Phylogenetic diversity analysis of Trichoderma species based on internal transcribed spacer (ITS) marker

Abstract

The phylogeny of Trichoderma and the phylogenetic relationships of its species was investigated by maximum parsimony analysis and distance analysis of DNA sequences from multiple genetic loci 18S rDNA sequence analysis suggests that the genus Trichoderma evolved at the same time as Hypomyces and Fusarium and thus about 110 Myr ago 28S rDNA sequence analysis shows that the genus Trichoderma is part of a monophyletic branch within the Hypocreaceae. Most isolates of the genus Trichoderma were found to act as mycoparasites of many economically important aerial and soil-borne plant pathogens. Trichoderma has attained importance as a substitute for chemical pesticides and hence an attempt was intended to corroborate the positive relatedness of molecular and morphological characters. Two fungal strains, Trichoderma koningii T_k-5201/CSAU and Trichoderma virens T_vi-4177/CSAU were isolated from a soil sample collected from CSA Farm, Kanpur district of Uttar Pradesh, India. The universal primers (internal transcribed spacer, ITS) were used for the amplification of 18S rRNA gene fragment and strains were thus characterized with the help of ITS marker. It is proposed that the identified strains T. koningii T_k-5201/CSAU and T. virens T_vi-4177/CSAU be assigned as the type strains of a species of genus Trichoderma based on phylogenetic tree analysis together with the 18S rRNA gene sequence search in Ribosomal Database Project, small subunit rRNA and large subunit rRNA databases. The sequence was deposited in GenBank with the accession numbers KC800923 and KC800924, respectively. Thus an integrated approach of morphological and molecular markers can be employed to identify a superior strain of Trichoderma for its commercial exploitation.

Keywords: 18S ribosomal RNA gene, Trichoderma, phylogenetic analysis, internal transcribed spacer (ITS), DNA sequencing, GenBank

African Journal of Biotechnology, Vol. 13(3), pp. 449-455, 15 January, 2014