Development of a strain-specific SCAR marker for the detection of Trichoderma atroviride 11, a biological control agent against soilborne fungal plant pathogens

The genus Trichoderma includes biocontrol agents (BCAs) effective against s oilborne plant pathogenic fungi. Several potentially useful strains for bio logical control are difficult to distinguish from other strains of Trichode rma found in the field. So, there is a need to find ways to monitor these s trains when applied to natural pathosystems. We have used random amplified polymorphic DNA (RAPD) markers to estimate genetic variation among: sixteen strains of the species T. asperellum, T. atroviride, T, harzianum, T. inha matum and T. longibrachiatum previously selected as BCAs, and to obtain fin gerprinting patterns. Analysis of these polymorphisms revealed four distinc t groups, in agreement with previous studies. Some of the RAPD products gen erated were used to design specific primers. Diagnostic PCR performed using these primers specifically identify the strain T. atroviride 11, showing t hat DNA markers may be successfully used for identification purposes. This SCAR (sequence-amplified region) marker can clearly 11 from other closely r elated characterised distinguish strain Trichoderma strains.