Phytoplasma strains detected in ornamental plants in Lithuania

During recent years, increasing attention has been devoted to the development of field floriculture in Lithuania. Since the quality of ornamental plants is adversely affected by diseases attributed to phytoplasmas, we surveyed plant collections in botanical gardens and floriculture farms in Lithuania for phytoplasmal diseases. 37 ornamental species belonging to 18 plant families exhibiting disease symptoms including general yellowing and stunting, proliferation of shoots, phyllody, virescence and reduced size of flowers, and reddening of leaves were collected in commercial floriculture farms and botanical gardens. Analysis of phytoplasmal 16S rRNA gene sequences amplified in the polymerase chain reaction revealed that the plants were infected by phytoplasmas belonging to five distinct subgroups (16SrI-A, 16SrI-B, 16SrI-C, 16SrI-L, and 16SrI-M) of group 16SrI (aster yellows phytoplasma group) and two subgroups (16SrIII-B, 16SrIII-F) of group 16SrIII (X-disease phytoplasma group).