Detection and Identification of an Elm Yellows Group Phytoplasma Associated with Camellia in China

In 2012, yellowing of camellias was observed in Tai'an in Shandong province, China. Transmission electron microscopy (TEM) revealed phytoplasma in the phloem sieve tube elements of symptomatic plants. A specific fragment of phytoplasma 16S rRNA gene was amplified by polymerase chain reaction (PCR) using the universal phytoplasma primers P1/P7 followed by R16F2n/R16R2. Sequence and restriction fragment length polymorphism (RFLP) analyses allowed us to classify the detected phytoplasma into the elm yellows (EY) group (16SrV), subgroup 16SrV-B. Sequence analyses of the ribosomal protein (rp) gene confirmed a close relationship with phytoplasmas belonging to the rpV-C subgroup. Thus, the phytoplasma associated with yellows disease in camellia, designated as ‘CY’, is a member of the 16SrV-B subgroup. This is the first report of phytoplasma associated with camellia.