﻿Dendrocorticiopsisorientalis gen. et sp. nov. of the Punctulariaceae (Corticiales, Basidiomycota) revealed by molecular data

﻿Abstract Dendrocorticiopsisorientalis is presented in this study as a new genus and new species based on morphological and phylogenetic evidence. This new taxon is characterized by resupinate, smooth and membranaceous basidiomata, monomitic hyphal system with clamps, colorless dendrohyphidia, variable presence of cystidia, and ellipsoid to ovoid basidiospores measuring 5–7 × 3.2–5.2 μm. The phylogenetic analyses based on the ITS1-5.8S-ITS2 (ITS) + nuclear 28S rDNA (28S) dataset of Corticiales indicated that the new taxon is nested in Punctulariaceae, separated from other genera with strong support values. Descriptions, specimen photo, and illustrations of the new taxon are provided in this study. A morphological comparison of the four genera of Punctulariaceae is given.

Most of the previous studies of Punctulariaceae focused on European species (Bernicchia and Gorjón 2010; Gorjón and Bernicchia 2017), although species from other continents received attention as well (Ghobad-Nejhad et al. 2010;Baltazar et al. 2013;Ariyawansa et al. 2015). However, the study of this family in Asia is insufficient and needs an update (Petch 1916;Cooke 1956;Guan et al. 2021). During surveys of corticioid fungi in East Asian regions, we found an unknown species morphologically similar to Dendrocorticium spp. Phylogenetic analyses were conducted by using ITS+28S sequences to evaluate the generic placement of the target taxon, and the results indicated that it represents a new genus and a new species of the Punctulariaceae.

Morphological studies
Descriptions and illustrations are based on dried specimens deposited at the herbaria of the National Museum of Natural Science (TNM) and Beijing Forestry University (BJFC). Specimens were sliced into thin sections under stereo microscope (Nikon SMZ645) and mounted in 5% KOH with 1% phloxine in preparation for observations and measurements. Melzer's reagent (IKI) and cotton blue were applied to detect amyloidity or dextrinoidity, and cyanophily, respectively. Microscopic studies were carried out under 1,000× magnification using an optical microscope (Olympus BX43). For presenting the range of basidiospore dimensions, 5% values of minimum and maximum are given in parentheses.

DNA extraction and sequencing
DNA was extracted from dried specimens using the Plant Genomic DNA Extraction Miniprep System (Viogene Biotek corporation, New Taipei City, Taiwan), following the manufacturer's protocol. ITS1-5.8S-ITS2 and partial 28S regions were amplified with the primer pairs ITS1/ITS4 (White et al. 1990) and LR0R/LR5 (Vilgalys and Hester 1990). The PCR protocols for ITS and 28S followed Chen et al. (2020). PCR products were purified and sequenced by MB Mission Biotech company (Taipei City, Taiwan). New sequences were assembled and adjusted using BioEdit v7.2.5 (Hall 1999) and subsequently submitted to GenBank (Table 1).

Phylogenetic analyses
The selection of species and samples for the ITS+28S dataset was inspired by Ghobad-Nejhad and Duhem (2014) and Guan et al. (2021 Wu et al. (2018). Only the phylogram inferred from the ML analysis is shown since the BI and ML analyses produced similar topologies. The statistical support values are presented above the branches of the ML tree when bootstrap values (BS) ≥ 70 and BI posterior probability (PP) ≥ 0.9. The complete phylogenetic trees and alignment were submitted to TreeBASE (submission number 29602; www.treebase.org).

Phylogenetic inference
The final alignment of 43 sequences contained 1,647 sites (including gaps) of which 724 sites were from the ITS region and 923 sites from the 28S gene. Totally, 565 (34%) sites were parsimony informative. The ML tree (Fig. 1)  Diagnosis. Dendrocorticiopsis differs from other genera by having strictly resupinate basidiomata, ivory hymenphore, a compact texture, a monomitic hyphal system, nodoseseptate hyphae, encrusted cystidia, dendrohyphidia and ellipsoid to ovoid basidiospores.
Type species. Dendrocorticiopsis orientalis. Etymology. Dendrocorticiopsis refers to the morphological resemblance to Dendrocorticium. Etymology. The epithet refers to the Eastern world, where the specimens were collected.
Distribution. In subtropical regions, known from China: Jiangxi and Taiwan Notes. Both of the ITS and 28S sequences BLAST results showed that Dendrocorticiopsis orientalis is close to the strain BCRC 36235 that is annotated as Ganoderma applanatum (Pers.) Pat. in GenBank. According to personal communication with Bioresource Collection and Research Center (BCRC, Taiwan), the strain BCRC 36235 was indeed isolated from a Ganoderma specimen collected by Dr. Jin-Torng Peng in Nantou, Central Taiwan, on wood of Acacia confusa Merr. However, as suggested by Suldbold (2017), the ITS (EU232219) and 28S (EU232303) sequences of the strain BCRC 36235 are not true G. applanatum, and we supposed that the strain could be contaminated by D. orientalis, which is known to grow on Acacia. The specimen He 4195 collected on Castanopsis (Fagaceae) from Jiangxi Province has slightly smaller basidiospores (L = 5.8 μm, W = 4.2 μm) than the holotype.