Investigation on phytoplasma diseases of sweet pepper in the Bekaa valley of Lebanon

In July 2018, several sweet pepper plants showing symptoms of leaf chlorosis, yellowing and stunted leaves, typically associated with phytoplasma infection, were observed in different locations in the Bekaa Valley, Lebanon. Polymerase chain reaction (PCR) was used to amplify the 16S ribosomal gene of phytoplasmas with the universal primers P1/P7 and R16F2n/R16R2 primers in nested PCR assay. The amplifications from all the symptomatic plants yielded a product of 1.2 kb in nested PCR. BLAST and phylogenetic analysis of the amplified 16S rRNA gene sequences confirmed the presence of 'Candidatus Phytoplasma solani' and 'Ca. P. trifolii' phytoplasmas. This is the first report of the occurrence of 'Ca. P. solani' in pepper in Lebanon