Liu Q L, Li J Q, Wingfield M J, Duong T A, Wingfield B D, Crous P W, Chen S F
China Eucalypt Research Centre (CERC), Chinese Academy of Forestry (CAF), ZhanJiang, 524022, GuangDong Province, China.
State Key Laboratory of Tree Genetics and Breeding (SKLTGB), Chinese Academy of Forestry (CAF), Haidian District, 100091, Beijing, China.
Stud Mycol. 2020 Oct 7;97:100106. doi: 10.1016/j.simyco.2020.08.001. eCollection 2020 Sep.
represents a genus of phytopathogenic ascomycetous fungi with a worldwide distribution. In recent years, there has been an increase in the number of taxonomic studies on these fungi. Currently, there are 169 described species of based on comparisons of DNA sequence data, combined with morphological characteristics. However, for some of these species, the sequence data utilised at the time of their description were relatively limited. This has justified an urgent need to reconsider the species boundaries for based on robust genus-wide phylogenetic analyses. In this study, we utilised 240 available isolates including the ex-types of 128 species, and re-sequenced eight gene regions (, , , ITS, LSU, and ) for them. Sequences for 44 species, for which cultures could not be obtained, were downloaded from GenBank. DNA sequence data of all the 169 species were then used to determine their phylogenetic relationships. As a consequence, 51 species were reduced to synonymy, two new species were identified, and the name was validated. This resulted in the acceptance of 120 clearly defined spp. The overall data revealed that the genus includes 11 species complexes, distributed across the Prolate and Sphaero-Naviculate Groups known to divide . The results also made it possible to develop a robust set of DNA barcodes for spp. To accomplish this goal, we evaluated the outcomes of each of the eight candidate DNA barcodes for the genus, as well as for each of the 11 species complexes. No single gene region provided a clear identity for all species. Sequences of the and genes were the most reliable markers; those for the , , and gene regions also provided a relatively effective resolution for spp., while the ITS and LSU failed to produce useful barcodes for species discrimination. At the species complex level, results showed that the most informative barcodes were inconsistent, but that a combination of six candidate barcodes (, , , , and ) provided stable and reliable resolution for all 11 species complexes. A six-gene combined phylogeny resolved all 120 species, and revealed that , , , , and gene regions are effective DNA barcodes for .
代表一类在全球范围内分布的植物病原子囊菌。近年来，对这些真菌的分类学研究数量有所增加。目前，基于DNA序列数据比较并结合形态特征，已描述了169种该属真菌。然而，对于其中一些物种，其描述时所使用的序列数据相对有限。这使得基于全面且可靠的全属系统发育分析重新考虑该属物种界限成为当务之急。在本研究中，我们利用了240个可用分离株，包括128种该属真菌的模式菌株，并对它们的八个基因区域（，，，ITS，LSU，和）进行了重新测序。对于44种无法获得培养物的该属真菌，其序列从GenBank下载。然后，使用所有169种该属真菌的DNA序列数据来确定它们的系统发育关系。结果，51个物种被归为异名，鉴定出两个新物种，并确认了该属名称。这使得120个明确界定的该属物种被接受。总体数据显示，该属包括11个物种复合体，分布在已知可划分该属的长圆形和球形舟形组中。研究结果还使得能够为该属真菌开发一套可靠的DNA条形码。为实现这一目标，我们评估了该属的八个候选DNA条形码以及11个物种复合体中每个复合体的评估结果。没有单个基因区域能为所有该属物种提供明确的鉴定。和基因的序列是最可靠的标记；，，和基因区域的序列也为该属真菌提供了相对有效的分辨率，而ITS和LSU未能产生用于物种区分的有用条形码。在物种复合体水平上，结果表明最具信息性的条形码并不一致，但六个候选条形码（，，，，和）的组合为所有11个物种复合体提供了稳定可靠的分辨率。一个六基因联合系统发育分析解析了所有120种该属真菌，并表明，，，，和基因区域是该属真菌有效的DNA条形码。
