1Saga Prefectural Ariake Fisheries Research and Development Center, Ashikari, Saga 849-0313, 2Department of Biology, Faculty of Science and Engineering, Konan University, Kobe, Hyogo 658-8501, Japan
Chytrid disease, which is caused by Olpidiopsis sp., damages Nori cultivation every year. We have developed a polymerase chain reaction (PCR) based technique for the detection of Olpidiopsis sp. from the seawater in Nori culture farms. The PCR primers used here are Olpidiopsis sp. specic and encompass a 420 bp (1st PCR) and 256 bp (2nd PCR) region from the 18S rDNA gene of Olpidiopsis sp. The PCR was performed using supernatant seawater, after incubating for 60 minutes in seawater of 35 psu salinity. Zoospores of Olpidiopsis sp. were detected 14 days before detection by bio-assay method, and 33 days before nding by inspection under a microscope. From the results, the technique developed in the present study is useful for the early detection of Olpidiopsis sp. in the eld.