First report of Phytophthora palmivora as a causal pathogen of citrus brown rot in Japan

摘要

A fruit rot, similar to brown rot, occurred on extremely early ripening Satsumas in Saga Prefecture in the early autumn of 1999. A single species of Phytophthora was isolated from the affected fruit. After nonwounding inoculation of healthy fruits of Citrus spp. including Satsuma with the isolated fungus, the fungus was reisolated from fruit with symptoms similar to those in nature. On the basis of its morphology and molecular analysis of the rDNA-internal transcribed spacer regions, the pathogen was identified as P. palmivora. This is the first report of P. palmivora as a causal pathogen of citrus brown rot in Japan.