Genetic differentiation of Phoma sp. isolates using retrotransposon-based iPBS assays

Phoma blight is a disease affecting Norway spruce, Scots pine and other conifer seedlings in many forest tree nurseries throughout the world. Members of the Phoma genus, the causatives of this disease, are difficult to distinguish morphologically and genetically. In this study the use of a retrotransposon-based polymerase chain reaction approach using iPBS amplification for intra-species genetic discrimination between Phoma samples is described. Eight retrotransposon-based iPBS primers were used to genotype DNA from pure cultures of several Phoma species. The utilised markers were able to discriminate between Phoma species, but not all of them were able to differentiate all Phoma sp. isolates investigated. Belarusian samples were found to be distinct from the Latvian Phoma isolates. The Belorussian isolates were very similar to each other. A combination of three iPBS markers (2001, 2076 and 2242) enabled partial differentiation of the investigated Belarusian Phoma isolates.