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Article

Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity

by
Zheng Wang
1,
Ya Liu
1,
Caixia Liu
1,
Zhenyu Liu
2,*,
Lijun Liang
3 and
Quan Lu
1,*
1
Key Laboratory of Forest Protection of National Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Natural Conservation, Chinese Academy of Forestry, Beijing 100091, China
2
College of Plant Protection, Shandong Agricultural University, Tai’an 271018, China
3
Shanxi Forestry and Grassland Technical Extension (Prevention and Quarantine) Station, Taiyuan 030012, China
*
Authors to whom correspondence should be addressed.
Forests 2021, 12(12), 1795; https://doi.org/10.3390/f12121795
Submission received: 21 November 2021 / Revised: 13 December 2021 / Accepted: 14 December 2021 / Published: 17 December 2021
(This article belongs to the Special Issue Forest Pathology and Entomology—Series II)
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Abstract

:
Ophiostomatoid fungi are known for their associations with bark beetles, and some species are important sources of tree diseases. Ceratocystiopsis is a genus of the ophiostomatoid fungi in order Ophiostomatales. The shortage of DNA barcodes for many species in this genus has resulted in the presence of many unnamed cryptic species. In this study, Ceratocystiopsis subelongati sp. nov. associated with Ips subelongatus infesting Pinus sylvestris var. mongolica in Inner Mongolia, China, was identified and described based on phylogenetic inference of multi-gene DNA sequences and morphological characteristics. The species is characterized by a hyalorhinocladiella- to sporothrix-like asexual state and an optimal growth temperature of 30 °C. Artificial inoculation tests in the field showed that it is mildly pathogenic to five-year-old larch trees, the main host of I. subelongatus. It is also the first described Ceratocystiopsis species associated with I. subelongatus in China. This discovery should provide new avenues for studying the symbiosis between bark beetles and ophiostomatoid fungi.

1. Introduction

Ophiostomatoid fungi belong to the Ascomycota (orders Ophiostomatales and Microascales), which have similar basic morphological features, such as ascomata with long necks and sticky drops on the conidiogenous apparatus [1,2]. These morphological features are thought to represent convergent evolution to be better transmitted by vector insects [3]. Many of these species can form symbiotic relationships with bark and ambrosia beetles [4,5], mainly because the fungi can provide nutrients for and emit the pheromones of bark beetles [6,7,8,9,10,11,12,13].
Ceratocystiopsis is a member of the family Ophiostomataceae and was originally described by Upadhyay and Kendrick [14]. The genus was thought to be synonymous with Ophiostoma for some time [15], until Zipfel et al. [16] reinstated it and distinguished it from other genera in the Ophiostomatales by the presence of short-necked ascomata and elongated, falcate, sheathed ascospores [1]. A total of 13 species and five unnamed cryptic species have been confirmed based on phylogenetic analyses of the nuclear ribosomal large subunit region (LSU) sequences [1]. Subsequently, C. synnemata, C. lunata, C. yantaiensis, and C. weihaiensis were identified and described based on internal transcribed spacer regions 1 and 2 of the nuclear ribosomal DNA operon, including the 5.8S region (ITS), the β-tubulin gene region (Tub2), and the transcription elongation factor1-α gene region (TEF1-α) sequences by Strzałka et al. [17], Nel et al. [18], and Chang et al. [19]. However, there remains a shortage of DNA barcodes for many species in this genus, resulting in the persistence of many unnamed cryptic species [1,20] and posing a challenge for developing a unified taxonomy of the genus.
Although the idea that the pathogenic fungi associated with bark beetles are critically important for overcoming host tree defenses has been challenged in the literature [21], none deny that some of these fungi are important phytopathogens of forest diseases [22,23,24,25]. The best-known examples are Dutch elm disease [24,26], black stain root disease [27], and laurel wilt [28], which are caused by ophiostomatoid fungi associated with ambrosia or bark beetles. In China, a total of 44 new ophiostomatoid fungi species associated with several bark beetles infesting conifers have been reported in the last three years [19,20,29,30,31,32,33,34,35,36,37]. However, their pathogenicity in their respective hosts remains unknown. In this study, we aimed to elucidate the identity of the unnamed taxa Ceratocystiopsis cf. pallidobrunnea associated with Ips subelongatus collected during previous surveys from Northeastern China [20], based on morphological and multilocus phylogenetic methods. Additionally, we tested the pathogenicity of this species in larch, the main host of the beetle in the field.

2. Materials and Methods

2.1. Fungal Strains

Strains were isolated from galleries of I. subelongatus infesting Pinus sylvestris var. mongolica in Inner Mongolia, China. Other sampling and isolate details followed the descriptions of Wang et al. [20]. The strains were deposited at the China Forestry Culture Collection Center (CFCC) in Beijing and Shandong Agricultural University in Tai’an, Shandong province.

2.2. Morphological and Cultural Studies

The microscopic features of the studied fungal strains were observed and recorded by using an Olympus SZX16 stereomicroscope and an Olympus DP70 digital camera (Olympus Corp., Beijing, China). The lengths and widths of 30 reproductive structures per strain were measured in 80% lactic acid on glass slides and presented as minima, averages (±standard deviations), and maxima. A mycelium disk (5 mm diameter) cut from an actively growing culture was placed in the center of a 90 mm–diameter Petri dish containing 2% malt extract agar (MEA, AoBoXing Company Ltd., Beijing, China), which was used to measure growth rates. Five replicate plates were incubated in the dark at 5–40 °C with different treatments at 5 °C intervals. Two colony diameters perpendicular to each other were measured and recorded daily until the mycelium reached the margin of the MEA plates. The color descriptions were based on Rayner’s [38] charts.

2.3. DNA Extraction, PCR, and Sequencing

Fungal strains were grown in 2% MEA at 25 °C for 10 days before DNA extraction. The actively growing mycelium was scraped from the surface of the MEA and transferred into 2 µL Eppendorf tubes. DNA extraction was performed by using an Invisorb Spin Plant Mini Kit (Tiangen Biotech Co., Ltd., Beijing, China) according to the manufacturer’s instructions. The primers ITS1 and ITS4 [39] were used to amplify ITS, Bt2a and Bt2b [40] were used to amplify Tub2, and EF1F and EF2R were used to amplify TEF1-α [41].
Polymerase chain reaction (PCR) was conducted by using the 2 × Tap PCR MasterMix (Tiangen Biotech Co., Ltd., Beijing, China) according to the manufacturer’s instructions. The PCR conditions for the two regions were as follows: an initial denaturation step at 95 °C for 3 min, followed by 35 cycles of 1 min at 94 °C, 45 s at 55 °C (ITS) or 56 °C (Tub2 and TEF1-α), and 1 min at 72 °C, and a final elongation step at 72 °C for 8 min. The PCR products were transported to the Majorbio Company (Beijing, China) for sequencing.

2.4. Phylogenetic Analysis

Referenced sequences of Ceratocystiopsis spp. in the analyses were downloaded from GenBank (Table 1). Alignments were performed by using the online tool MAFFT v. 7 [42] with iterative refinement methods (L-INS-i). Molecular evolutionary genetic analyses (MEGA) v. 7.0 [43] was used to compile our datasets, while maximum likelihood (ML), maximum parsimony (MP), and Bayesian inference (BI) methods were used for phylogenetic analyses. For the combined gene dataset, PAUP v. 4.0b10 [44] was performed to homogeneity test before phylogenetic analysis. Maximum likelihood analyses were performed by using RAxML-HPC v.8.2.3 [45] with the GTR + G model of site substitution, including estimates of gamma-distributed rate heterogeneity and proportions of invariant sites [46]. A total of 1000 trees were retained, and bootstrap support values were estimated with 1000 replicates.
Maximum parsimony analyses were performed by using PAUP v. 4.0b10 [44], and the gaps were treated as a fifth base. Branch node confidence was estimated by using 1000 bootstrap replicates. The 50% majority of clades compatible in the bootstrap consensus tree was retained. The analytical settings were as follows: tree bisection reconnection branch swapping, starting tree obtained via stepwise addition, steepest descent not in effect, and MulTrees effective. For BI analyses, jModelTest v. 2.1.7 [47] was used to establish the best-fit substitution models for each dataset. Bayesian inference analyses were performed with MrBayes v. 3.1.2 [48], using four Markov chain Monte Carlo (MCMC) chains, and chains were run simultaneously from a random starting tree for 5,000,000 generations to calculate posterior probabilities. Trees were sampled per 100 generations. The first 25% of trees sampled were set as burn-in values, and the remaining trees were used to calculate posterior probabilities. The final alignments and retrieved topologies were deposited in TreeBASE (No. 24415). Phylogenetic trees were edited by using FigTree v. 1.4.3 http://tree.bio.ed.ac.uk/software/figtree/ (accessed on 20 November 2021) and Adobe Illustrator CS6.

2.5. Pathogenicity Tests

The type strain CFCC52689 was selected for in vivo pathogenicity tests in the field. The pathogenicity test was conducted on five-year-old healthy trees of Larix olgensis at Dagujia Forest Farm, Liaoning province, China. The tree height was approximately 2.5 m, and the ground diameter was approximately 3 cm. One wound was made on the trunk 30 cm from the ground, using a cork borer (6 mm diameter), and a 6 mm–diameter MEA plug was taken from the margins of an actively growing fungal colony and placed on the freshly wounded surface. For the control treatment, a sterile MEA plug was used. In total, three trees were inoculated with fungus, and three were inoculated with an MEA plug. The inoculated area was covered with Parafilm and wrapped with sticky tape. Inoculations were conducted on 11 July 2019. Two months later, the outer bark near the inoculated area was removed with a scalpel, and the lengths and widths of the lesions were measured and recorded on 11 September 2019. We used SPSS v. 10.0.1 (IBM Corp., Armonk, NY, USA) to analyze the differences in these lesions, using a one-way analysis of variance (ANOVA). Tissues at the margin of the lesions were collected to isolate and identify fungi to support Koch’s postulates.

3. Results

3.1. Phylogenetics

For the phylogenetic inference of Ceratocystiopsis, ITS, Tub2, and combined (ITS + Tub2) datasets were constructed. For the combined dataset, the p-value of the homogeneity test is 0.029 (>0.01). The best models for the three datasets were estimated and applied in the BI as GTR+I+G (ITS, Tub2, and combined datasets). Alignments for the ITS and Tub2 datasets contained 679 and 550 characters (including gaps), respectively. The combined datasets included 31 sequences, representing 19 taxa with 1229 positions, including gaps. Our strains formed a separate branch with high node supports and were separated from a branch containing multiple species (C. minima, C. minuta, C. weihaiensis, and Ceratocystiopsis sp. 2) based on the phylogenetic trees of the combined datasets (Figure 1) and ITS datasets (Supplementary Materials Figure S1). In the phylogenetic analyses based on the individual Tub2 datasets, our strains clustered within a separate lineage with good supports (Supplementary Materials Figure S2).

3.2. Taxonomy

Ceratocystiopsissubelongati Z. Wang and Q. Lu, sp. nov. (Figure 2) MycoBank: MB 841972.
Etymology: The name is based on the vector (Ips subelongatus) from which this fungus was associated.
The sexual state was not observed. The asexual state is hyalorhinocladiella- to sporothrix-like. Sporothrix- to hyalorhinocladiella-like: Conidiophores mononematous, simple, upright or flexuous, arising from vegetative hyphae. Conidiogenous cells hyaline, blastic, not denticulate or occasionally denticulate, sometimes arising directly from hyphae, (12.7–) 15.6–31.8 (−48.0) × (1.2–) 1.3–1.7 (−2.0) μm. Conidia hyaline, smooth, clavate to ovate, and aseptate, (3.0–) 3.3–4.4 (−5.1) × (2.0–) 2.1–2.6 (−3.0) μm.
Culture characteristics: Colonies on 2% MEA initially hyaline, later becoming pure white, aerial mycelium sparse, and the colony margin thins radially, reaching 52 mm in diameter in 22 days, at 25 °C. The optimal temperature for growth was 30 °C, and no growth was observed at 5 or 40 °C.
Habitat: Mixed forest of Pinus sylvestris var. mongolica and Larix gmelinii.
Host tree: Pinus sylvestris var. mongolica.
Distribution: Inner Mongolia, China.
Type. CHINA, Inner Mongolia, Hulunbuir City, Hailar national forest park (43°45′16″ N, 125°27′48″ E), from Ips subelongatus infesting Pinus sylvestris var. mongolica, August 2010, Z. Wang and Q. Lu, holotype CXY2015, ex-holotype CFCC52689.
Notes: Ceratocystiopsis subelongati is characterized by a hyalorhinocladiella- to sporothrix-like asexual morph (Figure 2)—different from its sister taxon, C. minima (Figure 1 and Supplementary Materials Figure S1), which develops a hyalorhinocladiella-like asexual morph [49]. Different shapes of conidia are produced in C. subelongati (clavate to ovate) and C. minima (ellipsoid, cylindrical, clavate, or oblong). Although the phylogenetic relationships between C. subelongati and C. minima are very close, the hosts and distributions of the two differ markedly, with the latter being isolated from Pinus banksiana in Canada [49]. Ceratocystiopsis minuta was ever isolated from I. subelongatus infesting Larix kaempferi in Japan [50]; however, both species are distantly related in phylogenetic analyses (Figure 1 and Supplementary Materials Figures S1 and S2). It differs in hosts from C. subelongati (L. kaempferi vs. P. sylvestris var. mongolica), as well as in the shapes of the conidia (ellipsoidal or cylindrical; oblong or ovoid vs. clavate to ovate), and optimal temperature (20 and 22 °C vs. 30 °C) [49].

3.3. Pathogenicity

Two months after inoculation, although none of the three inoculated larch trees showed visual symptoms, 13.33 ± 0.58 mm × 14.0 ± 2.00 mm lesions were caused by C. subelongati under the bark in and around the site of inoculation, which was significantly different from the control (Table 2 and Supplementary Materials Figure S3). The inoculated fungus was easily re-isolated from the necrotic lesions, but it was not isolated from healthy tissue or control treatments inoculated with MEA plugs.

4. Discussion

In this study, Ceratocystiopsis subelongati was accurately identified and described based on the phylogenetic inference of multi-gene DNA sequences and morphological characteristics. Pathogenicity tests showed that this fungus was pathogenic to five-year-old L. olgensis in the field. Due to the lack of reference sequences of related species, this species was represented as C. cf. pallidobrunnea in a previous study by Wang et al. [20]. Since then, the availability and publication of ITS and Tub2 of C. pallidobrunnea [17] have made it possible to compare. Phylogenetic analysis based on ITS and Tub2 datasets showed that C. subelongati and C. pallidobrunnea were far related, which contradicted the results based on LSU dataset [20]. This is probably because the LSU sequence of C. pallidobrunnea available is incomplete—only 562 bp (GenBank accession number: EU913682)—and a large number of gaps after alignment may bring errors to phylogenetic analysis. For Ceratocystiopsis, DNA sequences available for phylogenetic analysis in public databases, such as GenBank, remain limited. For example, only incomplete LSU sequences were available for C. concentrica and C. parva. Therefore, there is an urgent need for multi-gene sequencing of type strains of different species in this genus to re-evaluate their taxonomic status. In addition, we sequenced the TEF1-α gene region of C. subelongati and presented it in the Supplementary Materials (named TEF1-α sequences).
Ips subelongatus is mainly distributed in China, Japan, Mongolia, North Korea, Russia, and South Korea [51]. In China, it has been recorded in ten northern provinces [51,52]. Twenty-two species of ophiostomatoid fungi have been so far reported to associate with this beetle, but the investigation was only based on four northeastern provinces [20,36,53,54,55,56]. There are likely to be more ophiostomatoid fungi associated with I. subelongatus awaiting discovery, especially in the vast coniferous forests of Northwest China.
To date, six species of ophiostomatoid fungi associated with I. subelongatus have been subjected to pathogenicity tests in China. Endoconidiophora fujiensis can cause lesions >70 cm in length in L. kaempferi over 2 months but are weakly virulent in the three local larches (L. principis-rupprechtii, L. gmelinii, and L. olgensis) [20]. Consistently, under artificial inoculation, the fungus demonstrated the ability to kill 30-year-old Japanese larch trees (L. kaempferi) within 3.5 months in Japan [50,57]. Endoconidiophora fujiensis seems to be the most threatening pathogenic fungi associated with I. subelongatus to its host conifers. Three Leptographium species (L. innermongolicum, L. taigense, and L. zhangii) and one Ophiostoma species (O. olgensis) have also been shown to be weakly virulent in different larch trees [55,56]. In this study, C. subelongati was weakly pathogenic to larch trees, either.
The ophiostomatoid fungi are well-known as symbionts of numerous bark beetles, playing roles of synergistically overcoming host defenses, nutrition suppliers, and regulating beetle behavior. Most Ceratocystiopsis species are recorded to associate with bark beetles infecting conifers. Among them, only C. brevicomi has been shown to be mutualistic with Dendroctonus brevicomis [58] and is involved in cascading speciation among P. ponderosa–D. brevicomis fungal mutualists (C. brevicomi and Entomocorticium sp. B) [59]. Thus, the role of other Ceratocystiopsis species in the evolution and lifecycle of bark beetles, as well as their pathogenicity in plants, remains to be studied.

Supplementary Materials

The following are available online at https://www.mdpi.com/article/10.3390/f12121795/s1. Figure S1: Phylogram of Ceratocystiopsis spp. based on based on ITS sequence data. Bold branches indicate posterior probability values ≥ 0.9. Bootstrap values of ML/MP ≥ 70% are recorded at nodes. T = ex-type isolates. * Bootstrap values < 70%. Figure S2: Phylogram of Ceratocystiopsis spp. based on Tub2 sequence data. Bold branches indicate posterior probability values ≥ 0.9. Bootstrap values of ML/MP ≥ 70% are recorded at nodes. T = ex-type isolates. * Bootstrap values < 70%. Figure S3: Symptoms developed in the trunk of Larix olgensis inoculated with Ceratocystiopsis subelongati two months after inoculation. (A) Inoculation of C. subelongati and (B) control.

Author Contributions

Conceptualization, Z.W., Z.L. and Q.L.; methodology, Z.W., Y.L. and Q.L.; software, Z.W. and Y.L.; validation, Z.W., Z.L. and Q.L.; formal analysis, Z.W., C.L. and Y.L.; investigation, Z.W., Y.L. and L.L.; resources, Z.W., Z.L. and Q.L.; data curation, Z.W., Y.L. and Q.L.; writing—original draft preparation, Z.W.; writing—review and editing, Q.L.; visualization, Z.W.; supervision, Q.L.; project administration, Q.L.; funding acquisition, Q.L. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the National Natural Science Foundation of China (Project No. 31770682, 32071769).

Data Availability Statement

The data presented in this study are openly available from GenBank.

Acknowledgments

We would like to thank Nianzhao Wang and Xiangying Li from Shandong Agricultural University for their help in the experimental process.

Conflicts of Interest

The authors declare no conflict of interest.

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Forests 12 01795 g001 550
Figure 1. Phylogram of Ceratocystiopsis spp. based on combined (ITS + Tub2) sequence data. Bold branches indicate posterior probability values ≥ 0.9. Bootstrap values of ML/MP ≥ 70% are recorded at nodes. T = ex-type isolates. * Bootstrap values < 70%.
Figure 1. Phylogram of Ceratocystiopsis spp. based on combined (ITS + Tub2) sequence data. Bold branches indicate posterior probability values ≥ 0.9. Bootstrap values of ML/MP ≥ 70% are recorded at nodes. T = ex-type isolates. * Bootstrap values < 70%.
Forests 12 01795 g001
Forests 12 01795 g002 550
Figure 2. Morphological characteristics of Ceratocystiopsis subelongati: (A) 22-day-old culture on MEA, (B–D) conidiogenous cells of sporothrix- to hyalorhinocladiella-like asexual morph and conidia, and (E) conidia. Scale bars: (B–D) = 10 μm.
Figure 2. Morphological characteristics of Ceratocystiopsis subelongati: (A) 22-day-old culture on MEA, (B–D) conidiogenous cells of sporothrix- to hyalorhinocladiella-like asexual morph and conidia, and (E) conidia. Scale bars: (B–D) = 10 μm.
Forests 12 01795 g002
Table
Table 1. Information of strains used for phylogenetic analysis in this study.
Table 1. Information of strains used for phylogenetic analysis in this study.
Species Name 1Strain Number 2,3Host 4Vector 5OriginGenBank Accession No. 6
ITSTub2
Ceratocystiopsis brevicomiCBS333.97UnknownDendroctonus brevicomisUSAEU913722EU913761
C. colliferaCBS126.89Pinus teocoteD. valensMexicoEU913721EU913760
C. longisporaUM48P. banksianaUnknownCanadaEU913723-
C. lunataCMW55897UnknownXylosandrus crassiusculusSouth AfricaMW028169MW066754
CMW55898UnknownX. crassiusculusSouth AfricaMW028170MW066755
C. manitobensisUM214P. resinosaUnknownCanadaEU913715EU913754
UM237P. resinosaBark beetleCanadaEU913714EU913753
C. minimaUM85P. resinosaBark beetleCanadaEU913701EU913740
C. minutaCBS116796Picea abiesIps typographusPolandEU913695EU913734
UM1532Pi. abiesI. typographusPolandEU913697EU913736
C. minuta-bicolorUM480P. contortaBark beetleCanadaEU913705EU913744
CBS635.66P. contortaIps sp.USAEU913706EU913745
C. pallidobrunneaUM51Populus tremuloidesUnknownCanadaMN901004MN901013
C. ranaculosaCBS216.88P. teocoteD. frontalisUSAEU913713EU913752
C. rollhansenianaUM110P. sylvestrisBeetleNorwayEU913719EU913758
UM113P. sylvestrisBeetleNorwayEU913718EU913757
C. subelongatiCFCC52689 TP. sylvestris var. mongolicaI. subelongatusChinaOL605962OL622040
CFCC52690P. sylvestris var. mongolicaI. subelongatusChinaOL605963OL622041
C. synnemataKFL16918DAPo. tremulaDr. alniPolandMN900988MN901009
KFL17718DAPo. tremulaDr. alniPolandMN900989MN901010
Ceratocystiopsis sp. 1WY13TX1-3P. contortaD. ponderosaeCanadaEU913707EU913746
WY21TX1-2P. contortaD. ponderosaeCanadaEU913708EU913747
Ceratocystiopsis sp. 2YCC329Larix kaempferiI. subelongatusJapanEU913711EU913750
YCC330L. kaempferiI. subelongatusJapanEU913710EU913749
Ceratocystiopsis sp. 3SWT1Pi. glaucaI. perturbatusCanadaEU913716-
SWT3Pi. glaucaI. perturbatusCanadaEU913717-
C. weihaiensisSNM634P. thunbergiiCryphalus piceaeChinaMW989412MZ019524
SNM639P. thunbergiiCr. piceaeChinaMW989413MZ019525
C. yantaiensisSNM582P. thunbergiiCr. piceaeChinaMW989410MZ019522
SNM650P. thunbergiiCr. piceaeChinaMW989411MZ019523
Ophiostoma ipsCBS137.36UnknownIps sp.USAEU913685EU913724
1 Species names in bold are novel species described in this study. 2 CFCC: China Forestry Culture Collection Center, Beijing, China. 3 T = ex-holotype isolate. 4 P., Pinus; Pi., Picea; Po., Populus; L., Larix. 5 Cr., Cryphalus; D., Dendroctonus; Dr., Dryocoetes; I., Ips; X., Xylosandrus. 6 ITS, the internal transcribed spacer regions 1 and 2 of the nuclear ribosomal DNA operon, including the 5.8S region; Tub2, the β-tubulin gene region (Tub2).
Table
Table 2. Lesions observed in the inner bark of Larix olgensis two months after inoculation with Ceratocystiopsis subelongati.
Table 2. Lesions observed in the inner bark of Larix olgensis two months after inoculation with Ceratocystiopsis subelongati.
Strain No.Length (mm)Wide (mm)
CFCC5268913.33 ± 0.5814.0 ± 2.00
Control11.00 ± 0.8211.3 ± 1.26
p-value0.0090.074
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Wang, Z.; Liu, Y.; Liu, C.; Liu, Z.; Liang, L.; Lu, Q. Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity. Forests 2021, 12, 1795. https://doi.org/10.3390/f12121795

AMA Style

Wang Z, Liu Y, Liu C, Liu Z, Liang L, Lu Q. Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity. Forests. 2021; 12(12):1795. https://doi.org/10.3390/f12121795

Chicago/Turabian Style

Wang, Zheng, Ya Liu, Caixia Liu, Zhenyu Liu, Lijun Liang, and Quan Lu. 2021. "Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity" Forests 12, no. 12: 1795. https://doi.org/10.3390/f12121795

APA Style

Wang, Z., Liu, Y., Liu, C., Liu, Z., Liang, L., & Lu, Q. (2021). Morphological and Phylogenetic Analyses Reveal a New Species of Ceratocystiopsis (Ophiostomataceae, Ophiostomatales) Associated with Ips subelongatus in Inner Mongolia (China) with Weak Host Pathogenicity. Forests, 12(12), 1795. https://doi.org/10.3390/f12121795

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