A subgroup 16SrIII-B phytoplasma identified in honeyweed plants with leaf deformation in Brazil

Leonurus sibiricus (honeyweed) plants displaying small, shriveled and mildly chlorotic leaves were observed in commercial cassava fields. Based on nested PCR assays using a group-specific primer pair, computer-simulated RFLP analysis, similarity coefficient calculation and phylogenetic analysis, the phytoplasma identified in these plants was classified as a representative of subgroup 16SrIII-B. This is the first report of honeyweed as a host of phytoplasmas.