Molecular Evidence for the Presence of Aster Yellows-Related Phytoplasmas in Lilies with Leaf Scorch and Flower Virescence

Severe leaf scorch symptoms occurred on oriental lily hybrids cv. Woodriff's Memory cultivated in two commercial greenhouses in Poland. Symptoms included leaf necrosis and malformation, flower bud abscission and flower virescence, distortion and abortion. Naturally infected lily plants with severe symptoms in 1999 had retarded growth and leaf chlorosis and they failed to flower the following year. The presence of phytoplasmas in diseased lilies was demonstrated using nested polymerase chain reaction (PCR) assays with universal and 16SrI group specific primer pairs that amplified the phytoplasma 16S rDNA fragment. The PCR products (1.1 kb) of all samples used for restriction fragment length polymorphism analysis had the same restriction profiles after digestion with endonucleases Alu I and Mse I. The restriction profiles of phytoplasma DNA from these plants corresponded to those of an aster yellows phytoplasma reference strain.