﻿Ceriporiopsistianshanensis (Polyporales, Agaricomycetes) and Sideratianshanensis (Hymenochaetales, Agaricomycetes), two new species of wood-inhabiting fungi from Xinjiang, Northwest China

﻿Abstract Wood-inhabiting fungi are abundant in China, but their distribution is uneven, with more fungi in southwest China and fewer fungi in northwest China. During the investigation of wood-inhabiting fungi in Xinjiang, we collected a large number of specimens. Eight specimens growing on Piceaschrenkiana were collected from Tianshan Mountains, and they were described as two new species in Ceriporiopsis and Sidera based on morphological characters and molecular evidence. Ceriporiopsistianshanensis is characterized by a cream to salmon-buff pore surface, larger pores measuring 1–3 per mm, and broadly ellipsoid basidiospores 5–6.5 × 3–4 μm. Sideratianshanensis is characterized by annual to perennial basidiocarps, measuring 15 mm thick, pores 5–7 per mm, cream to rosy buff pore surface, and allantoid basidiospores 3–3.5 × 1–1.4 µm. Detailed illustrations and descriptions of the novel species are provided.


Introduction
China is rich in wood-inhabiting fungal resources, and more than 2000 species of the woody fungi have been reported (Dai 2010(Dai , 2012Cui et al. 2019;Wu et al. 2022a, b). In the past ten years, many new species of the wood-inhabiting fungi have been discovered in China, and mainly distributed in the southwest and south areas, and few new species have been published from northwest China (Li et al. 2014;Chen et al. 2016;Shen et al. 2019;Wang et al. 2021;Yuan et al. 2021;Ji et al. 2022;Wu et al. 2022b;Liu et al. 2023a).
The Xinjiang Uygur Autonomous Region is located in northwestern China, and, as the largest province in China, it covers an area of 1,664,900 square kilometers. There is a typical temperate continental arid climate, with an extremely uneven distribution of water resources in time and space, more in the west and less in the east, more in the north and less in the south, more in the mountains and less in the plains (Wu et al. 2010;Hu et al. 2021). Due to severe climatic conditions, natural forests are mainly distributed in the Tianshan Mountains dimitic hyphal system with generative hyphae bearing clamp connections, the presence of rosette-like crystals and allantoid to lunate basidiospores (Miettinen and Larsson 2011;Du et al. 2020;Liu et al. 2021bLiu et al. , 2022. In phylogenetic analysis, Sidera is a monophyletic genus and clustered into the Rickenella clade (Liu et al. 2021b(Liu et al. , 2023b. In this study, two new species are described based on morphological and phylogenetic evidence.

Morphological studies
The specimens used in this study were deposited at the herbarium of the Institute of Microbiology, Beijing Forestry University, China (BJFC). Macro-morphological descriptions were based on field notes and laboratory measurements. The microscopic routines used in this study followed Cui et al. (2019) and Liu et al. (2023a). Sections were studied at a magnification up to ×1000 using a Nikon E80i microscope and phase contrast illumination (Nikon, Tokyo, Japan). Line drawings were made with the aid of a drawing tube. Microscopic features, measurements and drawings were made from slide preparations of dried or fresh material stained with Cotton Blue and Melzer's reagent, as described by Dai (2010). To represent the variation in the size of the basidiospores, 5% of measurements were excluded from each end of the range and are given in parentheses. The following abbreviations were used: IKI = Melzer's reagent, IKI-= neither dextrinoid nor amyloid, KOH = 5% potassium hydroxide, CB = Cotton Blue, CB-= acyanophilous, L = mean spore length (arithmetic average of all spores), W = mean spore width (arithmetic average of all spores), Q = variation in the L/W ratios between the specimens studied, n = number of spores measured from a given number of specimens. Color terms followed Petersen (1996).

DNA extraction and sequencing
Total genomic DNA was extracted from dried specimens using a cetyltrime-thylammonium bromide (CTAB) Rapid Plant Genome Extraction Kit (Aidlab Biotech-nologies Company, Ltd., Beijing, China) according to the manufacturer's instructions with some modifications (Li et al. 2014;Ji et al. 2022). Two DNA gene fragments, ITS and nLSU, were amplified using the primer pairs ITS5/ITS4 and LR0R/LR7 (White et al. 1990). The PCR procedures for ITS and nLSU followed Song et al. (2022) and Sun et al. (2022) in the phylogenetic analyses. All PCR products were directly purified and sequenced at the Beijing Genomics Institute (BGI), China, with the same primers. Newly generated sequences were submitted to GenBank and are listed in Tables 1, 2.

Phylogenetic analysis
Phylogenetic analyses for Ceriporiopsis and Sidera were performed with maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) analyses based on the combined ITS+nLSU dataset. New generated sequences were aligned with the additional sequences retrieved from GenBank (Tables 1, 2) using BioEdit 7.0.5.3 (Hall 1999) and ClustalX 1.83 (Thompson et al. 1997  . Maximum parsimony (MP) analysis was performed in PAUP* version 4.0b10 (Swofford 2002). The settings for phylogenetic analyses in this study followed the approach of Ji et al. (2022) and Zhu et al. (2019). All characters were equally weighted, and gaps were treated as missing data. Trees were inferred using the heuristic search option with TBR branch swapping and 1000 random sequence additions. Max trees were set to 5000, branches of zero length were collapsed, and all parsimonious trees were saved. Clade robustness was assessed using a bootstrap (BT) analysis with 1000 replicates (Felsenstein 1985). Descriptive tree statistics tree length (TL), consistency index (CI), retention index (RI), rescaled consistency index (RC) and homoplasy index (HI) were calculated for each generated Maximum Parsimonious Tree (MPT) (Page 1996). Maximum likelihood (ML) analysis was conducted by RAxML-HPC252 through the CIPRES Science Gateway (www.phylo.org) and involved 100 ML searches. All model parameters were estimated by the program. Only the best maximum likelihood tree from all searches was retained. The maximum likelihood bootstrap values (ML-BS) were determined using rapid bootstrapping with 1000 replicates. The phylogenetic tree was visualized using Treeview (Page 1996).
Bayesian inference (BI) analysis was implemented in MrBayes 3.2.6 (Ronquist et al. 2012). There were two independent runs, each of which had four chains for 1,000,000 generations sampling from the posterior distribution every 1000 th generation to check that the PSRF (potential scale reduction factors) were reasonably close to 1.0 for all parameters indicative of chain convergence. The first 25% of the sampled trees were discarded as burn-in, while the remaining trees were used to obtain the Bayesian posterior probabilities (BPPs) of the clades. A majority rule consensus tree of all remaining trees was calculated.
Branches that received bootstrap support for maximum parsimony (MP), maximum likelihood (ML) higher than or equal to 75% (MP and ML-BS) and Bayesian posterior probabilities (BPP) higher than or equal to 0.95 (BPP) were considered significantly supported. The best topologies from MP analyses are shown in this study, and the final alignments and the retrieved topologies were deposited in TreeBASE (http://www.treebase.org accessed on 28 April 2023), under accession ID: 29931.

Molecular phylogeny
The phylogeny of Ceriporiopsis, based on a combined ITS and nLSU dataset, included 30 ITS sequences and 29 nLSU sequences from 30 fungal specimens, representing 17 species. The dataset had an aligned length of 2153 characters, of which 1399 characters were constant, 200 were variable and parsimony-uninformative and 554 were parsimony informative. Maximum parsimony analysis yielded one equally parsimonious tree (TL = 1902, CI = 0.601, RI = 0.763, RC = 0.459, HI = 0.399), and a strict consensus tree of these trees is shown in Fig. 1. The best model fit applied in the Bayesian inference analysis was GTR+I+G. Bayesian analysis and ML analysis resulted in a similar topology to MP analysis, with an average standard deviation of split frequencies of 0.006591 (BI).
The phylogeny of Sidera, based on a combined ITS and nLSU dataset, included 37 ITS sequences and 32 nLSU sequences from 37 fungal specimens, representing 19 species. The dataset had an aligned length of 2235 characters, of which 1453 characters were constant, 205 were variable and parsimony-uninformative and 577 were parsimony in-formative. Maximum parsimony analysis yielded one equally parsimonious tree (TL = 2233, CI = 0.583, RI = 0.760, RC = 0.443, HI = 0.417), and a strict consensus tree of these trees is shown in Fig. 2. The best model fit applied in the Bayesian inference analysis was GTR+I+G. Bayesian analysis and ML analysis resulted in a similar topology as MP analysis, with an average standard deviation of split frequencies of 0.007516 (BI).
Within the phylogenetic tree of Ceriporiopsis, the new species C. tianshanensis was closely related to C. subrufa with high supports (100% ML, 100% MP, 1.00 BPP; Fig. 1). However, the ITS sequences of Ceriporiopsis tianshanensis and C. subrufa were significantly different, with 31 different nucleobases, and the similarity was 94.80% by nucleotide blast. The difference in the nLSU sequence was not significant; there were 4 different nucleobases, and the similarity was 99.29% by nucleotide blast.
In addition, the phylogenetic tree of Sidera, the new species Sidera tianshanensis, was closely related to S. salmonea with high support (100% ML, 93% MP, 1.00 BPP; Fig. 2). However, the ITS sequences of Sidera tianshanensis and S. salmonea were significantly different, with 40 different nucleobases, and the similarity was 94.29% by nucleotide blast. The difference in the nLSU sequence was not significant; there were 7 different nucleobases, and the similarity was 99.55% by nucleotide blast. Diagnosis. Ceriporiopsis tianshanensis is characterized by a cream to salmon-buff pore surface when fresh, large pores measuring 1-3 per mm, broadly ellipsoid basidiospores measuring 5-6.5 × 3-4 μm, and growth on the stump  Fruiting body. Basidiocarps annual, resupinate, adnate, not easily separated from the substrate, soft corky when fresh, fragile to hard fibrous when dry, up to 12 cm long, 3 cm wide, 2 mm thick. Pore surface white to cream or salmon-buff when fresh, becoming buff to vinaceous-buff or fawn when dry; pores irregular, 1-3 per mm; dissepiments thin, entire. Subiculum cream to buff and fibrous to soft corky when dry, up to 4 mm thick. Tubes concolorous with pore surface, corky, up to 4 mm long.

Discussion
In this study, phylogenetic trees of Ceriporiopsis and Sidera were constructed using combined ITS and nLSU sequences, respectively. The two newly proposed species formed separate branches on the phylogenetic trees with high support. In addition, both Ceriporiopsis tianshanensis and Sidera tianshanensis differ from other recorded species through their morphological characteristics.
Based on the records in previous literature and the introduction in this study, 42 species of Ceriporiopsis have been recorded in the world, among which 9 species are distributed in China (Binder et al. 2005;Zhao and Wu 2017;Ryvarden 2018Ryvarden , 2019Ryvarden , 2020Zhao et al. 2023). Ceriporiopsis is widely distributed across five continents, with the exception of Antarctica and Oceania. The genus is most diverse in Africa, where it is represented by 17 species. South America has 10 species, North America has 7 species, Asia has 7 species, and Europe has 4 species. A total of 19 species of Sidera have been recorded worldwide, among which 10 species are distributed in China (Liu et al. 2023b). Sidera is currently a genus of fungi that has been relatively understudied. Among the discovered species that have been discovered so far, Asia has the highest number with 13 species, followed by Oceania with 4 species, Europe with 3 species, and North and South America with 1 species each. With the in-depth investigation of wood-inhabiting fungi in Xinjiang, an increasing number of new species of wood-inhabiting fungi will be discovered. The species diversity of wood-inhabiting fungi in China will also be richer.