RESTRICTION FRAGMENT LENGTH POLYMORPHISMS IN SEPTORIA-TRITICI OCCUR AT A HIGH-FREQUENCY

A set of probes that detect restriction fragment length polymorphisms (RFLPs) in nuclear DNA has been developed for genetic studies of the phytopathogenic fungus Septoria tritici. Two plasmid libraries containing 0.5-1.3 or 1.3-2.4 kb fragments of S. tritici nuclear DNA were constructed. Seventeen random clones from each library were used as probes to screen for RFLP variation among a geographically-diverse group of six S. tritici isolates. Among the 196 probe-enzyme combinations tested, 145 detected RFLPs among the six isolates. The restriction enzymes EcoRV and PstI detected RFLPs most efficiently. Three probes detected deletions. A ribosomal DNA probe from yeast did not detect a significant amount of variation. These probes will be useful for studying genetic variation, population genetics, and genome organization of S. tritici. © 1990 Springer-Verlag.