Using divergence times in fungal classification
作者单位：School of Life Science and Technology University of Electronic Science and Technology of China Chiang Mai University Center of Excellence in Fungal Research Mae Fah Luang University Biosystems and Integrative Sciences Institute Universidade de Lisboa
会议名称：《多彩菌物美丽中国——中国菌物学会2019年学术年会》
会议日期：2019年
学科分类：0710[理学-生物学] 071001[理学-植物学] 07[理学]
基 金：supported by The National Natural Science Foundation of China (NSFC 31600032)
关 键 词：Ascomycota1 Classification2 Divergence times3 Dothideomycetes4 Phylogeny5 Taxonomy6
摘 要：The current classification system for the recognition of taxonomic ranks among fungi, especially at highranking level, is subjective. With the development of molecular approaches and the availability of fossil calibration data, the use of divergence times as a universally standardized criterion for ranking taxa has now become possible. We can therefore date the origin of Ascomycota lineages by using molecular clock methods and establish the divergence times for the orders and families of Dothideomycetes. We chose Dothideomycetes, the largest class of the phylum Ascomycota, which contains 32 orders, to establish ages at which points orders have split;and Pleosporales, the largest order of Dothideomycetes contains 55 families, to establish family divergence times. We have assembled a multi-gene data set（LSU, SSU, TEF1 and RPB2） from 391 taxa representing most family groups of Dothideomycetes and utilized fossil calibration points solely from within the ascomycetes and a Bayesian approach to establish divergence times of Dothideomycetes lineages. Two separated datasets were analysed: i) 272 taxa representing 32 orders of Dothideomycetes were included for the order level analysis, and ii) 191 taxa representing 55 families of Pleosporales were included for the family level analysis. Our results indicate that divergence times（crown age） for most orders（20 out of 32, or 63%） are between 100 and 220 Mya, while divergence times for most families（39 out of 55, or 71%）) are between 20 and 100 Mya. We believe that divergence times can provide additional evidence to support establishment of higher level taxa, such as families, orders and classes. Taking advantage of this added approach, we can strive towards establishing a standardized taxonomic system both within and outside Fungi（Liu et al 2017）. A new family Striatiguttulaceae was introduced based on morphology and phylogeny, and the divergence times was used to justify its family level in Pleosporales（Zhang et al 2019）. Fami