Search

Twenty-two strains of Trichoderma spp. ( T. harzianum species complex [THSC], Trichoderma aggressivum f. europaeum, Trichoderma pleuroti, and Trichoderma pleuroticola ) causing green mold disease on edible mushrooms (button mushroom, shiitake and oyster mushroom), collected during 2004-2018 from four countries (Serbia, North Macedonia, Croatia, and Hungary) were examined. Based on their ITS (internal transcribed spacer) sequences, strains from shiitake mushroom in Serbia were identified as members of the THSC, while in samples obtained from Serbian and North-Macedonian oyster mushroom farms THSC, T. pleuroti and T. pleuroticola were detected, which represent the first findings in the region. In fungicide susceptibility tests, all examined Trichoderma strains were found to be highly sensitive to prochloraz (ED 50 <0.4 µg mL -1 ) and considerably susceptible to metrafenone (ED 50  < 4 µg mL -1 ). The most sensitive taxon to both fungicides was THSC from oyster mushroom. The toxicity of metrafenone was satisfying and strains from oyster mushroom showed the highest sensitivity (ED 50  < 1.43 µg mL -1 ), while strains originating from button mushroom and shiitake displayed similar susceptibilities (ED 50  < 3.64 µg mL -1 ). After additional in vivo trials, metrafenone might also be recommended for the control of green mold disease in mushroom farms.

Fourteen Trichoderma (Hypocreales) species were identified during a survey of the genus in South Africa. These include T. afroharzianum, T. asperelloides, T. asperellum, T. atrobrunneum, T. atroviride, T. camerunense, T. gamsii, T. hamatum, T. koningii, T. koningiopsis, T. saturnisporum, T. spirale, T. virens, and T. viride. Ten of these species were not known to occur in South Africa prior to this investigation. Five additional species were novel and are described here as T. beinartii, T. caeruleimontis, T. chetii, T. restrictum, and T. undulatum. These novel Trichoderma species display morphological traits that are typical of the genus. Based on molecular identification using calmodulin, endochitinase, nuc rDNA internal transcribed spacers (ITS1-5.8S-ITS2), RNA polymerase II subunit B, and translation elongation factor 1-α gene sequence data, T. beinartii, T. caeruleimontis, and T. chetii were found to belong to the Longibrachiatum clade, whereas T. restrictum is a member of the Hamatum clade. Trichoderma undulatum occupies a distinct lineage distantly related to other Trichoderma species. Strains of T. beinartii and T. chetii were isolated previously in Hawaii and Israel; however, T. caeruleimontis, T. restrictum, and T. undulatum are so far known only from South Africa.

Collections of hypocrealean fungi found on decaying wood in subtropical regions of China were examined. Two new species, Trichoderma confluens and T. hubeiense, were discovered and are described. Trichoderma confluens is characterized by its widely effuse to rarely pulvinate, yellow stromata with densely disposed yellowish brown ostioles, simple acremonium- to verticillium-like conidiophores, hyaline conidia and multiform chlamydospores. Trichoderma hubeiense has pulvinate, grayish yellow stromata with brownish ostioles, trichoderma- to verticillium-like conidiophores and hyaline conidia. The phylogenetic positions of the two fungi were investigated based on sequence analyses of RNA polymerase II subunit b and translation elongation factor 1-α genes. The results indicate that T. confluens belongs to the Hypocreanum clade and is associated with but clearly separated from T. applanatum and T. decipiens. Trichoderma hubeiense belongs to the Polysporum clade and related to T. bavaricum but obviously differs from other members of the clade in sequence data. Morphological distinctions between the new species and their close relatives are noted and discussed., (© 2016 by The Mycological Society of America.)

Trichoderma harzianum is known as a cosmopolitan, ubiquitous species associated with a wide variety of substrates. It is possibly the most commonly used name in agricultural applications involving Trichoderma, including biological control of plant diseases. While various studies have suggested that T. harzianum is a species complex, only a few cryptic species are named. In the present study the taxonomy of the T. harzianum species complex is revised to include at least 14 species. Previously named species included in the complex are T. guizhouense, T. harzianum, and T. inhamatum. Two new combinations are proposed, T. lentiforme and T. lixii. Nine species are described as new, T. afarasin, T. afroharzianum, T. atrobrunneum, T. camerunense, T. endophyticum, T. neotropicale, T. pyramidale, T. rifaii and T. simmonsii. We isolated Trichoderma cultures from four commercial biocontrol products reported to contain T. harzianum. None of the biocontrol strains were identified as T. harzianum s. str. In addition, the widely applied culture 'T. harzianum T22' was determined to be T. afroharzianum. Some species in the T. harzianum complex appear to be exclusively endophytic, while others were only isolated from soil. Sexual states are rare. Descriptions and illustrations are provided. A secondary barcode, nuc translation elongation factor 1-α (TEF1) is needed to identify species in this complex., (© 2015 by The Mycological Society of America.)

Collections of Trichoderma having hyaline ascospores from different areas of China were examined. Using combined analyses of morphological data, culture characters and phylogenetic information based on rDNA sequences of partial nuc translation elongation factor 1-α encoding gene (TEF1-α) and the gene encoding the second largest nuc RNA polymerase subunit (RPB2), three new species, Trichoderma applanatum, T. oligosporum and T. sinoluteum, were discovered and are described. Trichoderma applanatum produces continuous flat to pulvinate, white to cream stromata with dense orange or pale brown ostioles, and simple acremonium-like to verticillium-like conidiophores, belongs to the Hypocreanum clade and is closely related to T. decipiens. Trichoderma oligosporum forms reddish brown stromata with a downy surface, hyaline conidia and gliocladium-like conidiophores, and is closely related to but distinct from T. crystalligenum in the Psychrophila clade. Trichoderma sinoluteum, as a member of the Polysporum clade, is characterized by pale yellow stromata, white pustulate conidiomata, pachybasium-like conidiophores, and hyaline conidia. Differences between the new species and their close relatives are discussed., (© 2015 by The Mycological Society of America.)

Four isolates tentatively identified as Pseudaegerita matsushimae on the basis of the morphology of bulbil-like propagules were collected from substrates submerged in water in Thailand and Japan. In culture studies the two Thai isolates were found to produce phialoconidia on conidiogenous cells and phialoconidiophores whose morphology was similar to that of Trichoderma. Phylogenetic analysis based on D1/D2 regions of LSU rDNA sequences showed that the four isolates were nested in Hypocrea/Trichoderma (Hypocreales) while P. corticalis, the type species of Pseudaegerita, belongs to Hyaloscypha (Helotiales). Preliminary analysis by ISTH Web tools based on 5.8S-ITS rDNA and phylogenetic analysis based on rpb2 and tef1-int4 genes showed that the isolates have specific sequences of Trichoderma (anchors 1-5) and belong to the Hamatum clade but they grouped apart from any known species of Trichoderma. The sequences of the tef1-int4 gene, which were amplified from the authentic specimen of P. matsushimae (IMI 266915), also showed that it belongs to the Hamatum clade closely clustering with T. yunnanense but separate from our four isolates. The morphology of P. matsushimae (IMI 266915), especially the sizes of phialides and phialoconidia, were different from T. yunnanense. Thus, we conclude that IMI 266915 and our isolates are to be assigned to two different species in the Hamatum clade of Trichoderma, although both species have similar morphology of bulbils and phialoconidia. Morphology and molecular data revealed that P. matsushimae should be assigned to the genus Trichoderma as T. matsushimae and the Thai and Japanese isolates are placed in T. aeroaquaticum sp. nov. This finding supports the interpretation that aero-aquatic fungi have evolved from terrestrial fungi. We assume that these fungi probably were derived from typically soil-inhabiting species of Trichoderma; an adaptation to aquatic environments is shown by formation of bulbil-like propagules floating on water.

Two new species of Hypocrea are added here to the European funga. Hypocrea britdaniae, a fungus with unknown anamorph and large, conspicuous stromata resembling basidiomata of a corticiaceous fungus, is a sister species to the Longibrachiatum clade, while H. foliicola, a leaf-dwelling species that forms pulvinate stromata, is recognized as an additional member of the pachybasium core group. Hypocrea foliicola sporulates in culture in a reduced verticillium-like manner, while it produces a white, typical pachybasium-like anamorph in nature. Ecologically H. foliicola is remarkable in inhabiting leaves, a substrate rarely recorded for Hypocrea. All relevant morphological teleomorphic and anamorphic traits are given. The phylogenetic placement of the new species within Hypocrea/Trichoderma was determined with combined analyses of rpb2 and tef1 exon sequences.

Three new species of Hypocrea/Trichoderma sect. Trichoderma (Hypocreaceae, Hypocreales, Ascomycota, Fungi) are described from recent collections in southern Europe and the Canary Islands. They have been characterized by morphological and molecular methods, including microscopic examination of the teleomorph in thin sections, the anamorph, growth rate experiments and phylogenetic analyses based on a part of the translation elongation factor 1-alpha encoding gene (tef1) containing the two last introns and a part of the rpb2 gene, encoding the second largest RNA polymerase subunit. Analyses involving tef1 did not unequivocally resolve the sister clade relationship of Hypocrea caerulescens relative to the Koningii and Viride clades, while analyses based on rpb2 clearly suggest a close relationship with the former, although the phenotype of H. caerulescens is similar to H. viridescens, particularly by its warted conidia and a coconut-like odor in CMD culture. Hypocrea hispanica and T. samuelsii however are clearly related to the Viride clade by both phylogenetic markers, despite their morphological similarity to H. koningii and its relatives. An apparently specific blue pigment is formed in CMD cultures by Hypocrea caerulescens but could not be obtained by extraction with organic solvents.

A new species of Trichoderma (teleomorph Hypocrea, Ascomycota, Sordariomycetes, Hypocreales, Hypocreaceae), T. amazonicum, endophytic on the living sapwood and leaves of Hevea spp. trees is described. Trichoderma amazonicum is distinguished from closely related species in the Harzianum clade (e.g. Hypocrea alni, H. brunneoviridis, H. epimyces, H. parepimyces, T. aggressivum, T. harzianum, T. pleuroticola and T. pleuroti) by morphological and ecological characteristics and phylogenetic analysis of three loci (ITS nrDNA, tef1 and rpb2). The closest relatives of this species are the facultatively fungicolous species T. pleuroticola and T. pleuroti.

Analysis of a worldwide collection of strains of Trichoderma asperellum sensu lato using multilocus genealogies of four genomic regions (tef1, rpb2, act, ITS1, 2 and 5.8s rRNA), sequence polymorphism-derived (SPD) markers, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) of the proteome and classical mycological techniques revealed two morphologically cryptic sister species within T. asperellum, T. asperellum, T. asperelloides sp. nov. and a third closely related but morphologically distinct species. T. yunnanense. Trichoderma asperellum and T. asperelloides have wide sympatric distribution on multiple continents; T. yunnanense is represented by a single strain from China. Several strains reported in the literature or represented in GenBank as T. asperellum are re-identified as T. asperelloides. Four molecular SPD typing patterns (I-IV) were found over a large geographic range. Patterns I-III were produced only by T. asperellum and pattern IV by T. asperelloides and T. yunnanense. Pattern I was found in North America, South America, Africa and Europe and Asia (Saudi Arabia). Pattern III was found in Africa, North America, South America and Asia, not in Europe. Pattern II was found only in Cameroon (central Africa) and Peru. Pattern IV was found in all continents. All SPD II pattern strains formed a strongly supported subclade within the T. asperellum clade in the phylogenetic tree based on rpb2 and MLS (combined multilocus sequence). The diversity of DNA sequences, SPD markers and polypeptides in T. asperellum suggests that further speciation is under way within T. asperellum. MALDI-TOF MS distinguished T. yunnanense from related taxa by UPGMA clustering, but separation between T. asperellum and T. asperelloides was less clear.

The new species, Trichoderma evansii and T. lieckfeldtiae, resemble the closely related T. hamatum and T. pubescens in forming discrete, setose conidial pustules within which arise smooth, green conidia from pachybasium-like conidiophores. The phylogenetic position of these species was determined with combined partial sequences of ITS, translationelongation factor 1-alpha, RNA polymerase II subunit and actin genes. All are members of the Viride clade. Trichoderma evansii forms a sister group relationship with a clade that includes T. hamatum and T. pubescens. It differs from the latter two species in having subglobose conidia; it was isolated as an endophyte from sapwood of Lophira alata (Ochnaceae) and Cola verticillata (Malvaceae) in Cameroon and Theobroma gileri (Malvaceae) in Peru. Trichoderma lieckfeldtiae occupies an unresolved position in the Viride clade despite being virtually morphologically indistinguishable from T. hamatum; it was isolated from fruit of cacao infected with Moniliophthora roreri in Colombia, pseudostroma of Moniliophthora roreri on pods of Theobroma cacao in Peru and from soil in a cacao farm in Cameroon (central Africa).

The new species Hypocrea crystalligena (Hypocreales, Ascomycota, Fungi) is described as a holomorph and characterized based on an integrated phenotypic and phylogenetic approach, using teleomorph and anamorph morphologies, culture studies and analyses of phylogenetic markers including internal transcribed spacer 1 and 2 (ITS1 and 2), two last introns of the translation elongation factor 1-alpha encoding gene (tef1), and a portion of the rpb2 gene, encoding the second largest RNA polymerase subunit. Stromata of H. crystalligena show similarities with those of species from Trichoderma sect. Trichoderma but differ in several respects, including color, presence of white crystals on the surface and small ascospores. Colonies on CMD appear distinct, form colorless to white crystals on isolation, a yellowish to brown pigment and an anamorph with hyaline conidia exhibiting verticillium-like to gliocladium-like structural elements. ITS1 and 2 sequences exhibit all genus-specific features but also contain several unique hallmarks permitting development of a species-diagnostic barcode. Based on the analyses of partial rpb2 and tef1 sequences, H. crystalligena constitutes a separate evolutionary lineage with H. megalocitrina and H. psychrophila as its nearest neighbors. All these species form one phylogenetic clade with the H. pulvinata/H. citrina node.