Pythiogeton zeae sp nov causing root and basal stalk rot of corn in Korea

In South Korea, a pythiaceous fungus was consistently isolated from the dis eased tissues of field corn plants (Zea mays) showing severe rot of the roo ts and basal stalks. Based on the morphology, it was described as Pythioget on zeae sp, nov., and a taxonomic kev was constructed to differentiate it f rom the other known species of Pythiogeton. It is characterized by small to extremely large, ovoid, cylindrical, bursiform, ventricose, bilobulate, tr ilobulate to irregular saccate sporangia, large globose to ellipsoidal oogo nium, plerotic oospore with thick wall and mostly single, diclinous or mono clinous antheridium. Its pathogenicity to corn plants was confirmed by arti ficial inoculation and successful re-isolation. This is the first documente d report of a plant-pathogenic species of Pythiogeton, a genus known to be saprophytic usually on plant debris in freshwater.