First report of Phytophthora cinnamomi causing root and stem rot of blueberry (Vaccinium corymbosum) in China.
During autumn 2014, in a commercial nursery in Liancheng, Fujian, China, 2- to 3-year-old plants of V. corymbosum cv. Lan Mei 1 showed symptoms of sudden collapse, leaf discoloration, and severe wilt associated with root and basal stem rot. As the disease progressed, large dark brown to black water-soaked lesions girdled the basal part of the stem, and affected plants eventually died. A Phytophthora species was consistently isolated from symptomatic roots and stems on BNPRAH selective medium, and pure cultures were obtained by single hyphal tip transfers. All isolates formed distinctive coralloid-type mycelium with abundant hyphal swellings and chlamydospores. Based on morphological characteristics, molecular data (sequence analysis of the rDNA internal transcribed spacer region and cytochrome-c oxidase subunit I (COI) gene and ras-related protein (Ypt1v) gene) and pathogenicity tests, the causal agent was identified as P. cinnamomi. This is thought to be the first report of P. cinnamomi causing root and stem rot of V. corymbosum in China.