Phytoplasma Association with Gerbera Phyllody in Australia

Gerbera (Gerbera jamesonii L.) plants with phyllody symptoms (green flower) were observed in Central Queensland, Australia. Leaves and flowers from both symptomatic and asymptomatic healthy plants were examined by transmission electron microscopy (TEM). The presence of pleomorphic bodies similar to phytoplasma was observed exclusively in diseased plants. Polymerase chain reaction (PCR) with phytoplasmaspecific primers confirmed the presence of phytoplasma DNA in the infected plants. Further DNA sequencing analysis of the PCR product revealed high homology with other phytoplasma DNA in the database. Based on phylogenetic analysis of 16S rRNA the gerbera phyllody phytoplasma was grouped under Peanut witches broom as described by Lee et al. (1998). The results of TEM, PCR and sequencing analysis clearly indicate phytoplasmal association with phyllody disease of gerbera.