OCCURRENCE OF THE EELGRASS PATHOGEN LABYRINTHULA-ZOSTERAE IN JAPAN

The marine slime mold Labyrinthula zosterae, the causative agent of wa sting disease of eelgrass Zostera marina, has been isolated from both Z. marina and Z. caulescens on the south coast of Japan. In addition, wasting-disease symptoms were produced in disease tests on leaves of Z . japonica and Z. marina using axenic cultures of L. zosterae isolated from Z. caulescens and Z. marina. Thus, the known host species of L. zosterae are expanded to include 3 species of Zostera. Although sympto matic necrotic lesions were observed in field-collected seagrass leave s, widespread die-off from wasting disease was not evident on the sout h coast of Japan.