Molecular characterization of biocontrol isolates of Trichoderma aureoviride

Abstract

Trichoderma has gained immense importance since last few decades due to its biological control ability against several plant pathogens. Twenty isolates of T. aureoviride were collected from different geographical locations of Chhattisgarh. Molecular characterization of isolates of T. aureoviride revealed homogeneity with ITS primer (internal transcribed spacer). In the present study the genetic relatedness among twenty isolates of Trichoderma aureoviride was analyzed by using sixteen gene specific markers. PCR amplification with ITS primers showed homogeneity of all T. aureoviride isolates indicating that they belong to the same species. Six different chitinase gene specific primers produced amplification of chitinase genes in almost all T. aureoviride isolates except one of the exochitinase encoding gene (N-acetyl- -glucosaminidase), nag70 based primer Nag70F-R and two endochitinase encoding gene specific primers Ech42-2F-R and Ech42-3F-R that could not amplify any of the isolates of T. aureoviride. PCR amplification of fragments of cellulase gene using CBH1 primer amplified a nucleotide fragment of the expected size from some isolates while PR808-PRegl4 primer pair amplified 340, 140 & 100 bp bands in all the isolates. Primer pair fRPB2-5F2- fRPB2-7cR2 generated major band above 1000 bp confirming the amplification of a 1.2-kb fragment of subunit 2 of the RNA polymerase B gene (RPB2) containing an ITS-like region. Almost all the isolates showed the presence of endochitinase and cellulose gene fragments which proves their ability to antagonize phytopathogens.