SUBGROUP 16SrIII-F PHYTOPLASMA STRAINS IN AN INVASIVE PLANT, HERACLEUM SOSNOWSKYI, AND AN ORNAMENTAL, DICTAMNUS ALBUS

Phytoplasma strains were detected in an aggressive and widespread, invasive plant species, Heracleum sosnowskyi (hogweed), and in Dictamnus albus (gas-plant) exhibiting yellows disease symptoms in northern Lithuania. Analysis of PCR-amplified 16S rDNAs revealed that the strains, designated heracleum yellows (HerY) and dictamnus stunt (DicSt), respectively, belong to subgroup 16SrIII-F (milkweed yellows phytoplasma subgroup). The results established that phytoplasma is a natural enemy of hogweed and D. albus in the Baltic region. While subgroup 16SrIII-F strains occur in four plant species (Vaccinium corymbosum, V. myrtillus, H. sosnowskyi and D. albus) in Europe, Asclepias syriaca (milkweed) in North America is the only known host elsewhere.