation in the speciation events of these Phyllactinia species. Evolutionary timing calculated by molecular clock analysis suggests that these powdery mildews diverged in accordance with host phylogeny after divergence of host plants.
RESUMEN
The genus Entyloma consists of more than 160 species of smut fungi distributed worldwide on dicots, with Apiaceae being one of the main host families. This study aims to clarify the systematics and phylogeny of Entyloma on Eryngium (Apiaceae) with molecular and morphological data. Eleven species from Eryngium are discussed herein. Four of them are described as new taxa: E. carmeli sp. nov. on Eryngium falcatum, E. eryngii-cretici sp. nov. on Eryngium creticum, E. eryngii-maritimi sp. nov. on Eryngium maritimum and E. ho-chunkii sp. nov. on Eryngium yuccifolium. Analysis of the internal transcribed spacer (ITS) region of rDNA is presented and supports the polyphyly of Entyloma on Eryngium.
Asunto(s)
Basidiomycota/clasificación , Eryngium/microbiología , Enfermedades de las Plantas/microbiología , Secuencia de Bases , Basidiomycota/genética , Basidiomycota/fisiología , Basidiomycota/ultraestructura , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Técnicas de Tipificación Micológica , Filogenia , Análisis de Secuencia de ADN , Esporas FúngicasRESUMEN
The morphology and phylogeny of Anthracoidea on Carex meadii (sect. Paniceae) collected in Illinois, Iowa, Wisconsin, USA, were studied by light microscopy, scanning electron microscopy and LSU rDNA sequence analyses. As a result A. caricis-meadii sp. nov. is described. The fungus differs morphologically from Anthracoidea laxae and A. paniceae, which also occur on sedges from the section Paniceae. Molecular analyses support the placement of the latter species and Anthracoidea caricis-meadii in different phylogenetic lineages. Because of morphological discrepancies in the literature, A. laxae and A. paniceae also are described and illustrated based on re-examination of respective holotype and isotype specimens.
