@ARTICLE{TreeBASE2Ref22718,
author = {Shawn Christopher Kenaley and Lawrence B. Smart and George W. Hudler},
title = {Genetic evidence for three discrete taxa of Melampsora (Pucciniales) affecting willows (Salix spp.) in New York State },
year = {2014},
keywords = {ITS; LSU; Melampsora epitea; Phylogeny; Taxonomy},
doi = {},
url = {http://},
pmid = {},
journal = {Fungal Biology},
volume = {118},
number = {8},
pages = {704--720},
abstract = {Rust fungi belonging to the genus Melampsora (Pucciniales) are the most important pathogens of shrub willows (Salix spp.) cultivated for biomass and bioenergy in New York State and temperate regions worldwide. The taxonomy and species identification of these fungi historically have been problematic as they are morphologically indistinguishable on willow and often have complex life histories that include host alternation to taxonomically unrelated plant species. Subsequently, predominant Melampsora of Salix in North America previously have been treated as the collective species M. epitea Th?m. and further delineated to formae speciales according to aecial host. To test phylogenetic relationships, ribosomal DNA (rDNA) data was obtained from 75 collections/isolates of Melampsora in NY State affecting either native and cultivated shrub willow or suspected alternate hosts. Maximum likelihood (ML), maximum parsimony (MP), and Bayesian (BI) analyses were conducted separately on three data partitions (individual and concatenated): complete internal transcribed spacer (ITS) and partial large subunit (LSU) rDNA sequences for all 75 collections. Analyses of the ITS and concatenated ITS-LSU sequence information revealed that Melampsora rust on native and plantation-grown willows in NY State consisted of three phylogenetically delineable taxa (phylotaxa); monophyly for each phylotaxon was strongly supported by ML, MP, and BI credibility values as well as comparative differences in mean nucleotide similarity and genetic distances. The three identified phylotaxa were also delimited phylogenetically according to aecial host: Alpine currant (Ribes alpinum; Phylotaxon I), eastern larch (Larix laricina; Phylotaxon II), or balsam fir (Abies balsamea; Phylotaxon III). Melampsora within the Ribes-alternating group collected in NY State or inferred by molecular analyses likely represent an undescribed species as these taxa were not phylogenetically close to M. ribesii-purpureae ? the only described Melampsora in N. America reported to alternate between Salix and currants ? and shared a most recent common ancestor with Melampsora on arctic and temperate shrub willows in northeastern Canada and Scotland, respectively. Sister group relationships were also evident between the larch-alternating group and Melampsora spp. that alternate between poplars (Populus spp.) and various species of larch and pine (Pinus spp.) ? M. medusae and M. populnea. Likewise, Melampsora belonging to the fir-alternating group, obtained from infected balsam fir or willows in NY State, were more closely related to the poplar rust M. abietis-populi, which alternates to oriental Abies spp., rather than to either the Ribes- or larch-alternating groups. The putative identity and nomenclature as well as geographic and host distributions of Melampsora taxa affecting Salix in NY State are discussed. }
}
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Citation title: "Genetic evidence for three discrete taxa of Melampsora (Pucciniales) affecting willows (Salix spp.) in New York State ".
