Colletotrichum: complex species or species ... - CBS - KNAW

available online at www.studiesinmycology.orgStudies in Mycology 73: 115–180.The Colletotrichum gloeosporioides species complexB.S. Weir 1* , P.R. Johnston 1 , and U. Damm 21Landcare Research, Private Bag 92170 Auckland, New Zealand; 2 CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands*Correspondence: Bevan Weir, WeirB@LandcareResearch.co.nzAbstract: The limit of the Colletotrichum gloeosporioides species complex is defined genetically, based on a strongly supported clade within the Colletotrichum ITS gene tree.All taxa accepted within this clade are morphologically more or less typical of the broadly defined C. gloeosporioides, as it has been applied in the literature for the past 50 years.We accept 22 species plus one subspecies within the C. gloeosporioides complex. These include C. asianum, C. cordylinicola, C. fructicola, C. gloeosporioides, C. horii, C.kahawae subsp. kahawae, C. musae, C. nupharicola, C. psidii, C. siamense, C. theobromicola, C. tropicale, and C. xanthorrhoeae, along with the taxa described here as new,C. aenigma, C. aeschynomenes, C. alatae, C. alienum, C. aotearoa, C. clidemiae, C. kahawae subsp. ciggaro, C. salsolae, and C. ti, plus the nom. nov. C. queenslandicum(for C. gloeosporioides var. minus). All of the taxa are defined genetically on the basis of multi-gene phylogenies. Brief morphological descriptions are provided for specieswhere no modern description is available. Many of the species are unable to be reliably distinguished using ITS, the official barcoding gene for fungi. Particularly problematicare a set of species genetically close to C. musae and another set of species genetically close to C. kahawae, referred to here as the Musae clade and the Kahawae clade,respectively. Each clade contains several species that are phylogenetically well supported in multi-gene analyses, but within the clades branch lengths are short because ofthe small number of phylogenetically informative characters, and in a few cases individual gene trees are incongruent. Some single genes or combinations of genes, such asglyceraldehyde-3-phosphate dehydrogenase and glutamine synthetase, can be used to reliably distinguish most taxa and will need to be developed as secondary barcodes forspecies level identification, which is important because many of these fungi are of biosecurity significance. In addition to the accepted species, notes are provided for nameswhere a possible close relationship with C. gloeosporioides sensu lato has been suggested in the recent literature, along with all subspecific taxa and formae speciales withinC. gloeosporioides and its putative teleomorph Glomerella cingulata.Key words: anthracnose, Ascomycota, barcoding, Colletotrichum gloeosporioides, Glomerella cingulata, phylogeny, systematics.Taxonomic novelties: Name replacement - C. queenslandicum B. Weir & P.R. Johnst. New species - C. aenigma B. Weir & P.R. Johnst., C. aeschynomenes B. Weir & P.R.Johnst., C. alatae B. Weir & P.R. Johnst., C. alienum B. Weir & P.R. Johnst, C. aotearoa B. Weir & P.R. Johnst., C. clidemiae B. Weir & P.R. Johnst., C. salsolae B. Weir & P.R.Johnst., C. ti B. Weir & P.R. Johnst. New subspecies - C. kahawae subsp. ciggaro B. Weir & P.R. Johnst. Typification: Epitypification - C. queenslandicum B. Weir & P.R.Johnst.Published online: 21 August 2012; doi:10.3114/sim0011. Hard copy: September 2012.Studies in MycologyINTRODUCTIONThe name Colletotrichum gloeosporioides was first proposedin Penzig (1882), based on Vermicularia gloeosporioides, thetype specimen of which was collected from Citrus in Italy. Muchof the early literature used this name to refer to fungi associatedwith various diseases of Citrus, with other species established formorphologically similar fungi from other hosts. However, severalearly papers discussed the morphological similarity between manyof the Colletotrichum spp. that had been described on the basis ofhost preference, and used inoculation tests to question whether ornot the species were distinct. Some of these papers investigatedin culture the link between the various Colletotrichum species andtheir sexual Glomerella state (e.g. Shear & Wood 1907, Ocfemia& Agati 1925). Authors such as Shear & Wood (1907, 1913) andSmall (1926) concluded that many of the species described on thebasis of host preference were in fact the same, rejecting apparentdifferences in host preference as a basis for taxonomic segregation.Small (1926) concluded that the names Glomerella cingulata andColletotrichum gloeosporioides should be used for the sexual andasexual morphs, respectively, of the many Colletotrichum spp.they regarded as conspecific. Colletotrichum gloeosporioideswas stated to be the earliest name with a proven link to what theyCopyright CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands.regarded as a biologically diverse G. cingulata. The studies ofvon Arx & Müller (1954) and von Arx (1957, 1970) taxonomicallyformalised this concept.The “von Arxian” taxonomic concept for Colletotrichumsaw large numbers of species synonymised with the names C.graminicola (for grass-inhabiting species) and C. gloeosporioides(for non-grass inhabiting species with straight conidia). Thegenetic and biological diversity encompassed by these nameswas so broad that they became of little practical use to plantpathologists, conveying no information about pathogenicity, hostrange, or other attributes. The von Arx & Müller (1954) and vonArx (1957) studies were not based on direct examination of typematerial of all species and some of the synonymy proposedin these papers has subsequently been found to be incorrect.Examples include the segregation of C. acutatum (Simmonds1965) and C. boninense (Moriwaki et al. 2003) from C.gloeosporioides sensu von Arx (1957). Other studies publishedelsewhere in this volume (Damm et al. 2012a, b) show thatseveral species regarded as synonyms of C. gloeosporioidesby von Arx (1957) are members of the C. acutatum complex(e.g. C. godetiae, Gloeosporium limetticola, G. lycopersici, andG. phormii) or the C. boninense complex (e.g. C. dracaenae).Recent molecular studies have resulted in a much betterunderstanding of phylogenetic relationships amongst theYou are free to share - to copy, distribute and transmit the work, under the following conditions:Attribution:You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).Non-commercial: You may not use this work for commercial purposes.No derivative works: You may not alter, transform, or build upon this work.For any reuse or distribution, you must make clear to others the license terms of this work, which can be found at http://creativecommons.org/licenses/by-nc-nd/3.0/legalcode. Any of the above conditions can be waived if you getpermission from the copyright holder. Nothing in this license impairs or restricts the author’s moral rights.115