Investigating species boundaries in Colletotrichum  

作　　者：Chitrabhanu S.Bhunjun Chayanard Phukhamsakda Ruvishika S.Jayawardena Rajesh Jeewon Itthayakorn Promputtha Kevin D.Hyde 

机构地区：[1]Center of Excellence in Fungal Research,Mae Fah Luang University,Chiang Rai 57100,Thailand [2]School of Science,Mae Fah Luang University,Chiang Rai 57100,Thailand [3]Institute of Plant Protection,College of Agriculture,Jilin Agricultural University,Changchun 130118,Jilin,People’s Republic of China [4]Engineering Research Center of Chinese Ministry of Education for Edible and Medicinal Fungi,Jilin Agricultural University,Changchun 130118,Jilin,People’s Republic of China [5]Department of Health Sciences,Faculty of Medicine and Health Sciences,University of Mauritius,Reduit,Mauritius [6]Department of Biology,Faculty of Science,Chiang Mai University,Chiang Mai 50200,Thailand

出　　处：《Fungal Diversity》2021年第2期107-127,共21页真菌多样性（英文）

基　　金：the Thailand Research Fund,grant RDG6130001 entitled“Impact of climate change on fungal diversity and biogeography in the Greater Mekong Subregion”;the support from University of Mauritius and the Mauritius Research and Innovative Council(MRC/RUN/1705);RS Jayawardena thanks the National Research Council of Thailand,grant for new researcher NRCT5-TRG630010-01,entitled“Biodiversity,taxonomy,phylogeny and evolution of Colletotrichum in northern Thailand”.

摘　　要：Colletotrichum is one of the most important plant pathogenic genera that is responsible for numerous diseases which can have a profound impact on the agricultural sector.Species delineation is difficult due to a lack of distinctive phenotypic vari-ation.Therefore,in this study three different genomic approaches based on phylogenetic,evolutionary and coalescent-based methods are applied to establish robust species boundaries.The reliability of five different DNA barcodes was also assessed to provide further insights into species delineation.The ITS region can resolve the placement of taxa up to the species complex level.The GAPDH and TUB2 markers are determined to be the most informative for most complexes.However,no single marker could discriminate between species in all complexes,therefore different molecular approaches based on multi-locus datasets are recommended.This is the first study to provide an estimated divergence time for all species complexes in Colle-totrichum.The estimated divergence time for species complexes ranged between 4.8 to 32.2 MYA.Based on the high level of congruent results obtained from the different molecular approaches,a new species complex,the Colletotrichum agaves complex is introduced.This complex consists of five taxa which are characterised by the presence of straight or slightly curved conidia with obtuse apices.This study shows that coalescent approaches and multi-locus phylogeny are crucial to establish species boundaries in Colletotrichum.The taxonomic placement of three singleton taxa Colletotrichum axonopodi,C.cariniferi and C.parallelophorum is revised.We accept 248 species and provide recommendations regarding species boundaries in the graminicola-caudatum complex.

关 键 词：BEAST General mixed yule coalescent method Glomerellaceae Multi-rate poisson tree process SORDARIOMYCETES Taxonomy 

分 类 号：O62[理学—有机化学]