First Report of an Aster Yellows Phytoplasma as the Cause of Rose Balsam Phyllody in China

In July 2010, symptoms suggestive of phytoplasma infection were observed on Rose Balsam (Impatiens balsamina) around Yangling, China. Nested polymerase chain reaction with universal 16S rDNA phytoplasma primers P1/P6 and R16F2n/R16R2 yielded amplicons of expected size (1.2 kb) from all symptomatic, but not asymptomatic, leaf samples. Sequencing results and NCBI BLASTn analysis of the 1246 bp products (R16F2n/R16R2) showed that the phytoplasma belonged to group 16SrI. Restriction fragment length polymorphism and phylogenetic analysis showed the phytoplasma had a close relationship to subgroup 16SrI-D. This is the first report of a phytoplasma infecting Rose Balsam.