Comparison of the behaviour of a transformed hygromycin resistant strain of Trichoderma atroviride (M1057hygR) with the wildtype strain (M1057)

The biocontrol isolate Trichoderma atroviride M1057 and a transformed hygromycin resistant biotype (M1057hygR) were compared using biological control rhizosphere competence and antibiosis studies to determine whether the transformed biotype performed in a similar manner to the wildtype strain In an onion growth chamber trial using soil naturally infested with the onion white rot pathogen Sclerotium cepivorum there was no significant difference (P>005) in the level of disease control given by the two T atroviride strains Similarly populations of T atroviride M1057 and M1057hygR were equivalent (P>005) in the rhizosphere of onion seedlings There was no significant difference (P>005) between the mycelial growth rates of S cepivorum when grown on agar amended with culture filtrate of T atroviride M1057 and M1057hygR Thus T atroviride M1057hygR has similar biological attributes to the wildtype isolate and can be used in future field studies looking at the population ecology of the biological control agent