The use of DNA-fingerprint analysis in the classification of some species of the Trichoderma aggregate

We have analyzed nine different species of the filamentous fungus Trichoderma and three strains of T. reesei for the presence of hypervariable loci in their genomes by hybridization with simple repeat oligonucleotides ((CT) sub(8), (GTG) sub(5), and (GACA) sub(4)). On the basis of the DNA-fingerprints obtained, the Trichoderma) aggregate is re-classified into five groups: I (T. reesei, T. todica ), II (T. polysporum, T. longibrachiatum, T. koningii , and T. pseudokoningii ), III (T. virgatum ), IV (T. saturnisporum ) and V (T. harzianum ). The results contradict the claim that T. reesei is a subspecies of T. longibrachiatum . Furthermore, hybridization with (CA) sub(8) allowed a subdivision of group II, wherein T. pseudokoningii) formed a subgroup, IIb, which is highly homologous with, but distinct from subgroup IIa.