Molecular identification of phloem-restricted bacteria in insects and sugar beet crops in Italy

Ruberry taproot disease and “basses richesses” syndrome are seriously damaging the sugar beet production in Europe. The study evaluated the presence of ‘Candidatus Phytoplasma’ and ‘Ca. Arsenophonus phytopathogenicus’ in insects and sugar beet fields in Italy. ‘Ca. P. solani’ was found in several insect species, in some cases for the first time; moreover in three insect species, bacteria of the genus Arsenophonus were found having high 16S rRNA gene identity to those detected in sugar beet. Group 16SrIX phytoplasmas were identified for the first time in two sugar beet plants. These data suggest further investigation to understand the possible correlation of the presence of phloem-restricted bacteria with the reduction in yield and sugar polarization.