AN ASSAY BASED ON THE POLYMERASE CHAIN-REACTION FOR THE DETECTION OF N-TYPES AND L-TYPES OF PSEUDOCERCOSPORELLA-HERPOTRICHOIDES IN WHEAT

A polymerase chain reaction (PCR) test combined with restriction enzym e digestion of an amplified ribosomal DNA fragment is currently availa ble for the identification of N- and L-type isolates of Pseudocercospo rella herpotrichoides from purified fungal DNA. This study shows that both types of the fungus can be differentiated in the plant using the PCR assay and that the test is extremely sensitive. The PCR assay is u sed to compare the development of one isolate of each the N- and L-typ e in wheat under glasshouse conditions. The results indicate that for an identical infection date, the N-type tends to penetrate the tissues faster than the L-type.