Random Primer Dependent PCR Differentiates Aggressive from Non‐Aggressive Isolates of the Oilseed Rape Pathogen Phoma lingam (Leptosphaeria maculans)

A number of isolates of the aggressive an d non‐aggressive pathotype group of the rape seed (Brassica napus) pathogen Phoma lingam (teleomorph: Leptosphaeria maculans) were analyzed by means of a simple, random primer dependent PCR (polymerase chain reaction) approach. Using the four synthetic nona‐ and decamer oligonucleotides 5′‐GGAGCCCAC‐3′, 5″‐ACGGTCTTGG‐3′, 5′GAAACAGCGG‐3′, and 5′‐GGCATCGGCC‐3′ informative bands for both of the pathotype groups could be obtained. These amplified bands were shown to originate not only from repeated but also from single and low copy target sequences. This is the first report on molecular diagnostics of a plant pathogenic fungus, based on random primer dependent PCR. The experimental system is fast and reliable, does not require cloning and sequencing of L. maculans DNA, and works without time‐consuming blotting or hybridization steps.