Detection and characterization of palm lethal decline phytoplasmas, subgroups 16SrIV-A and -D, in Phoenix canariensis and Syagrus romanzoffiana in Puebla, Mexico

Phytoplasma subgroups 16SrIV-A and -D are the agents associated with two diseases that significantly threaten palm cultivation in the Americas, namely lethal yellowing (LY) and Texas Phoenix palm decline (TPPD), respectively. Recently, in Puebla State, Mexico, several Phoenix canariensis Chabaud and Syagrus romanzoffiana (Cham.) Glassman palms used as ornamentals began to show symptoms resembling those of TPPD and LY. Therefore, the present study aimed to demonstrate the spread of group 16SrIV phytoplasmas to Puebla, Mexico. Ten symptomatic individuals of both palms were sampled and a nested PCR assay with primer pair P1/P7 followed by LY16Sf/LY16Sr was performed to detect phytoplasma presence. A fragment of about 1.4 kb was amplified in six palms, three (of four) P. canar­iensis and three (of six) S. romanzoffiana. Sequence analysis of the amplicons revealed that the phytoplasma isolates from Puebla were members of group 16SrIV, subgroups – A (one isolate from P. canariensis) and -D (rest of isolates). This study reports the first occurrence of TPPD and LY on ornamental palm species in the state of Puebla, Mexico.