Institut für Resistenzforschung und Stresstoleranz
We report the first detection of a ‘Candidatus Phytoplasma’ belonging to group 16SrI associated with stunting symptoms in wheat and barley in Germany. Phytoplasmas are obligate intracellular bacteria that colonize the phloem of plants and pose a serious threat to agricultural crops worldwide. Their spread and epidemiology depend on transmission by phloem-feeding insect vectors. In cereals, phytoplasma infections typically cause symptoms such as leaf yellowing, dwarfing, and reduced ear development.The presence of phytoplasmas in cereal fields in Germany was confirmed by nested PCR targeting the 16S rRNA gene. Sequencing of the amplified fragments revealed 100% sequence identity with ‘Candidatus Phytoplasma tritici’, the causal agent of Wheat Blue Dwarf disease previously reported from China. The leafhopper Psammotettix alienus was identified as a vector species in Germany.As data on the spatial distribution and prevalence of phytoplasmas in cereals in Germany are currently lacking, a systematic monitoring program is strongly recommended. Further studies are required, including full-length genome sequencing for precise phytoplasma species identification and the development of improved diagnostic methods. In addition, because phytoplasma infections can interfere with Wheat Dwarf Virus (WDV) transmission experiments, the establishment of a phytoplasma-free Psammotettix alienus rearing at JKI is essential to enable reliable and efficient infection studies in cereals with both WDV and phytoplasmas.
Federal Ministry of Agriculture, Food and Regional Identity
