Detection and Identification of Phytoplasmas in the 16SrIV-A, -B, and -D Subgroups in Palms in Tabasco, Mexico

Abstract

TThe 16SrIV-A phytoplasmas are associated with the devastating disease Lethal Yellowing (LY) of palms. In Tabasco (Mexico), the death of Cocos nucifera, Adonidia merrillii and Attalea butyracea palms have been suspected to be associated with LY based on symptomatology. Samples from the trunk of both symptomatic and non-symptomatic palms were collected in three different environments, two species of palms within a rural zone and the other within an urban zone. DNA was extracted to perform a nested PCR with phytoplasma primers P1/P7-LY16SF/R16R2. A 1,345 bp fragment was amplified from the DNA extracted from each of the 29 LY-symptomatic palms sampled. Phytoplasma identification was achieved by amplicon sequencing and virtual restriction fragment length polymorphism analyses. Three 16SrIV phytoplasma subgroups were detected: 16SrIV-A in C. nucifera, 16SrIV-B in A. merrillii, and 16SrIV-D in C. nucifera, A. merrillii and A. butyracea. Phylogenetic analysis showed also that the three phytoplasma strains found in the palms species clustered with phytoplasmas reported in the literature in the three subgroups identified. This is the first report of phytoplasmas associated with these palm species in Tabasco.