RAPD-PCR and UP-PCR techniques distinguish a Pithomyces chartarum isolate with biocontrol capabilities against Botrytis cinerea on grape (Vitis vinifera)

Previous work identified an Ulocladium atrum (LU850) isolate with potential as biocontrol against Botrytis on grape (Vitis vinifera). The aim of this study was to find a molecular marker that would distinguish the biocontrol isolate from other isolates of the same species and closely related genera to enable subsequent monitoring of its survival, establishment, and spread in the field. DNA of 53 fungal isolates representing the three genera Ulocladium, Alternaria, and Pithomyces were screened with 10 universally primed polymerase chain reaction (UP-PCR) primers and 28 random amplified polymorphic DNA (RAPD-PCR) primers to screen for bands unique to the biocontrol isolate. Three RAPD-PCR primers produced a single band unique to isolate LU850. However, resultant band patterns and subsequent more detailed morphological studies revealed the biocontrol isolate to be Pithomyces chartarum and not U. atrum. Since some isolates of P. chartarum produce the toxin sporidesmin, which is responsible for facial eczema in cattle and sheep, the toxin producing status of isolate LU850 will need to be determined before it can be considered for further development as a biological control agent.