Hypocrea voglmayriisp. nov. from the Austrian Alps represents a new phylogenetic clade inHypocrea/Trichoderma

Biocontrol of Diplodia bulgarica, the causal agent of apple canker, using Trichoderma zelobreve

Apple (Malus domestica Borkh) is one of the most consumed and nutritious fruits. Iran is one of the main producers of the apple in the world. Diplodia bulgarica is the major causal agent of apple tree decline in Iran. Biological control is a nature-friendly approach to plant disease management. Trichoderma zelobreve was isolated from apple trees infected with Diplodia bulgarica in West Azarbaijan province of Iran. The results showed that T. zelobreve strongly inhibited the colony growth of D. bulgarica. In vivo assay on detached branches of apple tree cv. Golden Delicious using T. zelobreve mycelial plug showed that canker length/stem length (CL/SL) and canker perimeter/stem perimeter (CP/SP) indices decreased by 76 and 69%, respectively, 21 days after inoculation. Additionally, wettable powder formulation (WPF) containing the antagonistic fungus "T. zelobreve" decreased CL and CP/SP by 75 and 67%, respectively, 6 months after inoculation. Moreover, canker progress curves and the area under the disease progress curve (AUDPC) supported these findings. The growth temperatures of the antagonist and pathogen were similar, indicating the adaptation of T. zelobreve for biocontrol of apple canker caused by D. bulgarica. The results also showed that T. zelobreve-based WPF stored at 25 °C assure excellent shelf life at least 4 months, allowing the bioproduct to be stored at room temperature, which is a great advantage and cost-effective option.

Trichoderma koningiopsis Tk905: an efficient biocontrol, induced resistance agent against banana Fusarium wilt disease and a potential plant-growth-promoting fungus

Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) is a devastating phytopathogen responsible for significant losses in banana production worldwide. Trichoderma and other biocontrol agents (BCAs) have been used as suitable disease control methods for banana Fusarium wilt. In this study, the endophytic T. koningiopsis Tk905 strain was isolated from the roots of dendrobe plants and identified utilizing morphological and molecular analyses. Antifungal activity tests revealed that Tk905 effectively inhibited mycelial growth with inhibition rates ranging from 26.52 to 75.34%. Additionally, Tk905 covered the pathogen mycelia, and spores were observed on or around the pathogen hyphae. The average root and shoot fresh weights and plant height, of Tk905-inoculated plants were significantly higher than those of the untreated plants. Furthermore, Tk905 treatment significantly increased the activity of antioxidant enzymes, such as catalase (CAT), phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD), suggesting that Tk905 may enhance plant defence systems by activating their antioxidant mechanisms. Most importantly, Tk905-treated plants inoculated by three methods exhibited significantly lower disease incidence and severity than untreated plants. The protective effects of Tk905 against FocTR4 infection were not only observed in the early stages of infection but persisted throughout the experiment, suggesting that T. koningiopsis Tk905 can provide long-lasting protection against Fusarium wilt.

Transboundary milRNAs: Indispensable molecules in the process of Trichoderma breve T069 mycoparasitism of Botrytis cinerea

Despite the increasing number of fungal microRNA-like small RNAs (milRNAs) being identified and reported, profiling of milRNAs in biocontrol fungi and their roles in the mycoparasitism of pathogenic fungi remains limited. Therefore, in this study, we constructed a GFP fluorescence strain to evaluate the critical period of mycoparasitism in the interaction system between T. breve T069 and B. cinerea. The results showed that the early stage of Trichoderma mycoparasitism occurred 12 h after hyphal contact and was characterized by hyphal parallelism, whereas the middle stage lasted 36 h was characterized by wrapping. The late stage of mycoparasitism occurred at 72 h was characterized by the degradation of B. cinerea mycelia. We subsequently identified the sRNAs of T. breve T069 and B. cinerea during the critical period of mycoparasitism using high-throughput sequencing. In ltR1, 45 potential milRNA targets were identified for 243 genes, and 73 milRNAs targeted 733 genes in ltR3. Additionally, to identify potential transboundary miRNAs in T. breve T069, we screened for miRNAs that were exclusively expressed and had precursor structures in the T. breve T069 genome but were absent in the B. cinerea genome. Next, we predicted the target genes of B. cinerea. Our findings showed that 14 potential transboundary milRNAs from T. breve T069 targeted 41 genes in B. cinerea. Notably, cme-MIR164a-p5_1ss17CT can target 15 genes, including Rim15 (BCIN_15g00280), Nop53 (BCIN_12g03770), Skn7 (BCIN_02g08650), and Vel3 (BCIN_03g06410), while ppe-MIR477b-p3_1ss11TC targeted polyketide synthase (BCIN_03g04360, PKS3). The target gene of PC-5p-27397_41 was a non-ribosomal peptide synthetase (BCIN_01g03730, Bcnrps6). PC-3p-0029 (Tri-milR29) targeted chitin synthetase 7. These genes play crucial roles in normal mycelial growth and pathogenicity of B. cinerea. In conclusion, this study highlights the significance of milRNAs in Trichoderma mycoparasitism of B. cinerea. This discovery provides a new strategy for the application of miRNAs in the prevention and treatment of fungal pathogens.

Biocontrol Potential of Trichoderma asperellum Strain 576 against Exserohilum turcicum in Zea mays

Maize is a crucial cereal crop in China, serving both as a staple food and an essential industrial resource. Northern corn leaf blight (NCLB) is a disease of corn caused by a fungus, Exserohilum turcicum (sexual stage Setosphaeria turcica). This study aimed to assess the biocontrol potential of various Trichoderma strains against Exserohilum turcicum 101 in Jilin, China. Through dual culture tests, the Trichoderma strains were categorized into four groups based on their antagonistic abilities. Eleven Trichoderma strains exhibited strong antagonistic behavior, with comparable or faster growth rates than E. turcicum 101. Microscopic observations confirmed that T. asperellum 576 hyphae effectively encircled E. turcicum 101 hyphae, reinforcing their antagonistic behavior. The production of non-volatile and volatile substances by the Trichoderma strains was evaluated, with T. asperellum 576 showing the highest potency in producing non-volatile and volatile substances, leading to an impressive 80.81% and 65.86% inhibition of E. turcicum 101 growth. Remarkably, co-culture suspensions of T. asperellum 576 + E. turcicum 101 and T. atroviride 393 + E. turcicum 101 exhibited strong antifungal activity. Furthermore, the activities of chitinase, β-1.3-glucanase, and cellulase were evaluated using the 3, 5-dinitrosalicylic acid (DNS) method. T. asperellum 576 + E. turcicum 101 displayed stronger cell wall degradation enzyme activity compared to T. atroviride 393 + E. turcicum 101, with values of 8.34 U/mL, 3.42 U/mL, and 7.75 U/mL, respectively. In greenhouse conditions, the application of a 107 spores/mL conidia suspension of T. asperellum 576 significantly enhanced maize seed germination and plant growth while effectively suppressing E. turcicum 101 infection. Maize seedlings inoculated/treated with both E. turcicum 101 and T. asperellum 576 demonstrated substantial improvements compared to those inoculated solely with E. turcicum 101. The T. asperellum 576 treatment involved a 107 spores/mL conidia suspension applied through a combination of foliar spray and soil drench. These findings highlight T. asperellum 576 as a promising biocontrol candidate against northern leaf blight in maize. Its antagonistic behavior, production of inhibitory compounds, and promotion of plant growth all contribute to its potential as an effective biocontrol agent for disease management.

Two new Trichoderma species (Hypocreales, Hypocreaceae) isolated from decaying tubers of Gastrodiaelate

Species of Trichoderma are widely distributed around the world. In this study, two new species in Trichoderma, named as T.albidum and T.variegatum, were introduced and illustrated. These species were isolated from diseased tubers of Gastrodiaelata in China and identified based on morphological characteristics and multi-gene sequence analyses of three loci that is the internal transcribed spacer regions of the ribosomal DNA (ITS), the translation elongation factor 1-α encoding gene (tef1-α) and the gene encoding the second largest nuclear RNA polymerase subunit (rpb2). Distinctions between the new species and their close relatives were discussed. According to results of the phylogenetic analyses, T.albidum belonged to the Harzianum clade and T.variegatum are grouped with species of the Spirale clade. The expansion of two clades provided research foundations for the prevention and control of tuber diseases in G.elata.

Morphological and phylogenetic analyzes reveal two new species of Melanconiella from Fujian Province, China

Introduction

Species of Melanconiella include a diverse array of plant pathogens as well as endophytic fungi. Members of this genus have been frequently collected from the family Betulaceae (birches) in Europe and North America. Little, however, if known concerning the distribution of Melanconiella and/or their potential as pathogens of other plant hosts.

Methods

Fungi were noted and isolated from diseased leaves of Loropetalum chinense (Chinese fringe flower) and Camellia sinensis (tea) in Fujian Province, China. Genomic DNA was extracted from fungal isolates and the nucleotide sequences of four loci were determined and sued to construct phylogenetic trees. Morphological characteristics of fungal structures were determined via microscopic analyses.

Results

Four strains and two new species of Melanconiella were isolated from infected leaves of L. chinense and C. sinensis in Fujian Province, China. Based on morphology and a multi-gene phylogeny of the internal transcribed spacer regions with the intervening 5.8S nrRNA gene (ITS), the 28S large subunit of nuclear ribosomal RNA (LSU), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF1-α), Melanconiellaloropetali sp. nov. and Melanconiellacamelliae sp. nov. were identified and described herein. Detailed descriptions, illustrations, and a key to the known species of Melanconiella are provided.

Discussion

These data identify new species of Melanconiella, expanding the potential range and distribution of these dark septate fungi. The developed keys provide a reference source for further characterization of these fungi.

Evaluation of Biological Control Agents for the Protection of Almond Pruning Wounds Against Infection by Fungal Canker Pathogens

Fungal canker pathogens of almond initiate infection in trees primarily through pruning wounds. Biological control agents (BCAs) have the potential to provide long-term protection of pruning wounds by colonizing the wound surfaces and underlying tissues. Laboratory and field tests were performed to assess the efficacy of various commercial and experimental BCAs as wound protectants against almond canker pathogens. Four Trichoderma-based BCAs were evaluated using detached almond stems in the laboratory against the canker pathogens Cytospora plurivora, Eutypa lata, Neofusicoccum parvum, and Neoscytalidium dimidiatum. Results indicated that Trichoderma atroviride SC1 and T. paratroviride RTFT014 significantly reduced infections by all four pathogens. The abilities of these four BCAs to protect almond pruning wounds against E. lata and N. parvum were further evaluated in field trials using two almond cultivars and during two consecutive years. Both T. atroviride SC1 and T. paratroviride RTFT014 protected almond pruning wounds against E. lata and N. parvum as efficiently as thiophanate-methyl, the recommended fungicide for treatment of almond pruning wounds. Comparisons of different application timings of BCA in relation to pathogen inoculation revealed a significant improvement in wound protection when inoculations were conducted 7 days versus 24 h post-BCA application for N. parvum, but not for E. lata. T. atroviride SC1 and T. paratroviride RTFT014 are promising candidates for the preventive protection of almond pruning wounds and for inclusion in integrated pest management programs and organic almond production systems.

A Multilocus Phylogeny Places Hymenula cerealis (syn. Cephalosporium gramineum) in the Helotiales, Leotiomycetes

The soilborne fungus Hymenula cerealis causes Cephalosporium stripe, a vascular wilt disease of wheat and other grasses in the United States and other wheat-producing countries where winter wheat is subjected to snow cover and frozen soil. No sexual stage is known for H. cerealis, and consequently, its phylogenetic position relative to other fungi has been difficult to establish. The purpose of this study was to conduct a multilocus sequence analysis to determine the phylogenetic position of H. cerealis. Sequence data for five genes, the internal transcribed spacer (ITS), partial large subunit nrDNA (LSU), partial RNA polymerase II second largest subunit region (RPB2), β-tubulin gene, and translation elongation factor 1-α (TEF1-α), from a diverse set of C. gramineum isolates and other related fungi was obtained from GenBank or directly from isolates in the Murray lab and used to construct maximum-likelihood and Bayesian trees. Based on phylogenetic analysis of the single LSU and β-tubulin genes, Cephalosporium gramineum is closely related to the Drepanopezizaceae and Ploettnerulaceae of Helotiales. Based on analyses of the DNA sequence of the ITS, RPB2, and TEF1-α genes, as well as the combined five-gene data set, C. gramineum belongs to the family Drepanopezizaceae, which is a sister taxon to the Ploettnerulaceae, and formed a well-supported clade (MLBP/BIPP = 95%/100%). In conclusion, H. cerealis belongs to the Helotiales, Leotiomycetes.

Assessment of Tunisian Trichoderma Isolates on Wheat Seed Germination, Seedling Growth and Fusarium Seedling Blight Suppression

Beneficial microorganisms, including members of the Trichoderma genus, are known for their ability to promote plant growth and disease resistance, as well as being alternatives to synthetic inputs in agriculture. In this study, 111 Trichoderma strains were isolated from the rhizospheric soil of Florence Aurore, an ancient wheat variety that was cultivated in an organic farming system in Tunisia. A preliminary ITS analysis allowed us to cluster these 111 isolates into three main groups, T. harzianum (74 isolates), T. lixii (16 isolates) and T. sp. (21 isolates), represented by six different species. Their multi-locus analysis (tef1, translation elongation factor 1; rpb2, RNA polymerase B) identified three T. afroharzianum, one T. lixii, one T. atrobrunneum and one T. lentinulae species. These six new strains were selected to determine their suitability as plant growth promoters (PGP) and biocontrol agents (BCA) against Fusarium seedling blight disease (FSB) in wheat caused by Fusarium culmorum. All of the strains exhibited PGP abilities correlated to ammonia and indole-like compound production. In terms of biocontrol activity, all of the strains inhibited the development of F. culmorum in vitro, which is linked to the production of lytic enzymes, as well as diffusible and volatile organic compounds. An in planta assay was carried out on the seeds of a Tunisian modern wheat variety (Khiar) by coating them with Trichoderma. A significant increase in biomass was observed, which is associated with increased chlorophyll and nitrogen. An FSB bioprotective effect was confirmed for all strains (with Th01 being the most effective) by suppressing morbid symptoms in germinated seeds and seedlings, as well as by limiting F. culmorum aggressiveness on overall plant growth. Plant transcriptome analysis revealed that the isolates triggered several SA- and JA-dependent defense-encoding genes involved in F. culmorum resistance in the roots and leaves of three-week-old seedlings. This finding makes these strains very promising in promoting growth and controlling FSB disease in modern wheat varieties.

What was old is new again: Phenotypic screening of a unique fungal library yields pyridoxatin, a promising lead against extensively resistant Acinetobacter baumannii (AB5075)

Due to the emergence of resistance, the World Health Organization considers Gram-negative pathogen Acinetobacter baumannii a top priority for therapeutic development. Using this priority pathogen and a phenotypic, agar plate-based assay, a unique library of extracts from 2,500 diverse fungi was screened for antimicrobial activity against a highly virulent, drug-resistant strain of A. baumannii (AB5075). The most potent hit from this screen was an extract from the fungus Tolypocladium sp., which was found to produce pyridoxatin. Another active extract from the fungi Trichoderma deliquescens was characterized and yielded trichokonin VII and trichokonin VIII. Evaluation of pyridoxatin against A. baumannii (AB5075) in a broth microdilution assay revealed a minimum inhibitory concentration (MIC) of 38 μM, compared to the known antibiotic levofloxacin with MIC of 28 μM. Mass spectrometry, Marfey's analysis and nuclear magnetic resonance spectroscopy analyses confirmed the structures of trichokonins VII and VIII to be consistent with previous reports. In an in vivo Galleria mellonella model, pyridoxatin tested at 150 mg/kg exhibited minimal toxicity (90% survival) and promising antimicrobial efficacy (50% survival) after 5 days. Trichokonins VII and VIII tested at 150 mg/kg were toxic to G. mellonella, with 20% survival and 40% survival after 5 days, respectively. The findings of this project suggest that pyridoxatin may serve as a lead compound for the development of antimicrobials against A. baumannii. They also demonstrate the value of the phenotypic screening approach employed herein.

Regulation of Intracellular Reactive Oxygen Species Levels after the Development of Phallus rubrovolvatus Rot Disease Due to Trichoderma koningii Mycoparasitism

Phallus rubrovolvatus is a unique mushroom used for medicinal and dietary purposes in China. In recent years, however, the rot disease of P. rubrovolvatus has seriously affected its yield and quality, becoming an economically important threat. In this study, samples of symptomatic tissues were collected, isolated, and identified from five major P. rubrovolvatus production regions in Guizhou Province, China. Based on combined analyses of phylogenies (ITS and EF1-α), morphological characteristics and Koch's postulates, Trichoderma koningiopsis and Trichoderma koningii were identified as the pathogenic fungal species. Among these, T. koningii exhibited stronger pathogenicity than the other strains; thus, T. koningii was used as the test strain in the follow-up experiments. Upon co-culturing T. koningii with P. rubrovolvatus, the hyphae of the two species were intertwined, and the color of the P. rubrovolvatus hyphae changed from white to red. Moreover, T. koningii hyphae were wrapped around P. rubrovolvatus hyphae, leading to their shortening and convolution and ultimately inhibiting their growth due to wrinkling; T. koningii penetrated the entire basidiocarp tissue of P. rubrovolvatus, causing serious damage to the host basidiocarp cells. Further analyses revealed that T. koningii infection resulted in the swelling of basidiocarps and significantly enhanced the activity of defense-related enzymes, such as malondialdehyde, manganese peroxidase, and polyphenol oxidase. These findings offer theoretical support for further research on the infection mechanisms of pathogenic fungi and the prevention of diseases caused by them.

A Salt-Tolerant Strain of Trichoderma longibrachiatum HL167 Is Effective in Alleviating Salt Stress, Promoting Plant Growth, and Managing Fusarium Wilt Disease in Cowpea

Salt stress is a constraint factor in agricultural production and restricts crops yield and quality. In this study, a salt-tolerant strain of Trichoderma longibrachiatum HL167 was obtained from 64 isolates showing significant salt tolerance and antagonistic activity to Fusarium oxysporum. T. longibrachiatum HL167 inhibited F. oxysporum at a rate of 68.08% in 200 mM NaCl, penetrated F. oxysporum under 200 mM NaCl, and eventually induced F. oxysporum hyphae breaking, according to electron microscope observations. In the pot experiment, pretreatment of cowpea seedlings with T. longibrachiatum HL167 reduced the accumulation level of ROS in tissues and the damage caused by salt stress. Furthermore, in the field experiment, it was discovered that treating cowpea with T. longibrachiatum HL167 before root inoculation with F. oxysporum can successfully prevent and control the development of cowpea Fusarium wilt, with the best control effect reaching 61.54%. Moreover, the application of HL 167 also improved the K+/Na+ ratio of cowpea, alleviated the ion toxicity of salt stress on cowpea, and HL167 was found to effectively colonize the cowpea roots. T. longibrachiatum HL167, which normally survives in saline–alkali environments and has the functions of disease prevention and plant growth promotion capabilities, has important research implications for improving the saline–alkali soil environment and for the sustainable development of green agriculture.

Six Additions to the Genus Periconia (Dothideomycetes: Periconiaceae) from Graminaceous Plants in China

Periconia is a polyphyletic and asexual morphic genus within the family Periconiaceae (Pleosporales). The genus is characterized by a pale to dark brown stipe with an apical conidial head and ellipsoidal to oblong conidia. Species of Periconia are widely distributed throughout the world in various hosts, while most species are isolated from graminaceous plants. During our investigations of microfungal in Sichuan Province, China, 26 Periconia isolates were collected from a wide variety of graminaceous plants. These isolates corresponded to 11 species based on the examination of morphology and multi-locus phylogenetic analysis (SSU, ITS, LSU, TEF1, RPB2). This includes six new species (P. chengduensis, P. cynodontis, P. festucae, P. imperatae, P. penniseti, and P. spodiopogonis) and five new records (P. byssoides, P. chimonanthi, P. cookie, P. pseudobyssoides, and P. verrucosa). A comprehensive description and illustrations of the new species are provided and discussed with comparable taxa. These discoveries expand our knowledge of the species diversity of Periconia taxa in graminaceous plants in China.

Four New Species of Torula (Torulaceae, Pleosporales) from Sichuan, China

Torula is an asexual and hyphomycetous genus in the family Torulaceae. Torula species are generally saprophytic. They have a worldwide distribution and abound in humid or freshwater habitats. In order to better understand this genus, we carried out several field collections from Sichuan, China. As a result, we obtained nine Torula isolates from dead woody substrates in terrestrial and freshwater habitats. Based on a biphasic approach of morphological examination and multi-locus phylogenetic analyses (ITS, SSU, LSU, TEF, RPB2), these collections were identified as belonging to seven Torula species. Four of them were new species (Torula chinensis, T. longiconidiophora, T. sichuanensis and T. submersa), and the other three belonged to existing species, though one was found for the first time in China (T. masonii). Morphological and updated phylogenetic delamination of the new discoveries is also discussed. This study provides further insights into our understanding of wood-based Torula species in China.

Diversity of Trichoderma species associated with soil in the Zoige alpine wetland of Southwest China

The ecology of soil fungi is poorly understood, and recent comprehensive reports on Trichoderma are unavailable for any region, including the Zoige alpine wetland ecological region in China. One hundred soil samples were collected from different soil types and soil layers in Zoige alpine wetland ecological regions. Using the traditional suspension plating method, 80 Trichoderma strains were chosen to analyze species diversity. After a preliminary classification of morphological characteristics and the genes glyceraldehyde-3-phosphate dehydrogenase (gpd), 57 representative strains were selected and eventually identified as seven species via phylogenetic analyses of multilocus sequences based on the genes transcription elongation factor 1 alpha (tef1), encoding RNA polymerase II subunit B (rpb2) and ATP citrate lyase (acl1). Among them, T. harzianum was the dominant species isolated from five soil layers and four soil types, and had the highest isolation frequency (23%) in this zone, while T. polysporum and T. pyramidale were rare species, with isolation frequencies of less than 1%. Our detailed morphological observation and molecular phylogenetic analyses support the recognition of Trichoderma zoigense was described for the first time as a new species, while T. atrobrunneum as a new record for China was found. Our results will be used as a reference for a greater understanding of soil microbial resources, ecological rehabilitation and reconstructions in the Zoige alpine wetland.

Three New Trichoderma Species in Harzianum Clade Associated with the Contaminated Substrates of Edible Fungi

Trichoderma is known worldwide as biocontrol agents of plant diseases, producers of enzymes and antibiotics, and competitive contaminants of edible fungi. In this investigation of contaminated substrates of edible fungi from North China, 39 strains belonging to 10 Trichoderma species isolated from four kinds of edible fungi were obtained, and three novel species belonging to the Harzianum clade were isolated from the contaminated substrates of Auricularia heimuer and Pholiota adipose. They were recognized based on integrated studies of phenotypic features, culture characteristics, and molecular analyses of RNA polymerase II subunit B and translation elongation factor 1-α genes. Trichoderma auriculariae was strongly supported as a separate lineage and differed from T. vermifimicola due to its larger conidia. Trichoderma miyunense was closely related to T. ganodermatigerum but differed due to its smaller conidia and higher optimum mycelial growth temperature. As a separate lineage, T. pholiotae was distinct from T. guizhouense and T. pseudoasiaticum due to its higher optimum mycelial growth temperature and larger conidia. This study extends the understanding of Trichoderma spp. contaminating substrates of edible fungi and updates knowledge of species diversity in the group.

Taxonomy and control of Trichoderma hymenopellicola sp. nov. responsible for the first green mold disease on Hymenopellis raphanipes

Trichoderma spp. are a group of widespread fungi with important applications in many aspects of human life, but they are also pathogens that cause green mold disease on mushrooms. During a survey of mushroom cultivation in Guizhou, China, five strains of Trichoderma from three different localities were isolated from soil in mushroom bags of Hymenopellis raphanipes. The typical morphology of having gregarious, reddish stromata and gregarious phialides and the results of phylogenetic analyses based on a combined dataset of RPB2, TEF, and ITS gene sequences demonstrated that these green-spored Trichoderma belong to a new taxon, Trichoderma hymenopellicola. Pathogenicity tests by covering fungal mycelial blocks or soil mixed with spore suspension in mushroom bags showed similar symptoms to those in the field, and the same fungal pathogen had been observed and re-isolated from these symptoms, which fulfill Koch’s postulates. A primary screening test of nine common fungicides indicated that prochloraz-manganese chloride complex and propiconazole are the top two effective fungicides inhibiting the pathogen, whereas the former was further indicated as a suitable fungicide to control Trichoderma hymenopellicola, with a high inhibition ratio to the pathogen and low toxicity to the mushroom.

First Report of Leaf Spot and Blight on Crown Daisy Caused by Cercospora apii in China

Crown daisy (Glebionis coronaria L.), also known as chrysanthemum greens, is a popular vegetable in Asia, especially in China. The leaves have been used in folk medicine as a tonic for the liver, blood, intestines and to control anemia and high blood pressure. In November 2020, severe leaf spot and blight was observed with 80% to 95% incidence on crown daisy growing in greenhouses in Fengxian, Shanghai, China (121°22'E, 30°53'N). Irregular rounded spots appeared with a light gray center and water-soaked margins. Round lesions enlarged and merged with age, followed by the development of a necrotic area resulting in the typical "frog-eye" and causing a continuous deterioration of crown daisy. Diseased leaves were washed in running water for 30 min. Small fragments (5 × 5 mm) taken from the margin of lesions were disinfected with 1% NaClO for 3 min, rinsed three times with sterile water, cultured on potato sucrose agar (PSA) augmented with 50 mg streptomycin/liter at 26 oC,and incubated in the dark. Colonies had identical morphology, and TH11290202 was selected and deposited in the plant pathology lab of Shanghai Academy of Agricultural Sciences. Mycelium was initially cottony and white and became appressed to the medium and dark brown with time. Conidia did not form on any media, including PSA, PDA, V8 agar (V8A), maize leaf carbonate agar (MLPCA), pepper leaf carbonate agar (PLPCA), etc. To confirm the identity of the pathogen, genomic DNA was extracted from TH11290202 with the cetyltrimethylammonium ammonium bromide (CTAB) method from the mycelia. Five loci were PCR amplified, namely, the internal transcribed spacer (ITS), translation elongation factor (TEF), calmodulin (cmdA), histone (H3) and actin (ACT), using primers ITS1/ITS4 (White et al. 1990), EF1-728F/EF1-986R (Jaklitsch et al. 2005), CAL-F/CAL-R (O'Donnell et al. 2000), cylh3f/cylh3r (Glass and Donaldson 1995), and ACT-512F/ACT-783R (Carbone and Kohn 1999), respectively. The resulting sequences were deposited in GenBank (MW819910, MW981277, MW981278, ON798723, and MW981279). Analysis of the ITS, TEF, cmdA, H3 and ACT gene sequences of isolate TH11290202 revealed that it was a member of the genus Cercospora, sharing 99.79%, 99.66%, 98.10% 99.74% and 100% sequence similarity with type strain of Cercospora apii CBS 116455. A multilocus phylogenetic analysis was performed using sequences from other closely related taxa obtained from GenBank. Based on morphological and molecular characteristics, TH11290202 was identified as C. apii (Crous and Braun 2003; Groenewald et al. 2006; Milosavljević et al. 2014). To confirm pathogenicity, Koch's postulates were fulfilled on 30 mature plants, which were maintained in a growth chamber (at 26 °C, relative humidity 90%, 12/12 h light/dark). Surface-sterilized leaves were sprayed with a mycelial suspension. Brown lesions were formed 7 days after inoculation on 15 plants, whereas the noninoculated controls remained asymptomatic on the other 15 plants. To our knowledge, this is the first report of C. apii causing leaf spot and blight on G. coronaria in China and will provide useful information for developing effective control strategies.

Characterization of Chitinolytic and Antifungal Activities in Marine-Derived Trichoderma bissettii Strains

Trichoderma fungi have been intensively studied for mycoparasitism, and the latter is closely related to their cell-wall degrading enzymes including chitinase. Here, we studied marine-derived Trichoderma spp., isolated from distinct sources and locations, for chitinolytic and antifungal activity. Based on morphological and phylogenetic analyses, two strains designated GJ-Sp1 and TOP-Co8 (isolated from a marine sponge and a marine alga, respectively) were identified as Trichoderma bissettii. This species has recently been identified as a closely related species to Trichoderma longibrachiatum. The extracellular crude enzymes of GJ-Sp1 and TOP-Co8 showed activities of chitobiosidase and β-N-acetylglucosaminidase (exochitinase) and chitotriosidase (endochitinase). The optimum chitinolytic activity of the crude enzymes was observed at 50 °C, pH 5.0, 0-0.5% NaCl concentrations, and the activities were stable at temperatures ranging from 10 to 40 °C for 2 h. Moreover, the crude enzymes showed inhibitory activity against hyphal growth of two filamentous fungi Aspergillus flavus and Aspergillus niger. To the best of our knowledge, this is the first report of the chitinolytic and antifungal activity of T. bissettii.

Identification of Two Fungal Pathogens Responsible for Liriodendron chinense × tulipifera Black Spot and Screening of Trichoderma sp. for Disease Control

Liriodendron chinense × tulipifera black spot is a newly discovered disease that causes yellowing and early shedding of leaves, affecting the growth of Liriodendron trees, and significantly reducing their ornamental value as a garden species. The pathogen responsible for this disease, and how it can be prevented and controlled, are not clear. In this study, the occurrence of this disease was first investigated according to Koch's postulates, and the primary pathogens causing Liriodendron black spot were determined to be Colletotrichum gloeosporioides and Alternaria alternata. Biocontrol strains antagonistic to these two pathogens were then screened from the leaf microorganisms of L. chinense × tulipifera, and a preliminary investigation of the biological control of Liriodendron black spot was performed. Through the screening of antagonistic microorganisms on the leaf surface of L. chinense × tulipifera, the strain Trichoderma koningiopsis T2, which displayed strong antagonism against C. gloeosporioides and A. alternata, was obtained. The T2 strain could inhibit the growth of the two pathogens via three mechanisms: hyperparasitism, volatile and nonvolatile metabolite production, and environmental acidification. The biocontrol experiments in the greenhouse and field showed that initial spraying with a T. koningiopsis T2 spore suspension followed by the two pathogens resulted in the lowest disease incidence. These results confirmed the black spot pathogens of L. chinense × tulipifera, clarified the antagonistic mechanism of T. koningiopsis T2 against the two pathogens, and provided a theoretical basis and technical support for the biological control of the disease.

Biocontrol of Phytophthora xcambivora on Castanea sativa: Selection of Local Trichoderma spp. Isolates for the Management of Ink Disease

Ink disease is a devastating disease of chestnut (Castanea sativa) worldwide, caused by Phytophthora species. The only management measures of this disease are chemical and agronomic interventions. This work focuses on the evaluation of the in vitro antagonistic capacity of 20 isolates of Trichoderma spp. selected in a diseased chestnut orchard in Tuscan Apennines (San Godenzo, Italy) for the biocontrol of Phytophthora xcambivora. Each Trichoderma isolate was tested to investigate pathogen inhibition capability by antagonism in dual cultures and antibiosis by secondary metabolites production (diffusible and Volatile Organic Compounds). The six most performing isolates of Trichoderma spp. were further assessed for their aptitude to synthesize chitinase, glucanase and cellulase, and to act as mycoparasite. All six selected isolates displayed the capability to control the pathogen in vitro by synergistically coupling antibiosis and mycoparasitism at different levels regardless of the species they belong to, but rather, in relation to specific features of the single genotypes. In particular, T. hamatum SG18 and T. koningiopsis SG6 displayed the most promising results in pathogen inhibition, thus further investigations are needed to confirm their in vivo efficacy.

Synhelminthosporium gen. et sp. nov. and Two New Species of Helminthosporium (Massarinaceae, Pleosporales) from Sichuan Province, China

Helminthosporium is a polyphyletic genus in Massarinaceae (Pleosporales). Species of Helminthosporium are characterized by having septate and erect conidiophores, acro-pleurogenous and distoseptate conidia with a ring-shaped scar at the base. During a survey of fungal diversity in Sichuan Province, China, six Helminthosporium-like isolates were collected from dead branches of unknown trees. Five barcodes, including ITS (ITS1-5.8S-ITS2), SSU, LSU, TEF1, and RPB2 were amplified and sequenced. Morphological examination and multi-locus phylogenetic analyses revealed two new Helminthosporium species (H. chengduense sp. nov., and H. chinense sp. nov.), a new genus (Synhelminthosporium gen. nov.) with a type species Synhelminthosporium synnematoferum sp. nov., and two known species (Helminthosporium submersum and H. velutinum) within Massarinaceae. The new genus Synhelminthosporium differs from the phylogenetically closest genus Helminthosporium by producing synnematous conidiophores. This work expands our understanding of the diversity of Helminthosporium-like taxa in Sichuan Province, China.

Phylogenetic Analysis of Trichoderma Species Associated with Green Mold Disease on Mushrooms and Two New Pathogens on Ganoderma sichuanense

Edible and medicinal mushrooms are extensively cultivated and commercially consumed around the world. However, green mold disease (causal agent, Trichoderma spp.) has resulted in severe crop losses on mushroom farms worldwide in recent years and has become an obstacle to the development of the Ganoderma industry in China. In this study, a new species and a new fungal pathogen on Ganoderma sichuanense fruitbodies were identified based on the morphological characteristics and phylogenetic analysis of two genes, the translation elongation factor 1-α (TEF1) and the second-largest subunit of RNA polymerase II (RPB2) genes. The new species, Trichoderma ganodermatigerum sp. nov., belongs to the Harzianum clade, and the new fungal pathogen was identified as Trichoderma koningiopsis. Furthermore, in order to better understand the interaction between Trichoderma and mushrooms, as well as the potential biocontrol value of pathogenic Trichoderma, we summarized the Trichoderma species and their mushroom hosts as best as possible, and the phylogenetic relationships within mushroom pathogenic Trichoderma species were discussed.

Branch blight of Juglans sigillata caused by Juglanconis appendiculata in China

Juglans sigillata Dode, an endemic walnut species native in southwest China, is mainly used as nuts in Sichuan Province (Jin et al., 2019). In May 2021, symptoms of branches blight were observed in an orchard measuring 10 hectares located in Mianyang City, Sichuan Province (31°5' 25″N, 105°27'36″E, 365 m above sea level). About 40% of plants were diseased in the quadrat consisting of twenty walnut trees, and 20% of branches were dead on each affected tree. Initially, light brown spots appeared; then, the spots expanded to surround the whole branches; finally, the branches changed from brown to reddish-brown and died. Four symptomatic branches were sampled randomly from different trees. Next, four fungal isolates were obtained from the acervuli of each branch using the single-conidium isolation (Chomnunti et al. 2014) and cultured on potato dextrose agar (PDA). The Petri dishes were placed in an incubator and cultured at 25 °C under a 12-h photoperiod. Colonies were initially white with thin aerial mycelia and gradually turned dark grey with irregular margins. Conidiomata were acervular, black and scattered, with a diameter of 0.3 - 0.7 mm. Conidiophores were narrowly cylindrical, simple or branched at the base, 30 - 43 × 3 - 8 µm (x = 36.5 × 5.5 µm, n = 40). Conidiogenous cells were annellidic with distinct annellations. Conidia were unicellular, brown when mature, narrowly ellipsoid with gelatinous sheaths and truncate scars at the base, 17 - 32 × 7 - 12 µm (x = 27 × 9 µm, n = 40). The genomic DNA of a representative isolate SICAUCC 22-0064 was extracted, and the internal transcribed spacer (ITS) region, guanine nucleotide-binding protein subunit beta gene (ms204), translation elongation factor 1-alpha (tef1-α), and partial sequences of β-tubulin (tub2) were amplified by polymerase chain reaction and sequenced with primers V9G/LR5 (de Hoog & van den Ende 1998), MS-E1F1/MS-E5R1 (Walker et al. 2012), EF1-728F (Carbone & Kohn 1999)/TEF1LLErev (Jaklitsch et al. 2005), and T1/BtHV2r (Voglmayr et al. 2017), respectively. The sequences of ITS, ms204, tef1-α, and tub2 were deposited in NCBI with accession numbers ON000068, ON112376, ON112374, and ON112375, respectively. With the consideration of the sequence lack of ms204 and tub2 in the ex-type strain (D96) of Juglanconis appendiculata Voglmayr & Jaklitsch, the isolate D140 was used for nucleotide blast. The results showed 99.68%, 100%, 100%, and 100% identities of ITS, ms204, tef1-α, and tub2 with D140 (accession numbers KY427138, KY427157, KY427207, KY427226). Phylogenetic analysis based on a combined dataset showed 100% bootstrap with J. appendiculata, and the morphology was consistent with the asexual stage of J. appendiculata (Voglmayr et al., 2017). To verify Koch's postulates, five branches wounded by pin-prick were sprayed with conidial suspension (1 × 105 conidia/mL) in each plant, and three repetitions were performed on healthy 2-year-old potted plants. The same number of branches were sprayed with sterile distilled water as controls. The plants were placed in a greenhouse at 25 ℃ under 90% relative humidity and a 12-h fluorescent light/dark regime. After five weeks, all the inoculated branches showed brown necrosis similar to that observed in the field, and no symptoms occurred on the controls. The pathogens were re-isolated from the necrotic lesions and identified by morphology and phylogeny. J. appendiculata has been reported on Juglans nigra and J. regia in Austria, France, Spain and Greece (Farr & Rossman 2022). This paper is the first report of branch blight on Juglans sigillata caused by J. appendiculata in China. This result may develop the understanding of walnut diseases and lay a foundation for further management.

Changes in the Density and Composition of Rhizosphere Pathogenic Fusarium and Beneficial Trichoderma Contributing to Reduced Root Rot of Intercropped Soybean

The dynamic of soil-borne disease is closely related to the rhizosphere microbial communities. Maize–soybean relay strip intercropping has been shown to significantly control the type of soybean root rot that tends to occur in monoculture. However, it is still unknown whether the rhizosphere microbial community participates in the regulation of intercropped soybean root rot. In this study, rhizosphere Fusarium and Trichoderma communities were compared in either healthy or root-rotted rhizosphere soil from monocultured and intercropped soybean, and our results showed the abundance of rhizosphere Fusarium in intercropping was remarkably different from monoculture. Of four species identified, F. oxysporum was the most aggressive and more frequently isolated in diseased soil of monoculture. In contrast, Trichoderma was largely accumulated in healthy rhizosphere soil of intercropping rather than monoculture. T. harzianum dramatically increased in the rhizosphere of intercropping, while T. virens and T. afroharzianum also exhibited distinct isolation frequency. For the antagonism test in vitro, Trichoderma strains had antagonistic effects on F. oxysporum with the percentage of mycelial inhibition ranging from 50.59–92.94%, and they displayed good mycoparasitic abilities against F. oxysporum through coiling around and entering into the hyphae, expanding along the cell–cell lumen and even dissolving cell walls of the target fungus. These results indicate maize–soybean relay strip intercropping significantly increases the density and composition proportion of beneficial Trichoderma to antagonize the pathogenic Fusarium species in rhizosphere, thus potentially contributing to the suppression of soybean root rot under the intercropping.

Phylogeny and Optimization of Trichoderma harzianum for Chitinase Production: Evaluation of Their Antifungal Behaviour against the Prominent Soil Borne Phyto-Pathogens of Temperate India

Trichoderma is the most commonly used fungal biocontrol agent throughout the world. In the present study, various Trichoderma isolates were isolated from different vegetable fields. In the isolated microflora, the colony edges varied from wavy to smooth. The mycelial forms were predominantly floccose with hyaline color and conidiophores among all the strains were highly branched. Based on morphological attributes, all the isolates were identified as Trichoderma harzianum. The molecular identification using multilocus sequencing ITS, rpb2 and tef1α, genes further confirmed the morphological identification. The average chitinase activity varied from 1.13 units/mL to 3.38 units/mL among the various isolates, which increased linearly with temperature from 15 to 30 °C. There was an amplified production in the chitinase production in the presence of Mg⁺ and Ca²⁺ and Na⁺ metal ions, but the presence of certain ions was found to cause the down-regulated chitinase activity, i.e., Zn²⁺, Hg²⁺, Fe²⁺, Ag⁺ and K⁺. All the chitinase producing Trichoderma isolates inhibited the growth of tested pathogens viz., Dematophora necatrix, Fusarium solani, Fusarium oxysporum and Pythium aphanidermatum at 25% culture-free filtrate concentration under in vitro conditions. Also, under in vivo conditions, the lowest wilt incidence and highest disease control on Fusarium oxysporum was observed in isolate BT4 with mean wilt incidence and disease control of 21% and 48%, respectively. The Trichoderma harzianum identified in this study will be further used in formulation development for the management of diseases under field conditions.

Antagonistic Potential of Native Trichoderma spp. against Phytophthora cinnamomi in the Control of Holm Oak Decline in Dehesas Ecosystems

Phytophthora root rot caused by the pathogen Phytophthora cinnamomi is one of the main causes of oak mortality in Mediterranean open woodlands, the so-called dehesas. Disease control is challenging; therefore, new alternative measures are needed. This study focused on searching for natural biocontrol agents with the aim of developing integrated pest management (IPM) strategies in dehesas as a part of adaptive forest management (AFM) strategies. Native Trichoderma spp. were selectively isolated from healthy trees growing in damaged areas by P. cinnamomi root rot, using Rose Bengal selective medium. All Trichoderma (n = 95) isolates were evaluated against P. cinnamomi by mycelial growth inhibition (MGI). Forty-three isolates presented an MGI higher than 60%. Twenty-one isolates belonging to the highest categories of MGI were molecularly identified as T. gamsii, T. viridarium, T. hamatum, T. olivascens, T. virens, T. paraviridescens, T. linzhiense, T. hirsutum, T. samuelsii, and T. harzianum. Amongst the identified strains, 10 outstanding Trichoderma isolates were tested for mycoparasitism, showing values on a scale ranging from 3 to 4. As far as we know, this is the first report referring to the antagonistic activity of native Trichoderma spp. over P. cinnamomi strains cohabiting in the same infected dehesas. The analysis of the tree health status and MGI suggest that the presence of Trichoderma spp. might diminish or even avoid the development of P. cinnamomi, protecting trees from the worst effects of P. cinnamomi root rot.

New Species of Trichoderma Isolated as Endophytes and Saprobes from Southwest China

During the investigation of endophytic fungi diversity in aquatic plants and the fungal diversity in soil in southwest China, we obtained 208 isolates belonging to Trichoderma, including 28 isolates as endophytes from aquatic plants and 180 isolates as saprobes from soil, respectively. Finally, 23 new species of Trichoderma are recognized by further studies. Their phylogenetic positions are determined by sequence analyses of the combined partial sequences of translation elongation factor 1-alpha (tef1) and gene encoding of the second largest nuclear RNA polymerase subunit (rpb2). The results revealed that the 23 new species are distributed in nine known clades. The morphology and culture characteristics are observed, described and illustrated in detail. Distinctions between the new species and their close relatives were compared and discussed. These include: Trichoderma achlamydosporum, T. amoenum, T. anaharzianum, T. anisohamatum, T. aquatica, T. asiaticum, T. asymmetricum, T. inaequilaterale, T. inconspicuum, T. insigne, T. obovatum, T. paraviride, T. pluripenicillatum, T. propepolypori, T. pseudoasiaticum, T. pseudoasperelloides, T. scorpioideum, T. simile, T. subazureum, T. subuliforme, T. supraverticillatum, T. tibetica, and T. uncinatum.

Pentadecaibins I-V: 15-Residue Peptaibols Produced by a Marine-Derived Trichoderma sp. of the Harzianum Clade

In the course of investigations on peptaibol chemodiversity from marine-derived Trichoderma spp., five new 15-residue peptaibols named pentadecaibins I-V (1-5) were isolated from the solid culture of the strain Trichoderma sp. MMS1255 belonging to the T. harzianum species complex. Phylogenetic analyses allowed precise positioning of the strain close to T. lentiforme lineage inside the Harzianum clade. Peptaibol sequences were elucidated on the basis of their MS/MS fragmentation and extensive 2D NMR experiments. Amino acid configurations were determined by Marfey's analyses. The pentadecaibins are based on the sequences Ac-Aib¹-Gly²-Ala³-Leu⁴-Aib/Iva⁵-Gln⁶-Aib/Iva⁷-Val/Leu⁸-Aib⁹-Ala¹⁰-Aib¹¹-Aib¹²-Aib¹³-Gln¹⁴-Pheol¹⁵. Characteristic of the pentadecaibin sequences is the lack of the Aib-Pro motif commonly present in peptaibols produced by Trichoderma spp. Genome sequencing of Trichoderma sp. MMS1255 allowed the detection of a 15-module NRPS-encoding gene closely associated with pentadecaibin biosynthesis. Pentadecaibins were assessed for their potential antiproliferative and antimicrobial activities.

Molecular Identification of Trichoderma reesei

Fungi comprise one of the most diverse groups of eukaryotes with many cryptic species that are difficult to identify. In this chapter, we detail a protocol for the molecular identification of the most industrially relevant species of Trichoderma-T. reesei. We first describe how a single spore culture should be isolated and used for the sequencing of the diagnostic fragment of the tef1 gene. Then, we provide two alternative methods that can be used for molecular identification and offer the diagnostic oligonucleotide hallmark of the tef1 sequence that is present in sequences of all T. reesei strains known to date and that is therefore suitable for reliable and straightforward identification.

Four new species of Trichoderma in the Harzianum clade from northern China

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.

Ascomycetes from the Qilian Mountains, China - Hypocreales

To investigate fungi from the Qilian Mountains in Gansu Province, ascomycetous specimens were collected and hypocrealean fungi were examined. Eighteen species belonging to six genera in the families Hypocreaceae and Nectriaceae were identified, including 11 species of Hypomyces and Trichoderma in Hypocreaceae and seven species of Nectria, Stylonectria, Thelonectria, and Thyronectria in Nectriaceae. Among them, Stylonectria qilianshanensis and Trichoderma gansuanum are new to science. DNA sequence analyses of combined ACL1, ITS, RPB2, and TEF1 regions confirmed their taxonomic placements. Morphological distinctions between the new species and their close relatives are discussed. Hypomyces tremellicola is reported for the first time in China.

MIST: a Multilocus Identification System for Trichoderma

Due to the rapid expansion in microbial taxonomy, precise identification of common industrially and agriculturally relevant fungi such as Trichoderma species is challenging. In this study, we introduce the online multilocus identification system (MIST) for automated detection of 349 Trichoderma species based on a set of three DNA barcodes. MIST is based on the reference databases of validated sequences of three commonly used phylogenetic markers collected from public databases. The databases consist of 414 complete sequences of the nuclear rRNA internal transcribed spacers (ITS) 1 and 2, 583 sequence fragments of the gene encoding translation elongation factor 1-alpha (tef1), and 534 sequence fragments of the gene encoding RNA polymerase subunit 2 (rpb2). Through MIST, information from different DNA barcodes can be combined and the identification of Trichoderma species can be achieved based on the integrated parametric sequence similarity search (blastn) performed in the manner of a decision tree classifier. In the verification process, MIST provided correct identification for 44 Trichoderma species based on DNA barcodes consisting of tef1 and rpb2 markers. Thus, MIST can be used to obtain an automated species identification as well as to retrieve sequences required for manual identification by means of phylogenetic analysis.IMPORTANCE The genus Trichoderma is important to humankind, with a wide range of applications in industry, agriculture, and bioremediation. Thus, quick and accurate identification of Trichoderma species is paramount, since it is usually the first step in Trichoderma-based research. However, it frequently becomes a limitation, especially for researchers who lack taxonomic knowledge of fungi. Moreover, as the number of Trichoderma-based studies has increased, a growing number of unidentified sequences have been stored in public databases, which has made the species identification more ambiguous. In this study, we provide an easy-to-use tool, MIST, for automated species identification, a list of Trichoderma species, and corresponding sequences of reference DNA barcodes. Therefore, this study will facilitate the research on the biodiversity and applications of the genus Trichoderma.

Biodiversity of Trichoderma from grassland and forest ecosystems in Northern Xinjiang, China

Trichoderma spp., a cosmopolitan fungal genus, has remarkable economic value in industry and agriculture. The resources of Trichoderma spp. in the grassland and forest ecosystems of northern Xinjiang were explored in this study. A total of 634 soil samples was collected, and 312 strains assigned to 23 species of Trichoderma spp. were identified. T. harzianum was the dominant species with 28.2% from all isolates. The principal components analysis indicated that ecosystem was the most dominant impact factor among longitude, latitude, altitude and ecosystems for the species diversities of Trichoderma spp. with the decreasing trend from the north to the south of northern Xinjiang (e.g., from Altay, followed by Yili, Changji, Bayingolin and finally Urumqi). Overall, Trichoderma spp. were more frequently encountered in forest ecosystems (coniferous forest and coniferous and broadleaf mixed forest) than in grassland ecosystems (desert steppe and temperate steppe). Frequency of Trichoderma spp. was significantly decreased along with increased altitude and only a few strains were isolated from altitudes above 3000 m. The results provided essential information on Trichoderma occurrence and distribution, which should benefit the application of Trichoderma in agriculture.

El-Meihy R. Phylogenetic Diversity of Trichoderma Strains and Their Antagonistic Potential against Soil-Borne Pathogens under Stress Conditions

Trichoderma species are known as excellent biocontrol agents against soil-borne pathogens that cause considerable crop losses. Eight strains of Trichoderma were isolated from five Egyptian regions. They identified based on translation elongation factor-1α (TEF1) sequencing as four different Trichoderma species: Trichoderma asperellum, Trichoderma harzianum, Trichoderma viride, and Trichoderma longibrachiatum. Optimal growth conditions (temperature and media), and the phosphate solubilization capability of Trichoderma strains were evaluated in vitro. Further, the ability of these strains to antagonize Fusarium solani, Macrophomina phaseolina, and Fusarium graminearum was also evaluated. The results revealed that Trichoderma harzianum (Th6) exhibited the highest antagonistic ability against F. solani, M. phaseolina and F. graminearum with inhibition rates of 71.42%, 72.97%, and 84.61%, respectively. Trichoderma viride (Tv8) exhibited the lowest antagonism against the same pathogens with inhibition rates of 50%, 64% and 69.23%, respectively. Simple-sequence repeats (SSRs) and random amplified polymorphic DNA (RAPD) markers were used to evaluate the genetic variability of the Trichoderma strains. The results revealed that of 45 RAPD amplified bands, 36 bands (80%) were polymorphic and of SSRs amplified 36 bands, 31 bands (86.11%) were polymorphic. The amplification of calmodulin and β-1,3-endoglucanase was noted at 500 bp and 230 bp, respectively. Data indicated that T. viride (Tv8) had the highest phosphate solubilization index (10.0 mm), while T. harzianum (Th6) had the lowest phosphate solubilization index (4.0 mm). In conclusion, T. harzianum (Th6) had the highest antagonistic activity in dual culture assay along with the growth rate; while T. viride (Tv8) had the highest phosphate solubilization activity. There are still gaps in obtaining new formulations, selecting potent Trichoderma strains to confirm disease control in planta. For improving Trichoderma recommendation in the organic agricultural system and sustaining the fertility of the soil, the field application of highly antagonistic biocontrol agents in different types of soil and plant species will be the first approach toward bio-pesticide treatments along with bio-fertilizer inoculation. Furthermore, secondary metabolites will be investigated for the most promising strains with the combination of different pathogens and application timing.

Trichoderma panacis sp. nov., an endophyte isolated from Panax notoginseng

An endophytic member of the genus Trichoderma was isolated from the root of a healthy 3-year-old Panax notoginseng in Yunnan province, PR China. The results of phylogenetic analyses based on a combined of ITS, tef1 and rpb2 indicated that this isolate was distinct from other species of the genus Trichoderma and closely related to Trichoderma songyi. It can be distinguished from T. songyi by its slower growth rates on PDA and colony morphology. The novel isolate formed conidia in thick white pustules scattered mostly at the margin. Its conidiophores tended to be regularly verticillium-like, little branched, sometimes substituted by phialides singly or in whorls. Conidia are smooth, mostly broadly subglobose to ellipsoidal. In combination with the genotypic and phenotypic characteristics, all data demonstrated that the fungus studied represented a unique and distinguishable novel species of the genus Trichoderma, for which the name Trichoderma panacis sp. nov. is proposed.

Ochraceocephala foeniculi gen. et sp. nov., a new pathogen causing crown rot of fennel in Italy

A new disease of fennel is described from Sicily (southern Italy). Surveys of the disease and sampling were conducted during spring 2017 and 2018 in Adrano and Bronte municipalities (Catania province) where this crop is widely cultivated. Isolations from the margin of symptomatic tissues resulted in fungal colonies with the same morphology. Pathogenicity tests with one isolate of the fungus on 6-month-old plants of fennel reproduced similar symptoms to those observed in nature. Inoculation experiments to assess the susceptibility of six different fennel cultivars to infection by the pathogen showed that the cultivars 'Narciso', 'Apollo', and 'Pompeo' were more susceptible than 'Aurelio', 'Archimede', and 'Pegaso'. Phylogenetic analyses based on a matrix of the internal transcribed spacer (ITS), the large subunit (LSU), and the small subunit (SSU) rDNA regions revealed that the isolates represent a new genus and species within the Leptosphaeriaceae, which is here described as Ochraceocephala foeniculi gen. et sp. nov. This study improves the understanding of this new fennel disease, but further studies are needed for planning effective disease management strategies. According to the results of the phylogenetic analyses, Subplenodomus iridicola is transferred to the genus Alloleptosphaeria and Acicuseptoria rumicis to Paraleptosphaeria.

The genus Melanconis (Diaporthales)

The genus Melanconis (Melanconidaceae, Diaporthales) in the strict sense is here re-evaluated regarding phylogenetic structure, taxonomy, distribution and ecology. Using a matrix of sequences from ITS, LSU, ms204, rpb2, tef1 and tub2, eight species are recognised and their phylogenetic positions are determined. Based on phylogenetic, morphological and geographical differentiation, Melanconis marginalis is subdivided into four subspecies. Melanconis italica is reduced to a subspecies of Melanconis marginalis. The two species Melanconis larissae from Betula sp. and M. pacifica from Alnus rubra are described as new. Melanconis alni and M. stilbostoma are lectotypified and M. alni, M. marginalis and M. stilbostoma are epitypified. All GenBank sequences deposited as Melanconis alni are shown to actually represent M. marginalis and those as M. marginalis belong to the newly described M. pacifica. Currently, Alnus and Betula are the sole host genera of Melanconis. All species and subspecies are (re-)described and illustrated. In addition, the neotypification of Melanconium pterocaryae is here validated.

Taxonomy of two synnematal fungal species from Rhus chinensis, with Flavignomonia gen. nov. described

Rhuschinensis represents a commercially and ecologically important tree species in China, but suffers from canker diseases in Jiangxi Province. Synnemata, pycnidia and ascomata were discovered on cankered tissues. Strains were obtained from single ascospore or conidium within the fruiting bodies and identified based on morphological comparison and the phylogenetic analyses of partial ITS, LSU, tef1 and rpb2 gene sequences. As a result, two species were confirmed to represent two kinds of synnemata. One of these species is described herein as Flavignomoniarhoigenagen. et sp. nov.; and Synnemasporellaaculeans is illustrated showing ascomata, pycnidia and synnemata. Flavignomonia is distinguished from Synnemasporella by the colour of the synnematal tips. Additionally, Flavignomonia can be distinguished from the other gnomoniaceous genera by the formation of synnemata.

Bioremediation of Dichlorodiphenyltrichloroethane (DDT)-Contaminated Agricultural Soils: Potential of Two Autochthonous Saprotrophic Fungal Strains

DDT (dichlorodiphenyltrichloroethane) was used worldwide as an organochlorine insecticide to control agricultural pests and vectors of several insect-borne human diseases. It was banned in most industrialized countries; however, due to its persistence in the environment, DDT residues remain in environmental compartments, becoming long-term sources of exposure. To identify and select fungal species suitable for bioremediation of DDT-contaminated sites, soil samples were collected from DDT-contaminated agricultural soils in Poland, and 38 fungal taxa among 18 genera were isolated. Two of them, Trichoderma hamatum FBL 587 and Rhizopus arrhizus FBL 578, were tested for tolerance in the presence of 1-mg liter^-1 DDT concentration by using two indices based on fungal growth rate and biomass production (the tolerance indices Rt:Rc and TI), showing a clear tolerance to DDT. The two selected strains were studied to evaluate catabolic versatility on 95 carbon sources with or without DDT by using the Phenotype MicroArray system and to investigate the induced oxidative stress responses. The two strains were able to use most of the substrates provided, resulting in both high metabolic versatility and ecological functionality in the use of carbon sources, despite the presence of DDT. The activation of specific metabolic responses with species-dependent antioxidant enzymes to cope with the induced chemical stress has been hypothesized, since the presence of DDT promoted a higher formation of reactive oxygen species in fungal cells than the controls. The tested fungi represent attractive potential candidates for bioremediation of DDT-contaminated soil and are worthy of further investigations.IMPORTANCE The spread and environmental accumulation of DDT over the years represent not only a threat to human health and ecological security but also a major challenge because of the complex chemical processes and technologies required for remediation. Saprotrophic fungi, isolated from contaminated sites, hold promise for their bioremediation potential toward toxic organic compounds, since they might provide an environment-friendly solution to contamination. Once we verified the high tolerance of autochthonous fungal strains to high concentrations of DDT, we showed how fungi from different phyla demonstrate a high metabolic versatility in the presence of DDT. The isolates showed the singular ability to keep their functionality, despite the DDT-induced production of reactive oxygen species.

European species of Dendrostoma (Diaporthales)

European species of the genus Dendrostoma (Erythrogloeaceae, Diaporthales) occurring on Castanea sativa and Quercus spp. based on freshly collected material are presented. Using a matrix of sequences from ITS, LSU, rpb2, and tef1, five species are recognized, and their phylogenetic positions are determined. Four species are added to the 14 described species of Dendrostoma. Dendrostoma atlanticum on Castanea sativa, D. creticum on Quercus coccifera and D. istriacum on Q. ilex are described as new species, Valsa castanea is combined in Dendrostoma, and D. leiphaemia is redescribed and illustrated. A key to the European species of Dendrostoma is provided.

Understanding fungal potential in the mitigation of contaminated areas in the Czech Republic: tolerance, biotransformation of hexachlorocyclohexane (HCH) and oxidative stress analysis

The study of the soil microbial community represents an important step in better understanding the environmental context. Therefore, biological characterisation and physicochemical integration are keys when defining contaminated sites. Fungi play a fundamental role in the soil, by providing and supporting ecological services for ecosystems and human wellbeing. In this research, 52 soil fungal taxa were isolated from in situ pilot reactors installed to a contaminated site in Czech Republic with a high concentration of hexachlorocyclohexane (HCH). Among the identified isolates, 12 strains were selected to evaluate their tolerance to different isomers of HCH by using specific indices (Rt:Rc; T.I.) and to test their potential in xenobiotic biotransformation. Most of the selected taxa was not significantly affected by exposure to HCH, underlining the elevated tolerance of all the tested fungal taxa, and different metabolic intermediates of HCH dechlorination were observed. The oxidative stress responses to HCH for two selected species, Penicillium simplicissimum and Trichoderma harzianum, were investigated in order to explore their toxic responses and to evaluate their potential functioning in bioremediation of contaminated environments. This research suggests that the isolated fungal species may provide opportunities for new eco-friendly, integrated and cost-effective solutions for environmental management and remediation, considering their efficient adaptation to stressful conditions.

Phalangispora sinensis sp. nov. from Yunnan, China and two new members of Wiesneriomycetaceae

Phalangispora sinensis, an aquatic hyphomycete collected from south-western PR China, is described as a new species. This new species is characterized by having multicellular branched conidia composed of a curved main axis and one or two laterals, with the laterals arising from the third or fourth cell of the base of the main axis. Combined analyses of the LSU, SSU, RPB2 and TEF1 gene sequence data revealed that Phalangispora and another aquatic hyphomycete genus, Setosynnema, belonged to Wiesneriomycetaceae, Tubeufiales, Dothideomycetes, Ascomycota.

Two New Species and a New Chinese Record of Hypocreaceae as Evidenced by Morphological and Molecular Data

To explore species diversity of Hypocreaceae, collections from Guangdong, Hubei, and Tibet of China were examined and two new species and a new Chinese record were discovered. Morphological characteristics and DNA sequence analyses of the ITS, LSU, EF-1α, and RPB2 regions support their placements in Hypocreaceae and the establishments of the new species. Hypomyces hubeiensis sp. nov. is characterized by occurrence on fruitbody of Agaricus sp., concentric rings formed on MEA medium, verticillium-like conidiophores, subulate phialides, rod-shaped to narrowly ellipsoidal conidia, and absence of chlamydospores. Trichoderma subiculoides sp. nov. is distinguished by effuse to confluent rudimentary stromata lacking of a well-developed flank and not changing color in KOH, subcylindrical asci containing eight ascospores that disarticulate into 16 dimorphic part-ascospores, verticillium-like conidiophores, subcylindrical phialides, and subellipsoidal to rod-shaped conidia. Morphological distinctions between the new species and their close relatives are discussed. Hypomyces orthosporus is found for the first time from China.

Morphology and phylogeny reveal two novel Coryneum species from China

Coryneum is currently the sole genus of Coryneaceae in Diaporthales, distinguished from other diaporthalean genera by transversely distoseptate brown conidia. However, Coryneum species are presently difficult to identify because of variability and overlap of morphological characters and the lack of sequence data for most described species. During fungal collection trips in China, 13 Coryneum isolates were obtained from cankered branches of Ilex and Quercus. Morphological and phylogenetic analyses (ITS, LSU, TEF1-α and RPB2) revealed that these strains belong to two new species (viz. Coryneumilicissp. nov. and C.songshanensesp. nov.), and three known species, C.gigasporum, C.sinense, and C.suttonii. Coryneumilicis has larger conidia and more distosepta than most Coryneum species. Coryneumsongshanense was similar to C.sinense from the same host genus, Quercus, in conidial length, but distinct in conidial width and by molecular data.

Occurrence of Mycotoxigenic Fusarium Species and Competitive Fungi on Preharvest Maize Ear Rot in Poland

Maize has become one of the most important crops for food and feed production-both as a silage and crop residue worldwide. The present study aimed to identify the co-occurrence of Fusarium subglutinans, Fusarium verticillioides, Trichoderma atroviride, Sarocladium zeae, and Lecanicillium lecanii on maize ear rot. Further, the accumulation of mycotoxins as secondary metabolites of Fusarium spp. in maize ear samples was also analyzed. Maize ear samples were collected between 2014 and 2017 from two main maize growing areas in Poland (Greater Poland and Silesia region). A significant difference was found in the frequency of two main Fusarium spp. that infect maize ears, namely F. subglutinans and F. verticillioides. In addition to Fusarium spp. T. atroviride, S. zeae, and L. lecanii were also identified. T. atroviride species was found in 14% of maize samples examined between 2014 and 2017, particularly with a high percentage of Trichoderma spp. recorded in 2014, i.e., in 31% of samples. However, mycotoxin content (beauvericin and fumonisins) varied, depending on both the location and year of sampling. The interaction of fungi and insects inhabiting maize ear and kernel is very complex and not yet elucidated. Therefore, further research is required in this area.

The genus Juglanconis (Diaporthales) on Pterocarya

Based on molecular phylogenetic analyses of a multigene matrix of partial nuSSU-ITS-LSU rDNA, cal, his, ms204, rpb1, rpb2, tef1 and tub2 sequences, recent European and Iranian collections of Melanconium pterocaryae from the type host, Pterocarya fraxinifolia, are shown to be distinct from the Japanese Melanconis pterocaryae from Pterocarya rhoifolia, and both are confirmed as closely related members of the recently described genus Juglanconis. Therefore, the new name Juglanconis japonica is proposed for Melanconis pterocaryae. As no type collection could be traced, Melanconium pterocaryae (syn. J. pterocaryae) is neotypified, described and illustrated, and it is recorded for Europe for the first time. During field surveys in natural stands of P. fraxinifolia in Guilan province (Iran), Juglanconis pterocaryae was consistently isolated from tissues affected by branch and trunk cankers, twig dieback and wood necrosis, indicating that it is the causal agent of these diseases. The external and internal symptoms associated with these trunk diseases are described and illustrated.

Taxonomy of the Sphaerostilbella broomeana-group (Hypocreales, Ascomycota)

Three new species, closely related to Sphaerostilbella broomeana, are described from the USA and India. These species form septate conidia from simple conidiophores with individual branches terminating in a single phialide and chlamydospores. Teleomorphs, known for S. broomeana and S. appalachiensis, are characterised by hairy perithecia and fusiform, apiculate, and conspicuously warted ascospores. This combination of characters distinguishes the S. broomeana-group from other members of Sphaerostilbella that all form gliocladium-type anamorphs and mostly grow on basidiomata of Stereum spp. Like in other species of the genus, the majority of hosts of the species described in this paper belong to wood-inhabiting taxa of Russulales. Sphaerostilbella broomeana had been recorded from a few regions in Europe and exclusively on Heterobasidion annosum. Herein, it is reported also from H. parviporum in many other localities and on H. insulare s.l. at the foothills of the Himalayas. Its sister species, found in the same region in northern India on another member of Russulales (Dichostereum effuscatum), is described as S. himalayensis. The two species described from North America colonize polypores from various taxa. Whereas S. appalachiensis occurs in eastern USA, with H. irregulare among its hosts, S. toxica is so far known only from two locations in eastern Texas, growing on Gloeophyllum striatum (Polyporales). Despite their great similarity in morphology and ITS rDNA, TEF1 sequences clearly distinguish these two North-American species. Moreover, the two strains of S. toxica appeared metabolically distinct as their organic extracts strongly inhibited the growth of human pathogenic microbes grown in vitro. Phylogenetic analysis of rDNA sequences supports monophyly of the genus Sphaerostilbella and the included S. broomeana-group, established here.