title: Systematics of the Trichoderma harzianum species complex and the re-identification of commercial biocontrol strains.
abstract: 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.
authors: University of Maryland, Department of Plant Science and Landscape Architecture, 2112 Plant Sciences Building, College Park, Maryland 20742, and Universidad de Costa Rica, Escuela de Biología, Apartado 11501-2060, San Pedro, San José, Costa Rica.
authors: Priscila
authors: P
authors: Chaverri
authors: Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina - EPAGRI, Estação Experimental de São Joaquim, São Joaquim, Santa Catarina, 88600-000, Brazil.
authors: Fabiano
authors: F
authors: Branco-Rocha
authors: University of Vienna, Department of Systematic and Evolutionary Botany, Faculty Centre of Biodiversity, Rennweg 14, 1030 Vienna, Austria.
authors: Walter
authors: W
authors: Jaklitsch
authors: Clark University, Biology Department, 950 Main Street, Worcester, Massachusetts 01610.
authors: Romina
authors: R
authors: Gazis
authors: Interdisciplinary Research Centre for BioSystems, Land Use and Nutrition (IFZ), Department of Food Science, Institute of Nutritional Science, University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
authors: Thomas
authors: T
authors: Degenkolb
authors: United States Dept. of Agriculture, Agriculture Research Service, Systematic Mycology and Microbiology Lab., B-010, Beltsville, Maryland 20705.
authors: Gary J
authors: GJ
authors: Samuels
mesh_terms: D059827:Agricultural Inoculants / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D010572:Pest Control, Biological / Q000191:economics; D010802:Phylogeny; D012988:Soil Microbiology; D013172:Spores, Fungal / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D014242:Trichoderma / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005656:Fungal Proteins; D020648:Peptide Elongation Factor 1
keywords: Hypocrea; cryptic speciation; endophytes; fungal barcode; phylogenetics; species concepts; taxonomy