Data from: Multigene phylogenetic analyses of the Thelonectria coronata and T. veuillotiana species complexes

Thelonectria is a recently established genus of common and ubiquitous fungi on woody hosts, previously placed in the genus Neonectria. Thelonectria coronata and T. veuillotiana occur sympatrically in several geographical areas in tropical, subtropical, and temperate regions. Previous taxonomic studies including T. coronata and T. veuillotiana suggested these fungi could represent species complexes; however, the morphological features used to define species exhibited few differences useful for testing this hypothesis. In order to assess the status of T. coronata and T. veuillotiana, phylogenetic analyses of six genomic regions were combined with a morphological examination of specimens. A multigene phylogeny reconstructed using Maximum Parsimony, Maximum Likelihood, and Bayesian approaches identified five phylogenetic groups in T. coronata and six in T. veuillotiana. As is common for cryptic species, unequivocal diagnostic morphological characters could not be identified; however, average values of morphological traits correspond to the phylogenetic groups. An increased level of non-synonymous/synonymous substitutions in the β-tubulin gene and a decreased or absent production of conidia was detected within the T. coronata complex, possibly indicating the homothallic nature of these isolates. Here, T. coronata and T. veuillotiana and related species are described and illustrated; a dichotomous key to all species is provided.

裸囊壳菌属（Thelonectria）是新近确立的一类常见且广布于木质寄主上的真菌类群，此前曾被划归新赤壳属（Neonectria）。冠突裸囊壳（T. coronata）与维耶洛裸囊壳（T. veuillotiana）在热带、亚热带及温带的多个地理区域呈同域分布。此前针对冠突裸囊壳与维耶洛裸囊壳开展的分类学研究提示，这两类真菌可能属于复合种；但用于界定物种的形态特征仅存极细微差异，难以验证这一假说。为明确冠突裸囊壳与维耶洛裸囊壳的分类地位，本研究将6个基因组区域的系统发育分析与标本形态学检查相结合。采用最大简约法、最大似然法及贝叶斯法重建的多基因系统发育树显示，冠突裸囊壳可划分为5个系统发育群，维耶洛裸囊壳则可划分为6个系统发育群。与隐存种的常见情况一致，研究未能找到明确的诊断性形态特征；但各类形态性状的平均值可与各系统发育群一一对应。在冠突裸囊壳复合体中，β-微管蛋白基因的非同义替换/同义替换比值升高，且分生孢子的产生量降低甚至缺失，这或许暗示这些菌株具有同宗配合特性。本文对冠突裸囊壳、维耶洛裸囊壳及其近缘物种进行了描述与图示，并提供了所有物种的二歧检索表。