First report of Phytophthora palmivora causing foliar blight of Pachira aquatica in Florida.
During August 2011, Pachira aquatica samples from local nurseries were subjected to disease diagnosis in Homestead, Florida, USA. The foliage exhibited dark brown to black water-soaked spots that became papery as the disease progressed, and rapidly enlarged and coalesced, resulting in severe leaf blight. Both young and mature leaves were affected. Phytophthora was initially confirmed by serological testing. On closer examination, the pathogen was further identified as Phytophthora palmivora by the presence of numerous papillate, deciduous, ellipsoidal to ovoid sporangia with short pedicels. The sporangia averaged 53 × 32 µm. The sequence from the isolate was nearly identical (exhibited 99% nucleotide identity) to an isolate of Phytophthora palmivora (GenBank accession no. HE580280) collected from diseased cassava in China. This is thought to be the first report of Phytophthora palmivora causing foliar blight of Pachira aquatica in Florida.