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Four new species of Trichoderma in the Harzianum clade from northern China
expand article infoXin Gu, Rui Wang, Quan Sun, Bing Wu§, Jing-Zu Sun§
‡ Ningxia University, Yinchuan, China
§ Chinese Academy of Sciences, Beijing, China
Open Access

Abstract

The Harzianum clade of Trichoderma comprises many species, which are associated with a wide variety of substrates. In this study, four new species of Trichoderma, namely T. lentinulae, T. vermifimicola, T. xixiacum, and T. zelobreve, were encountered from a fruiting body and compost of Lentinula, soil, and vermicompost. Their colony and mycelial morphology, including features of asexual states, were described. For each species, their DNA sequences were obtained from three loci, the internal transcribed spacer (ITS) regions of the ribosomal DNA, the gene encoding the second largest nuclear RNA polymerase subunit (RPB2), the translation elongation factor 1-α encoding gene (TEF1-α). The analysis combining sequences of the three gene regions distinguished four new species in the Harzianum clade of Trichoderma. Among them, T. lentinulae and T. xixiacum clustered with T. lixii, from which these new species differ in having shorter phialides and smaller conidia. Additionally, T. lentinulae differs from T. xixiacum in forming phialides with inequilateral to a strongly-curved apex, cultural characteristics, and slow growth on PDA. Trichoderma vermifimicola is closely related to T. simmonsii, but it differs from the latter by producing phialides in verticillate whorls and smaller conidia. Trichoderma zelobreve is the sister species of T. breve but is distinguished from T. breve by producing shorter and narrower phialides, smaller conidia, and by forming concentric zones on agar plates. This study updates our knowledge of species diversity of Trichoderma.

Keywords

compost, fungicolous, Hypocreaceae, mycoparasite

Introduction

The genus Trichoderma Pers., introduced by Persoon (1794), is cosmopolitan, including saprotrophs and mycoparasites in a diversity of ecosystems, such as agricultural fields, prairies, forests, salt marshes, and fungal fruiting body (Gazis and Chaverri 2010; Chaverri et al. 2015; Qiao et al. 2018). Species of this genus have been widely used in the biocontrol of plant pathogens (Chaverri et al. 2015; Degenkolb et al. 2015; Bunbury-Blanchette and Walke 2019) and production of enzymes and bioactive compounds (Sun et al. 2016). Nevertheless, some of them are associated with green mold diseases in the commercial production of mushrooms (Innocenti et al. 2019; Sun et al. 2019a) . Morphologically, the asexual-morphs are similar in producing branched tree-like conidiophores with cylindrical to nearly subglobose phialides and ellipsoidal to globose conidia, but their variation is insufficient to differentiate the Trichoderma species (Chaverri et al. 2015; Qin and Zhuang 2017; Qiao et al. 2018). Multilocus molecular phylogeny, based on combined sequence data of the internal transcribed spacer (ITS) regions, RNA polymerase II subunit (RPB2), and the translation elongation factor 1-α gene (TEF1-α), enables rapid and accurate identification of the Trichoderma species (Druzhinina et al. 2005; Atanasova et al. 2013; Chaverri et al. 2015). Currently, the combination of multi-gene phylogenetic analysis and phenotypic characteristics is extensively applied in species delimitation of Trichoderma (du Plessis et al. 2018; Qiao et al. 2018; Innocenti et al. 2019).

Trichoderma harzianum Rifai is one of the most well-known Trichoderma species, due to its antifungal properties and effective bio-control ability, used to suppress soil-borne plant pathogens (Chaverri et al. 2015; Degenkolb et al. 2015; Bunbury-Blanchette and Walker 2019). As a cosmopolitan and ubiquitous fungus, it has been isolated from diverse substrates, such as soil, plant tissue, and mushrooms (Chaverri et al. 2015; Jaklitsch and Voglmayr 2015; Innocenti et al. 2019; Sun et al. 2019b). Since Chaverri et al. (2015) provided a systematic revision of species in the Harzianum clade, numerous new species have been described (Jaklitsch and Voglmayr 2015; Qin and Zhuang 2016a; Sun et al. 2016; Chen and Zhuang 2017b; Qiao et al. 2018). Currently, more than 60 species are placed in the Harzianum clade (Jaklitsch and Voglmayr 2015; Qin and Zhuang 2016a, b, 2017; Chen and Zhuang 2017b; Qiao et al. 2018; Phookamsak et al. 2019;) .

It is estimated that 136 new species of Trichoderma have been recognised since 2015 (www.indexfungorum.org 2020), with 84 among these reported from China (Sun et al. 2012; Qin and Zhuang 2016a, b, 2017; Chen and Zhuang 2017a, b; Qiao et al. 2018), which evidenced that China has a high species diversity of Trichoderma (Zhu and Zhuang 2015; Jiang et al. 2016). In our survey of Trichoderma, eighteen isolates were obtained from soil, mushroom substrates, and vermicompost from northern China. Four new species belonging to the Harzianum clade were identified based on morphological features and DNA sequence data at three loci: the genes encoding RNA polymerase II subunit (RBP2) and translation elongation factor 1-α gene (TEF1-α), and the internal transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene.

Materials and methods

Sampling sites and strains isolation

Since Trichoderma is easily isolated from soil, mushroom substrates, and earthworm substrates, the soil, mushroom substrates, and earthworm were therefore collected from Yinchuan, Ningxia Hui Autonomous Region, and Chaoyang district, Beijing, China. All the samples were stored at 4 °C before fungal isolation. Trichoderma strains were isolated by gradient dilution and the spread plate method or directly from the mushroom substrates. Three dilutions (10-1, 10-2, and 10-3) were prepared with 1 g soil and sterile water, and 100 µl of each dilution was spread on a 9 cm diameter Petri dish of PDA agar with100 mg/L chloramphenicol added. The plates were then incubated at 25 °C. Each of the individual colonies was transferred to a new PDA dish after 1–3 days and incubated at 25 °C. Dried cultures from the single spore or specimens of new species were deposited in the Herbarium Mycologicum Academiae Sinicae (HMAS) and the ex-type strains were preserved in the China General Microbiological Culture Collection Center (CGMCC)

Morphological analysis

For morphological studies, we used three different media: cornmeal dextrose agar (CMD, Difco, BD Science, USA), PDA (Difco, BD Science, USA), and synthetic low nutrient agar (SNA, Difco, BD Science, USA) (Chaverri et al. 2015). Each strain was first cultured on an SNA plate for 3 days and a small agar piece of 0.5 cm diameter with mycelium was then transferred, respectively, to new CMD, PDA, and SNA plates. Strains were incubated in 9 cm diam with three replicates. Petri dishes at 25 °C with a 12 h natural light and 12 h darkness interval. Colony diameter at 25 °C was measured three days after inoculation, and the time when mycelium entirely covered the surface of the agar plate was also recorded. Micromorphological characters were examined from the cultures of one-week-old colonies on SNA (Chaverri et al. 2015). A Nikon Ellipse 80i light microscope, equipped with differential interference contrast (DIC) optics, was used to capture digital images.

DNA extraction, PCR and sequencing

Genomic DNA of each strain was extracted from fresh mycelium growing on PDA after 5 days of growth following the rapid “thermolysis” method described in Zhang et al. (2010). For the amplification of ITS, RPB2, and TEF1-α gene fragments, ITS4 and ITS5 for ITS (White et al. 1990), EF1-728F (Carbone and Kohn 1999) and TEF1LLErev (Jaklitsch et al. 2005) for TEF1, and RPB2-5F and RPB2-7R for rpb2 (Liu et al. 1999) were used. Each PCR reaction consisted of 12.5 μl T5 Super PCR Mix (containing Taq polymerase, dNTP, and Mg2+, Beijing TsingKe Biotech Co. Ltd., Beijing), 1.0 μl of forward primer (10 μM), 1.0 μl of reverse primer (10 μM), 0.5 μl DMSO, 3 μl DNA template and 7 μl double sterilized water. PCR reactions were in Eppendorf Mastercycler, following the protocols described by Sun et al. (2016). PCR products were purified with the PCR product purification kit (TIANGEN Biotech, Beijing, China), and sequencing was carried out in both directions on an ABI 3730 XL DNA sequencer (Applied Biosystems, Foster City, California) with primers used during PCR amplification.

Phylogenetic analyses

Preliminary BLAST searches with ITS, RPB2, and TEF1-α gene sequences of the new isolates against NCBI, TrichOKey (Druzhinina and Kopchinski 2006), and TrichoBlast (Kopchinskiy et al. 2005) databases identified species closely related to our isolates. Based on this information, sequences of ITS, RBP2, and TEF1-α of 133 strains, representing 59 species were downloaded from GenBank, following recent publications (Qin and Zhuang 2017; Qiao et al. 2018; Innocenti et al. 2019). Among them, 139 strains are belonging to the Harzianum clade, and Trichoderma ceramicum, T. parestonicum, and T. estonicum were chosen to represent the outgroup.

Tree alignment files were generated by using MAFFT version 7.03 with the Q-INS-I strategy (Katoh and Standley 2013). Conserved blocks were selected from the initial alignments with Gblocks 0.91 b (Castresana 2000). The appropriate nucleotide substitution model for each gene was determined by using MrModeltest v2.4 (Nylander 2004). HKY + I + G was estimated as the best-fit model for RPB2, and GTR + I + G was estimated as the best-fit model for TEF1-α and ITS under the output strategy of AIC. The partition homogeneity test (p = 0.01) indicated that the individual partitions were not significantly incongruent (Cunningham 1997), thus the aligned sequences of ITS, RPB2, and TEF1-α were combined for analyses. The multi-locus phylogenetic analyses included 1065 characters for RBP2, 587 characters for TEF1-α, and 555 characters for ITS. All characters were weighted equally and gaps were treated as missing characters.

Maximum Likelihood (ML) analyses were performed by RAxML (Stamatakis 2006), using the GTR-GAMMA-I model. The maximum likelihood bootstrap proportions (MLBP) were using 1000 replicates. Bayesian Inference (BI) analyses were conducted with MrBayes v3.2.6 (Ronquist et al. 2012). Metropolis-coupled Markov Chain Monte Carlo (MCMC) searches were calculated for 10,000,000 generations, sampling every 100th generation with the best best-fit model for each gene. Two independent analyses with six chains each (one cold and five heated) were carried out until the average standard deviation of the split frequencies dropped below 0.01. The initial 25% of the generations of MCMC sampling were discarded as burn-in. The refinement of the phylogenetic tree was used for estimating Bayesian inference posterior probability (PP) values. The Tree was viewed in FigTree v1.4 (Rambaut 2012), values of Maximum likelihood bootstrap proportions (MLBP) greater than 50% and Bayesian inference posterior probabilities (BIPP), greater than 95% at the nodes, are shown along branches. The final alignments and the trees obtained have been deposited in TreeBASE (TreeBASE accession number: 25400).

Results

Phylogeny

The preliminary BLAST searches with ITS, RPB2, and TEF1-α gene sequences of the new isolates suggest our isolates were highly similar to species from Trichoderma in the Harzianum-complex. Therefore, as the next step phylogenetic analyses were conducted by using a single gene of ITS, RPB2, TEF1-α, and multi-gene dataset of cascaded ITS, RPB2, and TEF1-α, respectively. The phylogenetic trees showed that our isolates were placed in the Harzianum clade (Fig. 1, Suppl. material 1: Fig. S1, Suppl. material 2: Fig. S2, Suppl. material 3: Fig. S3). In the phylogenetic tree conducted by a combined matrix of ITS, RPB2, and TEF1-α sequences, isolates of T. lentinulae, T. xixiacum, and T. lixii formed a well-supported clade (MLBP/BIBP = 73%/1.00). Within this clade, isolates of T. lentinulae and T. xixiacum formed a subclade with maximum support. Isolates of T. vermifimicola clustered together with T. simmonsii (BIBP = 1.00), both forming a subclade with maximum support (MLBP/BIBP = 100%/1.00, Fig. 1). Trichoderma zelobreve and T. breve, were distinguished by maximum support to respective clades while forming a highly supported clade (MLBP/BIBP = 100%/1.00, Fig. 1).

Figure 1. 

Phylogenetic tree based on Maximum Likelihood analysis of a combined ITS, RPB2, and TEF1α sequence dataset. Trichoderma estonicum, Trichoderm parastinicum, Trichoderm ceramicum were chosen as the outgroup. Bootstrap Values higher than 70% from RAxML (BSML) (left) and Bayesian posterior probabilities greater than 0.95 (BYPP) (right) are given above the nodes. T indicates the type; ET indicates the ex-living type. Isolates obtained in this study are in red.

Figure 1. 

Continued.

The ITS gene could not distinguish our isolates from other species within the Harzianum clade (Suppl. material 1: Fig. S1). In the phylogenetic tree resulted from the RPB2 gene, Trichoderma lentinulae, T. xixiacum, and T. lixii formed a highly supported clade (MLBP/BIBP = 100%/1.00), but within this clade, T. lentinulae, T. xixiacum were not distinguished (Suppl. material 2: Fig. S2). Isolates of T. vermifimicola formed a distinct clade (MLBP/BIBP = 100%/1.00) and grouped with T. simmonsii, T. guizhouense, and T. rugulosum but weakly supported (Suppl. material 3: Fig. S3). Trichoderma zelobreve and T. breve also formed a highly supported clade (MLBP/BIBP = 98%/1.00), but T. zelobreve and T. breve, were distinguished by maximum support to respective clades while forming a highly supported clade (MLBP/BIBP = 100%/1.00, Suppl. material 2: Fig. S2). In the phylogenetic tree resulted from the TEF1-α gene, T. zelobreve and T. breve also formed a highly supported clade (MLBP/BIBP = 98%/1.00), but were not distinct from each other (Suppl. material 3: Fig. S3). Isolates of T. lentinulae, T. xixiacum, T. vermifimicola, and T. simmonsii clustered together but this clade was not well-supported. Within this clade, isolates of T. lentinulae formed a well-supported subclade (MLBP/BIBP = 91%/1.00). Trichoderma xixiacum and T. vermifimicola formed a highly supported subclade (MLBP/BIBP = 100%/1.00). Within this group, isolates of T. vermifimicola clustered together with well-supported (MLBP/BIBP = 93%/1.00, Suppl. material 3: Fig. S3).

Taxonomy

Trichoderma lentinulae Jing Z. Sun & X.Z. Liu, sp. nov.

MycoBank No: 833233
Fig. 2

Etymology

Latin, lentinulae, refers to the host from which the fungus was isolated.

Type

China. Haidian District, Beijing, 39°57'40"N, 116°19'40"E, ca. 27 m elev., from a fruiting body and mushroom spawn of Lentinula edodes, 19 Oct 2018, Jing Z. Sun (HMAS 248256, holotype), ex-type culture CGMCC 3.19847.

Description

On CMD after 72 h, colony radius 57–58 mm at 25 °C, covering the plate at 30 °C, 4–5 mm at 35 °C. Colony hyaline, weak, indistinctly radial. Aerial hyphae short, inconspicuous. No diffusing pigment noted, odor indistinct (Fig. 2B). Conidial production noted after 3 days, scant, effuse in aerial hyphae, becoming blue-green after 7 days. Chlamydospores not observed.

On PDA after 72 h, colony radius 45–46 mm at 25 °C, mycelium covering the plate at 30 °C, 11–12 mm at 35 °C. Colony white to yellowish-white, regularly circular, indistinctly zonate; mycelium dense and radial. No diffusing pigment, not distinct odor (Fig. 2A). Conidial production noted after 3 days, starting around the original inoculum, effuse in the aerial hyphae, first white, turning green after 3 d. Chlamydospores unobserved.

Figure 2. 

Trichoderma lentinulae (CGMCC 3.19847). Cultures at 25 °C after 3 days (A on PDA B on CMD C on SNA) D conidiation pustules on CMD after 10 days E conidiation pustules on CMD after 10 d F conidiophores G–I Conidiophores and phialides J conidia K–M chlamydospores. Scale bars: 25 µm (F); 10 µm (G–M).

On SNA after 72 h, colony radius 51–52 mm at 25 °C, 52–53 mm at 30 °C, 4–5 mm at 35 °C. Colony hyaline, indistinctly zonate; mycelium loose, especially at the margin. Aerial hyphae loose. No diffusing pigment, not distinct odor (Fig. 2C). Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae. Small pustules formed around the inoculum, first white, turning green after 3 d, with hairs protruding beyond the surface. Conidiophores pyramidal with opposing branches, less frequently solitary, closely-spaced branches, each branch, and the main axis terminating in 2–5 cruciately to nearly verticillately disposed phialides (Fig. 2F, H, I). Phialides ampulliform, typically strongly constricted below the tip, less frequently lageniform and then usually apex and inequilateral to strongly curved, hyaline, (3.5–)4.0–6.0(–6.5) × (2.0–)2.5–3.0(–3.5) µm (= 4.5 × 3.0 μm, n = 30), length/width ratio (1.5–)2.0–3.0(–5.0) (= 2.0, n = 30), base 1.0–2.5 μm (= 1.5 μm)(Fig. 2G, H, I). Conidia ovoid to globose, smooth, hyaline when young, becoming green to dark green with age, (2.0–)2.5–3.0(–3.5) × (1.5–)2.0–2.5(–3.0) µm (= 2.5 × 2.2 μm, n = 50), length/width ratio (1.0–)1.1–1.4 (–1.5) (= 1.2, n = 50) (Fig. 2J). Chlamydospores common, apex or intercalary, ellipsoid or subglobose, (3.5–)5.0–6.5(–7.0) × (3.0–)4.0–5.0(–6.0) µm (= 5.5 × 4.5 μm, n = 30), length/width ratio (1.0–)1.2–1.5 (–1.7) (= 1.2, n = 30) (Fig. 2K–M).

Additional specimen examined

China. Haidian District, Beijing, 39°57'40"N, 116°19'40"E, ca. 27 m elev., From a fruiting body and mushroom spawn of Lentinula edodes, 19 Oct 2018, Jing Z. Sun, living culture CGMCC 3.19848; Xixia District, Yinchuan, Ningxia Hui Autonomous Region, 38°38'52"N, 106°9'33"E, ca. 1127 m elev., from rhizosphere soil of Lycium chinois, 17 Oct 2018, Jing Z. Sun, living culture CGMCC 3.19699; ibid., living culture CGMCC 3.19670.

Teleomorph

Undetermined.

Note

The species is characterized by tree-like conidiophores, phialides verticillate or in whorls of 3–4, spindle-like to fusiform phialides (4.0–6.0 × 2.5–3.0 μm) and ovoid to subglobose conidia. Differs from T. lixii by shorter and wider phialides and smaller conidia. Differs from Trichoderma xixiacum by compact, relatively smaller phialides, and the pustules not forming distinctly zonate of pustules on SNA.

Trichoderma vermifimicola Jing Z. Sun & X.Z. Liu, sp. nov.

MycoBank No: 833234
Fig. 3

Etymology

Latin, vermifimicola, refers to the habitat of the type species.

Type

China. Yongning, Yinchuan, the Ningxia Hui Autonomous Region, 40°0'41"N, 116°23'37"E, ca. 1678 m elev., from the substrates for earthworm cultivation, 18 Oct 2018, Jing Z. Sun (HMAS 248255, holotype), ex-type culture CGMCC 3.19694.

Description

On CMD after 72 h, colony radius 49–51 mm at 25 °C, 51–52 mm at 30 °C, 4–5 mm at 35 °C. Colony hyaline, irregularly circular, indistinctly zonate; mycelium loose. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. Conidial production noted after 3 days, starting around the inoculum (Fig. 3B). Small pustules formed at the colony margin, first white, turning blue-green after 7 d, with hairs protruding beyond the surface. Chlamydospores unobserved.

Figure 3. 

Trichoderma vermifimicola (CGMCC 3.19694). Cultures at 25 °C after 3 days (A on PDA B on CMD C on SNA) D conidiation pustules on CMD after 10 days E conidiation pustules on SNA after 10 d F, H conidiophores G, J, K conidiophores and phialides I conidia. Scale bars: 25 µm (F, H); 10 µm (G, J–K).

On PDA after 72 h, colony radius 55–58 mm at 25 °C, 55–56 mm at 30 °C, 5–6 mm at 35 °C. Colony white-green to bright green, regularly circular, distinctly zonate; mycelium dense and radial. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae, first white, turning green after 2 d (Fig. 3A). Chlamydospores unobserved.

On SNA after 72 h, colony radius 48–50 mm at 25 °C, 51–52 mm at 30 °C, 3–4 mm at 35 °C. Colony hyaline, regularly circular, distinctly zonate; mycelium loose, especially at the margin. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae. Small pustules formed along with two concentric rings, first white, turning yellow-green after 3 d, with hairs protruding beyond the surface (Fig. 3C). Conidiophores pyramidal with opposing branches, the distance between branches relatively large, each branch terminating in a whorl of 2–3 phialides, phialides sometimes solitary on the main axis (Fig. 3F, H, K); whorls typically cruciate, but often nearly verticillate (Fig. 3K); rarely conidiophores nodose and phialides disposed in more or less botryose clusters (Fig. 3H). Phialides ampulliform to lageniform, often constricted below the tip to form a narrow neck, hyaline, (4.4–)5.0–10.5(–11.2) × (2.0–)2.5–3.0(–3.5) µm (= 6.6 × 2.7 μm, n = 30), length/width ratio (1.5–)1.8–2.8(–5.3) (= 2.4, n = 30), base 1.6–2.5 μm (= 1.9 μm) (Fig. 3G, I, K). Conidia ovoid to subglobose, smooth, hyaline when young, becoming green to dark green with age, (2.0–)2.3–2.6(–3.0) × (1.5–)2.0–2.4(–2.8) µm (= 2.4 × 2.2 μm, n = 50), length/width ratio (1.0–)1.1–1.4(–1.7) (= 1.2, n = 50) (Fig. 3J). Chlamydospores unobserved. No odor; no diffusing pigment observed.

Additional specimen examined

China. Xixia District, Yinchuan, Ningxia Hui Autonomous Region, 38°38'52"N, 106°9'33"E, ca. 1127 m elev., from rhizosphere soil of Lycium chinois, 17 Oct 2018, Jing Z. Sun, living CGMCC 3.19697.

Teleomorph

Undetermined.

Note

Characterized by tree-like conidiophores, verticillate or in whorls of 3–4, ampulliform to lageniform phialides (5.0–10.5 × 2.5–3.0 μm), ovoid to subglobose conidia (2.4–2.6 × 2.0–2.5 μm). Differs from Trichoderma simmonsii by forming loose branches in whorls, relatively longer and thinner phialides, smaller conidia, and the fewer pustules on SNA.

Trichoderma xixiacum Jing Z. Sun & X.Z. Liu, sp. nov.

MycoBank No: 833235
Fig. 4

Etymology

Latin, xixiacum, refers to the type locality.

Type

China. Xixia District, Yinchuan, Ningxia Hui Autonomous Region, 38°38'52"N, 106°9'33"E, ca. 1127 m elev., from rhizosphere soil of Lycium chinois, 17 Oct 2018, Jing Z. Sun (HMAS 248253, holotype), ex-type culture CGMCC 3.19697.

Description

On CMD after 72 h, colony radius 55–56 mm at 25 °C, covering the plate at 30 °C, 9–11 mm at 35 °C. Colony hyaline, indistinctly zonate, mycelia loose. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor (Fig. 4B). Conidial production noted after 3 days, effuse in aerial hyphae, becoming blue-green after 4 days. Chlamydospores unobserved.

Figure 4. 

Trichoderma xixiacum (CGMCC 3.19697). Cultures at 25 °C after 3 d (A on PDA B on CMD C on SNA) D conidiation pustules on CMD after 10 d E conidiation pustules on SNA after 10 d F, G, I conidiophores and phialides H conidia. Scale bars: 10 µm (F, G); 10 µm (H, I).

On PDA after 72 h, colony radius 59–60 mm at 25 °C, covering the plate at 30 °C, 7–8 mm at 35 °C. Colony white to yellow-white, regularly circular, indistinctly zonate; mycelium dense and radial. Aerial hyphae conspicuous. No diffusing pigment, not distinct odor (Fig. 4A). Conidial production noted after 3 days, starting around the original inoculum, effuse in the aerial hyphae, first white, turning blue-green after 7 d. Chlamydospores unobserved.

On SNA after 72 h, colony radius 51–52 mm at 25 °C, 52–53 mm at 30 °C, 4–5 mm at 35 °C. Colony hyaline, indistinctly zonate; mycelium loose, especially at the margin. Aerial hyphae short. No diffusing pigment, not distinct odor (Fig. 4C). Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae. Small pustules formed around the inoculum, first white, turning green after 3 d, with hairs protruding beyond the surface. Conidiophores pyramidal with opposing branches, less frequently solitary, closely-spaced branches, each branch, and the main axis terminating in 2–5 cruciately to nearly verticillately disposed phialides (Fig. 4F, G, I). Phialides ampulliform to lageniform, often constricted below the tip to form a narrow neck, hyaline, (3.2–)3.5–7.0(–9.3) × (2.3–)2.6–3.3(–3.6) µm (= 5.0 × 3.0 μm, n = 50), length/width ratio (1.2–)1.5–2.5(–4) (= 1.8, n = 50), base 1.6–2.2 μm (= 1.8 μm, n = 50) (Fig. 4I). Conidia subglobose to globose, smooth, hyaline when young, becoming green to dark green with age, (2.0–)2.3–2.7(–3.0) × (1.6–)2.0–2.6(–3.0) µm (= 2.5 × 2.2 μm, n = 50), length/width ratio 1.0–1.3(–1.7) (= 1.1, n = 50) (Fig. 4H). Chlamydospores unobserved. No odor; no diffusing pigment observed.

Additional specimen examined

China. Xixia District, Yinchuan, Ningxia Hui Autonomous Region, 38°38'52"N, 106°9'33"E, ca. 1127 m elev., from rhizosphere soil of Lycium chinois, 17 Oct 2018, Jing Z. Sun, living CGMCC 3.19697.

Teleomorph

Undetermined.

Note

Characterized by tree-like conidiophores, verticillate or in whorls of 3–4, ampulliform to lageniform phialides (3.5–7.0 × 2.6–3.4 μm), subglobose to globose conidia (2.2–2.6 × 2.0–2.4 μm). Differs from Trichoderma lentinulae by compact, relatively smaller phialides, and the character of pustules on SNA. Differs from Trichoderma lixii by shorter and wider phialides and smaller conidia.

Trichoderma zelobreve Jing Z. Sun & X.Z. Liu, sp. nov.

MycoBank No: 833236
Fig. 5

Etymology

Greek zelo, meaning emulation + breve, referred to Trichoderma breve.

Type

China. Chaoyang District, Beijing, 40°0'41"N, 116°23'37"E, ca. 35 m elev., 19 Oct 2018, isolated from soil, Jing Z. Sun (HMAS 248254, holotype), ex-type culture CGMCC 3.19695.

Description

On CMD after 72 h, colony radius covering the plate at 25 °C and 30 °C, 11–12 mm at 35 °C. Colony hyaline, indistinctly radial; Aerial inconspicuous. No diffusing pigment, not distinct odor (Fig. 5B). Conidial production noted after 5 days, starting around the original inoculum. Small pustules formed at the colony margin, first white, olivaceous after 6 d, with hairs protruding beyond the surface. Chlamydospores unobserved.

On PDA after 72 h, colony radius 55–58 mm at 25 °C, covering the plate at 30 °C, 8–9 mm at 35 °C. Colony white to yellow-white; mycelium dense and radial. Aerial conspicuous. No diffusing pigment, not distinct odor (Fig. 5A). Conidial production noted after 3 days, starting around the inoculum, effuse in the aerial hyphae, first white, turning green after 4 d. Chlamydospores unobserved.

Figure 5. 

Trichoderma zelobreve (CGMCC 3.19695). Cultures at 25 °C after 3 days (A on PDA B on CMD C on SNA) D conidiation pustules on CMD after 10 days E conidiation pustules on SNA after 10 d F conidiophores G, I conidiophores and phialides H phialides with conidia J conidia. Scale bars: 25 µm (F); 10 µm (G–J).

On SNA after 72 h, colony radius 62–63 mm at 25 °C, covering the plate at 30 °C, 7–8 mm at 35 °C. Colony hyaline, regularly circular; mycelium loose. Aerial conspicuous. No diffusing pigment, not distinct odor (Fig. 5A). Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae. Small pustules formed along with two concentric rings, first white, turning yellow-green after 3 d, with hairs protruding beyond the surface. Conidiophores pyramidal with opposing branches, the distance between branches relatively large (Fig. 5F). Phialides, sometimes solitary, often paired or in whorls of 2–3 (Fig. 5F); whorls typically cruciate but often nearly verticillate; rarely conidiophores nodose and phialides disposed in more or less botryose clusters (Fig. 5G, H). Phialides ampulliform to lageniform, often constricted below the tip to form a narrow neck, hyaline (Fig. 5G, H, I), (3.5–)4.0–6.0(–7.0) × (2.2–)2.6–3.2(–3.5) µm (= 4.8× 2.9 μm, n = 30), length/width ratio (1.1–)1.4–2.1(–2.5) (= 1.5, n = 30), base 1.4–2.1 μm (= 1.7 μm). Conidia ovoid to subglobose, smooth, hyaline when young, becoming green to dark green with age, (2.0–)2.3–2.6(–2.9) × (1.5–)1.8–2.2(–2.5) µm (= 2.4 × 2.0 μm, n = 30), length/width ratio (0.8–)1.1–1.4(–1.7) (= 1.2, n = 30) (Fig. 5J). Chlamydospores unobserved.

Additional specimen examined

China. Chaoyang District, Beijing, 40°0'41"N, 116°23'37"E, ca. 35 m elev., isolated from soil, 19 Oct 2018, Jing Z. Sun, living culture CGMCC 3.19696.

Teleomorph

Undetermined.

Note. Characterized by tree-like conidiophores, branches paired or in whorls of 3–4, ampulliform to lageniform (4.0–6.0 × 2.6–3.2 μm), ovoid to subglobose conidia (2.2–2.6 × 1.8–2.2 μm). Differs from Trichoderma breve by shorter phialides and smaller conidia, as well as the cultural characteristics and growth rates.

Discussion

A combination of phylogenetic, morphological, ecological, and biogeographical data has robustly resolved the taxonomy of Trichoderma (Jaklitsch and Voglmayr 2015; Qin and Zhuang 2016a; Sun et al. 2016; Chen and Zhuang 2017b; Qiao et al. 2018). In this study, phylogenetic analysis based on a single gene of ITS could not distinguish species of Trichoderma in the Harzianum clade from each other (Suppl. material 1: Fig. S1), which confirmed that the ITS region is not suitable for species delimitation of Trichoderma (Jaklitsch et al. 2012; Qin et al. 2018). Sequences of RPB2 and TEF1-α were powerful due to their suitable interspecific variations (Jaklitsch and Voglmayr 2015), and these have extensively been used in solving the taxonomy of Trichoderma (Jaklitsch and Voglmayr 2015; Qin and Zhuang 2016a; Chen and Zhuang 2017a, b; Qiao et al. 2018). Despite the phylogenetic analyses based on the single gene of RPB2 and TEF1-α generally revealed the phylogenetic relationship within the Harzianum clade (Suppl. material 1: Fig. S2, Suppl. material 3: Fig. S3), but the relationships among T. lentinulae, T. xixiacum, T. vermifimicola, T. zelobreve, and their closed taxa were not well distinct. Consideration of the universality and reliability of barcodes for species in the Trichoderma genus (Qiao et al. 2018), combined ITS, RPB2, and TEF1-α dataset was used for phylogenetic analysis in this study, revealing phylogenetic relationship among species in Harzianum clades, and suggesting that T. lentinulae, T. xixiacum, T. vermifimicola, and T. zelobreve are distinguishable from each other and species within and outside of Harzianum clade as well.

Table 1.

Species, strains and their corresponding GenBank accession numbers of sequences used for phylogenetic analyses.

Species Voucher/ culture Nos. Origin Substrate GenBank accession No.
ITS RPB2 TEF1-a
Trichoderma afarasin CBS 130755 ET Cameroon Soil AY027784 AF348093
DIS 314F Cameroon Wood FJ442259 FJ442778 FJ463400
GJS 06 98 Cameroon Soil FJ442630 FJ463327
Trichoderma afroharzianum CBS 124620 ET Peru Moniliophthora roreri FJ442265 FJ442691 FJ463301
CBS 466.94 Netherlands KP009262 KP009150 KP008851
GJS 04-193 Cameroon Soil FJ442233 FJ442709 FJ463298
Trichoderma aggressivum CBS 100525 UK Mushroom compost AF057600 AF545541 AF348095
DAOM 222156 ET Mushroom compost AF456924 FJ442752 AF348098
CBS 100526 Ireland Mushroom compost FJ442607 KP009166 KP008993
Trichoderma alni CBS 120633 ET UK, England Alnus glutinosa EU518651 EU498349 EU498312
CPK 2494 EU518652 EU498350 EU498313
HMAS 252890 KT343763 KT343758
Trichoderma alpinum HMAS 248821 T China, Sichuan Soil KY687906 KY687958 KY688012
HMAS 248830 KY687912 KY687961 KY688015
HMAS 248870 KY687953 KY687963 KY688017
Trichoderma amazonicum CBS 126898 ET Peru Hevea brasiliensis HM142358 HM142367 HM142376
IB95 HM142359 HM142368 HM142377
LA265 HM142360 HM142369 HM142379
Trichoderma atrobrunneum GJS 05-101 FJ442677 FJ442745 FJ463392
GJS 90-254 AF443926 FJ442735 AF443943
Trichoderma atrogelatinosum BMCC LU498 New Zealand KJ871087
CBS 237.63 ET New Zealand MH858272 KJ842201
DAOM 167632 KJ871083
Trichoderma bannaense HMAS 248840 T China, Yunan Soil KY687923 KY687979 KY688037
HMAS 248865 KY687948 KY688003 KY688038
Trichoderma breve HMAS 248844 T China, Beijing Soil KY687927 KY687983 KY688045
HMAS 248845 KY687928 KY687984 KY688046
Trichoderma brevicrassum HMAS 248871 T Soil KY687954 KY688008 KY688064
HMAS 248872 Soil KY687955 KY688009 KY688065
Trichoderma brunneoviride CBS 120928 EU518661 EU498358 EU498318
CBS 121130 ET EU518659 EU498357 EU498316
Trichoderma camerunense CBS 137272 ET Cameroon Soil AY027780 AF348107
GJS 99 231 AY027783 AF348108
Trichoderma catoptron DAOM 232830 KJ842166 KJ871245
GJS 02 76 ET Sri Lanka Wood AY737766 AY737726
Trichoderma ceramicum CBS 114576 FJ860743 FJ860531 FJ860628
Trichoderma cerinum BMCC LU784 KJ871244
DAOM 230012 ET Nepal KC171336 KJ842184 KJ871242
Trichoderma christiani CBS 132572 ET Spain KJ665244 KJ665439
S93 KJ665245 KJ665442
Trichoderma cinnamomeum GJS 96-128 AY391916 AY391977
GJS 97-233 AY391919 AY391978
Trichoderma cinnamomeum GJS 97-237 ET USA, Missour Decaying wood AY737759 AY391920 AY737732
Trichoderma compactum CBS 121218 AY941822 KF134789 KF134798
Trichoderma concentricum HMAS 248833 T China, Hubei Soil KY687915 KY687971 KY688027
HMAS 248858 KY687941 KY687997 KY688028
Trichoderma corneum GJS 97-82 ET Thailand KJ665252 KJ665455
Trichoderma endophyticum CBS 130729 ET Ecuador Theobroma gileri FJ442243 FJ463319
GS 2014a FJ884177 FJ967822
Trichoderma epimyces CBS 120534 ET Austria EU518663 EU498360 EU498320
CPK 1980 EU518662 EU498359 EU498319
CPK 2487 ET EU518665 EU498361 EU498322
Trichoderma estonicum GJS 96-129 AY737767 AF545514 AF534604
Trichoderma guizhouense DAOM 231435 EF191296 EF191321
HGUP0038 T JN191311 JQ901400 JN215484
S628 KJ665273 KJ665511
Trichoderma harzianum CBS 226.95 ET U.K. Soil AJ222720 AF545549 AF348101
CBS 227.95 AF057605 AF348100
GJS 05 107 FJ442679 FJ442708 FJ463329
IMI 359823 EF113587 AF348092
Trichoderma hausknechtii CBS 133493 France KJ665276 KJ665515
Trichoderma helicolixii CBS 133499 ET Spain KJ665278 KJ665517
Trichoderma helicolixii CBS 135583 KJ665277 KJ665516
Trichoderma hengshanicum HMAS 248852 T China, Hubei Soil KY687935 KY687991 KY688054
HMAS 248853 KY687936 KY687992 KY688055
Trichoderma hirsutum HMAS 248834 T China, Hubei Soil KY687916 KY687972 KY688029
HMAS 248859 KY687942 KY687998 KY688030
Trichoderma hunanense HMAS 248841 T China, Hunan Soil NR_154571 KY687980 KY688039
HMAS 248867 KY687950 KY688005 KY688040
Trichoderma ingratum HMAS 248822 T China, Sichuan Soil KY687917 KY687973 KY688018
HMAS 248827 KY687909 KY687966 KY688021
HMAS 248873 KY687956 KY688010 KY688022
Trichoderma inhamatum CBS 273.78 ET Colombia Soil FJ442680 FJ442725 AF348099
Trichoderma italicum CBS 132567 KJ665282 KJ665525
S15 ET Italy KJ665283 KJ665526
Trichoderma lentiforme CBS 100542 ET French Guiana Decorticated wood AF469189 AF469195
DIS 253B FJ442619 FJ442756 FJ851875
DIS 94D FJ442615 FJ442749 FJ463379
Trichoderma lentinulae HMAS 248256 T China Lentinula MN594469 MN605867 MN605878
CGMCC 3.19848 China Lentinula MN594470 MN605868 MN605879
CGMCC 3.19849 China Lentinula MN594471 MN605869 MN605880
CGMCC 3.19699 China Soil MN594478 MN605876 MN605887
CGMCC 3.19670 China Soil MN594479 MN605877 MN605888
Trichoderma liberatum HMAS 248831 T China,Hubei Soil KY687913 KY687969 KY688025
Trichoderma liberatum HMAS 248832 KY687914 KY687970 KY688026
Trichoderma linzhiense HMAS 248846 T China, Tibet Soil KY687929 KY687985 KY688047
HMAS 248874 KY687957 KY688011 KY688048
Trichoderma lixii CBS 110080 ET Thailand Decayed Ganoderma AF443920 KJ665290 AF443938
Trichoderma neotropicale LA11 ET HQ022407 HQ022771
T51 FJ884180 FJ967825
Trichoderma parestonicum CBS 120636 ET FJ860803 FJ860565
Trichoderma parepimyces CBS 122768 FJ860801 FJ860563 FJ860665
CBS 122769 ET Austria Wood MH863234 FJ860562 FJ860664
Trichoderma perviride HMAS 273786 China,Hubei Wood KX026962 KX026954
Trichoderma pinicola KACC 48486 ET Korea root of Pinus densiflora MH050354 MH025993 MH025981
SFC20130926-S014 MH025991 MH025978
SFC20130926-S111 MH025992 MH025980
Trichoderma pleuroti CBS 124387 ET Korea Pleurotus substrate HM142363 HM142372 HM142382
CPK 2117 EU279975
Trichoderma pleuroticola CBS 124383 ET Korea Pleurotus substrate HM142362 HM142371 HM142381
GJS 95 81 AF345948 AF348102
TRS70 ET KP009264 KP009172 KP008951
Trichoderma polypori HMAS 248855 T Hunan Soil KY687938 KY687994 KY688058
HMAS 248861 KY687944 KY688000 KY688059
Trichoderma polysporum S72 KJ665685
Trichoderma priscilae CBS 131487 ET Spain KJ665333 KJ665691
Trichoderma pseudodensum HMAS 248828 T Hubei Soil KY687910 KY687967 KY688023
HMAS 248829 KY687911 KY687968 KY688024
Trichoderma pseudogelatinosum CNUN309 ET Japan Shiitake mushroom HM769754 HM920173 HM920202
Trichoderma purpureum HMAS 273787 T China,Hubei KX026961 KX026953
Trichoderma pyramidale CBS 135574 ET Italy Olea europaea KJ665334 KJ665699
Trichoderma rifaii CBS 130746 Ecuador Theobroma gileri FJ442663 FJ463324
DIS 337F ET FJ442621 FJ442720 FJ463321
Trichoderma rufobrunneum HMAS 266614 T China,Jilin Rotten wood KF729998 KF730010 KF729989
isolate 8155 KF730007 KF729992
Trichoderma rugulosum SFC20180301-001 T MH050353 MH025986 MH025984
SFC20180301-002 MH025987 MH025985
Trichoderma simmonsii CBS 130431 USA, Maryland Decaying wood bark AF443917 FJ442757 AF443935
S297 KJ665711
S7 KJ665337 KJ665719
Trichoderma simplex HMAS 248842 T China, Guangxi Soil KY687925 KY687981 KY688041
HMAS 248860 KY687943 KY687999 KY688042
Trichoderma solum HMAS 248847 KY687930 KY687986 KY688049
HMAS 248848 T China, Hubei Soil KY687931 KY687987 KY688050
HMAS 248849 KY687932 KY687988 KY688051
Trichoderma stramineum CBS 114248 ET Sri Lanka Decaying wood AY737765 AY391945 AY737746
TAMA 0425 AB856609 AB856748 AB856675
Trichoderma tawa CBS 114233 ET Thailand Decaying bark AY737756 AY391956 FJ463313
DAOM 232841 KJ842187 EU279972
Trichoderma tenue HMAS 273785 ET China,Hubei Wood KX026960 KX026952
Trichoderma tomentosum DAOM 171918 AY605715 AY605759
DAOM 178713a ET Canada, Ontario Ulmus wood EU330958 AF545557 AY750882
DAOM 234236 EU280083 EU279971
Trichoderma velutinum DAOM 230013 ET Nepal Soil AF149873 JN133569 AY937415
HMAS 273865 T China, Heilongjiang Soil KX026965 KX026957
Trichoderma vermifimicola CGMCC 3.19850 China Compost MN594472 MN605870 MN605881
HMAS 248255 T China Compost MN594473 MN605871 MN605882
Trichoderma xixiacum HMAS 248253 T China Soil MN594476 MN605874 MN605885
CGMCC 3.19698 China Soil MN594477 MN605875 MN605886
Trichoderma zayuense HMAS 248835 T China,Tibet Soil KY687918 KY687974 KY688031
HMAS 248836 KY687919 KY687975 KY688032
Trichoderma zelobreve HMAS 248254 T China Mushroom MN594474 MN605872 MN605883
CGMCC 3.19696 China Soil MN594475 MN605873 MN605884
Trichoderma zeloharzianum YMF 1.00268 ET China,Yunan Soil MH113932 MH158996 MH183181

Trichoderma lentinulae was phylogenetically close to T. xixiacum and T. lixii but represents a taxon (Fig. 1). Morphologically, it differed from T. xixiacum in producing less frequently lageniform phialides with inequilateral to a strongly-curved apex. The conidia of T. lentinulae are usually more slender (= 2.0), than those of T. xixiacum (= 1.8). In addition, the conidia of T. lentinulae (length/width ratio, x‒= 1.2) are slightly more slender than T. xixiacum (length/width ratio, x‒= 1.1). The two species also differ from each other in their cultural characteristics and growth rates (Figs 2A–C, 4 A–C). Trichoderma lentinulae differed from T. lixii in producing less frequently lageniform phialide with inequilateral to a strongly-curved apex. Additionally, T. lentinulae forms 2–5 apex phialides on the main axis (Fig. 2F, I) in contrast to 2–4 apex phialides of T. lixii (Chaverri et al. 2015). Trichoderma lentinulae is also clearly distinguished from T. lixii (phialides, 6.5–3.5 μm; conidia, 3.0–2.7 μm)(Chaverri et al. 2015) in producing shorter phialides (= 4.5 × 3.0 μm) and smaller conidia (= 2.5 × 2.2 μm). Trichoderma vermifimicola was phylogenetically associated with T. simmonsii (Fig. 1). Morphologically, it is hard to distinguish T. vermifimicola from T. simmonsii , because both form similar tree-like conidiophores, ampulliform to lageniform phialides and ovoid to subglobose conidia, but phialide whorls of T. vermifimicola were often nearly verticillate rather than cruciate in T. simmonsii (Chaverri et al. 2015). Furthermore, T. simmonsii grew fast (PDA 25–55 mm, SNA 10–35 mm) at 35 °C than T. vermifimicola. Additionally, the length/width ratio phialide of T. vermifimicola is larger (= 2.4) than that of T. simmonsii (= 1.9) (Chaverri et al. 2015), and T. vermifimicola also produces smaller conidia (= 2.4 × 2.2 μm) (Fig. 3) than T. simmonsii (3.0–2.7 μm) (Chaverri et al. 2015). Trichoderma zelobreve was closely related to Trichoderma breve in the multi-gene phylogenetic analysis (Fig. 1). Morphologically, both fungi have short phialides, however, T. zelobreve differs from T. breve by producing shorter and narrower phialides (4.0–6.0 × 2.6–3.2 μm) than that of T. breve (6.7–10.0 × 2.8–3.9 μm) (Chen and Zhuang 2017a). The conidia of T. zelobreve are smaller (= 2.4 × 2.0 μm) than those of T. breve (= 3.0 × 2.8 μm). Additionally, T. zelobreve does not form a zonate colony on CMD, PDA, and SNA, whereas the colony of T. breve presents concentric zones on CMD and PDA and finely concentric zones on SNA (Chen and Zhuang 2017a). In a previous study, the phylogenetic analysis indicated that T. breve was a sister taxon of T. bannaense, but morphologically more similar to T. harzianum (Chen and Zhuang (2017a). Herein, our phylogenetic analyses presented T. breve was associated with T. zelobreve (Fig. 1), resulted from the little genetic variation of sequences of ITS and TEF1-α between them. The phylogenetic analysis in Chaverri et al. (2015) presented that T. simmonsii was associated with T. camerunense. In this study, our phylogenetic analysis presented that T. simmonsii was phylogenetically closed to T. vermifimicola, and T. camerunense phylogenetic to T. rifaii (Fig. 1, Suppl. material 3: Fig. S3). In a previous study, these species were recognized as the cryptic species in under T. harzianum (Chaverri et al. (2015).

Currently, the Harzianum clade contains more than 60 species which were isolated from soil, plant tissues, and other fungi (Jaklitsch and Voglmayr 2015; Qin and Zhuang 2016a; Chen and Zhuang 2017b; Qiao et al. 2018; Sun et al. 2019a, b). Several studies have confirmed that species in this clade are important because of their mycoparasitism (Chaverri et al. 2015; Chen and Zhuang 2017a; Sun et al. 2019). When numerous biological control agents were explored deriving from species in the Harzianum clade (Chaverri et al. 2015, several taxa, such as T. atrobrunneum T. pleuroti, and T. pleuroticola were recognized as causing agents of “Green mold” disease of cultivated mushroom (Innocenti et al. 2019; Sun et al. 2019a, b). In this study, T. lentinulae was isolated from a fruiting body and the cultivated substrates of L. edodes, causing the decay of the host as well. How T. lentinulae affect the cultivation of Lentinula edodes is worthy of further studies. Since T. lentinulae was isolated from mushroom, T. lentinulae and T. vermifimicola were isolated from the mushroom spawn and substrates for earthworm cultivation, T. xixiacum and T. zelobreve were isolated from soil, confirming that species in the Harzianum clade have flexible nutrition modes (Chaverri and Samuels 2013; Zhang et al. 2018). The new species introduced here are not only potential candidates for biological agent exploration, but also improve our understanding of the diversity of Trichoderma, especially of the Harzianum clade in China.

Acknowledgements

This research was jointly supported by Key Research and Development Programs in Ningxia Hui Autonomous Region (2018BBF02004) and the Natural Science Foundation of China (no. 31600024).

References

  • Atanasova L, Druzhinina IS, Jaklitsch WM, Mukherjee P, Horwitz B, Singh U (2013) Two hundred Trichoderma species recognized on the basis of molecular phylogeny. Trichoderma: Biology and Applications CABI, Wallingford: 10–42. https://doi.org/10.1079/9781780642475.0010
  • Bunbury-Blanchette AL, Walker AK (2019) Trichoderma species show biocontrol potential in dual culture and greenhouse bioassays against Fusarium basal rot of onion. Biological Control 130: 127–135. https://doi.org/10.1016/j.biocontrol.2018.11.007
  • Chaverri P, Branco-Rocha F, Jaklitsch W, Gazis R, Degenkolb T, Samuels GJ (2015) Systematics of the Trichoderma harzianum species complex and the re-identification of commercial biocontrol strains. Mycologia 107: 558–590. https://doi.org/10.3852/14-147
  • Chaverri P, Samuels GJ (2013) Evolution of habitat preference and nutrition mode in a cosmopolitan fungal genus with evidence of interkingdom host jumps and major shifts in ecology. Evolution 67: 2823–2837. https://doi.org/10.1111/evo.12169
  • Chen K, Zhuang WY (2016) Trichoderma shennongjianum and Trichoderma tibetense, two new soil-inhabiting species in the Strictipile clade. Mycoscience 57: 311–319. https://doi.org/10.1016/j.myc.2016.04.005
  • Chen K, Zhuang WY (2017b) Three new soil-inhabiting species of Trichoderma in the Stromaticum clade with test of their antagonism to pathogens. Current Microbiology 74: 1049–1060. https://doi.org/10.1007/s00284-017-1282-2
  • Degenkolb T, Nielsen KF, Dieckmann R, Branco-Rocha F, Chaverri P, Samuels GJ, Thrane U, von Dohren H, Vilcinskas A, Bruckner H (2015) Peptaibol, secondary-metabolite, and hydrophobin pattern of commercial biocontrol agents formulated with species of the Trichoderma harzianum Complex. Chemistry & Biodiversity 12: 662–684. https://doi.org/10.1002/cbdv.201400300
  • Druzhinina IS, Kopchinskiy AG (2006) TrichOKEY v. 2 – A DNA Oligonucleotide BarCode Program for the Identification of Multiple Sequences of Hypocrea and Trichoderma. In: Meyer W, Pearce C (Eds) International Proceedings of the 8th International Mycological Congress. Cairns, Australia, Medimond, Bologna, Italy.
  • Druzhinina IS, Kopchinskiy AG, Komoń M, Bissett J, Szakacs G, Kubicek CP (2005) An oligonucleotide barcode for species identification in Trichoderma and Hypocrea. Fungal Genetics and Biology 42: 813–828. https://doi.org/10.1016/j.fgb.2005.06.007
  • du Plessis IL, Druzhinina IS, Atanasova L, Yarden O, Jacobs K (2018) The diversity of Trichoderma species from soil in South Africa, with five new additions. Mycologia 110: 559–583. https://doi.org/10.1080/00275514.2018.1463059
  • Innocenti G, Montanari M, Righini H, Roberti R (2019) Trichoderma species associated with green mould disease of Pleurotus ostreatus and their sensitivity to prochloraz. Plant Pathology 68: 392–398. https://doi.org/10.1111/ppa.12953
  • Jaklitsch WM, Komon M, Kubicek CP, Druzhinina IS (2005) Hypocrea voglmayrii sp. nov. from the Austrian Alps represents a new phylogenetic clade in Hypocrea/Trichoderma. Mycologia 97: 1365–1378. https://doi.org/10.1080/15572536.2006.11832743
  • Jiang Y, Wang JL, Chen J, Mao LJ, Feng XX, Zhang CL, Lin FC (2016) Trichoderma biodiversity of agricultural fields in East China reveals a gradient distribution of species. PLoS ONE 11(8): e0160613. https://doi.org/10.1371/journal.pone.0160613
  • Katoh K, Standley DM (2013) MAFFT Multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution 30: 772–780. https://doi.org/10.1093/molbev/mst010
  • Kopchinskiy A, Komoń M, Kubicek CP, Druzhinina IS (2005) TrichoBLAST: a multilocus database for Trichoderma and Hypocrea identifications. Mycological Research 109: 658–660. https://doi.org/10.1017/S0953756205233397
  • Phookamsak R, Hyde KD, Jeewon R, Bhat DJ, Jones EBG, Maharachchikumbura SSN, Raspé O, Karunarathna SC, Wanasinghe DN, Hongsanan S, Doilom M, Tennakoon DS, Machado AR, Firmino AL, Ghosh A, Karunarathna A, Mešić A, Dutta AK, Thongbai B, Devadatha B, Norphanphoun C, Senwanna C, Wei D, Pem D, Ackah FK, Wang GN, Jiang HB, Madrid H, Lee HB, Goonasekara ID, Manawasinghe IS, Kušan I, Cano J, Gené J, Li J, Das K, Acharya K, Raj KNA, Latha KPD, Chethana KWT, He MQ, Dueñas M, Jadan M, Martín MP, Samarakoon MC, Dayarathne MC, Raza M, Park MS, Telleria MT, Chaiwan N, Matočec N, de Silva NI, Pereira OL, Singh PN, Manimohan P, Uniyal P, Shang QJ, Bhatt RP, Perera RH, Alvarenga RLM, Nogal-Prata S, Singh SK, Vadthanarat S, Oh SY, Huang SK, Rana S, Konta S, Paloi S, Jayasiri SC, Jeon SJ, Mehmood T, Gibertoni TB, Nguyen TTT, Singh U, Thiyagaraja V, Sarma VV, Dong W, Yu XD, Lu YZ, Lim YW, Chen Y, Tkalčec Z, Zhang ZF, Luo ZL, Daranagama DA, Thambugala KM, Tibpromma S, Camporesi E, Bulgakov T, Dissanayake AJ, Senanayake IC, Dai DQ, Tang LZ, Khan S, Zhang H, Promputtha I, Cai L, Chomnunti P, Zhao RL, Lumyong S, Boonmee S, Wen TC, Mortimer PE, Xu J (2019) Fungal diversity notes 929–1036: taxonomic and phylogenetic contributions on genera and species of fungal taxa. Fungal Diversity 95: 1–273. https://doi.org/10.1007/s13225-019-00421-w
  • Qin WT, Zhuang WY (2016b) Two new hyaline-ascospored species of Trichoderma and their phylogenetic positions. Mycologia 108: 205–214. https://doi.org/10.3852/15-144
  • Rambaut A (2012) FigTree v1. 4. Molecular evolution, phylogenetics and epidemiology. Edinburgh: University of Edinburgh, Institute of Evolutionary Biology.
  • Ronquist F, Teslenko M, van der Mark P, Ayres DL, Darling A, Hohna S, Larget B, Liu L, Suchard MA, Huelsenbeck JP (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. https://doi.org/10.1093/sysbio/sys029
  • Sun JZ, Liu XZ, Jeewon R, Li YL, Lin CG, Tian Q, Zhao Q, Xiao XP, Hyde KD, Nilthong S (2019a) Fifteen fungicolous Ascomycetes on edible and medicinal mushrooms in China and Thailand. Asian Journal of Mycology 2(1): 129–169. https://doi.org/10.5943/ajom/2/1/7
  • Sun JZ, Liu XZ, McKenzie EH, Jeewon R, Liu JK, Zhang XL, Zhao Q, Hyde KD (2019b) Fungicolous fungi: terminology, diversity, distribution, evolution, and species checklist. Fungal Diversity 95(1): 337–430. https://doi.org/10.1007/s13225-019-00422-9
  • Sun JZ, Pei YF, Li EW, Li W, Hyde KD, Yin WB, Liu XZ (2016) A new species of Trichoderma hypoxylon harbours abundant secondary metabolites. Scientific Reports 6, 37369. https://doi.org/10.1038/srep37369
  • White T, Bruns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR protocols: a guide to methods and applications, 315–322. https://doi.org/10.1016/B978-0-12-372180-8.50042-1
  • Zhang WW, Zhang XL, Li K, Wang CS, Cai L, Zhuang WY, Xiang M, Liu XZ (2018) Introgression and gene family contraction drive the evolution of lifestyle and host shifts of hypocrealean fungi. Mycology 9: 176–188. https://doi.org/10.1080/21501203.2018.1478333