Transmission studies of phytoplasma causing sesamum phyllody

Abstract

Phyllody is a serious disease of sesame caused by phytoplasma. Different types of disease symptoms are reported to be associated with sesame phyllody. The major symptoms are phyllody (production of leafy structures of floral parts). In the present study investigations were carried out on the transmission and molecular characterization of phytoplasma associated with phyllody. Phyllody disease was successfully transmitted by grafting infected sesame scion to periwinkle stock. The grafted periwinkle plants exhibiting yellowing of leaves and floral virescence was analysed by PCR to confirm the transmission of phytoplasmas from phyllody infected sesame scion to healthy plants. A fragment size of 1200bp was obtained from periwinkle corresponding to the partial 16S rRNA genes. Thus it can be confirmed that transmission of phytoplasma from infected sesame plant to healthy periwinkle was positive. The seeds were collected from phyllody infected sesame plants for seed transmission studies. In an insect proof cage house two hundred seeds were sown in 20 earthen pots. Typical phyllody symptoms were not observed throughout the observation period. It was clearly indicated that the disease is not transmitted through the seeds collected from phyllody infected sesame plants.