Phytoplasma associated with C hinese tallow tree yellowing disease in China represents a new 16Sr III subgroup

Summary Recently, samples of the C hinese tallow tree ( Sapium sebiferum ) displaying yellowing symptoms were collected from a grove in T ai'an, S handong P rovince, C hina. The association of phytoplasma with yellowing disease was ascertained using nested polymerase chain reaction ( PCR ) of the 16S r RNA gene by using the phytoplasma‐specific universal primer pair P1/P7, followed by R16F2n/R16R2 as nested primers, and rp genes primed using rpL2F3/rp(I)R1A followed by rp(III)‐FN/rp(I)R1A. The sequence and phylogenetic analyses of the 16S rRNA gene and rp genes revealed that the phytoplasma associated with the C hinese tallow tree belonged to the 16SrIII group (the X ‐disease group). Computer‐simulated and gel‐based restriction fragment length polymorphism ( RFLP ) analyses revealed that the RFLP patterns were different from the reference patterns of all previously established 16SrIII subgroups, with the maximum similarity coefficient exceeding the threshold for delineation of a new subgroup RFLP pattern type within the 16SrIII group. Thus, the phytoplasma associated with the C hinese tallow tree yellowing disease, designated as ‘ CTTY ’, represents a new subgroup (16SrIII‐Y). This study shows the C hinese tallow tree as a new host of phytoplasma belonging to the 16SrIII group in C hina and worldwide.