First report of mortality in Phoenix canariensis associated with subgroup 16SrIV‐D phytoplasmas in Coahuila, Mexico

In 2015, a disease of unknown origin appeared in Torreon, Coahuila, in the Northeast of Mexico, causing great mortality in Phoenix palms, especially in Phoenix canariensis. Until early 2019, around 1300 palms died from this disease. The aim of this study was to determine its etiology. The symptoms registered in affected palms were similar to those described for Texas Phoenix Palm Decline (TPPD). Phytoplasmas were detected in samples from nine P. canariensis individuals using a TaqMan/real-time PCR assay specific for group 16SrIV detection. DNA of positive samples was amplified by nested PCR using primer pair P1/P7 followed by LY16Sf/LY16-23Sr and R16F2n/R16R2. In silico analysis of the sequences obtained revealed the presence of phytoplasmas associated with TPPD, belonging to subgroup 16SrIV-D. This is the first report of a disease associated with subgroup 16SrIV-D phytoplasmas in the Northeast of Mexico, further extending the known geographical range of this pathogen.   Key words: Texas Phoenix palm decline, 16SrIV-D phytoplasmas, nested polymerase chain reaction (PCR), sequence analysis.